Children with cerebral venous thrombosis diagnosed with magnetic resonance imaging and magnetic resonance angiography.

From 1985 to 1991, 13 children were diagnosed at the University of Illinois College of Medicine at Peoria, Saint Francis Medical Center, with cerebral venous thrombosis (CVT) by magnetic resonance imaging scan. Ages ranged from newborn to 5 years. Six children were premature neonates, five were term neonates and two were 5 years old. In the premature neonates, thrombosis was usually associated with other problems. All the term neonates had seizures. In all neonates, thrombosis resolved without any specific treatment. In the two older children, one presented with pseudotumor cerebri and one with coma. These children required neurosurgical intervention. Follow-up magnetic resonance imaging scans were obtained in 9 of 13 children and showed thrombus resolution in each case. Three children were studied in the acute and convalescent stages by magnetic resonance angiography using time-of-flight techniques. Each follow-up magnetic resonance angiogram showed improvement in venous flow consistent with their clinical course and other imaging studies. We conclude that 1) CVT in children encompasses a range of clinical conditions which may or may not require neurosurgical intervention; 2) magnetic resonance imaging is superior to other modalities for the diagnosis of CVT; and 3) magnetic resonance angiography is an alternative means to monitor the evolution of CVT and efficacy of therapeutic intervention.     

Missed cervical disc bulges diagnosed with kinematic magnetic resonance imaging

Purpose

To determine if adding flexion and extension MRI studies to the traditional neutral views would be beneficial in the diagnosis of cervical disc bulges.

Methods

Five hundred patients underwent MRI in neutral, flexion and extension positions. The images were analyzed using computer software to objectively quantify the amount of disc bulge.

Results

Compared to the neutral position, cervical disc bulges were significantly increased in the extension position (P < 0.05), but on flexion position, there was no significant difference (P > 0.05). For patients without or <3 mm of disc bulge in neutral, 2.97 % demonstrated an increase in bulge to ≥3 mm bulge in flexion, and 16.41 % demonstrated an increase to ≥3 mm bulge in extension. For patients in the neutral view that had a baseline disc bulge of 3?5 mm, 3.73 % had increased bulges to ≥5 mm in flexion and 11.57 % had increased bulges to ≥5 mm in extension.

Conclusion

A significant increase in the degree of cervical disc bulge was found by examining extension views when compared with neutral views alone. Kinematic MRI views provide valuable added information, especially in situations where symptomatic radiculopathy is present without any abnormalities demonstrated on traditional neutral MRI.     

Percutaneous renal tumor cryoablation with magnetic resonance imaging guidance

PURPOSE: Cryoablation of small renal tumors has been performed mainly via the laparoscopic or open approach. This study was done to assess the feasibility and safety of performing percutaneous renal tumor cryoablation using interventional magnetic resonance imaging (MRI) for monitoring. MATERIALS AND METHODS: Patients with radiography documented small renal tumors 4 cm or less in diameter were offered percutaneous renal tumor cryoablation performed in an interventional MRI unit. Patients received general anesthesia or intravenous sedation and were placed into the interventional MRI unit. Under MRI guidance a 2 or 3 mm cryoprobe was advanced into the renal mass and the mass was subjected to 3 freeze-thaw cycles at -80 to 70C. Patients were hospitalized overnight for observation. Followup imaging with MRI or computerized tomography and physical examinations were done at 1 week, and 1, 3, 6 and 12 months. RESULTS: Ten men and 10 women 49 to 76 years old (mean age 58) with a total of 22 tumors have been treated, including 1 with bilateral lesions and another with 2 tumors in 1 kidney. Mean tumor diameter was 3 cm. (range 1.8 to 7.0). Two patients with a mass exceeding study entry criteria (5 and 7 cm, respectively) who were not open surgery candidates were treated on a compassionate basis. Average treatment time was 97 minutes (range 56 to 172). To date 1 patient has had evidence of persistent tumor on followup imaging and required re-treatment. The only complication was a superficial wound abscess. Mean followup was 9.1 months (range 3 to 14) with no radiographic evidence of disease recurrence or new tumor development. CONCLUSIONS: In this small series of patients percutaneous renal tumor cryoablation was technically feasible with minimal morbidity. At limited followup there appears to be no radiological evidence of new tumor development. Percutaneous cryoablation may prove to be an additional treatment option for small renal tumors.     

Mobile schwannoma of the cauda equina diagnosed by magnetic resonance imaging

Three cases of a mobile cauda equina schwannoma, preoperatively diagnosed by magnetic resonance imaging, are described. When dealing with tumors of the cauda equina, it is important to carry out a second magnetic resonance imaging scan after changes in posture, bearing in mind the possibility of mobility of the tumor.     

Mapping intravascular extension of Wilms' tumor with magnetic resonance imaging

Accurate preoperative diagnosis of renal vein, vena caval, or intracardiac extension of Wilms' tumor allows the surgeon to better plan operative vascular control and assess the potential benefits of preoperative chemotherapy. Magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound were used to study four consecutive patients presenting with Wilms' tumor. Three had vena caval involvement, with one of these having a massive right atrial tumor thrombus. A fourth patient had renal vein involvement only. We found MRI to be superior to both CT and ultrasound for mapping intravascular extension of Wilms' tumor and for delineating nonvascular disease. Because of its noninvasiveness, multiplane imaging capabilities, and image contrast and resolution, MRI is a valuable complimentary imaging modality for the diagnosis and follow-up of patients with Wilms' tumor.     

