A prospective study of preoperative and postoperative sequential magnetic resonance imaging and early clinical outcome in automated percutaneous lumbar discectomy.

The authors evaluated the size of the disc herniation with magnetic resonance imaging (MRI) before and after surgery in patients undergoing automated percutaneous lumbar discectomy (APLD) and compared the MRI findings with the early clinical outcome. This study includes 20 consecutive patients with a contained lumbar disc herniation. Sequential MRI were performed immediately before and after surgery, on the day of surgery, and 6 weeks after surgery. The development of pain, nerve root tension sign (SLR), and neurological findings were analyzed, as was the need for subsequent open surgery. There was no significant difference in the maximum protrusion of the disc herniation between the three measurements. The sciatic pain improved significantly on the first day after surgery but not at 1 week or 6 weeks after surgery. The SLR was reduced significantly after surgery and at 1 and 6 weeks after surgery. There was no correlation between the MRI findings and the early clinical outcome. Seven patients needed subsequent open surgery. The findings indicate that the effect of APLD is not mediated by reducing the size of the disc herniation. In this small series of patients, APLD was ineffective in the treatment of a contained lumbar disc herniation. There was no correlation between the MRI findings and the early clinical outcome.

Spontaneous spinal epidural hematoma: findings at MR imaging and clinical correlation.

PURPOSE: To evaluate radiologic findings and clinical data in patients with spontaneous spinal epidural hematoma (SSEH). MATERIALS AND METHODS: Thirteen patients (10 men aged 28-71 years; three women aged 40-65 years) with SSEH from 1986 to 1995 underwent magnetic resonance (MR) imaging; six also underwent spinal angiography. Patients with minor trauma, anticoagulant therapy, increased bleeding tendency, or vascular lesions were included. RESULTS: The incidence was estimated to be 0.1 patients per 100,000 patients per year. On MR images, the hematoma was in the anterior (n=8) or posterior (n=4) epidural space or both (n=1). The most common location was the upper thoracic region. T1-weighted images were most useful owing to the pathognomonic signal shift from isointensity with the cord in the early period to hyperintensity in the intermediate stage. Five patients had minor trauma, and four were receiving anticoagulant therapy. CONCLUSION: A rough estimation of the incidence of SSEH is provided,and the results confirm the previously described association with minor trauma and anticoagulant therapy and low frequency of arteriovenous malformations.

Evaluation of time-of-flight and phase-contrast MRA sequences at 1.0 T for diagnosis of carotid artery disease. I. A phantom and volunteer study.

UNLABELLED: PURPOSE AND MATERIAL: The aim of this work was, firstly, to compare different manufacturer-provided MRA sequences in a 1.0 T MR unit, with respect to the visibility of an artificial stenosis in a flow phantom and, secondly, to evaluate the same sequences in healthy volunteers with respect to S/N ratio levels and practical in vivo implementation routines. METHODS: The studied sequences were 2D and 3D TOF and sequences with an acquisition time of approximately 10 min. Quantitative signal evaluation was made using single transverse partitions in all phantom experiments. MIP angiograms and MPR reconstructions were made for visual inspection of image quality. In vivo, the images were individually evaluated by visual inspection by experienced neuroradiologists. RESULTS: In the evaluation of the grade and length of a stenosis, a combination of MIP and MPR was seen to be the optimal and necessary procedure. A shortening of TE played an important and significant role in the visualization of the poststenotic flow in the phantom using TOF MRA. However, the shortest TE values gave poor S/N ratio in vivo. The good results achieved in the phantom studies for 3D phase-contrast were somewhat reversed in the volunteer studies, whereas 3D TOF sequences showed good results in both the phantom and the volunteer studies.

Efficacy of inverted digital luminescence radiography in evaluating chest neoplasms.

Inverted (positive) digital chest radiographs of patients with lung tumors were compared with commonly used (negative) digital images, consisting of one simulated normal and one contrast enhanced image. The first part of the material consisted of 80 patients of whom 40 had tumors and 40 were normal. Five radiologists with different experience reviewed the examinations. From their answers, ROC curves were constructed. The second part of the material consisted of 100 chest phantom examinations with a simulated tumor in the mediastinum (45 examinations) and/or the left lung (46 examinations). In 31 exposures there was no abnormality. These were reviewed by 3 observers and performed as an ROC study as well. There was no statistical difference between the different types of images or between the observers in the 2 studies.