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Efficacy of magnetic resonance angiography in the evaluation of vascular malformations of the hand.

Conventional arteriography has been the accepted standard technique for demonstrating the anatomic details in vascular malformations of the hand. The technique of magnetic resonance angiography provides detailed anatomy for vascular anomalies of the hand without the use of an invasive technique or contrast enhancement. When magnetic resonance angiography is combined with magnetic resonance imaging, the extent of the lesion with respect to the surrounding tissues and the flow characteristics of the lesion can be determined noninvasively. In our institution, magnetic resonance angiography has replaced conventional arteriography as the technique of choice for the evaluation of these lesions. This report evaluates the efficacy of magnetic resonance imaging/ magnetic resonance angiography in the management of vascular malformations of the hand. Ten consecutive patients over 30 months (median age 37 years) underwent magnetic resonance imaging/magnetic resonance angiography evaluation after the clinical diagnosis of a vascular malformation of the hand was made. Four patients in the group had conventional arteriography performed before referral. Magnetic resonance imaging/magnetic resonance angiography clearly defined the anatomic extent of the lesion, its relationship to surrounding tissues, and the flow characteristics in each patient. In the four patients in whom conventional arteriography had been performed, the magnetic resonance angiography findings matched the arteriographic findings. On the basis of the magnetic resonance imaging/magnetic resonance angiography findings, six patients were treated nonoperatively with compressive garments and four patients had operative treatment (resection of lesion n = 2, digital ray resection n = 2). In this series, magnetic resonance imaging/magnetic resonance angiography was efficacious in the management of vascular malformations of the hand. This technique provides detailed images of both the arterial and venous components of the lesions without the requirements of contrast enhancement, ionizing radiation, or an invasive procedure. Furthermore, the resectability can be determined based on the extent of involvement and the flow characteristics.

Adolescent↗

Indocyanine green angiography anomalies in ocular syphilis.

OBJECTIVE: To report indocyanine green (ICG) angiography anomalies in ocular syphilis. DESIGN: A noncomparative, interventional case series. PARTICIPANTS: Eight patients (16 eyes) affected by ocular syphilis. METHODS: All patients presenting with a diagnosis of active ocular syphilis between January 1994 and December 2001 were evaluated by a standard fluorescein and ICG angiography protocol. ICG angiography was repeated after completion of systemic antitreponemal and antiinflammatory treatment. RESULTS: ICG angiography anomalies were detected in 12 (75%) of 16 eyes. Two types of anomalies were observed: late-phase scattered hyperfluorescent spots (11 eyes) and persistent staining of retinal vessels (1 eye). Of these 12 eyes, 4 had no alteration by concomitant fluorescein angiography. When ICG angiography was repeated (5 +/- 1 weeks after the beginning of treatment), ICG angiography anomalies disappeared. CONCLUSIONS: ICG angiography may be a valuable tool in the assessment of patients with active ocular syphilis. Retinal and choroidal vascular anomalies can be determined that would otherwise go undetected by funduscopy and/or fluorescein angiography. It can also be useful in monitoring antitreponemal therapy.

Anti-Bacterial Agents↗

Assessment of coronary plaque morphology by contrast-enhanced computed tomographic angiography: comparison with intravascular ultrasound.

BACKGROUND: Computed tomographic (CT) angiography provides accurate noninvasive assessment for coronary artery stenosis. The ability of CT angiography to determine plaque morphology remains unclear. METHODS: Twelve patients undergoing intravascular ultrasound for clinical indications underwent CT angiography for the evaluation of plaque morphology. Plaque morphology was classified as (1) soft, (2) fibrous, (3) fibrocalcific or (4) calcific. CT angiography data sets were evaluated for the presence and morphology of plaque in the coronary artery segments. The results were blindly compared with intravascular ultrasound results on a segment by segment basis using angiographic landmarks. RESULTS: Fifty-nine coronary segments were analyzed; 10 segments were normal and 49 contained plaque. Plaque morphology by intravascular ultrasound was soft in 12 segments, fibrous in four, fibrocalcific in 29 and calcific in four. To determine coronary segments with any plaque, CT angiography had a sensitivity of 100% (49 of 49) and specificity of 90% (9 of 10). To determine plaque morphology as calcified (fibrocalcific and calcific) versus noncalcified (soft and fibrous), CT angiography had a sensitivity of 100% (33 of 33) and a specificity of 94% (15 of 16). Overall accuracy for CT angiography to determine plaque morphology was 92% (54 of 59). CT angiography density values (Hounsfield units, mean+/-standard deviation) were significantly different for each plaque morphology: soft 23+/-71, fibrous 108+/-79, fibrocalcific 299+/-112 and calcific 404+/-264 (P<0.0001). CONCLUSIONS: CT angiography accurately characterized plaque morphology and may be a useful tool in noninvasive evaluation of plaque morphology during drug therapy trials.

