Gd-EOB-DTPA is safe and efficient for MR imaging of the liver.
MR elastography (MRE) allows the noninvasive assessment of the viscoelastic properties of human organs based on the organ response to oscillatory shear stress. Shear waves of a given frequency are mechanically introduced and the propagation is imaged by applying motion-sensitive gradients. An experiment was set up that introduces multifrequency shear waves combined with broadband motion sensitization to extend the dynamic range of MRE from one given frequency to, in this study, four different frequencies. With this approach, multiple wave images corresponding to the four driving frequencies are simultaneously acquired and can be evaluated with regard to the dispersion of the complex modulus over the respective frequency. A viscoelastic model based on two shear moduli and one viscosity parameter was used to reproduce the experimental wave speed and wave damping dispersion. The technique was applied in eight healthy volunteers and eight patients with biopsy-proven high-grade liver fibrosis (grade 3-4).
The diagnostic performance of multifrequency MR elastography in determining the degree of hepatic fibrosis increases with stage of fibrosis. Metrics obtained at the higher frequencies provide better diagnostic performance compared with the lower frequencies. Results of the AUROC analysis demonstrate the high accuracy of frequency-independent cutoff values for staging higher grades of hepatic fibrosis.
Background and aims Overall obesity has recently been established as an independent risk factor for critical illness in patients with coronavirus disease 2019 (COVID-19). The role of fat distribution and especially that of visceral fat, which is often associated with metabolic syndrome, remains unclear. Therefore, this study aims at investigating the association between fat distribution and COVID-19 severity. Methods Thirty patients with COVID-19 and a mean age of 65.6 ± 13.1 years from a level-one medical center in Berlin, Germany, were included in the present cross-sectional analysis. COVID-19 was confirmed by polymerase chain reaction (PCR) from nasal and throat swabs. A severe clinical course of COVID-19 was defined by hospitalization in the intensive care unit (ICU) and/or invasive mechanical ventilation. Fat was measured at the level of the first lumbar vertebra on routinely acquired low-dose chest computed tomography (CT). Results An increase in visceral fat area (VFA) by ten square centimeters was associated with a 1.37-fold higher likelihood of ICU treatment and a 1.32-fold higher likelihood of mechanical ventilation (adjusted for age and sex). For upper abdominal circumference, each additional centimeter of circumference was associated with a 1.13-fold higher likelihood of ICU treatment and a 1.25-fold higher likelihood of mechanical ventilation. Conclusions Our proof-of-concept study suggests that visceral adipose tissue and upper abdominal circumference specifically increase the likelihood of COVID-19 severity. CT-based quantification of visceral adipose tissue and upper abdominal circumference in routine chest CTs may therefore be a simple tool for risk assessment in COVID-19 patients.
Background— The success of percutaneous intervention in peripheral arterial disease is limited by restenosis. The aim of the present pilot study was to evaluate a novel method of local drug delivery. Methods and Results— This randomized multicenter study with blinded reading enrolled 87 patients in Rutherford class 1 to 4 with occlusion or hemodynamically relevant stenosis, restenosis, or in-stent restenosis of femoropopliteal arteries. Treatment was performed by either conventional uncoated or paclitaxel-coated balloon catheters. The primary end point was late lumen loss at 6 months. Secondary end points included restenosis rate, ankle brachial index, Rutherford class, target lesion revascularization, and tolerance up to >18 months. Before intervention, there were no significant differences in lesion characteristics such as reference diameter (5.3±1.1 versus 5.2±1.0 mm), degree of stenosis (84±11% versus 84±16%), proportion of restenotic lesions (36% versus 33%), and mean lesion length (5.7 cm [0.8 to 22.6 cm] versus 6.1 cm [0.9 to 19.3 cm]) between treatment groups. The 6-month follow-up angiography performed in 31 of 45 and 34 of 42 patients showed less late lumen loss in the coated balloon group (0.5±1.1 versus 1.0±1.1 mm; P =0.031). The number of target lesion revascularizations was lower in the paclitaxel-coated balloon group than in control subjects (3 of 45 versus 14 of 42 patients; P =0.002). Improvement in Rutherford class was greater in the coated balloon group ( P =0.045), whereas the improvement in ankle brachial index was not different. The difference in target lesion revascularizations between treatment groups was maintained up to >18 months. No adverse events were assessed as related to balloon coating. Conclusions— In this pilot trial, paclitaxel balloon coating caused no obvious adverse events and reduced restenosis in patients undergoing angioplasty of femoropopliteal arteries.
Experimental data show accumulation of superparamagnetic iron oxide (SPIO) particles in atherosclerotic plaques. SPIO uptake occurred in plaques, suggesting an increased endothelial permeability and macrophage infiltrates as signs of inflammatory plaque activity. We incidentally observed SPIO uptake in aortic and arterial wall segments in patients who had originally received the magnetic resonance (MR) contrast agent for staging lymph node metastases. Twenty patients (19 male, 1 female; mean age, 64; range, 41-78 years) with bladder or prostate cancer underwent MR imaging (MRI) using a T2*-weighted high-resolution gradient-echo sequence prior to and 24 -36 hours after intravenous injection of 2.6 mg of Fe/kg of SPIO (Sinerem ). The aorta, both common external and internal iliac, as well as both superficial femoral arteries, were retrospectively analyzed for atherosclerotic wall changes. One patient was excluded. A positive finding was defined as an area of pronounced signal loss on postcontrast images clearly confined to the arterial wall, which was absent in the precontrast examination or increased in size. Such a finding was observed in one to three arteries in 7 of the 19 patients. The pronounced signal loss in the wall of the aorta and pelvic arteries seen in part of an elderly patient population after intravenous SPIO administration strongly suggests that this contrast agent accumulates in human atherosclerotic plaques. J. Magn. Reson. Imaging 2001;14: 355-361.
T1w MRI was superior to radiography in the detection of structural lesion of the SI joints in patients with axSpA. Future studies should focus on finding an agreement on the definition of MRI-T1 positivity.
Background-Endoscopic ultrasonography (EUS) and somatostatin receptor scintigraphy (SRS) can detect a high percentage of gastroenteropancreatic neuroendocrine tumours especially in the upper gastrointestinal tract. The ability of these procedures to localise primary tumour lesions and metastases of gastrinomas and insulinomas was evaluated in comparison with transabdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) . Patients and Methods-In a prospective trial, patients with gastrinomas (n=10) and insulinomas (n=10) diagnosed by clinical signs and laboratory tests were assessed by EUS, SRS, US, CT and MRI. Results-In 10 patients with gastrinoma and 10 patients with insulinoma, a total of 14 separate primary tumour lesions were histologically confirmed for each of the tumour entities. The mean diameter was 2-1 cm for gastrinomas and 1l5 cm for insulinomas. All insulinomas and nine gastrinoma lesions were located in the pancreas. Three gastrinomas were found in the duodenal wall, one in a periduodenal lymph node, and one in the liver. For gastrinomas, sensitivities were 79% with EUS, 86% with SRS and 29% with CT, US, and MRI. For insulinomas, sensitivities were 93% with EUS, 14% with SRS, 21% with CT and 7% with US and
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