Foreword

The Office of Health Technology Assessment (OHTA) evaluates the risks, benefits, and clinical effectiveness of new or unestablished medical technologies. In most instances, assessments address technologies that are being reviewed for purposes of coverage by federally funded health programs.

OHTA's assessment process includes a comprehensive review of the medical literature and emphasizes broad and open participation from within and outside the Federal Government. A range of expert advice is obtained by widely publicizing the plans for conducting the assessment through publication of an announcement in the Federal Register and solicitation of input from Federal agencies, medical specialty societies, insurers, and manufacturers. The involvement of these experts helps ensure inclusion of the experienced and varying viewpoints needed to round out the data derived from individual scientific studies in the medical literature.

After OHTA receives information from experts and the scientific literature, the results are analyzed and synthesized into an assessment report. Each report represents a detailed analysis of the risks, clinical effectiveness, and uses of new or unestablished medical technologies. If an assessment has been prepared to form the basis for a coverage decision by a federally financed health care program, it serves as the Public Health Service's recommendation to that program and is disseminated widely.

OHTA is one component of the Agency for Health Care Policy and Research (AHCPR), Public Health Service, Department of Health and Human Services.

• Thomas V. Holohan, M.D.
• Director
• Office of Health Technology Assessment
• Clifton R. Gaus, Sc.D.
• Administrator
• Agency for Health Care Policy and Research
• Questions regarding this assessment should be directed to:
• Office of Health Technology Assessment
• AHCPR
• Willco Building, Suite 309
• 6000 Executive Boulevard
• Rockville, MD 20852
• Telephone: (301) 594-4023

Introduction

Magnetic resonance angiographies (MRAs) are magnetic resonance imaging (MRI) techniques applied to the noninvasive visualization of both blood flow and blood vessel morphology in which images are created in a projection format similar to that of conventional x-ray angiography (CA). MRA has evolved as a modification of MRI technology, in which the body is placed in a homogeneous magnetic field and a selected volume of flowing blood is magnetically depolarized with a radio frequency (RF) pulse to act as an internal contrast agent to static tissue which can generate images using computer hardware and software.(1,2) Contrast between flowing blood and surrounding tissue can be obtained because the excited protons of the flowing blood in the RF fields or magnetic-field gradients move out of the imaging field before signal acquisition by the sensor, resulting in a differential high-signal intensity in the blood vessels compared with the magnetically saturated surrounding tissues.(3) MRA signals are MRI signals encoded with spatial information by one of a variety of imaging techniques, , Fourier imaging, echo-planar imaging, projection reconstruction, and spiral scanning.(4) Ideally, MRA achieves adequate image resolution with freedom from flow-related artifacts during a short imaging time.(5) MRA is predominantly accomplished by fast imaging methods, which permit the accrual of more information in a shorter time than do conventional scans, e.g., 2-3 minutes vs. 20-30 minutes.(4)

MRA creates a large number of thin, contiguous-image slices that can be viewed individually or reconstructed into a slab of images collapsed into a three-dimensional (3D) projection for visualization of both the lumen and the surrounding vessel wall.(6) Projected 3D images can thus be regarded as a "flow map" of the vasculature which incorporates both anatomic and physiologic information.(7)

The primary issues addressed in this assessment are the safety, effectiveness, and clinical utility of MRA for the determination of blood vessel morphology and the measurement of blood flow. In addition, indications, contraindications, and patient selection criteria will be addressed.

Background

All materials exhibit some magnetic properties caused by electron motion and nuclear spin.(2) Proton MRI technology is based on the principle that protons within body tissues and fluids can absorb and subsequently emit RF signals when placed in a magnetic field.(8),^[a] These signals can be detected and displayed to provide data for spatial location and contrast discrimination of specific tissues based on their individual biophysical characteristics. Signal changes during MRI occur as the result of blood flow, i.e., moving protons through magnetic-field gradients and RF fields. MRA uses these changes to differentiate flowing blood from surrounding stationary structures and generate images (angiograms) depicting vasculature based on flow phenomena.

The application of MRI principles to the noninvasive measurement of blood flow in humans began at the National Institutes of Health (NIH) in 1956 and was first reported in 1959.(9) These blood-flow measurements depended on the interaction of motion with RF excitation and involved spin-tagging experiments in which a bolus of magnetically "tagged" spins (protons) moving along a vessel were subsequently detected downstream.(10, 11) In extending the techniques from tagging experiments to angiography, vessel morphology was extracted and a series of contiguous sections were reformatted using computer processing. Determination of velocity can also be derived by measuring changes in signal amplitude between the stronger signal of freshly magnetized spins compared with that of saturated spins.(9, 12) Problems of poor spatial resolution, which typically occur when reformatting angiography images, were later circumvented by using phase contrast and subtraction to produce direct images of pulsatile arterial flow.(13)

The earliest clinical application of MRA was described by Weeden et al in 1985.(14). Their technique exploited those differences between systolic and diastolic arterial flow on cardiac-gated spin-echo images. In that same year, Hale et al(15) described the first MRA 3D reconstruction of blood vessels.

The subsequent development of additional MRA techniques and their successful clinical application have been derived primarily from the variety of methods for image acquisition and complementary display algorithms.(16) MRA methods manipulate variables in RF, including timing and rates of change, to generate signals from flowing blood, while signals from stationary tissue are subtracted or suppressed in a manner analogous to that used with conventional digital subtraction angiography.(17-20) In effect, MRA angiograms are physiologic studies (rather than anatomically weighted conventional angiograms) in which moving blood, as the contrast agent, is displayed as high-signal intensity.(21, 22) The nature of the magnetic resonance (MR) signal from flowing blood is complex and partially depends on the spin density and relaxation properties of the blood plus the dynamics of blood flow and the thickness of the imaged section.(23)

The effects of flow in MRA include signal enhancement caused by the inflow of spins before exposure to a RF pulse (unsaturated), signal loss caused by outflow of excited spins from the imaged section, and dephasing of signal caused by motion along magnetic-field gradients.(24) Signal intensity is determined by the combined effects of these mechanisms.

