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Biomedical subjects

M Oelerich

Publications and source records attributed to M Oelerich.

15 recordsLinked to original sources

[Primary central nervous system lymphoma as a neurological manifestation of AIDS stage].

In patients infected with human immunodeficiency virus (HIV), the risk of developing non-Hodgkin's lymphoma is over 100 times greater than with noninfected persons. Primary central nervous system lymphoma as a complication of the acquired immunodeficiency syndrome (AIDS) occurs in up to 2.4% of all cases and is strongly associated with the Epstein-Barr virus. The prognosis is very poor, with a mean survival time of 21 to 27 days without therapy and up to 119 days with radiation therapy. We describe the course of seven AIDS patients with histologically proven primary central nervous system lymphoma and present a review of clinical symptoms, diagnosis, and therapy. The main criteria for differential diagnosis from other secondary neuromanifestations such as cerebral toxoplasmosis, progressive multifocal leukoencephalopathy, abscesses, and infarctions are described.

AIDS-Related Opportunistic Infections↗

Efficacy of botulinum toxin A for treatment of upper esophageal sphincter dysfunction.

OBJECTIVES: To investigate the efficacy of botulinum toxin A (BTA)-induced chemodenervation of the upper esophageal sphincter (UES) in patients with dysphagia and UES dysfunction. STUDY DESIGN: Prospective clinical trial in 10 selected patients with pure UES dysfunction. METHODS: In each patient 30 units of BTA were injected into the UES under brief general anesthesia. Videofluoroscopic swallowing study (VSS) was done and a clinical symptom score was determined before and after treatment. RESULTS: On VSS relative opening of the UES improved in all patients (mean +/- SD: 47 +/- 14% before versus 71 +/- 24% after treatment; P < .01). Hypopharyngeal retention or laryngeal penetration of barium was significantly reduced in four of seven patients. Clinical symptom scores improved in all patients. One patient was free of symptoms, mild dysphagia persisted in six patients, and moderate dysphagia persisted in three patients. CONCLUSIONS: Our results support the use of BTA in selected patients with pure UES dysfunction. Its efficacy is limited by the possibility of a persistent structural stenosis of the UES and the risk of BTA diffusion into the larynx or hypopharynx.

Adult↗

Selenium-based digital radiography in the detection of bone lesions: preliminary experience with experimentally created defects.

PURPOSE: To compare the diagnostic performance of selenium-based digital radiography with that of conventional screen-film radiography and storage phosphor radiography for the detection of bone lesions simulating osteolyses. MATERIALS AND METHODS: Artificial osseous lesions 1.0-3.0 mm in diameter were created in 80 of 160 predefined regions in 16 porcine femoral specimens. Specimens were enclosed in containers filled with paraffin to ensure accurate repositioning and to obtain an absorption condition comparable to that of a human extremity. Imaging was performed with a selenium-based digital radiography system, a conventional screen-film system, and a storage phosphor radiography system with an exposure identical to that used during clinical imaging. The presence of a lesion was assessed with a five-point confidence scale. Receiver operating characteristic (ROC) analysis was performed for a total of 1,440 observations (480 per modality), and diagnostic performance was estimated with the area under the ROC curve (A(z)). Differences in diagnostic performance were assessed with the paired Student t test. RESULTS: ROC analysis results showed A(z) values of 0.656 for selenium-based digital radiography, 0.679 for storage phosphor radiography, and 0.680 for conventional screen-film radiography. Differences between the three modalities were not significant (P =.60-.93). CONCLUSION: Image quality with selenium-based digital radiography was comparable to that with conventional screen-film radiography and storage phosphor radiography.

Animals↗

Craniocervical artery dissection: MR imaging and MR angiographic findings.

Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena.

Adolescent↗

Intracranial vascular stenosis and occlusion: comparison of 3D time-of-flight and 3D phase-contrast MR angiography.