Contrast Media↗

"Renalism": inappropriately low rates of coronary angiography in elderly individuals with renal insufficiency.

Higher risk patients (including the elderly) receive more conservative therapy for cardiovascular diseases, even though the relative benefits of therapy tend to be greater. The perceived risk of radiocontrast-associated nephrotoxicity may influence the provision of coronary angiography and subsequent revascularization, especially among individuals with chronic kidney disease (CKD). The aim of this study was to determine whether there is excessive variation in the provision of coronary angiography after acute myocardial infarction on the basis of the presence of CKD and whether there is an association between angiography and mortality. Elderly (age 65 to 89 yr) individuals with acute myocardial infarction from the Cooperative Cardiovascular Project were classified by the presence or absence of CKD (defined as a baseline serum creatinine of 1.5 to 5.0 mg/dl). In CKD patients, the propensity to undergo coronary angiography was determined and the effect of coronary angiography on mortality was estimated using multivariable logistic regression and stratification. Mortality was significantly higher with CKD (52.6 versus 26.4%). Fewer patients with CKD underwent coronary angiography (25.2 versus 46.8%) despite the observation that a similar proportion of patients were deemed appropriate for angiography by standard, published criteria. When limiting the analysis to CKD patients who are considered appropriate, the multivariable estimate of the odds of death associated with coronary angiography was 0.58 (95% confidence interval, 0.50 to 0.67). With adjustment using propensity scores, the odds ratio averaged across propensity score quintiles was 0.62 (95% confidence interval, 0.54 to 0.70). Results were qualitatively similar when patients were stratified by CKD stage IV (estimated GFR <30 ml/min per 1.73 m(2)). There is a large relative decrease in utilization of coronary angiography among patients with CKD. Alteration in practice because of an aversion to the risk of radiocontrast-associated nephrotoxicity ("renalism") is inappropriate, even if the true relative benefit of invasive strategies is a fraction of what is estimated here.

Age Factors↗

The effect of catheter-directed CT angiography on yttrium-90 radioembolization treatment of hepatocellular carcinoma.

PURPOSE: Yttrium 90 radioembolization is a transcatheter therapy for unresectable hepatocellular carcinoma (HCC) that delivers internal radiation to tumors. In contrast to the usual method of lobar regional delivery, catheter-directed computed tomographic (CT) angiography was investigated as a potentially useful technique to evaluate the administration of segmental 90Y tumor radiation doses superselectively without significantly altering liver function or Child-Pugh classification. MATERIALS AND METHODS: Fourteen patients underwent 90Y therapy for unresectable HCC. After standard angiographic placement of a 3-F microcatheter in a segmental hepatic artery supplying the tumor, each patient underwent CT angiography with use of segmental hepatic artery injection of iodinated contrast agent to confirm segmental perfusion and delineate segmental liver volume. 90Y was later injected into the same segmental artery. Target dose was calculated according to infused 90Y activity and targeted hepatic volume with standard lobar volume (before CT angiography) versus segmental liver volume (after CT angiography). The Wilcoxon signed-rank test (alpha = 0.05) was used to compare the estimated 90Y dose before CT angiography with the actual 90Y dose after CT angiography, as well as changes in serum bilirubin level and Child-Pugh classification as a result of treatment. RESULTS: The mean estimated tumor dose before CT angiography (SD) was 100 Gy +/- 43 (range, 35-169 Gy). The mean actual tumor dose after CT angiography was 348 Gy +/- 204 (range, 105-857 Gy), which was significantly greater (P < .001). The mean bilirubin level before treatment was 1.0 mg/dL +/- 0.97 (range, 0.2-4.0 mg/dL), whereas the mean bilirubin level after treatment was 1.3 mg/dL +/- 0.85 (range, 0.5-3.8 mg/dL). This difference, although statistically significant (P = .03), was not clinically important. Thirteen of 14 patients had no change in Child-Pugh class. CONCLUSION: CT angiography can be used to delineate the blood supply and volume to a targeted hepatic segment, allowing superselective 90Y radioembolization. This approach significantly increases effective 90Y tumor radiation dose without clinically altering liver function or Child-Pugh class.

