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PubMed2006

Angiography and the pediatric trauma patient: a 10-year review.

BACKGROUND/PURPOSE: Although interventional radiology has played an increasing role in the management of adult trauma patients, little has been written regarding its application in the care of the injured child. This study analyzed the indications, results, and complications for angiography in pediatric trauma patients. METHODS: A retrospective review of pediatric patients (14 years or younger) admitted to Los Angeles County-University of Southern California Medical Center, Los Angeles, Calif (an urban level I trauma center), over a 10-year period (1993-2003) was performed. Patients who underwent angiography were identified using hospital angiography records, and further information was recorded from the trauma registry and medical records. Variables collected included age, sex, mechanism of injury, and injury severity score (ISS). Angiographic data analyzed included indications, results, therapeutic interventions, and procedure-related complications. RESULTS: Twenty-five pediatric trauma patients who underwent angiography were identified (18 boys, 7 girls). The average age was 11 years (range, 1-14 years), with an ISS of 16 +/- 10. Indications for angiography included suspected limb ischemia (n = 9), suspected pelvic (n = 8) or solid organ bleeding (n = 8), suspected aortic injury (n = 6), and expanding hematoma (n = 1). Eleven patients (44%) had an abnormal finding, and 10 of 11 underwent a subsequent therapeutic intervention. There was 1 minor procedure-related complication and no procedure-related mortality. CONCLUSIONS: Though used infrequently in pediatric trauma patients, the result of the angiography was abnormal in almost half of the children in this series. An abnormal finding prompted further therapeutic intervention in most cases. Angiography was associated with minimal morbidity and should be considered as a useful and safe adjunct when caring for injured children.

Angiography↗
PubMed2005

Imaging of hepatic arterial anatomy for depicting vascular variations in living related liver transplant donor candidates with multidetector computed tomography: comparison with conventional angiography.

AIMS: The aim of this study was to evaluate liver arteries to depict variations by using multidetector computed tomography (CT) in donor candidates for living related liver transplantation. METHODS: Computed tomographic hepatic angiography was carried out using a multidetector 16-row CT scanner (Sensation 16; Siemens) in 48 candidates between April 2003 and August 2004. Multidetector CT was performed after intravenous injection of 150 mL of contrast material at a rate of 4 mL/s. Arterial phase images were acquired after contrast injection. Afterward, maximum intensity projections and volume-rendered images were produced from the axial image data. Twenty-eight of these patients underwent conventional catheter angiography. RESULTS: Excellent arterial opacification was shown on multidetector CT scans in all patients; arteries up to tertiary branches were identified with CT. Of 28 patients who had both multidetector CT angiography and conventional angiography, only a branch of hepatic artery originating from superior mesenteric artery that supplied the posterior segment of the right lobe was not identified on multidetector CT angiography. In 27 donors, hepatic arterial anatomy depicted at multidetector CT angiography was identical to that at conventional angiography. We identified hepatic vascular variants in 22 of 48 patients with multidetector CT. The most common arterial variant was an accessory hepatic artery arising from the left gastric artery. CONCLUSIONS: Preoperative imaging evaluation of hepatic vascular anatomy is crucial for surgical planning in living related transplant donors. Multidetector CT is useful to depict hepatic arterial anatomy with high accuracy.

Adolescent↗
PubMed2003

Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography.

BACKGROUND: Contrast-induced nephropathy (CIN) after coronary angiography is associated with increased morbidity and mortality rates. Preliminary studies with N-acetylcysteine (NAC) have found conflicting results in the prevention of CIN in patients undergoing coronary angiography. This study was designed to evaluate the efficacy and safety of NAC in the prevention of CIN in patients undergoing coronary angiography. METHODS: This study was prospective, randomized, double-blind, and placebo-controlled. Patients referred for elective coronary angiography with a baseline creatinine clearance level <50 mL/min and serum creatinine >1.2 mg/dL were randomly assigned to 1500 mg NAC or placebo, starting the evening before angiography and given every 12 hours for 4 doses. The primary study end point was the development of CIN, which was defined as an increase of >0.5 mg/dL or an increase of > or =25% in serum creatinine over baseline within 48 hours of angiography. Secondary end points included changes in serum creatinine and blood urea nitrogen, requirement of dialysis, side effects of study medication, hospital length of stay, and hospital charges. RESULTS: CIN occurred in 8.2% (4/49) of patients taking NAC and 6.4% (3/47) of patients taking placebo. Changes in BUN and serum creatinine from baseline were not significantly different in the two treatment groups. Baseline BUN and volume of contrast were the only independent predictors of CIN. More patients with diabetes had development of CIN (5/43; 12%) compared with nondiabetic patients (2/52; 4%), but the difference was not significant (P =.15). The incidence of CIN in diabetic patients was not different in the two treatment groups. No patient with development of CIN required dialysis. Side effects (mostly gastrointestinal) occurred in 16% of patients taking NAC and in none of the patients taking placebo. Length of stay and hospital charges were not different between the treatment groups. CONCLUSIONS: In patients with reduced renal function undergoing elective coronary angiography, NAC does not reduce the risk of CIN.