The goal of MRA in imaging vessels is to produce a signal from the blood that has sufficient contrast to permit an image of the vasculature to be extracted from the background tissue in adequate detail.(25) There are a variety of MRA techniques used to accomplish this, and the method selected is related to its clinical application.(26) The techniques applied to isolate the vasculature from surrounding tissue, and the differential signal enhancement for fast and slow flow, form the basis for vascular imaging obtained during systolic or diastolic flow.(27) These techniques, in effect, render the background structures transparent and enable the 3D vasculature to be projected and imaged on a two-dimensional (2D) image plane.(14) Using MRA technology, a single vessel may be viewed separately by limiting the field of view of the postprocessing algorithm used to display individual slices from volume-image data.(22)

Images must be acquired during diastole for arterial visualization. Specialized pulsing sequences, not generally used for routine clinical imaging, are required for the determination of blood-flow velocity and direction.(28) None of these techniques requires the use of contrast media (although some may be enhanced by them).(29-32)

All MR flow measurements and imaging techniques exploit either longitudinal (tagging or wash-in-wash-out procedures for the inflow or outflow of saturated or unsaturated spins) or transverse spin magnetization (phase-shift or dephasing procedures, which compensate for a decreased MR signal) (33, 34) These commonly preferred MRA techniques are termed time-of-flight (TOF) or phase-contrast (PC) methods.(5, 27, 35) TOF effects refer to signal changes generated by protons flowing perpendicular to the plane of sectioning during a MRI pulse sequence and are related to the increase in amplitude of the signal returning from flowing blood in the imaged area. TOF effects occur whenever blood flows out of a region in which its longitudinal magnetization has been modified. PC effects relate to the increase in phase angle of the returning signal (which is proportional to the velocity of flowing blood) and occur whenever blood having transverse magnetization moves in the direction of a magnetic-field gradient.(7, 26)

TOF methods, first described by Feinberg et al in 1984, (36) use a velocity-compensated sequence, which refocuses moving MR spins to obtain the proper contrast based on the differential saturation of magnetization between flowing blood and surrounding tissue.(37) Imaging MRA using TOF relies on flow-compensated gradient-echo pulse sequences. Using this technique, nonsaturated spins of blood flowing into an imaged volume produce a strong signal (flow-related enhancement) and appear bright when a motion-artifact-suppression technique (gradient-moment nulling) is used, and black when presaturation is used.(8, 38-40) Gradient-moment-nulling techniques compensate for velocity, acceleration, and motion errors by modifying gradient structures, whereas presaturation uses a set of RF pulses to saturate blood flow or moving tissue to avoid ghosting artifacts. Lymphatic or venous channels (slow flow) are very bright with presaturation of the spin-echo sequences and less bright with gradient-moment nulling. Areas of slow flow may also be associated with signal loss because of saturation.(40) TOF methods primarily provide morphologic information and only indirectly indicate flow rates.(41) However, TOF has a restricted range, and therefore long vessels are more difficult to visualize.(19) In PC methods, at least two scans in different directions are necessary so that subtraction techniques can be used to suppress background tissue and extract vessel structures. However, in vessels with minimal or absent flow, e.g., thrombus, MRA alone may fail to detect the lesion and a standard MRI may be used as a correlative study.(40)

Although MRA generally provides poorer resolution than does CA, it has greater flexibility in terms of permitting multiplanar projection images of blood vessels containing anatomic detail and quantitative information about flow.(42) A computer algorithm that automatically detects flowing blood provides reconstructed views of vessels while analyzing and displaying flow characteristics.(15)

All TOF techniques involve spin "tagging" in which spins outside an imaged region are labeled ("tagged") and subsequently detected as they enter the imaged region.(22, 26) TOF methods are commonly classified by acquisition mode; e.g., volumetric acquisition, 3D acquisition, or sequential-slice 2D acquisition. (31) Multiple thin-slab acquisition combines both 2D and 3D techniques in which many individual images can be compressed into a single image using a maximum-intensity projection algorithm that selects the maximum signal intensity along a line that cuts through the image space.(39)

In the 2D or 3D methods, the volume of tissue being imaged is subjected to repeated RF pulses, resulting in magnetic saturation and decreased signal intensity. Flowing blood entering this volume, not subjected to magnetic saturation, maintains its signal intensity. This effect, termed flow-related enhancement, is then used to generate images in which flowing blood exhibits high-signal intensity relative to the surrounding stationary tissue.(21)

2D MRA involves an imaging volume limited to very thin slices (approximately 1.5 mm) in which the flowing blood does not become saturated. Sequential slices are then imaged for the area of interest. (43) The major advantages of 2D techniques are the ability to image a large volume in a relatively short time, sensitivity to a wide range of velocities, and ability to obtain significant data even with significant patient motion.(42) Disadvantages include poor spatial resolution and significant signal loss and artifact production from vessels with complex flow.(44) 2D techniques are frequently applied for imaging venous flow in the head, chest, abdomen, and pelvis.(40)

3D MRA uses a relatively thick slice (approximately 4 cm) as the imaging volume, in which the inflowing blood remains for a relatively longer period of time and may become saturated, making 3D MRA relatively insensitive to slow-flowing blood. However, 3D imaging permits sections of less than 1 mm to be obtained in very brief scanning times. 3D MRA offers high spatial resolution with reduced signal loss, making it an excellent technique for imaging fast flow such as seen in arteriovenous malformations.(45) Another advantage of 3D techniques is minimal signal loss from vessels with complex flow. Disadvantages include the fact that saturation effects limit its usefulness in examination of small anatomic regions.(42) 3D techniques are commonly applied for rapid arterial flow generally seen in the head, neck, aorta, and renal arteries.(40)

MRA images may be computer postprocessed, by a variety of techniques, to create multiple-projection images (without additional imaging) in which the vasculature is displayed in a manner similar to that of CA, rather than transverse sections as displayed in MRI.(21, 44, 46)

Although no single 2D image can portray all the information acquired by 3D techniques, postprocessing can yield images of most of the information in the volume image by "compressing" the 3D data onto a 2D image similar to that obtained by CA. However, this postprocessing does not always eliminate the need to inspect individual-slice data from suspicious regions of interest.(47)

Spatial resolution depends on the volume element for a given slice thickness (voxel), and this minimum usable size is largest for 2D TOF and smallest for 3D techniques. Therefore, achievable spatial resolution is best for 3D and limited by slice thinkness for 2D techniques.(42)

PC angiography represents a groups of MRA techniques in which velocity and hemodynamic effects (physiologic information) are incorporated into the vascular image.(18) PC is only sensitive to motion, thereby having better suppression of stationary tissue than is possible with TOF imaging.

PC imaging relies on the concept of predictable phase shifts generated by flowing blood in a magnetic-field gradient.(40, 48) Using this method, the proportional relationship between signal intensity and velocity permits direct velocity measurement associated with marked suppression of background tissue. However, this requires multiple acquisitions and therefore much longer imaging times than those required for TOF methods, especially if only morphologic information is sought.(21, 26) PC methods are associated with more flow-artifact problems and signal loss than TOF methods, but offer unique opportunities for flow imaging.(26, 49) PC techniques have been further refined to produce quantitative measurements in a projected angiographic format to measure both venous and arterial flow at any point in the cardiac cycle without using contrast media.(13) As with TOF methods, computer postprocessing of MRA data is generally used to create projection angiograms in a format similar to that of CA, but which can be viewed in multiple directions.(25, 43, 50)

Essentially, all MRA techniques use variations of 2D or 3D TOF or PC techniques to produce a flow-sensitive image by gating of pulsatile flow and obtain background suppression by postprocessing or subtraction techniques. (51, 52) The original MRI technology, which relied on conventional spin-echo pulse sequencing, had significant limitations for assessing blood vessels relating to the production of complex signal patterns.(53) Newer techniques, which may be applied singly or combined, e.g., RF presaturation flow compensation, gradient-echo pulse sequence, and rapid-line scan angiography, permit the demonstration of vessel patency, flow velocity, and volume and direction of flow.(54)

