Robert Drescher

Superior mesenteric artery aneurysm stent graft

Visceral artery aneurysms represent 0.1% to 0.2% of all vascular aneurysms. They are mostly asymptomatic, but rupture is associated with a high mortality rate. We present a case of an asymptomatic aneurysm of the proximal superior mesenteric artery in a 64-year-old man that was successfully treated by implantation of a covered stent graft. The use of endovascular techniques to manage visceral artery aneurysms should be considered.

Benefit of repetitive intrathecal triamcinolone acetonide therapy in predominantly spinal multiple sclerosis: prediction by upper spinal cord atrophy.

Intrathecal injection of triamcinolone acetonide (TCA) has been shown to provide substantial benefit in a subset of progressive multiple sclerosis (MS) patients with predominant spinal symptoms. We examined whether atrophy of the upper spinal cord (USC) as measured by MRI can serve as a predictive marker for response to repetitive intrathecal TCA application. Repetitive administration of 40 mg TCA was performed in 31 chronic progressive MS patients up to six times within 3 weeks. Expanded Disability Status Scale (EDSS) and maximum walking distance (WD) were assessed before and after the treatment cycle. Cervical 3D T1-weighted images were acquired on a 1.5T scanner at baseline. Mean cross-sectional area of the USC was determined using a semi-automated volumetry method. Results were compared with a group of 29 healthy controls to group patients into those with and without atrophy. Results show a negative correlation between the degree of USC atrophy and treatment benefit. A higher treatment benefit in patients with little USC atrophy but short initial maximum WD was observed. Absence of USC atrophy as measured on MRI is a predictive marker for intrathecal TCA therapy outcome in progressive MS. Patients with initial poor walking abilities, but only little or no atrophy, benefited most from TCA therapy.

Mediastinal pancreatic pseudocyst with isolated thoracic symptoms: a case report

IntroductionMediastinal pancreatic pseudocysts represent a rare complication of acute or chronic pancreatitis.Case presentationA 55-year-old man with a history of chronic pancreatitis was admitted with intermittent dyspnea, dysphagia and weight loss. Chest X-ray, computed tomography and magnetic resonance imaging revealed a large paracardial pancreatic pseudocyst causing cardiac and esophageal compression.ConclusionMediastinal pancreatic pseudocysts are a rare complication of chronic pancreatitis. These pseudocysts may lead to isolated thoracic symptoms. For accurate diagnostic and therapy planning, a multimodal imaging approach is necessary.

Delineation of alar ligament morphology: comparison of magnetic resonance imaging at 1.5 and 3 Tesla.

Rupture of the alar and transverse ligaments due to whiplash injury can lead to upper cervical spine instability and subsequent neurological deterioration. The purpose of this study was to evaluate the normal anatomical variability of the alar ligaments in asymptomatic individuals with 3-T magnetic resonance imaging (MRI) and to compare the findings with standard 1.5-T examinations. Thirty-six participants underwent 3-T and 1.5-T MRIs. Magnetic resonance imaging findings were analyzed by classifying the alar ligaments with regard to the features detectability, signal intensity compared with muscle tissue, homogeneity, shape, spatial orientation, and symmetry. Delineation of the alar ligaments was significantly better on 3-T images, which were subjectively preferred for evaluation. The alar ligaments showed great variability. In the majority of participants, the alar ligaments were hypointense to muscle tissue, inhomogeneous, and different in shape and orientation. A statistically significantly higher number of ligaments appeared symmetric on 3-T imaging, indicating that 1.5-T imaging may underestimate the proportion of patients with normal, symmetric ligaments. This study demonstrates that high-field 3-T MRI provides better visualization of the alar ligaments compared with 1.5-T MRI. The higher signal-to-noise ratio allows detection of small signal changes. A great interindividual variety of the MRI morphology of the alar ligaments was found in participants with no history of neck trauma. Further studies with more participants are necessary to evaluate alar ligament pathologies in patients with a history of whiplash injury.

PET/US fusion as a problem-solving tool in oncology imaging: differentiation of hernia repair mesh plugs from malignancy suspected on PET/CT.

PET/CT is an established modality for evaluation of malignant disease. However, in many cases, specificity is impaired by false-positive findings. Recognition of these cases is crucial for correct diagnosis and subsequent patient management. In the presented case, malignant disease was suspected in a young man because of a history of B symptoms. F-FDG PET/CT showed hypermetabolic foci in both inguinal regions initially classified as possible lymphoma. Using a novel technique for PET/US fusion, ultrasound and PET were coregistered to clarify that PET hypermetabolism was due to a foreign body reaction after plug hernioplasty performed several years earlier.