Acetylcysteine↗
PubMed1997

Influence of regional cardiovascular mortality on the use of angiography after acute myocardial infarction.

Utilization of angiography after acute myocardial infarction (AMI) treated with thrombolytics has been shown in large clinical trials to be related primarily to the availability of the procedure and not individual clinical circumstances. This study evaluated the regional influence of overall population cardiovascular mortality on utilization of angiography in the United States participants of the Global Utilization of Streptokinase and t-PA for Occluded Arteries (GUSTO-1) trial. Published summary statistics from GUSTO-1 and U.S. Census Bureau 1991 data were evaluated using simple and multiple linear regression with analysis for outliers. Region predictor variables (age adjusted) included mean total cardiovascular deaths/100,000/year (ICD/9 codes 390 to 459), mean coronary artery disease deaths/ 100,000/year (ICD/9 codes 410 to 414), and mean stroke deaths/100,000/year (ICD/9 codes 430 to 438), with the major outcome being regional proportion of GUSTO-1 patients undergoing angiography during the hospital stay after treatment with thrombolysis. All 3 cardiovascular death rates varied significantly by region (p < 0.00002) with no significant difference in GUSTO-1 mortality by region (p = 0.25). Simple linear regression analysis revealed associations between regional death rates and angiography use (r = 0.60, p = 0.12; r = 0.39, p = 0.33; r = 0.81, and p = 0.015). Multiple stepwise linear regression analysis found regional death rate due to stroke as the strongest predictor of angiography use with 65.86% of the variation explained by the model. New England was found to be a consistent outlier with reduced angiography use because of its background regional disease burden. This study confirms regional bias in the use of angiography in GUSTO-1. This form of operator bias appears to be due to more aggressive practice patterns in regions, except New England, where the overall cardiovascular disease burden is greater in terms of lives lost per 100,000 per year.

Age Factors↗
PubMed1997

Intraoperative angiography during minimally invasive direct coronary artery bypass operations.

BACKGROUND: The technical demands of beating heart operations raise concerns about anastomotic patency. This feasibility study tested the usefulness of intraoperative angiography during minimally invasive direct coronary artery bypass grafting (MIDCABG). METHODS: Ten patients underwent intraoperative angiography of the internal thoracic artery (ITA) after MIDCABG. Minimally invasive direct coronary artery bypass grafting was performed on a beating heart through the fourth or fifth intercostal space. Angiography was performed through the right or left femoral artery with a 7F introducer system placed before the operation. Views were obtained in the right and left anterior oblique and straight anterior projections. RESULTS: There were no deaths or intraoperative morbidities related to MIDCABG or angiography. Seven patients demonstrated widely patent MIDCABG anastomoses with obliteration of all intercostals, widely patent ITA pedicles, good distal runoff, and placement of the ITA into the proper native coronary artery. Two patients had revisions of their ITA pedicles, which on repeated angiography showed correction. One patient's procedure was converted to a sternotomy because of poor distal runoff and haziness at the level of the MIDCABG anastomosis. CONCLUSIONS: This feasibility study demonstrates the utility of intraoperative ITA angiography in identifying problems after MIDCABG. Intraoperative angiography may facilitate MIDCABG by documenting proper placement of conduits, obliteration of intercostal vessels, and patency of the MIDCABG anastomosis and ITA pedicle.

Aged↗
PubMed1996

Magnetic resonance angiography demonstration of congenital heart disease in adults.