Rationale

The hazards and limitations associated with CA have led to the development of competing technologies applied to the evaluation of the vascular system. Ideally, the detection of either an obvious lesion or a normal vascular segment by noninvasive means would be the examination of choice.(55)

The rationale for the use of MRA is predicated on the fact that it involves no exposure to ionizing radiation, is repeatable and relatively rapid, avoids the risks associated with CA (i.e., vascular damage, ionizing radiation, neurologic complications, and systemic reactions to contrast agents), and may be used in an outpatient setting.(41,48,56-62) In addition, MRA can be reviewed retrospectively with little operator dependence, as is seen with ultrasonogaphy, and is not affected by factors that may compromise the use of CA, e.g., poor renal function, coagulopathies, lack of femoral pulses, or the inability to properly advance the catheter because of severe generalized atherosclerotic disease.(63-65)

Proponents claim that MRA can yield rapid and reproducible vascular images with excellent contrast in a manner that correlates well with morphologic results obtained using CA and can readily provide hemodynamic information not available by CA. MRA is easily combined with MRI to yield information on parenchymal morphology as well as vascular dynamics.(25,66)

Review of Available Information

The literature search encompassed all English-language journal articles and textbooks published between January 1985 and December 1993 available through the search capabilities of the National Library of Medicine. The key words used in the search were "MRI angiography" and "MRA." The search was expanded to include additional references cited in the reviewed articles and textbooks. Additional information was obtained via a Federal Register announcement of this assessment, (66). solicitation of information from professional societies and organizations having interest and/or experience with this technology, preprints of papers submitted for publication, and published abstracts. This review will emphasize those published studies comparing MRA with CA applied to various anatomic sites.

The safety of MRI was addressed in a 1985 Public Health Service Assessment, which concluded that MRI is without demonstrable adverse biologic effects when commercially marketed systems are operated within their specified parameters.(67) However, caution must be exercised with patients having metallic surgical clips or prostheses because of possible adverse effects of MRI-generated magnetic and electromagnetic fields on such items. MRA is contraindicated in patients with pacemakers. In the current "guidance" from the Food and Drug Administration's Center for Devices and Radiological Health (personal communication), the scanning of the fetus or infant is treated as a warning. Claustrophobic anxiety related to long imaging times for patients enclosed within the magnetic bore has been a problem in a small percentage of patients. These cited issues apply equally to the application of MRA. The preliminary and occasional intravenous use of the paramagnetic contrast agent, gadolinium, in MRA has been associated with approximately 1 percent of minor general and renal adverse effects in Phases III-IV studies involving more than 13,000 patients.(68) The observed adverse events were comparable with those seen after intravenous administration of iodinated nonionic x-ray contrast media.

Clinical Applications

The precise evaluation of the carotid arteries or the intracerebral vasculature has generally required CA; however, recent experience with MRA has in some instances proven to be reasonably useful and accurate for both diagnosis and treatment planning. Tables 1 and 2 summarize the results of recently published reports from 1988 to 1994, involving 10 or more patients, in which MRA of head and neck vasculature was compared with results obtained by CA (used as the accepted standard technology).

Table

Table 1. Summary of selected reports of MRA vs. conventional angiography applied to the study of carotid arteries (1988-1993).

Table

Table 2. Summary of selected reports of MRA vs. conventional angiography applied to the study of cerebral vessels (1989-1993).

Because of their large size and relative immobility, the aorta and renal arteries are readily imaged by MRA.(95,96) However, no strictly prospective study has been published that evaluates the clinical utility of MRA in the diagnosis of renal artery stenosis (RAS) or pathology of the aorta and its major abdominal branches. Table 3 is a summary of recent studies (involving more than 10 patients) comparing MRA with CA in evaluating the abdominal aorta and its branches.

Table

Table 3. Summary of selected reports of MRA vs. CA applied to the study of abdominal vasculature (1985-1993).

The effects of both cardiac and respiratory motion have been regarded as serious handicaps to the application of MRA in evaluating thoracic vasculature. However, recent technical advances, including echoplanar imaging (a method that collects 2D information from a single RF excitation) and steady-state methods (which use faster imaging to overcome the effects of motion), have served to overcome these problems.(104,105)

There is a relative paucity of data related to MRA compared with CA applied to the thoracic vasculature, and this is summarized in Table 4 with reports including five or more patients.

Table

Table 4. Summary of selected reports of MRA vs. CA applied to the study of thoracic vasculature.

The major clinical applications of MRA for peripheral vascular disease are defining the extent and distribution of disease and providing a preoperative roadmap for locating the optimal site of the distal anastomosis.(109) Recent reports of these applications of MRA involving 10 or more patients are seen in Table 5.

Table

Table 5. Summary of selected reports of MRA vs. CA applied to the study of peripheral vascular system.

Discussion

Although CA remains the diagnostic standard for most clinical applications, it is not unfailingly accurate, not always practical or feasible, and competing noninvasive technologies (e.g., MRA, ultrasound) are rapidly making inroads into its domain.(8,96,116-119) In some clinical situations, the application of MRA for the identification of vascular pathology is purported by some investigators to hold the potential for a complete noninvasive evaluation.(40,120-122). This includes the ability to distinguish dissections; slow flow from thrombus; occlusions from patent vessels; significant from insignificant degrees of stenosis; and the general assessment of direction of flow and velocity, including inflow and outflow vessels as roadmaps preceding surgery. In addition, it is claimed that MRA has the potential of being used as a followup for most, if not all, angiographic studies.(16) Clinically, the value of flow quantification is largely unproven, and MRA techniques are used to indicate direction of flow or assess collateral flow patterns.(40) However, none of the available MRA methods can accurately measure the full range of flow velocities, and this difficulty has contributed to the lack of widespread acceptance of MRA for routine clinical applications.(29) Because CA is the reference standard for evaluating the vascular system in most clinical situations, MRA continues to be clinically evaluated against angiography, and this research is mostly limited to larger centers using sophisticated MR equipment capable of providing high field strengths.(122,123)

Although it is expected that further refinements in techniques will result in MRA supplanting many current CA procedures, at present, controversy continues and opinions abound concerning both the current use and future applications of MRA; and, as yet, there are no prospective randomized trials comparing MRA with CA in evaluating any vascular region.(1,46,54,79,124,125) A major limitation of MRA compared with CA is its significantly poorer spatial resolution (2D image sharpness) (16,21,107,126-128) Improvements in spatial resolution and decreasing image acquisition time are primary goals of current MRA research.(128,129) Other limitations and drawbacks of MRA include prohibitions concerning patients with pacemakers or other metallic implants, motion artifacts, low cardiac ejection fractions, and distorted images related to high-velocity flow and its turbulence in areas of severe stenosis.(78,88,111,130).

The examination time and cost of MRA is often less than that of CA; however, its use as an adjunct to CA would obviously increase the total cost.(76,112,130-132)

Summary and Conclusions

MRA techniques generate contrast between flowing blood and surrounding tissue and provide anatomic images that can be projected in a format similar to that of CA and can also provide physiologic information.

