Alfred Hutzelmann

MR imaging of the central nervous system in diving-related decompression illness:

Purpose: This investigation was conducted to determine whether MR imaging showed cerebral or spinal damage in acute diving-related decompression illness, a term that includes decompression sickness (DCS) and arterial gas embolism (AGE) Material and Methods: A total of 16 divers with dysbaric injuries were examined after the initiation of therapeutic recompression. Their injuries comprised: neurological DCS II n=8; AGE n=7; combined cerebral-AGE/spinal-DCS n=1. T1- and T2-weighted images of the brain were obtained in 2 planes. in addition, the spinal cord was imaged in 7 subjects. the imaging findings were correlated with the neurological symptoms Results: MR images of the head showed ischemic cerebrovascular lesions in 6/8 patients with AGE but showed focal hyperintensities in only 2/8 divers with DCS. Spinalcord involvement was detected in 1/7 examinations, which was the combined cerebral-AGE/spinal-DCS case. There was agreement between the locations of the documented lesions and the clinical manifestations Conclusion: MR readily detects cerebral damage in AGE but yields low sensitivity in DCS. A negative MR investigation cannot rule out AGE or DCS. However, MR is useful in the examination of patients with decompression illness

Magnetic Resonance Signal Abnormalities and Neuropsychological Deficits in Elderly Compressed-Air Divers

We investigated the association between MR signal abnormalities of the central nervous system, neuropsychologic performance and exposure indices in 20 experienced elderly compressed-air divers who had no history of neurological decompression illness (DCI). Results of MRI of the brain and psychometric testing were compared with 20 matched healthy commercial employees who never dived: 60% of the divers and 45% of the controls had hyperintense MR abnormalities. Among divers, both the number and the size of abnormalities correlated with hours diving in the deep air-diving range of 40–60 m (p < 0.05). Divers’ mental flexibility and visual tracking performance were decreased in comparison with controls (p < 0.05 and p < 0.01). Divers thus are at risk of detrimental long-term effects of compressed-air diving on the central nervous system even in the absence of a history of neurological DCI.

Thoracic computed tomography prior to redo coronary surgery

OBJECTIVE Median resternotomy in coronary redo surgery represents a specific risk for injury of adjacent retrosternal structures. Aiming at improved preoperative evaluation of retrosternal structures, computed tomography (CT) techniques were routinely applied in redo cases. METHODS Of 99 patients undergoing coronary reoperations since April 93, thoracic CT scans were retrospectively analyzed for retrosternal vicinity of cardiovascular structures, condition of the ascending aorta and structural abnormalities of the sternum. RESULTS The minimal median distance between the posterior sternum surface and the anterior aortic wall was measured at 1.9 +/- 0.9 cm, whereas the mean closest distance to the anterior right ventricular wall was 0.4 +/- 0.5 cm. In 28 cases, the distance between sternum and aorta was smaller than or equal to 1 cm. No measurable distance between the sternum and the right ventricle was noted in 41 patients. Calcification of the ascending aorta became obvious 56 times. With respect to potential injury of the ascending aorta or the right ventricle, a safe reentry by resternotomy was facilitated in all cases. However, following complete sawing, the innominate vein became injured during retrosternal dissection in two cases. Preventive femoral vessel exposure was not performed and urgent femoral cannulation (n = 1) was infrequent. CONCLUSIONS Thoracic CT scanning prior to redo coronary surgery allows for detailed assessment of retrosternal relations and facilitates reopening of the sternum. Preventive femoral vessel exposure and lateral thoracotomies may be avoidable in many cases.

Dural invasion of meningiomas adjacent to the tumor margin on Gd-DTPA-enhanced MR images: histopathologic correlation

Abstract. In intracranial meningiomas a flat, contrast-enhancing, dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA-enhanced MR images. We wished to evaluate whether there is a correlation between MR images and meningeal invasion of intracranial meningiomas. The study included 54 patients with intracranial meningioma and the meningeal sign. MR studies included T2-weighted and gadolinium-DTPA-enhanced T1-weighted images in axial, coronal, and sagittal planes. Histopathologic examinations were done on the meningiomas adjacent to the dura mater. The meningeal sign on MRI was observed from 2 up to 35 mm from the main tumor mass in 31 (57 %) of the 54 patients. In 20 of these 31 the histopathologic examination showed tumor invasion, while 11 patients had no tumor invasion but tissue proliferation, hypervascularity, and vascular dilatation. Seven of the 23 meningiomas without the meningeal sign had histologically proven infiltration of the adjacent dura. MR imaging is not able to determine definitive whether or not there is dural infiltration of the meningiomas. In conclusion, resection of the tumor with a wide margin is necessary to achieve complete excision of meningioma and to avoid recurrence.