OBJECTIVE: There are limitations when using spin-echo MR imaging to evaluate congenital heart disease (CHD). These include limited ability to detect small shunts, long acquisition times, in-plane or slow flow signal and limited ability to represent complicated three-dimensional (3D) anatomy. However, MR angiography can image flow direction and disturbances, assess function and easily represents 3D anatomy. This may be valuable when evaluating adults with CHD. PATIENTS AND METHODS: Fifty consecutive adult patients were referred for MR evaluation of possible or known CHD using time-of-flight MR angiography. Cine, breathhold and presaturation cine MR angiography were acquired as appropriate, with 3D (MIP) reconstruction of all extracardiac anomalies. RESULTS: Forty-nine patients had a diagnostic examination (one was unsatisfactory because of arrhythmia). Correlation with alternative imaging (TTE = 36, TOE = 13, cardiac catheter = 16) or surgery was available in 39 patients (MR angiography correct in 36 patients). MRA demonstrated or excluded all confirmed congenital valve (12/12), aortic (9/9), and venous (7/7) anomalies. Thirty-five patients were evaluated for shunts. MR angiography detected 31/33 confirmed shunts (shunts present in 26 patients, sensitivity 94%, specificity 95%). Although not used in all cases, spin-echo was unreliable in demonstrating shunts as signal loss in the region of the secundum septum frequently mimicked atrial septal defects (reducing accuracy for excluding intracardiac shunts, specificity 58%). CONCLUSION: MR angiography accurately defines intra- and extra-cardiac anatomy and is superior to spin-echo in detecting or excluding shunts. MR angiography safely and accurately demonstrates many aspects of CHD in adults.

Adult↗
PubMed1986

The role of fluorescein angiography in national collaborative studies.

Over the past 20 years, fluorescein angiography has demonstrated its value in the diagnosis and management of most diseases of the retinal vessels and choroidal vessels, including diabetic retinopathy, aging macular degeneration, and venous occlusive disorders. Fluorescein angiography has become so important for diagnostic purposes and for laser management that it has become a standard technique in the authors' most carefully performed clinical research studies such as randomized clinical trials. These clinical trials demand fluorescein angiography not only for diagnosis and eligibility of patients, but also to document the adequacy of laser photocoagulation. The use of fluorescein angiography has encouraged the development of newer photographic techniques and has encouraged a commendable level of expertise among photographers. Experience with fluorescein angiography in clinical trials has led to the development of general guidelines for the use of angiography for the management of patients outside the confines of a clinical trial; we emphasize the importance of recent angiography as a general guideline for all patients with macular edema or choroidal neovascularization before consideration of laser photocoagulation.

Aspirin↗
PubMed1995

Indocyanine green angiography and choroidal neovascularization obscured by hemorrhage.

BACKGROUND AND OBJECTIVE: To determine the use of indocyanine green (ICG) angiography in detecting choroidal neovascularization obscured by hemorrhage. STUDY/DESIGN: Indocyanine green angiography was performed on 20 consecutive patients who were suspected to have choroidal neovascular membranes (CNVs) that were obscured by subretinal or intraretinal hemorrhage on fluorescein angiography. The etiology of choroidal neovascularization was age-related macular degeneration. RESULTS: In all patients, ICG angiography was able to detect some choroidal neovascularization. The entire extent of the CNV was identified in 12 (60%) of these patients after ICG angiography was performed. In the remaining eight eyes (40%), the CNV still was obscured partially by a thick layer of hemorrhage. Difficulty in detection was due to thick subretinal hemorrhage, lipid exudate, and pigment. CONCLUSION: The authors conclude that ICG angiography is superior to fluorescein angiography in showing the presence and extent of CNVs associated with age-related macular degeneration that are almost entirely obscured by hemorrhage.

Choroid↗
PubMed1997

Is coronary angiography necessary for vascular surgery patients who have positive results of dipyridamole thallium scans?