Adult↗

Role of additional angiography and chemoembolization in patients with hepatocellular carcinoma who achieved complete necrosis following transarterial chemoembolization.

BACKGROUND AND AIMS: Although transarterial chemoembolization (TACE) has been reported to have antitumor effects in patients with hepatocellular carcinoma (HCC), optimal time schedules and follow-up methods have not yet been determined. We therefore prospectively analyzed the effects of additional angiography and chemoembolization on HCC recurrence and survival in patients who underwent TACE and achieved complete necrosis (CN). METHODS: A total of 68 patients who achieved CN after TACE, as assessed using dynamic computed tomography (CT), were randomized into two groups. Patients in the CT group (n = 34) were followed using dynamic CT every 3 months without any further intervention, whereas patients in the angiography group (n = 34) received additional angiography 1 month after achievement of CN. We compared overall survival and disease-free survival between the two groups and analyzed the benefit of additional angiography. RESULTS: The cumulative recurrence rate did not differ between the angiography and CT groups (55%vs 48% at 12 months and 66%vs 67% at 24 months, P = 0.92). The overall survival rates at 12 and 24 months were 88% and 84% in the angiography group, and 88% and 70% in the CT group, respectively (P = 0.57). Of the 34 patients in the angiography group, 27 (79%) suffered from adverse reactions of additional angiography and subsequent chemoembolization, seven (20.6%) experienced serum bilirubin increases of >/=1 mg/dL over baseline, and two (5.9%) developed renal impairment. CONCLUSION: Additional angiography and chemoembolization did not reduce tumor recurrence or improve patient survival in HCC patients who achieved CN, as assessed using dynamic CT, following TACE.

Adult↗

Indocyanine green angiography in angioid streaks.

PURPOSE: To define the indocyanine green angiographic aspects of angioid streaks, peau d'orange and choroidal new vessels. METHODS: Fifty-seven consecutive patients (112 eyes) with angioid streaks were evaluated by fluorescein angiography and indocyanine green angiography. RESULTS: Indocyanine green angiography showed angioid streaks in all eyes. We identified three different indocyanine green patterns of streaks (four groups): fluorescent (63%), hypofluorescent (8%), 'track-like' (19%) and mixed (10%). Angioid streaks were visualized better by indocyanine green angiography and red-free retinography than fluorescein angiography. Peau d'orange was seen better and found to be more widespread by indocyanine green angiography. Fluorescein angiography visualized choroidal neovascularization better, except for occult forms. CONCLUSIONS: Our findings show that angioid streaks have different indocyanine green angiography patterns. Considering that the hypofluorescent pattern was significantly observed in younger patients, indocyanine green angiography aspects might be correlated with different stages of the disease.

Adult↗

Pulmonary embolism: radiation dose with multi-detector row CT and digital angiography for diagnosis.