MRA has been extensively applied to the study of head and neck vasculature (especially the carotid bifurcation) with a demonstrated diagnostic accuracy in many patients comparable to that seen with CA. The clinical utility of MRA in evaluating the cerebral vasculature (often combined with MRI) has also been documented for diagnosing patients with suspected intracerebral lesions. However, in the vast majority of cases, CA continues to be the definitive preoperative study.

The MRA evaluation of the thoracic and abdominal aorta and its major branches has also been shown to have a high degree of accuracy. It is being applied in many institutions for detection of aneurysms, occlusions, and stenoses, especially in circumstances in which the use of contrast agents are contraindicated or regarded as high risk.

Reports of MRA of the pulmonary and coronary vasculature represent preliminary experience, with the potential for future clinical utility in the noninvasive evaluation of coronary artery disease.

CA continues to be regarded as the standard technique for evaluating peripheral artery disease; however, the recently demonstrated superior ability of MRA to detect distal patent vessels has led to its use as the sole preoperative study.

The comparisons of conventional and MR venography have been few but suggest that the MR technique has the potential to become the imaging method of choice.

The availability of MRA is often limited to large medical centers, and there is a paucity of information regarding the costs of MRA vs. CA. However, the limited data indicate MRA to be less costly than CA, especially if performed in outpatient facilities. Although MRA may be individually less costly than arteriography, if it were used in "screening," the aggregate costs would likely be much higher due to a lower threshold for the use of MRA related to the relative risks and contraindications of CA.

With regard to the issue of the relative accuracy and agreement between MRA and CA, it should be noted that the clinically acceptable accuracy of MRA in identifying normal or abnormal vasculature may be clinically inadequate when treatment management decisions, such as those applied to carotid endarterectomy, depend on a high degree of precision. To date, MRA results are generally less precise than those obtained with CA methods.

MRA is more clinically useful in large rather than small diameter vessels and continues to be associated with significant technical limitations for some applications, e.g., coronary artery imaging.

On the basis of a growing clinical experience with MRA demonstrating clinical usefulness comparable to that of other imaging techniques (albeit fewer than 1,000 cases directly comparing MRA with CA), MRA appears to be a promising technology for accurately imaging blood flow and blood vessel morphology and potentially replacing competing invasive and noninvasive imaging methods in a variety of clinical situations.

Despite the conspicuous absence of prospective randomized trials demonstrating its clinical effectiveness, MRA is gaining wider acceptance. Although MRA cannot yet be regarded as a standard technique for routine imaging or as a reliable noninvasive alternative to CA in most clinical settings, clinical trials need to be conducted to define more clearly the roles MRA may play for both screening and patient management. MRA can be applied to patients who are poor candidates for standard angiography.

References

1.

Spritzer CE, Blinder RA. Practical aspects of vascular imaging using MRI Crit Rev Diagnostic Imaging 1990 31:145–185. [PubMed: 2288661]

2.

Battocletti JH, HalbackHalbach RE, Salles-Cunha SX, et al. The NMR blood flow meter-theory flowmeter—theory and history Med Phys 1981 8:435–443. [PubMed: 6459528]

3.

Evancho AM, Osbakken M, Weidner W. Comparison of NMR imaging and aortography for preoperative evaluation of abdominal aortic aneurysm Magn Reson Med 1985 2:41–55. [PubMed: 3831676]

4.

Sattin W. Haacke EM. Fast imaging and vessel contrast in Potchen EJ, Haacke EM, Siebert JE, et at. (Eds): Magnetic Resonance Angiography Concepts and Applications, St. Louis:Mosby Year Book, 1993, pp 35–55.

5.

Olcott EW. Magnetic resonance angiography, angiographic contrast media, and digital angiography Curr Opinion Radiol 1990 2:252–258. [PubMed: 2202394]

6.

Hasso AN. Magnetic resonance angiography in the head and neck West J Med 1992 156: 296–297. [PMC free article: PMC1003241] [PubMed: 1595250]

7.

Caputo GR, Higgins CB. Magnetic resonance angiography and measurement of blood flow in the peripheral vessels Invest Radiol 1992 27: Suppl 97-102. [PubMed: 1468883]

8.

Brown HK, Hazelton TK. Innovations in diagnostic angiography, magnetic resonance angiography and color image display J F1 Med Assoc 1991 78:309–312. [PubMed: 1856672]

9.

Bowman RL, Kudravcev V. Blood flow meter utilizing nuclear magnetic resonance IEEE Trans Biomed Eng 1959 6:267–269.

10.

Masaryk TJ., Modic MT, Ross JS, et al. Intracranial circulation: Preliminary clinical results with three-dimensional (volume) MR angiography Radiology 1989 171:793–799. [PubMed: 2717754]

11.

Crooks LE, Haacke EM. Historical overview of MR angiography, in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography Concepts and Applications, St. Lous: Mosby Year Book, 1993, pp 3–8.

12.

Singer JR. Blood flow rates by nuclear magnetic measurements Science 1959 130:1652–1653. [PubMed: 17781388]

13.

Dumoulin CL, Hart HR Jr. Magnetic resonance angiography Radiology 1986 161:717–720. [PubMed: 3786721]

14.

Weeden Wedeen VJ, Meuli RA, Edelman RR, et al. Projective imaging of pulsatile flow with magnetic imaging Science 1985 230:946–948. [PubMed: 4059917]

15.

Hale JD, Valk PE, Watts JC, et al. MR imaging of blood vessels using three-dimensional reconstruction: Methodology Radiology 1985 157:727–733. [PubMed: 4059560]

16.

Parker DL, Haacke EM. Signal-to-noise, contrast-to-noise and resolution in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): St. Louis: Magnetic Resonance Angiography Concepts and Applications Mosby Year book, 1993, pp 56–79.

17.

Nishimura DG, Macovski A, Pauly JM. Magnetic resonance angiography IEEE Trans Med Imaging 1986 5:140–151. [PubMed: 18244000]

18.

Dumoulin CL, Souza SP, Walker M, et al. Three-dimensional phase contrast angiography Magn Reson Med 1989; 9:139–149. [PubMed: 2709992]

19.

Dumoulin CL, Cline HE, Souza SP. Three-dimensional time-of-flight magnetic resonance angiography using spin saturation Magn Reson Med 1989; 11:35–46. [PubMed: 2747515]

20.

Nishimura DG, Macovski A, Jackson JI, et al. Magnetic resonance angiography by selective inversion recovery using a compact gradient echo sequence Magn Reson Med 1988 8:96–103. [PubMed: 3173074]

21.

Fram EK, Heiserman JE. Carotid and vertebral arteries in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 498–518.

22.

Keller PJ, Saloner D. Time-of-flight flow imaging in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 146–159.

23.

Kucharczyk W, Kelly WM, Davis DO, et al. Intracranial lesions: Flow-related enhancement on MR images using time-of-flight effects Radiology 1986 161:767–772. [PubMed: 3786730]

24.