PURPOSE: Because dipyridamole thallium (DT) scanning is a useful predictor of perioperative cardiac events, a positive results of a DT scan is frequently the basis for performing more invasive cardiac evaluation and for consideration for performing coronary revascularization procedures before performing peripheral vascular surgery. The rationale for this approach has been that the treatment of anatomically significant coronary artery disease would lower the risk of performing a subsequent vascular operation. However, the benefit of performing aggressive diagnostic and therapeutic cardiac procedures in such patients remains unproved. To examine this issue, data from patients who underwent coronary angiography because of thallium redistribution were compared with data from matched control subjects who underwent peripheral vascular operations without further cardiac evaluation. METHODS: The medical records of 70 consecutive patients who underwent coronary angiography because of the presence of two or more segments of redistribution on DT scan were reviewed and compared with 70 other patients matched with respect to age, gender, peripheral vascular operation, and number of segments of redistribution on DT scan who did not undergo additional cardiac evaluation. RESULTS: DT scans were performed on 934 preoperative peripheral vascular surgery patients to help in the assessment of operative risk. Ischemic responses, defined as two or more segments of redistribution, were observed in 297. Of these, 70 underwent cardiac catheterization and 25 underwent coronary revascularization procedures. Adverse outcomes affected 46% of the coronary angiography group and 44% of the control group (p = NS). Patients who underwent coronary angiography and were considered for myocardial revascularization had fewer cardiac events with a subsequent vascular operation than did the control subjects. However, any possible benefit from invasive cardiac evaluation was offset by the three deaths and two myocardial infarctions (MIs) that complicated the cardiac evaluation. There was no significant difference between the angiography group and the matched control subjects with respect to perioperative nonfatal MI (13% vs 9%), fatal MI (4% vs 3%), late nonfatal MI (16% vs 19%), or late cardiac death (10% vs 13%). In long-term follow-up, MIs occurred later in patients who underwent coronary angiography than the control subjects (p = 0.049), but this difference was not associated with an improvement in the overall survival rate. CONCLUSIONS: The risks of extended cardiac evaluation and treatment did not produce any improvement in either the perioperative or the long-term survival rate. For most vascular surgery patients who have a positive result of a DT scan, coronary angiography does not provide any additional useful information.

Case-Control Studies↗
PubMed1998

Vein graft surveillance: is graft revision without angiography justified and what criteria should be used?

PURPOSE: The objective of this study was to assess the accuracy of color-flow duplex surveillance parameters to detect infrainguinal vein graft stenoses and to investigate whether graft revision without angiography is justified. METHODS: In a prospective study in which three centers participated, the data of graft surveillance in 300 patients were analyzed. For the evaluation of surveillance criteria all patients underwent a digital subtraction angiography if a graft stenosis was suspected. To create a control group, in patients with normal grafts a consented digital subtraction angiography was performed also. From these data the accuracy of seven duplex and three ankle blood pressure-derived variables was assessed. The relation between various surveillance criteria and continued graft patency was determined with life table analysis with the transient state method. RESULTS: The mean follow-up period was 20 months (range, 1 to 40 months). At univariate and multivariate analysis the peak systolic velocity (PSV) ratio provided the best correlation with angiographic stenoses > or = 70% (PSV ratio cutoff 3.0: sensitivity 80%, specificity 84%). This finding did not differ between the participating centers. With life table methods it was demonstrated that the best combination of efficacy (limitation of the number of unnecessary revisions), safety (minimal number of correctable lesions missed), and reduction of angiograms was obtained by a two-parameter surveillance algorithm. This algorithm included a PSV ratio < 2.5 to delineate patients in whom a conservative approach without angiography or revision was appropriate, a PSV ratio > or = 4.0 to indicate patients in whom vein graft revision without angiography could be scheduled, and a group with PSV ratios between 2.5 and 4.0 in whom angiography was to be performed to determine clinical management on the basis of the stenosis severity. This algorithm had a positive predictive value of 93% and a negative predictive value of 89%. In addition, it resulted in a reduction of the number of angiograms of 49% compared with a policy of angiographies in all patients with a PSV ratio > or = 2.5. CONCLUSIONS: The best criterion to identify a failing graft is the PSV ratio. With a two-parameter algorithm for vein graft surveillance, the incidence of unnecessary revisions and of missed high-grade lesions was acceptably low, whereas the number of angiograms was reduced by one half.

Adult↗
PubMed1994

Intraoperative imaging techniques in infrainguinal arterial bypass grafting: completion angiography versus vascular endoscopy.

