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Purpose: Using the BLADE (PROPELLER) technique for T2-weighted MR imaging of the cervical spine has proven to be a reliable tool for reducing artifacts typically for this region. The aim of this study was to evaluate whether the application of BLADE sequences has an impact on the detection of small or low contrast spinal cord and epidural lesions., Materials and Methods: A standard TSE and a BLADE sequence were compared in 33 patients with 46 spinal cord and epidural lesions for T2-weighted sagittal imaging of the cervical spine. Image sharpness, visualization of the dura, reliability of spinal cord depiction as well as lesion contrast were evaluated by two independent readers. Additionally two experienced neuroradiologists selected in consensus the sequence they would prefer for diagnostic purposes. Statistical evaluations were performed using the sign and the χ2 test., Results: BLADE was significantly superior to TSE regarding image sharpness, visualization of the dura and reliability of spinal cord depiction. Regarding lesion contrast there was a positive trend towards the BLADE sequence. In 17 of 46 lesions, BLADE was judged superior to TSE, while TSE was favored in 10 lesions. In consensus reading both neuroradiologists preferred BLADE for overall image quality in 27 of 33 patients and for lesion contrast in 10 and TSE in 14 of the 33 patients, but 3 TSE sequences were rated as non-diagnostic regarding this criterion., Conclusion: For the detection of even small and low-contrast spinal cord lesions, BLADE is at least equivalent to TSE, yielding better overall image quality and fewer non-diagnostic images., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: The aim of this retrospective study was to evaluate peripheral MRA using time-resolved measurements at the femoral as well as the calf level with regard to the presence of unwanted venous overlap., Materials and Methods: 150 patients were examined using a 1.5 T MRI unit for a three-step CE MRA approach with three partial injections of contrast agent (0.1 mmol/kg body weight of 1 molar contrast agent). Dynamic time-resolved measurements were used at the femoral as well the calf level. The images were analyzed with respect to the presence and grade of unwanted venous overlap as well as inadequate bolus timing., Results: In all cases, MRA was technically successful. The overall image quality was assessed as excellent in 127 / 150 cases (84.7%), as mildly limited in 21 cases (14%) and as moderately limited, but still diagnostic in 2 cases (1.3%). No obvious overlap was found in 139 of 150 cases (92.7%). Non-diagnostically relevant minor overlap was found in 7 cases (4.6%) and non-diagnostically relevant moderate overlap in 4 cases (2.7%). Relevant venous overlap did not occur. Those 11 cases with minor or moderate overlap occurred at the calf level in 8 cases, at the calf and femoral level in 2 cases and at the femoral level only in one case. In 10 out of 11 cases, peripheral artery occlusive disease was classified as category IV (Fontaine)., Conclusion: Three-step time-resolved CE MRA with dynamic measurements at the calf as well the femoral level can be considered as a safe and accurate technique for MRA of the lower limbs without significant venous overlap and without risk of inadequate bolus timing. Furthermore, it solves the problem of run time differences., (© Georg Thieme Verlag KG Stuttgart · New York.)

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Purpose: To evaluate a novel multislice CT system (16-slice-spiral-CT scanner) for the diagnosis of carotid artery stenosis., Material and Methods: Five patients with symptomatic atherosclerotic disease of the carotid arteries were examined with a 16- slice-spiral-CT scanner. Collimation was 16 x 0.75 mm, table speed 36 mm/s (pitch of 1.5), rotation time 0.5 s, tube current was 160 eff.mAs at 120 kV. 60 ml of contrast material were injected with a power injector followed by a saline flush. The start delay was measured with test bolus method (20 ml CM). Interactive multiplanar reformation (iMPR) and thin slab MIP as well as volume rendering were used for image evaluation and presentation., Results: Scan time was 9 s for a range of 300 mm. This allowed imaging the whole length of the carotid artery (aortic arch to circle of Willis) in a true arterial phase. Pulsation artefacts did not impair the evaluation of the vessels at the level of the aortic arch. Overall image quality of both "source images" and 3D-reconstructions was excellent, due to a reduced voxel size of 0.03 mm (3). Image evaluation and postprocessing (iMPR, MIP) was done within 15 min. iMPR was highly accurate for demonstrating plaque morphology and determining the percentage of the stenosis., Conclusion: For the first time, true arterial phase images of the entire carotid artery with high spatial resolution could be acquired using a 16-slice-spiral-CT scanner. This method offers the potential to replace catheter angiography in the evaluation of carotid artery stenosis.

Purpose: To examine the diagnostic accuracy of pancreatic lesions using mangafodipir-trisodium (Mn-DPDP) enhanced MR imaging. The imaging results were correlated with the histopathological results., Material and Methods: 40 patients with suspicion of pancreatic carcinoma were examined with MRI before and after i. v. administration of Mn-DPDP (Philips Gyroscan ACS NT 1.5 T, phased array body-coil: TSE T 2 with and without SPIR, TR 2000 ms, TE 120ms; FFE T 1 breathhold, TR 115 ms, TE 4.6 ms; MRCP, TR 6000 ms, TE 1200 ms; Teslascan i. v. 5 micromol Mn/kg; FFE T 1 breathhold SPIR, TR 140 ms, TE 4,6 ms). Two observers evaluated in consensus the number and characteristics of focal pancreatic lesions. The MR findings were correlated with histopathological findings retrospectively., Results: The following lesions were found: adenocarcinoma (19), pancreatitis (8), adenocarcinoma within pancreatitis (3), insulinoma (2), hematoma (1), papillitis stenosans (1), signet ring cell carcinoma (1), metastasis of rectal carcinoma (1), papillary mesothelioma (1). In three patients there was no pathological finding. Mn-DPDP enhanced MRI showed a sensitivity of 100 % and a specificity of 56 %., Conclusion: Mn-DPDP enhanced MRI in conjunction with MRCP showed a high sensitivity for the detection of pancreatic lesions. However, the specificity is low, thus recommending Mn-DPDP enhanced MRI only as a complementary imaging method.