PURPOSE: To compare radiation dose delivered at four- and 16-detector row computed tomography (CT) with a dose-modulation program and that delivered at digital angiography for evaluation of pulmonary embolism (PE). MATERIALS AND METHODS: The part of the study involving patients (seven women, four men; mean age, 62 years +/- 16 [standard deviation]; range, 41-85 years) was approved by the institutional review board. Patients gave written informed consent. Exposure was performed with an anthropomorphic phantom with thermoluminescent dosimeters for four-detector row CT without the dose-modulation program and 16-detector row CT without and with the dose-modulation program with standard protocols for pulmonary CT angiography (120 kV, 144 mAs, four and 16 detector rows with 1.00- and 0.75-mm section thickness, respectively). Digital angiograms were acquired with four standard projections at 80 kV. For digital angiography, radiation dose was calculated according to phantom measurements and adapted to acquisition and fluoroscopy times. Distribution of dose was compared for CT and digital angiography. RESULTS: During pulmonary CT angiography, mean radiation dose delivered at middle of chest was 21.5, 19.5, and 18.2 mGy for four-detector row CT and for 16-detector row CT without and with dose-modulation program, respectively. At the same level, a mean dose of 91 mGy was delivered with digital angiography. The dose adjusted to clinical conditions was 139.0 mGy for digital angiography and could be reduced after technical adjustment. Ratios of maximum dose to mean dose were 1.15 and 2.96 for CT and digital angiography, respectively. With application of the dose-modulation program at 16-detector row CT, radiation dose was reduced 15%-20% at the upper chest. CONCLUSION: Multi-detector row CT delivers a lower radiation dose, with better spatial distribution of dose, than does pulmonary digital [corrected] angiography. With 16-detector row CT and a dose-modulation program, radiation dose is decreased during PE work-up.

Adult↗

Renal artery stenosis: CT angiography--comparison of real-time volume-rendering and maximum intensity projection algorithms.

PURPOSE: To compare results of helical computed tomographic (CT) angiography with real-time interactive volume rendering (VR) to CT angiography with maximum intensity projection (MIP) for the detection of renal artery stenosis. MATERIALS AND METHODS: Twenty-five patients underwent both conventional and CT angiography of the renal arteries. Images were blindly reviewed after rendering with MIP and VR algorithms. MIP images were viewed in conjunction with axial CT images; VR models were evaluated in real time at the workstation without CT images. Findings in 50 main and 11 accessory renal arteries were categorized as normal or by degree of stenosis. RESULTS: All arteries depicted on conventional angiograms were visualized on MIP and VR images. Receiver operating characteristic (ROC) analysis for MIP and VIR images demonstrated excellent discrimination for the diagnosis of stenosis of at least 50% (area under the ROC curve, 0.96-0.99). Although sensitivity was not significantly different for VR and MIP (89% vs 94%, P > .1), specificity was greater with VR (99% vs 87%, P = .008 to .08). Stenosis of at least 50% was overestimated with CT angiography in four accessory renal arteries, but three accessory renal arteries not depicted at conventional angiography were depicted at CT angiography. CONCLUSION: In the evaluation of renal artery stenosis, CT angiography with VR is faster and more accurate than CT angiography with MIP. Accessory arteries not depicted with conventional angiography were depicted with both CT angiographic algorithms.

Adult↗

Peripheral arterial disease: gadolinium-enhanced MR angiography versus color-guided duplex US--a meta-analysis.

PURPOSE: To summarize and compare the published data on gadolinium-enhanced magnetic resonance (MR) angiography and color-guided duplex ultrasonography (US) for the work-up for peripheral arterial disease. MATERIALS AND METHODS: Studies published between January 1984 and November 1998 were included if (a) gadolinium-enhanced MR angiography and/or color-guided duplex US were performed for evaluation of arterial stenoses and occlusions in the work-up for peripheral arterial disease of the lower extremities, (b) conventional angiography was the reference standard, and (c) absolute numbers of true-positive, false-negative, true-negative, and false-positive results were available or derivable. RESULTS: With a random effects model, pooled sensitivity for MR angiography (97.5% [95% CI: 95.7%, 99.3%]) was higher than that for duplex US (87.6% [95% CI: 84.4%, 90.8%]). Pooled specificities were similar: 96.2% (95% CI: 94.4%, 97.9%) for MR angiography and 94.7% (95% CI: 93.2%, 96.2%) for duplex US. Summary receiver operating characteristic analysis demonstrated better discriminatory power for MR angiography than for duplex US. Regression coefficients for MR angiography versus US were 1.67 (95% CI: -0.23, 3.56) with adjustment for covariates, 2.11 (95% CI: 0.12, 4.09) without such adjustment, and 1.73 (95% CI: 0.44, 3.02) with a random effects model. CONCLUSION: Gadolinium-enhanced MR angiography has better discriminatory power than does color-guided duplex US and is a highly sensitive and specific method, as compared with conventional angiography, for the work-up for peripheral arterial disease.