Valk PE, Hale JD, Crooks LE, et al. MRI of blood flow: Correlation of image appearance with spin-echo phase shift and signal intensity AJR 1986 146:931–939. [PubMed: 3485910]

25.

Lin W, Haacke EM, Edelman RR. Black blood angiography in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 160–172.

26.

Dumoulin CL, Souza SP, Pelc NJ. Phase-sensitive flow imaging in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 173–186.

27.

Bradley WG Jr. Flow phenomena in Magnetic Resonance Imaging, St Louis: CV Mosby, 1988, pp 108–137.

28.

Bradley WG Jr., Waluch V. Blood flow: Magnetic resonance imaging, Radiology 1985 154: 443–450. [PubMed: 3966131]

29.

Marchal G, Michiels J, Bosmans H, et al. Contrast-enhanced MRA of the brain J Comput Assist Tomogr 1992 16:25–29. [PubMed: 1729301]

30.

Lossef SV, Rajan SS, Patt RH, et al. Gadolinium-enhanced magnitude contrast MR angiography of popliteal and tibial arteries Radiology 1992; 184:349–355. [PubMed: 1620827]

31.

Marchal G, Bosmans H, McLachlan SJ. Magnetopharmaceuticals as contrast agents in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 305–322.

32.

Chakeres DW, Schmalbrock P, Brogram M et al. Normal venous anatomy of the brain: Demonstration with gadopenetate dimeglumine in enhanced 3-D MR angiography AJR 1991 156:161–172. [PubMed: 1898554]

33.

Dumoulin CL, Souza SP, Walker MF, et al. Time-resolved magnetic resonance angiography Magn Reson Med 1988; 6:275–286. [PubMed: 3362062]

34.

Price RR, Creasy JL, Lorenz CH, et al. Magnetic resonance angiography techniques Invest Radiol 1992 27:Suppl 27–32. [PubMed: 1468872]

35.

Dumoulin CL, Hart HR Jr. Magnetic resonance angiography in the head and neck Acta Radiol 1986 369: Suppl 17-20. [PubMed: 2980442]

36.

Feinberg DA, Crooks LE, Hoenninger J, et al. Pulsatile blood velocity in human arteries displayed by magnetic resonance imaging Radiology 1984 153: 177–180. [PubMed: 6473779]

37.

Valk PE, Hale JD, Kaufman L, et al. MR imaging of the aorta with three-dimensional vessel reconstruction: Validation by angiography Radiology 1985 157:721–725. [PubMed: 4059559]

38.

Hoffer FA. Facial vascular anomalies: Clarity with magnetic resonance imaging and biological classifications (editorial) Mayo Clin Proc 1992 67: 807–809. [PubMed: 1434923]

39.

Mattle HP, Wentz KU, Tuncdogan E, et al. Intracranial manifestation of thrombosis and vascular occlusion in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 432–451.

40.

Edelman RR. Basic principles of magnetic resonance angiography Cardiovasc Intervent Radiol 1992 15: 3–13. [PubMed: 1537062]

41.

Walker MF, Souza SP, Dumoulin CL. Quantitative flow measurement in phase contrast MR angiogrphy J Comput Assist Tomogr 1988 12:304–313. [PubMed: 3351045]

42.

Pernicone JR. Intracranial aneurysms in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 405–431.

43.

Keller PJ, Drayer BP, Fram EK, et al. MR angiography with two dimensional acquisition and three-dimensional display Radiology 1989 173:527–532. [PubMed: 2798885]

44.

Listerud J. First principles of magnetic resonance angiography Magn Reson Q 1991 7:136–170. [PubMed: 1911233]

45.

Turski PA, Korosec FR, Graves VB, et al. Vascular malformations, in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 380–404.

46.

Higgins CB. The potential role of magnetic resonance imaging in ischemic vascular disease N Engl J Med 1992 326(editorial):1624–1626. [PubMed: 1584264]

47.

Siebert JE, Rosenbaum TL. Image presentation and post-processing, in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 220–245.

48.

Wagle WA, Dumoulin CL, Souza SP. 3DFT MR angiography of carotid and basilar arteries AJNR 1989 10: 911–919. [PMC free article: PMC8335280] [PubMed: 2505533]

49.

Ruggieri PM, Masaryk TJ, Ross JS, et al. Intracranial magnetic resonance angiography Cardiovasc Intervent Radiol 1992 15:71–81. [PubMed: 1537068]

50.

Meyer CH, Macovski A, Nishimura DG. Square-spiral fast imaging Society Magnetic Resonance in Medicine, 1989, (Eighth Proc),

51.

Spickler E, McKenna KM, Lufkin RB. Approaches to MR angiography Comput Med Imaging Graph 1988 12:211–217. [PubMed: 3052793]

52.

Nishimura DG, Macovski A, Pauly JM. Considerations of magnetic resonance angiography by selective inversion recovery Magn Reson Med 1988; 7:472–484. [PubMed: 3173062]

53.

Edelman RR, Mattle HP, Atkinson DJ, et al. MR angiography AJR 1990; 154:937–946. [PubMed: 2108568]

54.

Frahm J, Merboldt KD, Hanicke W, et al. Rapid line scan NMR angiogrpahy angiography Magn Reson Med 1988 7:79–87. [PubMed: 3386524]

55.

Kricheff II. Arteriosclerotic ischemic cerebrovascular disease Radiology 1987 162:101–109. [PubMed: 3538142]

56.

Dumoulin CL, Souza SP, Hart HR. Rapid scan magnetic resonance angiography Magn Reson Med 1987 5:238–245. [PubMed: 3431392]

57.

Amparo E, Higgins C, Hoddick W, et al. Magnetic resonance imaging of aortic disease: Preliminary results Am J Roentgenol 1984 143:1203. [PubMed: 6149679]

58.

Amparo E, Higgins C, Hricak H, et al. Aortic dissection: Magnetic resonance imaging Am J Roentgenol 1985 155:399–406. [PubMed: 3983390]

59.

Hricak H, Amparo E, Fisher M, et al. Abdominal venous system: Assessment using MR Radiology 1985; 156:415–422. [PubMed: 4011904]

60.

Waugh JR, Sacharias N. Arteriographic complications in the DSA era Radiology 1992 182:243–246. [PubMed: 1727290]

61.

Hankey JH, Warlow CP, Sellar RJ. Cerebral angiographic risk in mild cerebrovascular disease Stroke 1990 21: 209–222. [PubMed: 2406993]

62.

Dawson P, Trewhella M. Intravascular contrast agents and renal failure Clin Radiol 1990 41:373–375. [PubMed: 2200630]

63.

Anderson CM, Saloner D, Lee RE, et al. Assessment of carotid artery stenosis by MR angiography: Comparison with x-ray angiography and color-coded Doppler ultrasound AJNR 1992 13:989–1003. [PMC free article: PMC8331703] [PubMed: 1590203]

64.

Masaryk TJ, Lewin JS, Laub G. Magnetic resonance angiography, in Stark DP, Brandley WG(Eds): Magnetic Resonance Imaging (2nd ed), St. Louis: Mosby Year Book, 1992, pp 299–334.

65.