We compared the value of 3D time-of-flight (TOF) and phase-contrast (PC) MR angiography (MRA) for detection and grading of intracranial vascular steno-occlusive disease. Unenhanced 3D-TOF MRA and 3D-PC MRA (30-60 cm/s velocity encoding) were performed at the level of the circle of Willis in 18 patients, mean age 56 +/- 10 years. Postprocessed images using a maximum-intensity projection reconstruction with multiple targetted projections were analysed. A total of 126 vessels was assessed by PC MRA and 143 by TOF MRA, with digital subtraction angiography (DSA) in 15 patients and/or transcranial Doppler sonography (TCD) in 18 as a standard. Two blinded readers reviewed the MRA, DSA and TCD examinations retrospectively. On DSA and/or TCD the two observers found 32 and 28 steno-occlusive lesions. 3D-TOF MRA was more sensitive than 3D-PC MRA (87% and 86% vs. 65% and 60%) and had a higher negative predictive value (96% vs. 89%). Correct grading of stenoses was achieved in 78 % by 3D-TOF and 65% by 3D-PC MRA.

Adult↗

Is image selection a useful strategy to decrease the transmission time in teleradiology? A study using 100 emergency cranial CTs.

This study examines the suitability of working with a selection of images in a teleradiology consulting system in neurological or neurosurgical emergency situations. The teleradiology system was based on IBM-compatible personal computers, video digitization for data acquisition, and data transmission by Integrated System Digital Network. Forty normal and 60 abnormal emergency cranial computed tomograms were shown to a radiologist on call who presented all cases he regarded as pathologic to a neuroradiologic expert by teleradiology. To reduce transmission time, only a selection of images from the CT study was presented (up to four images per case). For each case the on-call radiologist's diagnosis (D(on-call)), the expert's diagnosis on the teleradiology screen (D(monitor)), and the expert's diagnosis on the original film (D(original)) was documented, together with an estimation of the agreement between those diagnoses. There was clinically relevant disagreement between the on-call radiologist's diagnosis and the neuroradiologist's diagnosis based on the image selection on the teleradiology monitor in 23% of cases. A clinically important discrepancy between the neuroradiologist's diagnosis based on the image selection and his diagnosis using the original films was found in 30% of cases. This was due to the presence of clinically relevant information on images not transferred by the on-call radiologist. Image quality of the transferred images was sufficient in all cases. Drastic selection of images from a complete CT study leads to a high rate of incorrect diagnoses and is not appropriate to reduce transmission time in teleradiology.

Humans↗

Breath-hold gadolinium-enhanced MR angiography of the major vessels at 1.0 T: dose-response findings and angiographic correlation.

PURPOSE: To find the appropriate contrast agent dose for gadolinium-enhanced magnetic resonance (MR) angiography by using individual measurement of contrast agent transit times in a randomized study. MATERIALS AND METHODS: A total of 34 patients with disease of the aorta or its major branches or both were randomly assigned to receive a dose of 0.1, 0.2, or 0.3 mmol of gadopentetate dimeglumine per kilogram of body weight. Initially, contrast agent transit times were measured with use of a turbo fast-low-angle-shot sequence. Subsequently, a three-dimensional fast imaging with steady-state precession sequence (7.3-msec repetition time, 2.8-msec echo time) was used for breath-hold MR angiography. Gadopentetate dimeglumine was injected with an MR-compatible power injector. Efficacy was evaluated by measurement of vessel enhancement and by clinical correlation of MR angiograms with x-ray angiograms. RESULTS: Evaluation of contrast agent transit time was possible in all patients with the test doses, which provided contrast-enhanced MR angiograms of constant quality. Neither vessel enhancement nor diagnostic information was significantly different across the these study groups. CONCLUSION: The clinical gadolinium dose of 0.1 mmol/kg is sufficient for diagnostic assessment of the aorta and its major branches at contrast-enhanced MR angiography. High-dose studies appear not to be required for these large vessels.

Adult↗

[The color Doppler-guided compression therapy of pseudoaneurysms. The authors' own experiences and a review of the literature].

