Purpose:To compare the efficacy and safety of two different doses (0.1 and 0.3 mmol/kg of body weight [BW]) of gadodiamide for contrast-enhanced magnetic resonance angiography (ce-MRA) of the lower extremities with intraarterial digital subtraction angiography (IA-DSA). Materials and Methods:A total of 30 patients with peripheral arterial occlusive disease underwent IA-DSA and ce-MRA from the aortic bifurcation down to the ankle. Patients were randomized to receive a total dose of 0.1 or 0.3 mmol/kg of BW gadodiamide (Omniscan, Amersham Buchler), administered intravenously as a series of three automatic bolus injections. Ce-MRA was performed with a 1.5-T system using a body phased-array coil, centered stepwise over the calf, thigh, and pelvic region. A fast T1-weighted, three-dimensional gradient-echo sequence was obtained before and after injection of the allocated dose. IA-DSA was performed using the Seldinger technique and a femoral approach. The vessels under investigation were divided into 31 segments, and ce-MRA and IA-DSA image sets were evaluated in a double-blind fashion for the presence of stenosis, presence of collateral vessels, vessel delineation, and overall image quality. Both dose groups were compared with regard to contrast index (CI) and signal-and contrast-to-noise ratios (SNR, CNR). The occurrence of adverse events or side effects was also documented. Sensitivity, specificity, and accuracy were calculated in relation to the results of stenosis grading.Results: A total of 26 patients were entered in the efficacy evaluation, while all 30 patients were included in the safety assessment. The sensitivity, specificity, and accuracy for the 0.1 and 0.3 mmol/kg dose groups were 78.8%/93.0%/ 88.9% vs. 60.2.%/91.5%/83.2%, respectively. The detection of collaterals was similar to IA-DSA for the 0.3 mmol/kg dose group (30.2% vs. 27.4%), but was lower in the 0.1 mmol/kg dose group (27.3% vs. 12.3%). The highdose gadodiamide injection proved to be superior to the 0.1 mmol/kg dose group with regard to vessel delineation and overall image quality (P ϭ 0.007 and P ϭ 0.002, respectively). The difference between the two dose groups regarding CI, SNR, and CNR was significant (P ϭ 0.0001), in favor of the 0.3 mmol/kg dose group. No adverse events were observed in any of the patients. Conclusion:Ce-MRA with gadodiamide is safe and efficacious. Comparison of two different doses with IA-DSA as the standard of reference showed that the 0.3 mmol/kg dose is superior to the standard 0.1 mmol/kg dose with respect to contrast enhancement, vessel delineation, image quality, and detection of collaterals. However, the 0.1 mmol/kg dose was superior to the high dose in the grading of stenosis.

We have carried out a prospective, randomised study of prophylaxis for heterotopic ossification (HO) comparing indomethacin for 7 and 14 days, acetylsalicylic acid, and fractional (4 ‫ן‬ 3 Gy) or single exposure of 5 or 7 Gy irradiation after operation.We initially had 723 patients (733 hip replacements), but after withdrawals there were 685 hips of which 18.4% developed HO; 14% were grade I, 2.9% grade II and 1.5% grade III of the Brooker classification.We compared the results between these groups with those of a matched control series and found that indomethacin, 2 ‫ן‬ 50 mg for 7 and 14 days, and postoperative irradiation of 4 ‫ן‬ 3 Gy or 1 ‫ן‬ 7 Gy, significantly reduced the development of HO compared with the control group. Patients in the acetylsalicylic acid group and those with a single irradiation of 5 Gy after operation developed significantly more ossification than those in the indomethacin and other irradiation groups.We suggest the use of 2 ‫ן‬ 50 mg of indomethacin with mucoprotection for seven days as prophylaxis against HO after total hip replacement for all patients. A single irradiation of 7 Gy is recommended for patients who have developed HO after previous operations or to whom administration of indomethacin is contraindicated.

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The aim of this study was to optimize different magnetic resonance angiography (MRA) techniques and to evaluate MRA of the hand arteries compared to intraarterial digital subtraction angiography (IA-DSA). The MRA examinations were performed on a 1.5-T system equipped with a flexible surface coil. The protocol contained time-of-flight (TOF), rephased/dephased (Re/De), and contrast enhanced (CE) techniques. Maximum intensity projection (MIP) was used for postprocessing. The IA-DSA procedure was performed as pharmaco-angiography (after intraarterial injection of a vasodilatator) via a transbrachial approach. Nine patients suffering from peripheral vascular disease were examined with IA-DSA, TOF-MRA, and Re/De-MRA; six patients were examined with CE-MRA and IA-DSA. Best overall image quality was attained with IA-DSA, followed by TOF-MRA, Re/De-MRA, and CE-MRA. Selective arterial visualization of digital arteries was possible with IA-DSA and TOF-MRA. Rephased/dephased MRA showed venous overlay. Contrast-enhanced MRA was limited by inconstant quality of bolus timing. Appropriate arterial bolus timing was achieved in four of six patients; one examination showed venous overlay, one examination incomplete arterial enhancement. Time-of-flight MRA detected 96% of the digital artery segments that were identified with IA-DSA and revealed 34 segments that were failed on IA-DSA. Rephased/dephased MRA and CE-MRA were inferior to IA-DSA and TOF-MRA regarding detection of digital arteries. Magnetic resonance angiography with optimized protocols is a noninvasive procedure to visualize hand arteries in patients with ischemic disease. With TOF-MRA it is possible to detect angiographically occluded arterial segments of digital arteries.

The aim of this prospective study was to evaluate the feasibility and clinical use of time-resolved magnetic resonance angiography (MRA) of the lower extremity compared to intraarterial digital subtraction angiography (IA-DSA). Twenty-two patients suffering from peripheral arterial occlusive disease underwent MRA and IA-DSA. MRA examinations were performed on a 1.5 T system equipped with a 4-element-array coil. The area from the distal abdominal aorta to the distal lower limb was covered by 2-3 examination steps. A T1-weighted gradient echo sequence with a temporal resolution of 7-10 s was used. Single-dose contrast material (0.1 mm/kg) was injected with a flow rate of 2 mL/s, followed by a 40 mL saline flush. Pre and post contrast images were subtracted, and the subtracted data set was postprocessed with maximum intensity projection (MIP). In all patients diagnostic images could be obtained. Problems with venous overlay or incomplete arterial filling were not present. Sensitivity for the detection of relevant stenoses (>50%) was 96.7%, specificity was 97%. Concerning the detection of occlusions, sensitivity was 97.8%, specificity was 99.2%. Time-resolved contrast-enhanced MRA of the lower extremity is a robust procedure with high accuracy in the detection of relevant stenoses and occlusions.