Freeman J, Free T, Rayne H. Assessing extracranial carotid stenosis: Magnetic resonance angiography, duplex scanning, and digital angiography, South Dakota J Med 1993; 46:53–56. [PubMed: 8441927]

66.

[No authors listed] Federal Register, 1992, pp. pp 55259–55260.

67.

[no authors listed] Health Technology Assessment Report 1985, No. 13. Magnetic Resonance Imaging. , Rockville, MD: National Center for Health Services Research.

68.

Niendorf HP, Haustein J, Cornelius I, et al. Safety of gadolinium-DTPA: extended clinical experience Magn Reson Med 1991 22:222–228. [PubMed: 1812350]

69.

Masaryk TJ, Ross JS, Modic MT, et al. Carotid bifurcation MR imaging Radiology 1988 166:461–466. [PubMed: 3336721]

70.

Edelman RR, Mattle HP, Wallner B, et al. Extracranial carotid arteries: Evaluation with "black blood" MR angiography Radiology 1990 177:45–50. [PubMed: 2399337]

71.

Kido DK, Panzer RJ, Szumowski J, et al. Clinical evaluation of stenosis of the carotid bifurcation with magnetic resonance angiographic techniques Arch Neurol 1991 48:484–489. [PubMed: 2021361]

72.

Laster RE, Acker JD, Halford HH, et al. Carotid bifurcation evaluation with vascular MR imaging J Magn Reson Imaging 1991; 1(abstr):

73.

Litt AW, Eidelman EM, Pinto RS, et al. Diagnosis of carotid artery stenosis: Comparison of 2DFT time-of-fight MR angiography with contrast angiography in 50 patients AJNR 1991 12:149–154. [PMC free article: PMC8367569] [PubMed: 1903574]

74.

Masaryk AM, Ross JS, DiCello MC, et al. 3DFT MR angiography of the carotid bifurcation: Potential and limitations as a screening examination Radiology 1991 179:797–804. [PubMed: 2027995]

75.

Mattle HP, Kent C, Edelman RR, et al. Evaluation of the extracranial carotid arteries: correlation of magnetic resonance angiography, duplex ultrasonography, and conventional angiography J Vasc Surg 1991 13:838–845. [PubMed: 2038105]

76.

Wilkerson DK, Keller I, Mezrich R, et al. The comparative evaluation of three-dimensional magnetic resonance for carotid artery disease J Vasc Surg 1991 14:803–811. [PubMed: 1960811]

77.

Furuya Y, Isoda H, Hasegawa S. Magnetic resonance angiography of extracranial carotid and vertebral arteries, including their origins: comparison with digital subtraction angiography Neuroradiology 1992 35:42–45. [PubMed: 1289737]

78.

Pavone P, Marsili L, Catalano C et al. Carotid arteries: Evaluation with low-field strength MR angiography Radiology 1992 184:401–404. [PubMed: 1620836]

79.

Riles TS, Eidelman EM, Litt AW, et al. Comparison of magnetic resonance angiography, conventional angiography, and duplex scanning Stroke 1992 23:341–346. [PubMed: 1542893]

80.

Wesbey GE, Bergan JJ, Moreland SI, et al. Cerebrovascular magnetic resonance angiography: A critical verification J Vasc Surg 1992 16:619–632. [PubMed: 1404682]

81.

Anson JA, Heiserman JE, Drayer BP, et al. Surgical decisions on the basis of magnetic angiography of the carotid arteries Neurosurgery 1993 32:335–343. [PubMed: 8455757]

82.

Blatter DD, Bahr AL, Parker D, et al. Cervical carotid MR. Angiography with multiple overlapping thin-slab acquisition: Comparison with conventional angiography AJR 1993 161: 1269–1277. [PubMed: 8249741]

83.

Edelman RR, Wentz KV, Mattle HP, et al. Intracerebral arteriovenous malformations: Evaluation with selective MR angiography and venography Radiology 1989 173:831–837. [PubMed: 2813794]

84.

DeMarco JK, Dillon WP, Halbach Halback VV, et al. Dural arteriovenous fistulas: Evaluation with MR imaging Radiology 1990 175:193–199. [PubMed: 2315480]

85.

Marchal G, Bosmans H, Van fraeyenhoven L, et al. Intracranial vascular lesions: Optimization and clinical evaluation of three-dimensional time-of-flight MR angiography Radiology 1990 175:443–448. [PubMed: 2326471]

86.

Ross JS, Masaryk TJ, Modic MT. Intracranial aneurysms: Evaluation by MR angiography AJNR 1990 11:449–456. [PMC free article: PMC8367465] [PubMed: 2112306]

87.

Blatter DD, Parker DL, Robison RO. Cerebral MR angiography with multiple overlapping thin slab acquisition. Part I. Quantitative analysis of vessel visibility Radiology 1991 179:805–811. [PubMed: 2027996]

88.

Nadel L, Braun IF, Kraft KA, et al. Intracranial vascular abnormalities: Value of MR phase imaging to distinguish thrombus from flowing blood AJR 1991 156:373–380. [PubMed: 1898818]

89.

Nussel F, Wegmuller H, Huber P. Comparison of magnetic resonance angiography, magnetic resonance imaging and conventional angiography in cerebral arterial malformation Neuroradiology 1991; 33:56–61. [PubMed: 2027447]

90.

Applegate GR, Talagala SL, Applegate LJ, et al. MR angiography of the head and neck: value of two-dimensional phase-contrast projection technique AJR 1992 159:369–374. [PubMed: 1632359]

91.

Shuierer Schuierer G, Huk WJ, Laub G, Magnetic resonance angiography of intracranial aneurysms: Comparison with intraarterial intra-arterial digital subtraction angiography Neuroradiology 1992 35:50–54. [PubMed: 1289739]

92.

Awad IA, Mckenzie R, Magdinec M, et al. Application of magnetic resonance angiography to neurosurgical practice: A critical review of 150 cases Neurol Res 1992 14:360–368. [PubMed: 1362250]

93.

Ostertun B, Solymosi L. Magnetic resonance angiography of cerebral developmental cerebral anomalies: Its role in differential diagnosis Neurology 1993 35: 97–104. [PubMed: 8433801]

94.

Petereit D, Mehta M, Turski P, et al. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database Int J Radiation Oncol Biol Phys 1993 25:309–313. [PubMed: 8420879]

95.

Firman DN, Doumoulin CL, Mohiaddin RH. Quantitative flow imaging, in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 187–219.

96.

Vock P, Terrier F, Wegmuller H, et al. Magnetic resonance angiography of abdominal vessels: Early experience using the three dimensional phase-contrast technique Br J Radiol 1991 64:10–16. [PubMed: 1998832]

97.

Kim D, Edelman RR, Kent KC, et al. Abdominal aorta and renal artery stenosis: Evaluation with MR angiography Radiology 1990 174: 727–731. [PubMed: 2305057]

98.

Debatin JF, Spritzer CE, Grist TM, et al. Imaging of the renal arteries: Value of MR angiography AJR 1991 157:981–990. [PubMed: 1927823]

99.