Aged↗

Pulmonary arteriovenous malformations: three-dimensional gadolinium-enhanced MR angiography-initial experience.

PURPOSE: To determine whether three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography could be used to identify pulmonary arteriovenous malformations (PAVMs) and to accurately identify the size and number of feeding arteries. MATERIALS AND METHODS: Eight patients suspected of having PAVM were examined with three-dimensional MR angiography at 1.5 T. Images were reviewed by a single radiologist blinded to conventional angiographic findings who evaluated each image for the size, number, and location of PAVMs, as well as for the size and number of feeding arteries. Five patients underwent conventional angiography with embolization therapy, and one patient underwent lobectomy. Two patients did not undergo either surgery or angiography. RESULTS: Three-dimensional MR angiography revealed nine (90%) of 10 PAVMs that were confirmed at conventional angiography (n = 9) or examination of a surgical specimen (n = 1). The single PAVM that was not identified prospectively at MR angiography was small (3-4 mm) and peripheral. Two additional PAVMs were identified in the two patients who did not undergo surgery or angiography. CONCLUSION: Three-dimensional MR angiography is a promising technique for use in the diagnosis of PAVM, although small (<5-mm) PAVMs may be more difficult to identify with the technique. The technique is a particularly useful means of noninvasively demonstrating the size and number of feeding arteries prior to treatment.

Adolescent↗

Spiral computed tomography is comparable to angiography for the diagnosis of pulmonary embolism.

The use of spiral computed tomography (CT) for the diagnosis of pulmonary embolism has been compared to angiography, the current gold standard. However, the accuracy of pulmonary angiography has never been evaluated against an independent gold standard. The aim of this study was to compare contrast-enhanced spiral CT to pulmonary angiography for the detection of subsegmental-sized pulmonary emboli by using a methacrylate cast of porcine pulmonary vessels as an independent gold standard. We studied 16 anesthetized, juvenile pigs and injected colored methacrylate beads (3.8 mm, small; 4.2 mm, large) via the jugular vein. After embolization spiral CT (3 mm and 1 mm collimation), and pulmonary angiography were performed. Pigs were killed and the pulmonary arterial tree was cast using methacrylate. Spiral CT and angiography were interpreted independently by two radiologists. Sensitivity and 95% confidence intervals for 3 mm and 1 mm collimation CT and angiography, respectively, were: 82% (73 to 88%), 87% (79 to 93%), 87% (79 to 93%) (p = 0.42). Positive predictive values and 95% confidence intervals for 3 mm and 1 mm collimation CT and angiography, respectively, were: 94% (86 to 94%), 81% (73 to 88%), and 88% (80 to 93%). There was no difference between spiral CT and angiography for detection of subsegmental-sized pulmonary emboli. We conclude that spiral CT is comparable to angiography for detection of pulmonary emboli.

Angiography, Digital Subtraction↗

MR angiography.

The primary use of angiography in the neck, either conventional catheter angiography or non-invasive techniques (MR angiography, CT angiography and ultrasound), is for the evaluation of the presence and severity of carotid stenosis. Other conditions such as vertebral artery stenosis, carotid and vertebral artery dissection and fibromuscular dysplasia are much less common but easily detectable with conventional angiography and are becoming increasingly reliably evaluated by non-invasive imaging. Intracranially, the value of MR angiography is less clear cut. It is certainly of use presurgery to look for vessel occlusion and encasement of vessels by tumour. It is also useful in excluding venous thrombosis as a cause of stroke. MR angiography for the detection and screening of intracranial aneurysms is less clear cut and, at present, it is the author's belief that MR angiography cannot replace conventional catheter angiography. Straight-forward spin echo imaging is the most accurate way of detecting arteriovenous malformations (AVMs) with magnetic resonance.

