[Clinical course of a partially thrombosed, symptomatic aneurysm of the basilar artery tip with partial recanalization subsequent to coiling]. / Verlaufsbeschreibung eines teilthrombosierten symptomatischen Basilariskopfaneurysmas mit teilweiser Rekanalisierung nach Coiling.

A 72-year-old patient was referred to the neuroradiological department for diagnostic angiography. She was suffering from vertigo and double vision. Magnetic resonance imaging performed elsewhere had demonstrated a giant aneurysm of the basilar artery tip 2 cm in diameter. Angiography revealed a large aneurysm with a broad neck that was partially thrombosed, which precluded closure by coiling. Neurosurgical management by clipping also appeared to be unsuitable because of the proximity to the cerebrum. The decision was reached to proceed expectantly by closely monitoring the clinical course. When the aneurysm increased in size in the ensuing weeks, coiling was performed successfully. Angiographic follow-up showed reperfusion of the aneurysm neck and closure was again achieved by repeat coiling. Reperfusion is not a rare complication following coiling and often necessitates renewed intervention.

[Is the renal excretion of orally applied diatrizoate (Gastrografin) a reliable marker of gastrointestinal perforation or dehiscence of a gastrointestinal anastomosis?]. / Renale Diatrizoatexkretion (Gastrografin) als diagnostisch verwertbarer Hinweis auf ösophagogastrointestinale Nahtdehiszenzen und Perforationen?

PURPOSE: Renal excretion of orally or rectally applied Gastrografin is reported to be a reliable indicator of a perforation or a postoperative anastomotic dehiscence of the GI-tract. The study was conducted to determine whether increased attenuation of the urine measured by CT after oral or rectal application of Gastrografin can give reliable evidence of any leakage from the gastrointestinal tract. MATERIALS AND METHODS: Urine samples of 33 patients, who underwent a Gastrografin-enhanced fluoroscopic examination of the esophagus or the GI-tract for different clinical reasons, were examined by CT. The samples had been taken immediately before and 60 to 90 minutes after application of 100 ml Gastrografin. The results were compared with those of 5 healthy volunteers, who took urine samples before, 30, 60, 90, and 120 minutes after drinking 100 ml of Gastrografin. RESULTS: Maximal attenuation of the volunteers' urine samples was achieved 60 to 90 minutes after Gastrografin application with a mean of 50 Hounsfield units (HU), SD = 17 HU. The urine of three patients with radiologically proven fistula or dehiscence of a GI-tract anastomosis had no relevant increase in attenuation. Three other cases without any clinical or radiological evidence of an anastomotic leak had a substantial increase in the attenuation of the urine probes (87, 110, and 290 HU, respectively). CONCLUSION: The CT-measured urine samples as evidence of renal excretion of orally or rectally applied Gastrografin are not reliable for the detection of leaks from the GI-tract.

[Proximal protection systems using carotid artery stent]. / Proximale Protektionssysteme beim Karotisstent.

Controversies as to whether or not a protection device should be used in carotid artery stenting exist. Currently three temporary cerebral protection devices are being used. These are devices with distal balloon occlusion or filtration baskets and proximal occlusion devices with flow reversal in the internal carotid artery. This article focuses on flow reversal systems and aims to give some advice as to which patients could benefit from their use.

[Glomus tumors of the head-neck-region]. / Glomustumoren der Kopf-Hals-Region.

Glomus tumors of the head and neck are rare tumors of adulthood which arise from paraganglia or glomus cells within the carotid glomus, vagus nerve, middle ear or jugular foramen. The diagnosis of these mostly benign lesions is predominantly done with CT and MRI. DSA can provide important additional information. Besides surgical resection, one therapy option is radiological intervention with tumor embolisation. Because of the typical radiological imaging and the "salt and pepper appearance" in MRI, glomus tumors can be differentiated from other lesions in the head and neck. This review gives a survey of the classification, diagnosis and therapy of paragangliomas with images to demonstrate characteristic features.

Mechanisms of accumulation of small particles of iron oxide in experimentally induced osteosarcomas of rats: a correlation of magnetic resonance imaging and histology. Preliminary results.

RATIONALE AND OBJECTIVES: This study was conducted to investigate the distribution and kinetics of small particles of iron oxide in osteosarcoma-like tumors. METHODS: Magnetic resonance (MR) imaging was performed in eight athymic nude rats with an experimentally induced osteosarcoma of the right hind leg immediately after intravenous injection of a superparamagnetic iron oxide preparation. Five animals received 150 mumol iron oxide/ kg and three received 50 mumol iron oxide/kg. The iron oxide preparation consisted of polythylenglycol-coated particles with a core diameter of 6 to 8 nm. The MR images were correlated with histologic slices of the tumors. RESULTS: The tumors accumulated iron oxide rapidly. A marked decrease in signal intensity, preferentially along the periphery of the tumor, was followed by a partial return of the signal intensity within the first minute. The maximum signal decrement throughout the entire tumor exceeded 41% and 21% with one dose each of 150 mumol iron/kg and 50 mumol iron/kg, respectively. The rate of return depended on the injected dose and tumor area, with the signal intensity approaching the initial value before the injection of iron oxide after 45 minutes. Histologic correlation only showed deposition of contrast medium in the proliferative areas of the tumors, mainly confined to the tumor margin. In addition to a predominantly extracellular deposition, intracellular storage could be detected. CONCLUSIONS: The findings help to advance the understanding of the distribution and kinetics of intravenous-injected small particles of iron oxide in osteosarcoma-like tumors. A first-pass accumulation of iron oxide could be documented by MR imaging in the periphery of osteosarcomas. Due to sieving of iron oxide particles by liver, spleen, and bone marrow, the signal intensity at 45 minutes after the injection of iron oxide returned to 89% (150 mumol iron oxide/kg) and 95% (50 mumol iron oxide/kg) of the preinjection intensity.