Kent KC, Edelman R, Kim, D, et al. Magnetic resonance imaging: A reliable test for the evaluation of proximal atherosclerotic renal arterial stenosis J Vasc Surg 1991 13:311–318. [PubMed: 1990171]

100.

Linden A, Krestin GP, Theissen P, et al. Renal artery stenosis: Potentials of MR tomography possibilities of magnetic resonance tomography Nucl Med Commun 1989 28:226–233. [PubMed: 2608446]

101.

Gedroye Gedroyc WMW, Negus R, Al-Kutoubi A, et al. Magnetic resonance angiography of renal transplants Lancet 1992 339: 789–791. [PubMed: 1347813]

102.

Durham JR, Hackworth CA, Tober JC, et al. Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms Am J Med 1993 166: 173–178. [PubMed: 8352411]

103.

Smith HJ, Bakke SJ, R angiography of in situ and transplanted renal arteries. Early experience using a three-dimensional time-of-flight technique Acta Radiol 1993 34:150–155. [PubMed: 8452722]

104.

Duerk JL, Wendt RE, III. Motion artifacts and motion compensation, in Potchen EJ, Haache EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 80–133.

105.

Foo RKF, McFal MacFall JR, Hayes CE, et al. Pulmonary vasculature: Single breath-hold MR imaging with phased-array coils Radiology 1992 183:473–477. [PubMed: 1561352]

106.

Dinsmore RE, Liberthson RR, Wismer GL, et al. Magnetic resonance imaging of thoracic aortic aneurysm: Comparison with other imaging methods AJR 1986 146: 309–314. [PubMed: 3510513]

107.

Kauezo Kauczor HU, Layer G, Schad LP, et al. Clinical applications of MR angiography in intrathoracic masses J Comput Assist Tomogr 1991 15:409–417. [PubMed: 2026801]

108.

Manning WJ, Li W, Edelman RR. A preliminary report comparing magnetic resonance coronary angiography with conventional angiography N Engl J Med 1993 338:828–832. [PubMed: 8285929]

109.

Yucel EK, Steinberg FL. Lower extremity and renal angiography, in Potchen EJ, Haache EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 597–606.

110.

Mulligan SA, Matsuda T, Lanzer P, et al. Peripheral arterial occlusive disease: Prospective comparison of MR angiography and color duplex US with conventional angiography Radiology 1991; 178:695–700. [PubMed: 1994405]

111.

Gehl HB, Bohandorf K, Gladziva V, Bohndorf K, Gladziwa U, et al. Imaging of hemodialysis fistulas: Limitations of MR angiography J Comput Assist Tomog 1991 15:271–275. [PubMed: 2002107]

112.

Owen RS, Bau Baum RA, Carpenter JP, et al. Symptomatic peripheral vascular disease: Selection of imaging parameters and clinical evaluation with MR angiography Radiology 1993 187:627–635. [PubMed: 8497607]

113.

Hertz SM, Baum RA, Ower RS, et al. Comparison of magnetic resonance angiography and contrast angiography in peripheral artery stenosis Am J Surg 1993 166:112–116. [PubMed: 8352400]

114.

Spritzer CE, Norconk JJ Jr., Sostman HD, et al. Detection of deep venous thrombosis by magnetic resonance imaging Chest 1993 104:54–60. [PubMed: 8325117]

115.

Yucel EK, Kaufman JA, Geller SC, et al. Atherosclerotic occlusive disease of the lower extremity: Prospective evaluation with two dimensional time-of-flight MR angiography Radiology 1993 187:637–641. [PubMed: 8497608]

116.

Schiebler ML, Listerud J, Holland G, et al. Magnetic resonance angiography of the pelvis and lower extremities. Works in progress Investigative Radiology 1992 27:Suppl91–96. [PubMed: 1468882]

117.

Hart RG. Cardiogenic embolism to the brain Lancet 1992 339:589–594. [PubMed: 1347101]

118.

Rutt BK, Napel S. Magnetic resonance techniques for blood-flow measurement and vascular imaging Can Assoc Radiol J 1991 41:21–30. [PubMed: 2001525]

119.

Ross JS, Masaryk TJ, Ruggieri PM. Magnetic resonance angiography of the carotid bifurcation Top Magn Reson Imaging 1991 3:12–22. [PubMed: 2054195]

120.

Steinberg FL, Yucel EK, Doumoulin CL, et al. Peripheral vascular and abdominal application applications of MR flow imaging techniques Magn Reson Med 1990 14:315–320. [PubMed: 2345511]

121.

Finn JP, GoldmanGoldmann A, Edelman RR. Magnetic resonance angiography in the body Magn Reson Q 1992; 8:1–22. [PubMed: 1567756]

122.

Davis DO. Commentary in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications. , St. Louis: Mosby Year Book, 1993,

123.

Pavone P, Gallucci M, Passariello R. Magnetic resonance angiography at low field strength in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications., St. Louis: Mosby Year Book, 1993, pp 343–355.

124.

Cornacchia LG, Abitbol JJ, Heller J, et al. Blunt injuries to the extracranial cerebral vessels associated with spine fractures Spine 1991 16: Suppl506–510. [PubMed: 1801262]

125.

Spector ML, Wiznitzer M, Walsh-Sukys MC, et al. Carotid reconstruction in the neonate following ECMO J Pediatr Surg 1991 26:357–361. [PubMed: 2056394]

126.

Pernicone JR, Siebert JE, Potchen EJ, et al. Three-dimensional phase-contrast MR angiography in the head and neck: Preliminary report AJNR 1990 11:457–466. [PMC free article: PMC8367468] [PubMed: 2112307]

127.

Dumoulin CL, Souza SP, Feng H, Multiecho magnetic resonance angiography Magn Reson Med 1987 5:47–57. [PubMed: 3657494]

128.

Portman MA, Cooper TG, Potchen EJ, Physiologic alterations in cranial blood flow demonstrated by magnetic resonance angiography Invest Radiol 1992 27:240–244. [PubMed: 1551776]

129.

Bryan RN. (Reviewer Commentary), Intracranial aneurysms in Potchen EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications, St. Louis: Mosby Year Book, 1993, pp 405–431.

130.

Ruff SJ, Watson MR. Magnetic resonance imaging versus angiography in the preoperative assessment of abdominal aortic aneurysms Am J Surg 1988 155:651–654. [PubMed: 3369619]

131.

Edelman RR, Manning WJ, Burstein D, et al. Coronary arteries: Breath-hold MR angiography Radiology 1991 181:641–643. [PubMed: 1947074]

132.

Carpenter J. Magnetic resonance angiography in peripheral artery disease Hosp Pract 1992 27:79–97. [PubMed: 1400674]

133.

Thomas GI, Jones TW, Stavney LS, et al. Carotid endarterectomy after Doppler ultrasonographic examination without angiography Am J Surg 1986 151: 616–619. [PubMed: 3518513]

134.