This prospective study was designed to establish whether vascular endoscopy would provide more information on the graft lumen than standard completion angiography during infrainguinal bypass surgery. Ninety-nine patients with 102 infragenicular bypass grafts who underwent both angiography and angioscopy intraoperatively were evaluated. In 99 of the 102 patients the indication was critical limb ischaemia. Of the 102 bypass grafts, 81 were autogenous vein. Distally, 24 grafts were anastomosed to the below-knee popliteal segment, 64 extended to the crural and 14 to the pedal arteries. On completion of the distal anastomosis, grafts were first evaluated by angiography and then by angioscopy. The images obtained with the two monitoring modalities were compared by the operating surgeon and re-explorations were performed immediately if necessary. Completion angiography and angioscopy produced images of good quality in 96 and 97 cases, respectively. In 12 cases completion angiography showed abnormalities. Of these, five were located below the distal anastomosis and were not accessible to angioscopic examination. Conduit defects were found in seven instances. In one of them angioscopy showed the angiogram to be false-positive. Of the 90 grafts with normal completion angiograms, seven were found to show significant pathology on angioscopy. Compared to angioscopy, the sensitivity and specificity of angiography to detect abnormalities within the graft was 46% and 98%, respectively. Our results suggest that vascular endoscopy is superior to angiography for disclosing conduit defects, but that it does not provide adequate information about the distal arterial anatomy.

Aged↗
PubMed2001

Effect of MR angiography on the diagnosis and treatment of patients with suspected renovascular disease.

PURPOSE: Although the diagnostic accuracy of renal magnetic resonance (MR) angiography is established, its effect on referring physicians is unknown. The authors prospectively measured the effect of MR angiography results on referring physicians' diagnosis and treatment (plans) of patients with suspected renovascular disease. MATERIALS AND METHODS: Referring physicians prospectively completed questionnaires before and after MR angiography was performed during evaluation of their patients with suspected renovascular disease. The questionnaires asked them to estimate the probability (0%-100%) of their most likely diagnosis before and after receiving the imaging information. They were also asked for their anticipated and final treatment plans. The authors calculated the mean gain in diagnostic percentage confidence and the proportion of patients with changed initial diagnoses or anticipated management. A paired t-test was used to assess significance of the gains in diagnostic percentage confidence. RESULTS: Physicians prospectively completed pre- and post-MR-angiography questionnaires for 30 patients. MR angiography improved mean diagnostic certainty by 35% (P < .0001). MR angiography changed physicians' initial diagnoses in 12 patients (40%). Anticipated treatment plans were changed in 20 patients (67%). Invasive procedures were avoided in eight patients (27%). CONCLUSION: MR angiography has a substantial effect on the diagnostic and therapeutic decision-making of physicians managing patients with suspected renovascular disease.

Adult↗
PubMedDate not supplied

Cost-effective selection of patients for coronary angiography.

In patients suspected of having coronary artery disease (CAD), noninvasive testing has been playing an increasing role in selecting patients who would require coronary angiography for either the "definitive" diagnosis of CAD or as a prelude to planning myocardial revascularization. A mathematic model is presented that defines cost-effective utility of nuclear cardiology testing for diagnosis of CAD and selection of appropriate candidates for coronary angiography, according to quantitative methods of decision analysis. Clinical utility or effectiveness was defined in terms of percent correct diagnosis of CAD. Cost was defined as dollars of medical expenditure. Six competing strategies were compared in subsets of patients with different pretest likelihoods of CAD, based on age, sex, and symptoms. Nuclear cardiology testing was the most cost-effective initial modality of choice in patients with an intermediate pretest likelihood of CAD. In patients with a low pretest likelihood of CAD, nuclear cardiology testing was cost-effective in the subgroup of patients who had abnormal exercise treadmill electrocardiograms. In patients with a high pretest likelihood of CAD, direct referral to coronary angiography was the most cost-effective strategy for diagnosis of CAD. Coronary angiography, however, is performed most often as a prelude to myocardial revascularization. Because these invasive procedures are indicated only in patients who are at high risk with medical therapy, nuclear cardiology procedures, by virtue of incremental prognostic information, identify appropriate candidates for more invasive procedures, aimed at improving survival. Strategies for cost-effective prognostication of CAD depend on not only the patient's pretest likelihood of CAD but also the status of the rest electrocardiogram. In patients with a normal rest electrocardiogram, a low pretest likelihood of CAD indicates a low risk for cardiac events with medical therapy. Therefore coronary angiography is not indicated in these patients. Patients with an intermediate likelihood of CAD should first undergo exercise electrocardiographic testing; a negative response would indicate a low risk for cardiac events and a positive response would indicate the need for nuclear cardiology testing for further cost-effective risk stratification. In patients with a high pretest likelihood of CAD, the combined exercise electrocardiographic and nuclear cardiac testing is the most cost-effective strategy; a negative or a positive nuclear test result would imply low or high risk, respectively. The latter patients would then be candidates for coronary angiography. In all patients with an abnormal rest electrocardiogram, the most cost-effective strategy is uniform referral to nuclear cardiac testing (which is performed in conjunction with exercise electrocardiography), regardless of the pretest likelihood of CAD; a negative or a positive nuclear test result would indicate low or high risk for coronary events, respectively. The latter group would be proper candidates for referral to coronary angiography.