[A comparison between GE and SE sequences in MRT after the i.v. application of superparamagnetic iron particles in the assessment of experimentally induced soft-tissue osteosarcomas]. / Vergleich zwischen GE- und SE-Sequenzen in der MRT nach i.v. Applikation von superparamagnetischen Eisenpartikeln bei der Beurteilung von experimentell induzierten Osteosarkomen der Weichteile.

PURPOSE: An MRI study on experimentally induced osteosarcomas of the peripheral soft-tissues in nude rats was conducted, comparing SE and GE sequences after i.v. application of superparamagnetic iron oxides with regard to contrast and image quality. MATERIAL AND METHODS: 40 nude rats with an osteosarcoma in the right hind leg and 7 tumour-free animals were measured without, one and 48 hours after i.v.-injection of the contrast medium. 4 SE and 3 GE sequences with different parameters and slice orientation were applied. The contrast medium consisted of Fe3O4 particles with a core diameter of 6-8 nm and a coating material of polyethylene glycol (PEG). The laboratory animals were divided into 5 groups of 7-12 animals each. The rats of the first 4 groups were given a contrast-medium dosage of 100, 150, 200 and 250 mumol Fe/kg body weight, respectively. The animals of the fifth group were tumour-free and served as controls. RESULTS: The minimum dosage for detection of Fe3O4-containing PEG magnetites, one hour after application, was established at 100-150 mumol Fe/kg body weight. The higher the dosage of the contrast medium, the more signal alterations could be measured. The GE sequences were more sensitive than SE sequences. One GE sequence with the parameters TR 90 ms, TE 13 ms, FL 8 degrees turned out to be highly sensitive. CONCLUSION: Superparamagnetic iron oxides induce signal alterations in tumours of the peripheral soft tissue. GE sequences proved to be more sensitive than SE sequences.

Atrial and ventricular myosins from human hearts. II. Isoenzyme distribution after myocardial infarction.

Human atrial and ventricular myosins were prepared from autopsy specimens from subjects with coronary heart disease. Cardiac myosin light chain isotypes were resolved using two-dimensional gel electrophoresis, whereas myosin isozymes were detected by pyrophosphate gel electrophoresis. Myocardial infarction and associated work overload cause a transition in the light chain complements of the myosins. Thus ventricular myosin light chains were found in pressure overloaded atria and atrial light chains have also been identified in the infarct ventricle of the human heart. Two molecular isoenzymes of the human atrial myosin, the relative proportions of which are changed after infarction, were separated under non-dissociating conditions by gel electrophoresis. A decrease in HA-3 and a corresponding increase in HA-1 were observed. Ventricular hypertrophy in patients with coronary insufficiency induces a second ventricle isomyosin, called HV-1, with the same electrophoretic mobility as HA-1. The relative part of this myosin type amounts to 20%. Comparative peptide mapping studies were carried out on myosin subfragment-1 preparations from normal and infarct ventricles. In the primary structures, the chymotrypsic digestions produced slight differences. These data demonstrate the heterogeneity of human atrial and ventricular myosins in patients with coronary heart disease.

Myosin isoenzymes in normal and hypertrophied human hearts.

Distinct myosin isoforms were identified from the ventricles and atria of foetal, normal and hypertrophied human hearts. Ventricle and atrium myosins cannot be differentiated by their sedimentation behaviour in the analytical ultracentrifuge, they vary, however, with regard to the Ca2+-dependent ATPase and also the activation parameters in measurements of the enzyme activity in dependence on temperature. In agreement with other authors we observed a foetal light chain in the ventricular tissue of the latter half of gestation, when myosin was characterized by SDS-polyacrylamide gel electrophoresis and isoelectric focusing. Using pyrophosphate gel electrophoresis an additional foetal isomyosin was observed besides the typical ventricular myosin HV-3, which migrates faster. Two distinct myosin isoforms designated as HA-3 and HA-1 occur in the atrium of the normal human heart. It was found that besides their own isoenzymes normal atria also contain ventricular isomyosin, whose relative proportion is markedly increased in the hypertrophic atrium. In contrast, we usually observed only one isoenzyme in the normal ventricle. Moreover, in case of myocardial infarction a dramatic transformation of myosin heavy chain composition with a shift to an atrial myosin type took place in the ventricle.