Clinical Presentation, Magnetic Resonance Angiography, Ultrasound Findings, and Stroke Patterns in Patients with Vertebral Artery Dissection.

Background/Aims: Vertebral artery dissection (VAD) is an important cause of ischemic stroke. In this observational study, clinical data, magnetic resonance (MR) and ultrasound (US) imaging findings and ischemic patterns were analyzed. Methods: Forty-seven patients with a diagnosis of VAD underwent clinical examination, US, MR of the brain and neck and MR angiography (MRA) of the cervical arteries. Vascular abnormalities and ischemic brain lesions were noted. Data were evaluated separately and compared for spontaneous and traumatic VAD subgroups. Results: The most common overall clinical symptom was vertigo followed by neck pain. In the traumatic subgroup, vertigo was relatively rare (p = 0.022). Most common MRA findings were vessel irregularity and vessel occlusions. Ischemic lesions occurred significantly more frequently after spontaneous than after traumatic VAD (p = 0.009). Unilateral VAD was significantly more common in non-dominant vertebral arteries (p < 0.001). Mortality after trauma was not only due to VAD complications but also due to other trauma-related injuries. Conclusion: The variability of MR and US imaging findings in patients with VAD is illustrated. The algorithm of management should be based on a multimodality approach involving patient history and clinical neurological examination. Several types of vessel abnormalities and ischemic lesion in diverse locations may point to arterial dissection, and the differential diagnosis of VAD must be kept in mind.

F-18 Choline PET angiography of the pelvic arteries: evaluation of image quality and comparison with contrast-enhanced CT

PURPOSE The purpose was to show the feasibility of F-18 choline positron emission tomography (PET) angiography for the evaluation of abdominal and iliac arteries. METHODS Thirty-five patients were examined and image quality was scored. Findings were correlated with contrast-enhanced computed tomography. RESULTS Image quality was best in the aorta and common iliac arteries (100% and 93% of vessels). Negative predictive values of PET angiography were excellent (100%), and positive predictive values were impaired by disease overestimation. CONCLUSION PET angiography is technically feasible and of good image quality in large arteries. In selected cases, it may become an alternative to established angiographic methods.

Multimodal imaging of aortoiliac occlusive disease with three‐dimensional postprocessing of PET angiography and CT

Two patients with aortoiliac occlusive disease underwent dynamic and late-static positron emission tomography/computed tomography (PET/CT) acquisitions with 257 and 244 MBq F-18 FDG (CT scan parameters 50 mAs, 120 kV, pitch 1.25). Three-dimensional reconstructions revealed an occluded aortic stent and a high-grade aortic stenosis and demonstrated the relations of vascular pathologies to adjacent structures. Early-dynamic PET can be performed without additional radioactive tracer and may be valuable for evaluation and intervention planning in patients with contraindications to other angiographic modalities.

Heating of non-ferromagnetic total hip endoprostheses during magnetic resonance imaging in an animal model.

To determine the heating effects of magnetic resonance imaging (MRI) on non-ferromagnetic total hip endoprostheses, hip endoprostheses were tested in vitro and in an ex vivo animal model. The MRI protocol on a 1.5 T scanner consisted of five sequences with a total duration of 23 min. The maximum heating of prosthetic material was 0.17 K in vitro and 0.90 K ex vivo; the maximum heating of bone surrounding tissue was 0.73 K ex vivo. Slight heating of the prostheses and the surrounding tissue was noted, which should not have any side effects in patients with titanium total hip endoprostheses.

RADIATION EXPOSURE OF THE INVESTIGATOR DURING NAVIGATED FUSION OF 124IODINE PET IMAGING AND ULTRASOUND

To assess the radiation exposure of the investigator during navigated fusion of nuclear medicine images with ultrasound after application of I-124. Dosimetry with two different types of thermoluminescent detectors (TLD) was performed in 25 patients. The dose rate at the patients neck was measured with a calibrated dose rate meter (DRM) and served as the standard of reference. The average exposure per investigation at the patients neck measured by LiF:Mg,Cu,P TLDs (cumulative: 212 μSv), LiF:Mg,Ti TLDs (cumulative: 112 μSv) and DRM (cumulative: 150.3 μSv). The radiation exposure of the hand during navigated fusion of nuclear medicine imaging with 124I and ultrasound with a mean duration of 13 min is low and comparable between different methods. Yearly examinations are not expected to add a relevant cumulative risk.