Adult↗
PubMedDate not supplied

No gender bias in referral for coronary angiography after myocardial perfusion scintigraphy with technetium-99m tetrofosmin.

BACKGROUND: Several studies have shown that the application of diagnostic and invasive procedures varies between men and women. The purpose of this study was to assess if referral for coronary angiography after technetium-99m tetrofosmin myocardial perfusion scintigraphy in 616 patients with undiagnosed chest pain might demonstrate gender bias. METHODS AND RESULTS: The primary end point for this study was coronary angiography within 90 days of myocardial perfusion scintigraphy. Women had more normal perfusion images than men (207 [70.9%] vs 160 [50.5%], P < .05). Of 242 patients with abnormal images (157 men, 85 women), 28 men (17.7%) and 17 women (20.0%) were referred for further invasive testing (P = not significant). Referral for coronary angiography increased relative to the number of defects. Univariate analysis showed that reversible and persistent defects were the most predictive variables for referral to coronary angiography (odds ratio [OR] 5.45, 95% confidence interval [CI] 3.10-9.58, P < .001, and OR 2.67, 95% CI 1.52-4.67, P = .001, respectively). More importantly, multivariate analysis showed that reversible perfusion defects (OR 4.77, 95% CI 2.48-9.17, P < .001) and persistent perfusion defects (OR 2.14, 95% CI 1.11-4.14, P = .02) were predictive of subsequent coronary angiography. No significant association between gender and subsequent coronary angiography was found both in univariate and multivariate logistic regression analysis (OR 0.64, 95% CI 0.37-1.12, P = .12, and OR 0.70, 95% CI 0.36-1.36, P = .28, respectively). CONCLUSIONS: Our study reveals that after correction for the presence and the severity of myocardial perfusion abnormalities, men and women were referred to coronary angiography at a similar rate. Thus, based on the results of technetium-99m tetrofosmin myocardial perfusion imaging, no substantial evidence for a gender-related bias could be found in the referral for further invasive testing.

Analysis of Variance↗
PubMed2002

Validation of injection parameters for catheter-directed intraarterial gadolinium-enhanced MR angiography.

RATIONALE AND OBJECTIVES: Catheter-directed intraarterial (IA) injections of gadolinium contrast agents may be used during endovascular interventions with magnetic resonance (MR) imaging guidance. Injection protocols require further validation. Using a flow phantom and swine, the authors aimed to (a) measure the optimal arterial gadolinium concentration ([Gd]) required for MR angiography and (b) validate a proposed IA injection protocol for gadolinium-enhanced MR angiography. MATERIALS AND METHODS: For in vitro experiments, the authors placed a catheter in the aorta of an aorto-renal-iliac flow phantom. Injected [Gd], injection rates, and aortic blood flow rates were varied independently for 36 separate IA gadolinium injections. The authors performed 2D and 3D MR angiography with a fast spoiled gradient-recalled echo sequence. For subsequent in vivo experiments, they selectively placed catheters within the aorta, renal artery, or common iliac artery of three pigs. Injection rate and injected [Gd] were varied. The authors performed 32 separate IA gadolinium injections for 2D MR angiography. Signal-to-noise ratios (SNRs) were compared for the various combinations of injection rate and injected [Gd]. RESULTS: In vitro, an arterial [Gd] of 2%-4% produced an optimal SNR for 2D MR angiography, and 3%-5% was best for 3D MR angiography. In swine, an arterial [Gd] of 1%-4% produced an optimal SNR. In the phantom and swine experiments, SNR was maintained at higher injection rates by inversely varying the injected [Gd]. CONCLUSION: Dilute arterial [Gd] is required for optimal IA gadolinium-enhanced MR angiography. To maintain an optimal SNR, injection rates and injected [Gd] should be varied inversely. The postulated injection protocol was validated.

