Vascular lesions of the lumbar epidural space: magnetic resonance imaging features of epidural cavernous hemangioma and epidural hematoma.

The authors report the magnetic resonance imaging diagnostic features in two cases with respectively lumbar epidural hematoma and cavernous hemangioma of the lumbar epidural space. Enhanced MRI T1-weighted scans show a hyperintense signal rim surrounding the vascular lesion. Non-enhanced T2-weighted scnas showed hyperintense signal.

MR imaging of dislocation of the posterior tibial tendon.

OBJECTIVE: The purpose of this article is to describe the MR imaging appearance of seven cases of posterior tibial tendon dislocation and subluxation. CONCLUSION: Posterior tibial tendon dislocation is a rare but important entity usually related to a previous traumatic event. The clinical diagnosis is often missed because of its rarity. MR imaging provides important clues to the diagnosis and preoperative evaluation of this condition.

[Evaluation of chronic morphological changes in the latissimus dorsi, after cardiomyoplasty, with magnetic resonance]. / Avaliação das alterações morfológicas crônicas do músculo grande dorsal, após cardiomioplastia, através da ressonância magnética.

PURPOSE: Long term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans. METHODS: The latissimus dorsi muscle flap was evaluated by magnetic resonance imaging (MRI) in 5 patients submitted to DC for treatment of severe dilated cardiomyopathy. All patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement. In the interim, LD was stimulated with burst of 6 pulses (burst duration 185 msec, burst freq 30Hz) synchronized to every cardiac contraction with a maximum of 100 LD contractions/min. Images were acquired on a GE Sigma 1.5 T system (TE = 25ms, TR = R- Rx2, slice thickness 8mm). RESULTS: The thickness of was 7.6 +/- 0.8mm. In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be increased (2.19 +/- 0.42). The signal intensity was similar to that of subcutaneous fat in those images. CONCLUSION: Morphologic changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.

[Significance of the nuclear magnetic resonance in the detection of coronary artery patency after thrombolysis]. / Valor da ressonância nuclear magnética na detecção da perviabilidade da artéria coronária após trombólise.

PURPOSE: To determine the value of magnetic resonance imaging (MRI) in the noninvasive detection of infarct related coronary artery patency after thrombolysis. METHODS: We studied 26 patients with acute myocardial infarction submitted to thrombolysis underwent MRI studies before and after 0.1mmol/kg gadolinium-DTPA injection within the first 48 h of MI. Signal intensity was assessed by circumferential profile analysis techniques. RESULTS: The average ratio of signal intensity of infarcted tissue over normal myocardium (I/N) was significantly higher in patients with patent arteries (1.3 +/- 0.13 vs 1.12 +/- 0.07, p < 0.02). Compared to coronariography MRI, sensitivity of 81% and specificity of 100% for the diagnosis of coronary patency. CONCLUSION: Gadolinium infusion increased infarcted and normal myocardium differentiation. The study of gadolinium kinetics at MRI is a promising technique for noninvasive diagnosis of coronary patency.

Magnetic resonance imaging evaluation of chronic changes in latissimus dorsi cardiomyoplasty.

BACKGROUND: Long-term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans. METHODS AND RESULTS: The LD muscle flap was evaluated by magnetic resonance imaging (MRI) in 13 patients submitted to dynamic cardiomyoplasty for treatment of severe dilated cardiomyopathy. Eight patients were studied 15 days after the surgery (group 1) and 5 patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement (group 2). In the interim, LD was stimulated with burst of 6 pulses (duration, 185 milliseconds; burst frequency, 30 Hz) synchronized to every cardiac contraction, with a maximum of 100 LD contractions per minute. Images were acquired on a GE Sigma 1.5-T system (echo time, 25 milliseconds; repetition time, R-R x 2; slice thickness, 8 mm). The thickness of the LD decreased from 19.6 +/- 7.3 mm for group 1 to 7.6 +/- 0.8 mm for group 2 (P < .01). In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be significantly increased in group 2 (2.19 +/- 0.42) compared with group 1 (1.04 +/- 0.07, P < .001). The signal intensity for group 2 on the T1-weighted images was similar to that of subcutaneous fat in those images. CONCLUSIONS: Morphological changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.

[Traumatic spondylolysis]. / Espondilolise traumática.

The authors present the results of treatment of seven cases of spondylolysis with a two years follow up. Six patients were treated with the thoracolumbosacral orthosis and one with L5-S1 fusion. At the end of the follow up all patients were pain free.

Wilson's disease: MRI with clinical correlation.

We tried to establish possible correlations between clinical data and MRI in a group of patients with Wilson's disease. Eleven patients (6 male, 5 female), aged between 11 and 50 years old, with a duration of illness from 5 months to 32 years, were submitted to MRI on a 1.5 T System. Three patients were asymptomatic, two had mild neurological disturbances, two were moderately affected and the remaining four had a severe form of the disease. All were receiving D-penicillamine at the time of the study. In the most symptomatic patients there were abnormalities in five or more sites on MRI. The putamen was affected in all symptomatic patients, including five with dystonia. A striking feature was the peripheral location of high signal putaminal lesions on T2-weighted images. In five cases, lesions in the corpus striatum or substantia nigra explained the patient's Parkinsonian features. MRI is an efficient method for studying involvement of the central nervous system in Wilson's disease, and allows some interesting anatomoclinical correlations.

Herniation of the lumbar disk in adolescents.

The authors review eight cases of lumbar intervertebral disk herniation in adolescents aged less than 16 years, with a minimum follow-up treatment of 2 years during an 18-year period. All patients presented lower back and sciatic pain, antalgic scoliosis, and a positive Lasègue sign. Nerve compression signs were present in 25+ of the cases. Seventy-five percent of the cases underwent myelography and 25% underwent computerized axial tomography. Results were good in all cases.

[Magnetic resonance of spinal osteoid osteoma]. / Ressonância magnética do osteoma osteóide vertebral.

The authors report one case of spinal osteoid osteoma localized in the thoracic spine that was imaged through M. R. I. They report the M. R. I. aspects of the tumor. Precise localization is necessary for the correct surgical approach.