PURPOSE: The common use of interventional angiographic techniques and the sensitive detection of this vascular complication by ultrasound are major factors contributing to the increasing incidence of femoral artery pseudoaneurysms. ultrasound-guided compression repair of femoral artery pseudoaneurysms was prospectively evaluated. MATERIAL AND METHODS: 11 femoral artery pseudoaneurysms were detected in 10 patients who ranged from 45 to 79 years of age. In one patient two ipsilateral pseudoaneurysms occurred. All patients were considered to be candidates for ultrasound-guided compression repair. RESULTS: Successful compression repair was achieved in 9 of 11 pseudoaneurysms (82%) with a mean diameter of 2.2 +/- 1.0 cm. In two recurrent lesions (22%) definitive thrombosis required a second treatment. Compression was maintained between 10 and 40 minutes (mean 22 +/- 11 minutes). No complications have been observed. CONCLUSIONS: Ultrasound-guided compression repair provides an efficient, noninvasive and safe treatment of femoral artery pseudoaneurysms. More than 80% of pseudoaneurysms can be occluded successfully. In recurrent lesions a second attempt is valuable.

Aged↗

[Use of high frequency cinematography in diagnosis of globus sensation].

BACKGROUND: Globus pharyngis is a frequent symptom in patients who consult an otolaryngologist. In many cases, routine diagnostic work-up including history, clinical examination, and barium swallow fail to revealing the underlying pathogenesis. PATIENTS AND METHOD: In a retrospective study, we present 51 selected patients suffering from globus pharyngis of unknown origin who were investigated by high-speed cineradiography in a standardized manner. RESULTS: Twenty-four of the patients enrolled in the study (47.1%) showed functional and/or structural swallowing disorders. In 13 cases (25.5%) dyskinesias of the superior esophagus sphincter muscle were found. Five of these patients (9.8%) also had an inconstant hypopharyngeal diverticulum. Six cases (11.8%) showed laryngeal penetration or tracheal aspiration. In four cases (7.8%) functional disorders of pharyngeal, and in three cases (5.9%) functional disorders of oral bolus transport were found. Furthermore one hypopharyngeal web (1.9%) and two benign tumors (3.9%) were detected. In many cases, varying combinations of these findings occurred. CONCLUSION: Using high-speed cineradiography for evaluation of globus pharyngis results in an increased incidence of pathologic findings, and thus is an important method for interdisciplinary diagnostic work up of patients suffering from this symptom.

Adult↗

Artificial spine fractures: detection with helical and conventional CT.

PURPOSE: To compare the accuracy of detection of artificial spine fractures with helical computed tomography (CT) versus conventional CT. MATERIALS AND METHODS: Twenty-six motion segments from 15 human cadaver thoracolumbar spines were imaged with helical and conventional CT both before and after fractures were artificially induced. The vertebrae were scanned with different collimations, reconstruction indexes, and exposure doses. A total of 900 images were analyzed by four radiologists, and a receiver operating characteristic (ROC) analysis was performed. RESULTS: ROC analysis showed a large area under the curve for conventional CT (0.913) than for helical CT (0.844) when 3-mm collimation was used. The ability to detect fractures with helical CT increased when collimation was decreased and exposure dose was increased. CONCLUSION: Conventional CT allows more accurate detection of artificial spine fractures than does helical CT. Helical CT requires thinner collimation for fracture detection comparable with that of conventional CT.

Cadaver↗

[Efficacy of high-frequency cinematography in diagnosis of dysphagia].

Dysphagia is a common symptom in clinical practice. Due to the broad spectrum of underlying diseases many disciplines are involved in the therapy and diagnosis of dysphagia, where radiology plays a central role. The radiologist is confronted with different diagnostic problems and has to choose the most appropriate type of investigation. In many cases no organic disorder can be demonstrated by clinical examination, endoscopy or conventional radiological techniques. In this setting cineradiography is an outstanding tool for finding functional or structural changes in the swallowing chain. This study underlines the efficiency of cineradiography in the diagnosis of dysphagia.

Adult↗

Lumbar spinal neurinoma presenting with nocturnal pain. A case report.

Neurinomas are the most common intradural extramedullary tumors of the spine. Together with meningeoma they account for 80% to 90% of all tumors in this compartment. Radicular pain is the initial symptom in the majority of cases while motor disorders are less common and occur later in the course of the disease. We report a patient with spinal neurinoma and calf pain as the only presenting complaint. The differential diagnosis in this case required an interdisciplinary approach.

Aged↗