IN VITRO EFFECTIVENESS STUDY FOR HYDRODYNAMIC THROMBECTOMY DEVICES OF THE SECOND GENERATION

RATIONALE AND OBJECTIVES To determine the efficacy of clot removal and the amount of applied saline and aspirated fluid and to compare procedure-related particle embolization for the hydrodynamic thrombectomy devices the LF 140 Angiojet (LF 140), the double-lumen Hydrolyser (double HL), and the triple-lumen Hydrolyser (triple HL) in an in vitro flow model. METHODS Thrombectomy of clots (n = 42) from 7-day-old porcine blood (9.8 g) was performed with the LF 140, the double HL, and the triple HL in a flow model (flow 1 L/min) made of silicone tubes (7 mm inner tube diameter). All catheters were used according to the manufacturers recommendations. RESULTS Mean time of thrombectomy ranged from 20 seconds (triple HL) to 58 seconds (LF 140, P < 0.05). Only for the triple HL was remaining thrombus found within the tubes (41 mg). None of the tested devices worked isovolumetrically: the mean ratio of applied saline and aspirated fluid for the devices ranged from 0.79 (triple HL) to 0.89 (double HL, P < 0.05). Mean embolus weight and percentage of embolism from original thrombus were 675 mg/6.7% (LF 140, P < 0.05), 38 mg/0.4% (double HL), and 26 mg/0.3% (triple HL). CONCLUSIONS Thrombectomy time and embolus weight depend on the device chosen. The ratio of applied to aspirated fluid, indicating the capability to work nearly isovolumetrically, is acceptable for all tested devices. In vitro, the triple HL seems to be the most appropriate device for rapid mechanical, hydrodynamic thrombectomy. Because of the high in vitro particle embolization rate, the LF 140 seems to be strictly limited to small-caliber vessels.

Cervico-thoracic disc protrusions in controlled compressed-air diving: clinical and MRI findings.

Abstract Prevalence of cervical and thoracic disc protrusions was investigated by MRI in 24 military long-term compressed-air divers and 24 controls. A total of 26 disc protrusions (17 cervical disc protrusions) were detected in 58 % of the divers whereas 18 protrusions were detected in 38 % of the controls (13 disc cervical protrusions). There was no significant difference between groups and no correlation with the diving experience. Neurological examination revealed no clinical abnormalities. In contrast to a recent study, our results suggest that long-term divers are at no increased risk for accumulating spinal disc protrusions or intramedullary abnormalities.

Radiologic and histopathologic findings in a rare case of complex occult spinal dysraphism with association of a lumbar fibrolipoma, neurenteric cyst and tethered cord syndrome.

Abstract. We present the case of a 60-year-old farmer who reported non-specific back pains for the past 30 years. Increasing paralysis of the left leg led to hospitalization. A complex occult spinal dysraphism comprising a fibrolipoma of the conus medullaris, an neurenteric cyst, and a tethered cord syndrome was diagnosed and operated on. The radiological and histological findings are demonstrated.

Pseudotumour cerebri and optic hydrops—magnetic resonance imaging diagnostic and therapeutical considerations in a paediatric case

We report the case of a 4-year-old girl with progressive visual loss. Magnetic resonance imaging (MRI) demonstrated a perioptic subarachnoidal space dilatation. In this case, a clear differentiation between pseudotumour cerebri and optic hydrops was not possible. Administration of acetazolamid, furosemid and corticosteroids did not show any success. Progressive loss of visual function was halted with ventriculo-peritoneal shunting. We discuss MRI findings, aetiology and course of the disease, and its literature.

Spiral CT angiography for preoperative planning in patients with epigastric tumors: comparison with arteriography.

PURPOSE Spiral CT angiography (CTA) was performed on 22 patients for the preoperative assessment of epigastric tumors in comparison with intraarterial angiography. METHODS One hundred fifty milliliters of contrast material was administered with a flow of 4 ml/s. After a delay of 30 s, a spiral CT examination of the epigastrium was performed (slice thickness 3 mm, table feed 6 mm/s). Axial images were reconstructed at 2 mm increments. Postprocessing was performed with a maximum intensity projection and shaded surface display imaging program. Plain film arteriography was performed via a catheter inserted transfemorally and placed into the epigastric arteries. The following parameters were evaluated: visualization of the arteries and the portal vein and involvement of these vessels by disease. RESULTS The vessels (22/22 = 100%) and variations (1/22 = 4.5%) were clearly identified with both techniques. Involvement was diagnosed by angiography 15 times compared with 22 findings by CTA. CONCLUSION Concerning vessel anatomy, the correlation between both techniques was excellent and vessel involvement showed good correlation, especially when using the axial slices additionally. CTA has the potential to become a minimally invasive diagnostic tool for preoperative planning in epigastric tumors.

MRI follow-up in a case of clinically diagnosed Creutzfeld-Jakob disease

Abstract. We report the case of a 75-year-old woman suffering from Creutzfeld-Jakob disease (CJD). As brain biopsy was refused, diagnosis had to be based on clinical examination, EEC and findings on cranial MRI. Over a 4-month period MRI examinations demonstrated progressive cortical atrophy and bilateral enhanced signal intensity on T2-weighted images of caudate nuclei and putamina indicating development of spongioform degeneration. As clinical course and the characteristic pattern of brain lesions corresponded to cases of neuropathologically confirmed CJD, we suggest that MRI should be considered a valuable diagnostic tool in clinical diagnosis of the disease.