Carotid Stenosis↗

MR angiography of the iliac and upper femoral arteries using four different inflow techniques.

OBJECTIVE: The purpose of this study was to compare two inflow MR angiography pulse sequences obtained with and without systolic synchronization. We also compared these two MR angiography pulse sequences with conventional angiography. SUBJECTS AND METHODS: Thirty-one consecutive patients who were scheduled for conventional angiography because of symptomatic atherosclerotic occlusive disease of the iliac or femoral artery underwent MR angiography using four different MR angiography techniques. These techniques consisted of a multiple two-dimensional inversion prepulse gradient-recalled echo technique (turbo field-echo) obtained with and without systolic synchronization and a multiple two-dimensional gradient-recalled echo technique (fast field-echo) obtained with and without systolic synchronization. We then compared image quality and our ability to detect and grade degree and length of stenosis, using conventional angiography as the gold standard. RESULTS: The systolic-synchronized turbo field-echo sequence produced the best results both objectively and subjectively. Comparing systolic-synchronized turbo field-echo and fast field-echo techniques with conventional angiography regarding detection and grading degree of stenoses, we found no statistically significant differences. CONCLUSION: Systolic synchronization proved to be of significant importance for image quality. The systolic-synchronized turbo field-echo pulse sequence proved to be superior to the other three MR angiography techniques.

Aged↗

MR angiography versus color Doppler sonography in the evaluation of renal vessels and the inferior vena cava in abdominal masses of pediatric patients.

OBJECTIVE: Involvement of renal vessels and the inferior vena cava (IVC) plays a decisive role during operative planning for removal of abdominal masses in pediatric patients. Advantages and limitations of MR angiography and color Doppler sonography for determining these factors were evaluated. MATERIALS AND METHODS: MR angiography and color Doppler sonography were performed preoperatively in 42 neonates, infants, and children with abdominal masses and were compared with spin-echo MR imaging and with surgical findings. Variables evaluated were anatomic variants, vessel displacement, patency of vessels, collateral circulation, and intravascular tumor extension. Quality of vessel visualization was assessed in vessels not affected by tumor. RESULTS: In 88% of unaffected renal vessels, the entire vessel course could be visualized on MR angiography compared with 58% on color Doppler sonography and 43% on spin-echo MR imaging. In four of nine cases, color Doppler sonography revealed an accessory renal artery, whereas MR angiography revealed these variants in seven of nine cases. MR angiography showed 79% and color Doppler sonography 66% of displaced vessels. Unlike MR angiography, color Doppler sonography did not reveal five stenotic renal veins because they could not be completely imaged. In two cases, however, MR angiography falsely indicated an occlusion of the IVC, whereas color Doppler sonography showed residual flow. CONCLUSION: Anatomic variants, vessel displacement, collateral circulation, and neoplastic vessel infiltration were revealed more accurately by MR angiography than by color Doppler sonography. In cases in which patency of the IVC is unclear on MR angiography, color Doppler sonography should also be performed.

Abdominal Neoplasms↗

MR angiography of moyamoya disease before and after encephaloduroarteriosynangiosis.

OBJECTIVE: Our purpose was to evaluate the usefulness of MR angiography in revealing moyamoya disease before and after encephaloduroarteriosynangiosis. SUBJECTS AND METHODS: Twenty-six patients (51 hemispheres) with angiographically confirmed moyamoya disease who underwent encephaloduroarteriosynangiosis were included in the study. Findings on preoperative MR angiography were compared with those on conventional angiography. Postoperative neurologic status was categorized as poor, fair, good, or excellent. Postoperative MR angiography was examined for the appearance of the superficial temporal artery, changes in moyamoya vessels, and transdural collateral vessels into the middle cerebral artery territory. RESULTS: Preoperative MR angiography revealed moyamoya disease in all patients (diagnostic accuracy, 100%). MR angiography correctly depicted the degree of internal carotid artery stenosis in 37 arteries (73%), moyamoya vessels in 33 hemispheres (65%), and the degree of stenosis in the middle, anterior, and posterior cerebral arteries in 125 (82%) of 153 arteries. After surgery, 39 hemispheres showed an excellent outcome, eight showed a good outcome, two a fair outcome, and two a poor outcome. On postoperative MR angiography, vascular supply to the middle cerebral artery territory via transdural collateral vessels increased in 28 hemispheres (55%) and decreased in four (8%). The size of the superficial temporal artery increased in 41 (80%) of 51 hemispheres. The extent of moyamoya vessels decreased in 27 hemispheres (53%) after surgery. CONCLUSION: MR angiography can show the changes in the superficial temporal artery and development of transdural collateral vessels after encephaloduroarteriosynangiosis. Because MR angiography is noninvasive, it is valuable for evaluating postoperative changes.