Purpose: The VIBE (volume interpolated breath-hold examination) sequence in combination with parallel acquisition technique (iPAT: integrated parallel acquisition technique) allows dynamic contrast-enhanced MRI of the liver with high temporal and spatial resolution. The aim of this study was to obtain first clinical experience with this technique for the detection and characterization of focal liver lesions., Materials and Methods: We examined 10 consecutive patients using a 1.5 T MR system (gradient field strength 30 mT/m) with a phased-array coil combination. Following sequences were acquired: T 2 -w TSE and T 1 -w FLASH, after administration of gadolinium, 6 VIBE sequences with iPAT (TR/TE/matrix/partition thickness/time of acquisition: 6.2 ms/ 3.2 ms/256 x 192/4 mm/13 s), as well as T 1 -weighted FLASH with fat saturation. Two observers evaluated the different sequences concerning the number of lesions and their dignity. Following lesions were found: hepatocellular carcinoma (5 patients), hemangioma (2), metastasis (1), cyst (1), adenoma (1)., Results: The VIBE sequences were superior for the detection of lesions with arterial hyperperfusion with a total of 33 focal lesions. 21 lesions were found with T 2 -w TSE and 20 with plain T 1 -weighted FLASH. Diagnostic accuracy increased with the VIBE sequence in comparison to the other sequences., Conclusion: VIBE with iPAT allows MR imaging of the liver with high spatial and temporal resolution providing dynamic contrast-enhanced information about the whole liver. This may lead to improved detection of liver lesions, especially hepatocellular carcinoma.

Purpose: The value of a diagnostic technique does not only depend on its sensitivity, specificity and accuracy, but also on how its results affect clinical management. This effect is represented by the values effective accuracy and the diagnostic utility which were determined for CT-guided coaxial core biopsies in this study., Materials and Methods: 180 consecutive biopsies were analyzed. The results were analyzed with the help of a logistic regression analysis with regard to the organ regions biopsied, the size of the needle used, and the number of tissue cores taken. Correct results that were not accepted as diagnostic clinically and resulted in additional biopsies were scored together with the false results under negative utility coefficients., Results: The sensitivity, specificity and accuracy of all the tests amounted to 91.1 %, 100 %, and 93.3 %, respectively. The diagnostic utility of the biopsies varied between 66 % for the liver and pancreatic lesions, and 88 % for the non-organ related retroperitoneum. In those cases where more than three tissue cores were taken the results were statistically significantly better in terms of effective accuracy and diagnostic utility. No significant differences were found with regard to different needle sizes in the biopsied organ regions. The lowest clinical acceptance was observed for the histological findings "scar tissue" and "inflammation"., Conclusion: CT-guided coaxial biopsies offer a high degree of sensitivity, specificity and accuracy, as well as a low rate of therapeutically relevant complications. With increasing use of differentiated strategies in therapy for malignomas percutaneous biopsies play a very important role in the management of these diseases. Prospective studies should further evaluate the effective accuracy and diagnostic utility of core biopsies also in comparison to fine needle aspiration biopsies (FNAP).

Purpose: We introduce a hybrid technique which allows a high resolution MRA of the peripheral arteries with a dedicated phased-array coil using the floating table technique., Materials and Methods: Five patients with peripheral arterial occlusive disease were examined within one week with i.a. DSA and MRA using the hybrid technique. MRA examinations were done on a 1.5 T system. At first, pelvic arteries were examined in a single step mode applying the CareBolus technique. Subsequently, thighs and lower legs were examined using the floating table mode. 125 vascular segments were evaluated., Results: The hybrid technique proved to be robust and could be performed in each case. Mean examination time was about 30 min. For 117 vascular segments no difference was found between i.a. DSA and MRA. Three segments revealed a higher grade of stenosis in DSA than in MRA, five segments were graded higher in MRA than in DSA. Occlusions were visualized identically in both methods. Venous overlap had no relevant effects on image evaluation., Conclusions: This hybrid technique in combination with phased-array coils allows a high resolution MRA of the peripheral arteries with very good image quality. If future studies confirm reduced venous overlap, this method may be an alternative also for users of the floating table MRA with the body resonator.

Purpose: The influence of dental alloys on MRI of the temporomandibular joint was studied using a phantom model for this joint., Methods: At 1,5 T, 15 dental alloys and 14 of their most important components were investigated acquiring sagittal (FOV: 150 mm) and transverse (FOV: 250 mm) T1-weighted SE images. In 11 cases, T1- and T2*-weighted FLASH images were measured additionally. The artifacts were assessed qualitatively as well as quantitatively, and the samples were subdivided into four artifact categories., Results: Ag, Cu, Ga, In, Tl, Sn, Zn, amalgam, the precious alloys, the Au-Pd and Ag-Pd alloys showed no artifacts (category I). Minimal artifacts below 10 mm on transverse images (category II) were found for Cr, Pd, Pt and for the Ni-Cr alloy. Mn and the remaining non-precious alloys induced artifacts up to 30 mm (category III). Significant artifacts-more than 30 mm-(category IV) were caused by Ni-Cr and 18/8 wires and by Co, Fe, and Ni. T2*-weighted FLASH proved to be more susceptible for artifacts than T1-weighted SE and FLASH techniques., Conclusions: In contrast to dental alloys for fixed prosthodontics, Ni-Cr- or 18/8 wires used for orthodontic bands can influence not only the image quality, but also the diagnostic reliability of MRI of the temporomandibular joint.