Animals↗
PubMed1996

Accuracy of contrast-enhanced magnetic resonance angiography in chronic thromboembolic disease.

RATIONALE AND OBJECTIVES: We evaluated the accuracy of contrast-enhanced magnetic resonance (MR) angiography in demonstrating the findings of chronic pulmonary thromboembolism (CPTE) compared with conventional pulmonary angiography. METHODS: We examined 18 patients with CPTE proved by conventional pulmonary angiography and 16 healthy control patients. T1-weighted and single-breathhold, two-dimensional multiplanar spoiled gradient-recalled pulmonary images were obtained after injection of gadopentetate dimeglumine. Images were interpreted independently by two radiologists. RESULTS: All patients with CPTE were identified on MR angiography images by both readers. Sensitivity and specificity for MR angiography in diagnosing abnormal segments were 76% and 95% for reader 1 and 68% and 93% for reader 2, respectively. Sensitivity and specificity for MR angiography in depicting abnormal lobes were 83% and 96% for reader 1 and 82% and 93% for reader 2, respectively. Interobserver agreement was high; kappas for abnormal segments and abnormal lobes were .72 and .84, respectively. The T1-weighted spin-echo images demonstrated a mosaic signal intensity pattern in all patients with CPTE. CONCLUSION: Contrast-enhanced MR angiography accurately depicts abnormal segments and lobes in occlusive vascular disease and clearly distinguishes between patients with CPTE and those with healthy lungs.

Chronic Disease↗
PubMed2002

Routine use of intravascular ultrasound for endovascular aneurysm repair: angiography is not necessary.

INTRODUCTION: to assess the outcome of endovascular aortic aneurysm repair (EVAR) using intravascular ultrasound (IVUS) without angiography. MATERIALS/METHODS: eighty consecutive patients (median age 69 years (range 25-90): male 72 (90%), female 8 (10%)) underwent endovascular aneurysm repair (AAA 68 (85%), TAA 12 (15%)) using either angiography in 31/80 patients (39%) or IVUS in 49/80 patients (61%) in accordance to the surgeons preference. RESULTS: hospital mortality was 2/80 (3%), 1/68 for AAA (2%), 1/12 for TAA (8%), 2/31 for angiography (7%), and 0/49 for IVUS (0.0%: NS). Median quantity of contrast medium was 190 ml (range: 20-350) for angiography versus 0 ml for IVUS (p<0.01). Median X-ray exposure time 24 min (range 9-65 min) versus 8 min (range 0-60 min) for IVUS (p<0.05). No coverage of renal or suprarenal artery orifices occurred in either group. Conversion to open surgery was necessary in 4/80 patients (5%), 1/31 for angiography (3%) and 3/49 patients for IVUS (6%: NS). Early endoleaks were observed in 13/80 patients (16%): 8/31 patients for angiography (26%) versus 5/49 for IVUS (10%: p<0.05): 5/13 endoleaks resolved spontaneously (39%) whereas 8/13 (61%) required additional procedures. CONCLUSIONS: IVUS is a reliable tool for EVAR. In most cases, perprocedural angiography is not necessary.

Adult↗
PubMed2003

[Contrast-enhanced MR angiography for differentiation between perigastric and submucosal gastric fundal varices].

PURPOSE: To evaluate contrast-enhanced MR angiography for the distinction between perigastric and submucosal fundal varices. MATERIALS AND METHODS: Nineteen consecutive patients with clinically suspected fundal varices underwent contrast-enhanced MR angiography and endoscopic ultrasound (EUS) within one week. Diagnostic confidence for the detection of perigastric and submucosal fundal varices was compared between MR angiography (two radiologists) and EUS (one gastroenterologist), and the agreement of size and location was evaluated. RESULTS: Both MR angiography and EUS detected perigastric varices in all 19 patients and submucosal fundal varices in 14 of the 19 patients. The interobserver reliability of MR angiography was good for measuring the variceal diameter (kappa = 0.76) and excellent for localizing the varices (kappa = 1.0). EUS and MR angiography agreed in 12 of 14 patients (86 %) in determining variceal diameter and location. CONCLUSIONS: Contrast-enhanced MR angiography is comparable to endoscopic ultrasound in the detection and characterization of gastric fundal varices.

Adult↗