Adolescent↗

Three-dimensional gadolinium-enhanced MR angiography of vascular complications after liver transplantation.

OBJECTIVE: The goal of this study was to evaluate three-dimensional gadolinium-enhanced MR angiography as a tool for examination of liver transplant patients with potential vascular complications. MATERIALS AND METHODS: Thirty-eight consecutive three-dimensional gadolinium-enhanced MR angiograms were obtained in 34 patients. Results were retrospectively reviewed and correlated with conventional angiography in 20 of the 38 cases and sonography in 37 of the 38 cases. MR angiograms were evaluated for technical adequacy, vascular patency, and parenchymal abnormalities, and results were compared with angiography and sonography. Conventional angiography and surgery were used as gold standards when available. RESULTS: Thirty-four (90%) of 38 MR angiograms were technically adequate. Vascular abnormalities were identified in 20 patients, and 19 of these patients subsequently underwent angiography, surgery, or both. There were seven cases of hepatic artery thrombosis; all were detected with MR angiography with no false-positive or false-negative interpretations. Seven patients had moderate to severe hepatic artery stenosis (>50% narrowing as determined by conventional angiography). MR angiography revealed this stenosis in six of the seven patients, with one false-negative and three false-positive interpretations. Portal vein thrombosis was detected in three patients, and portal vein stenosis was detected in two patients. CONCLUSION: Three-dimensional gadolinium-enhanced MR angiography is useful in the examination of liver transplant patients and offers a noninvasive adjunct in patients with difficult or indeterminate sonographic examinations.

Adult↗

Gadobenate dimeglumine-enhanced MR angiography of the abdominal aorta and renal arteries.

OBJECTIVE: This study was conducted to determine the efficacy and safety of four different doses of gadobenate dimeglumine for contrast-enhanced three-dimensional MR angiography of the abdominal aorta and renal arteries. SUBJECTS AND METHODS: Ninety-four patients with suspected abnormality of the abdominal aorta or renal arteries underwent unenhanced three-dimensional gradient-recalled echo time-of-flight MR angiography and contrast-enhanced MR angiography after the IV injection of one of four doses of gadobenate dimeglumine (0.025, 0.05, 0.1, and 0.2 mmol/kg of body weight). Efficacy was assessed on-site and by two blinded off-site reviewers in terms of change in total diagnostic quality score and diagnostic quality score per vessel segment from baseline unenhanced time-of-flight MR angiography to contrast-enhanced MR angiography. Secondary efficacy end points included lesion count and level of confidence in lesion characterization. Safety assessments comprised adverse event monitoring, physical evaluation, vital signs, ECG, and laboratory investigations. RESULTS: A significant change in the total diagnostic quality score from unenhanced to contrast-enhanced MR angiography was observed at all doses. The change increased with increased dose, plateauing at the 0.1 mmol/kg dose level. More patients with lesions detected and increased reviewer confidence for lesion characterization were noted on contrast-enhanced MR angiography compared with unenhanced MR angiography, although no dose-related trends were observed. All doses were well tolerated, and no significant changes in safety parameters were observed. CONCLUSION: Gadobenate dimeglumine is an effective and safe agent for contrast-enhanced MR angiography of the abdominal aorta and renal arteries. A dose of 0.1 mmol/kg of body weight appears to be the most suitable.

Adult↗