Moore WS, Ziomek S. Quenones-Baldrich WJ, et al. Can clinical evaluation and noninvasive testing substitute for arteriography in the evaluation of carotid artery disease Ann Surg 1988 208:91–94. [PMC free article: PMC1493566] [PubMed: 3389948]

135.

Furst G, Steinmetz H, Fischer H, et al. Selective MR angiography and intracranial collateral blood flow J Comput Assist Tomogr 1993; 17:178–183. [PubMed: 8454742]

136.

Estol C, ClaassenClaasen D, Hirsch W, et al. Correlative angiographic and pathologic findings in the diagnosis of ulcerated plaques in the carotid artery Arch Neurol 1991 48:692–694. [PubMed: 1859295]

137.

Polak JF, Bajakian RL, O'Leary DH. Detection of internal carotid artery stenosis: Comparison of MR angiography, color Doppler sonography, and arteriography Radiology 1992 185:35–40. [PubMed: 1727306]

138.

Caplan LR, Wolpert SM. Angiography in patients with occlusive cerebrovascular disease; Veins of a stroke neurologist and neuroradiologist AJNR 1991 12:593–601. [PMC free article: PMC8331599] [PubMed: 1882733]

139.

Wiznitzer M, Masaryk TJ. Cerebrovascular abnormalities in pediatric stroke: Assessment using parenchymal and angiographic magnetic resonance imaging Ann Neurol 1991 29:585–589. [PubMed: 1892360]

140.

Ruggieri PM, Masaryk TJ, Ross JS. Magnetic resonance angiography. Cerebrovascular applications Stroke 1992 23: 774–780. [PubMed: 1579977]

141.

Wiznitzer M, Ruggieri PM, Masaryk TJ. Diagnosis of cerebrovascular disease in sickle cell anemia by magnetic resonance angiography J Pediatr 1990 117:551–555. [PubMed: 2213377]

142.

Grotta JC. Acute stroke management: Diagnosis (Part I) Stroke 1993 3(clinical update): 17–20.

143.

Hart RG. Cardiogenic embolism to the brain Lancet 1992 339: 589–594. [PubMed: 1347101]

144.

Gilman S. Advances in neurology N Engl J Med 1992 326:1671–1677. [PubMed: 1588981]

145.

Link KM, Lesko NM. The role of MR imaging in the evaluation of acquired diseases of the thoracic aorta AJR 1992; 158:1115–1125. [PubMed: 1566678]

146.

Wang SJ, Hu BS, Macovski A, et al. Coronary angiography using fast selective inversion recovery Magn Reson Med 1991 18:417–423. [PubMed: 2046523]

147.

Mostbeck GH, GaputoCaputo GR, Higgins CB. MR measurement of blood flow in the cardiovascular system AJR 1992 159:453–461. [PubMed: 1503004]

148.

Firmin DN, Klipstein RH, Hounsfield GL, et al. Echo-planar high-resolution flow velocity mapping Magn Reson Med 1989 12: 316–327. [PubMed: 2628682]

149.

Link KM, Loehr SP, Lesko NM, Cardiopulmonary vascular imaging Invest Radiol 1992; 27: Suppl 72-79. [PubMed: 1468879]

150.

Edelman RR, Manning WJ. Coronary angiography techniques in Potches EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications. , St. Louis: Mosby Year Book, 1993, pp 278–287.

151.

Link KM, Zerhouni EA. Cardiac imaging in Potches EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications., St Louis: Mosby Year Book 1993, pp 573–596.

152.

Steinberg EP. Magnetic resonance coronary angiography: Assessing an emerging technology (editorial) N Engl J Med 1993 328(editorial):879–880. [PubMed: 8441432]

153.

Wielopolski PA, Haacke EM, Adler LP. Three-dimensional pulmonary vascular imaging in Potches EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography: Concepts and Applications., St. Louis: Mosby Year Book, 1993, pp 246–277.

154.

Hartnell GG, Goldmann A, Finn JP. Thoracic venography in Potches EJ, Haacke EM, Siebert JE, et al. (Eds): Magnetic Resonance Angiography. Concepts and Applications., St. Louis: Mosby Year Book 1993, pp 534–545.

155.

Finn JP, Longmaid HE. Abdominal magnetic resonance venography Cardiovasc Intervent Radiol 1992 15: 51–59. [PubMed: 1537065]

156.

Arlart IP, Guhl L, Edelman RR. Magnetic resonance angiography of the abdominal aorta Cardiovasc Intervent Radiol 1992 15:43–50. [PubMed: 1537064]

157.

Farrugia E, King BF, Larson TS. Magnetic resonance angiography and detection of renal artery stenosis in a patient with impaired renal function Mayo Clin Proc 1993 68:157–160. [PubMed: 8423696]

158.

Chien D, Edelman RR. Basic principles and clinical applications of magnetic resonance angiography Semin Roentgenol 1992; 27:53–62. [PubMed: 1736376]

159.

Debatin JF, Spritzer CE, Grist TM, et al. Imaging of [the] renal arteries: Values Value of MR angiography AJR 1991 157: 981–990. [PubMed: 1927823]

160.

Davidson RA, Wilcox CS. Newer tests for the diagnosis of renovascular disease JAMA 1992 268:3353–3358. [PubMed: 1453529]

161.

Farrugia E, King BF, Larson TS. Magnetic resonance angiography and detection of renal artery stenosis in a patient with impaired renal function Mayo Clin Proc 1993 68:157–160. [PubMed: 8423696]

162.

Steinberg FL, Yucel EK, Dumoulin CL. Peripheral vascular and abdominal applications of MR flow imaging techniques Magn Reson Med 1990 14:315–320. [Note: duplicates reference # 120] [PubMed: 2345511]

163.

Linder A, Krestin GP, Theissen P, et al. Renal artery stenosis: Potentials of MR tomography Nuclearmedizin 1989 28:226–233. [PubMed: 2608446]

164.

Sommer G, Noorbehesht B, Pelc N, et al. Normal renal blood flow measurement using phase-contrast cine magnetic resonance imaging Invest Radiol 1992 27:465–470. [PubMed: 1607260]

165.

Lundin B, Cooper TG, Meyer RA, et al. Measurement of total and unilateral renal blood flow by oblique-angle velocity-encoded 2D-cine magnetic resonance angiography Magn Reson Imaging 1993 11:51–59. [PubMed: 8423722]

166.

Finn JP, Edelman RR, Jenkins RJ, et al. Liver transplantation: MR angiography with surgical validation Radiology 1991 179:265–269. [PubMed: 2006289]

167.

Strandness DE Jr., Andros G, Baker JD, et al. Vascular laboratory utilization and payment: Report of the ad hoc committee of the Western Vascular Society J Vasc Surg 1992 16:163–170. [PubMed: 1495140]

168.

Owen RS, Carpenter JP, Baum RA, et al. Magnetic resonance imaging of angiographically occult runoff vessels in peripheral arterial occulusive disease N Engl J Med 1992 326:1577–1581. [PubMed: 1584257]

Footnotes

[

a] MRI can also be based on elements as sodium or phosphorus, but experimental technology is outside the subject area of this assessment.

AHCPR Pub. No. 95-0004