Role of magnetic resonance imaging in managing selected women with newly diagnosed breast cancer

The purpose of this study is evaluation of therapeutic impact of magnetic resonance imaging (MRI) in breast cancer patients that cannot be imaged adequately with traditional radiology: dense breasts, microcalcifications suspicious for carcinoma in situ or discordance between mammography and ultrasound. A review was performed of 493 patients’ records: determination of breast MRI effect on clinical management was made for the selected 70 cases by analysing pre-MRI and post-MRI therapeutic plans. Analysis of final pathology was useful to determine if the change in surgical plan prompted by MRI was appropriate. Breast MRI added clinical information in 52.9% of patients that resulted in 44.3% of management changes that were judged as appropriate in 83.9% of cases. Breast MRI provides additional useful information, but causes more extensive surgery (40%) with no proven prognostic benefit. MRI should be considered optional in the clinical staging of breast cancer and performed in selected cases.     

Isolated nondisplaced capitate waist fracture diagnosed by magnetic resonance imaging.

Isolated capitate fractures are rare and may be underdiagnosed, especially when fracture displacement is minimal or absent. Our case report of a nondisplaced capitate waist fracture exemplifies the need for careful evaluation because initial plain radiographs were considered normal and appropriate treatment was delayed. This report also documents the use of magnetic resonance imaging in diagnosing such fractures.     

Intramedullary spinal schwannoma: case report and review of preoperative magnetic resonance imaging features

Intramedullary schwannomas are rare spinal cord tumours. Correct preoperative diagnosis is essential for proper surgical planning and complete resection. We present a case of cervical intramedullary schwannoma followed by discussion on its preoperative magnetic resonance imaging features and review of the literature.     

Intramedullary lesion expansion on magnetic resonance imaging in patients with motor complete cervical spinal cord injury

Object The authors performed a study to determine if lesion expansion occurs in humans during the early hours after spinal cord injury (SCI), as has been established in rodent models of SCI, and to identify factors that might predict lesion expansion. Methods The authors studied 42 patients with acute cervical SCI and admission American Spinal Injury Association Impairment Scale Grades A (35 patients) and B (7 patients) in whom 2 consecutive MRI scans were obtained 3-134 hours after trauma. They recorded demographic data, clinical information, Injury Severity Score (ISS), admission MRI-documented spinal canal and cord characteristics, and management strategies. Results The characteristics of the cohort were as follows: male/female ratio 37:5; mean age, 34.6 years; and cause of injury, motor vehicle collision, falls, and sport injuries in 40 of 42 cases. The first MRI study was performed 6.8 ±2.7 hours (mean ± SD) after injury, and the second was performed 54.5 ± 32.3 hours after injury. The rostrocaudal intramedullary length of the lesion on the first MRI scan was 59.2 ± 16.1 mm, whereas its length on the second was 88.5 ± 31.9 mm. The principal factors associated with lesion length on the first MRI study were the time between injury and imaging (p = 0.05) and the time to decompression (p = 0.03). The lesion's rate of rostrocaudal intramedullary expansion in the interval between the first and second MRI was 0.9 ± 0.8 mm/hour. The principal factors associated with the rate of expansion were the maximum spinal cord compression (p = 0.03) and the mechanism of injury (p = 0.05). Conclusions Spinal cord injury in humans is characterized by lesion expansion during the hours following trauma. Lesion expansion has a positive relationship with spinal cord compression and may be mitigated by early surgical decompression. Lesion expansion may be a novel surrogate measure by which to assess therapeutic effects in surgical or drug trials.     

Proton magnetic resonance spectroscopic imaging in brain tumor diagnosis

The current state of standard tumor diagnostics using contrast-enhanced MRI and biopsy is assessed in this review, and the progress of proton magnetic resonance spectroscopy (MRS) over the last 15 years is discussed. We summarize MRS basics and describe a typical magnetic resonance session for noninvasive routine tumor diagnostics at 1.5 T, including two-dimensional magnetic resonance spectroscopic imaging (MRSI). The results that can be obtained from such procedures are illustrated with clinical examples. Attention is turned to cutting-edge methodologic and clinical research at 3 T, with examples using high-resolution or very short echo-time three-dimensional MRSI. The current status and limitations in proton MRSI are discussed, and we look to the potential of faster data collection and even higher field strength.     

Anesthesiologic assistance to children undergoing magnetic resonance

The paper describes the anesthesiological technique used during magnetic resonance tomography in young patients. The Authors developed a neurosedative technique, based on the balanced use of thiopentone sodium, DBP and atropine, which was used in a large study involving 247 patients between November 1986 and April 1989. The results were found to be excellent in patients treated under day hospital conditions, and the Authors conclude that this method is the most efficacious of all solution tested in pediatric patients undergoing magnetic resonance tomography.     

Spinal cord herniation associated with an intradural spinal arachnoid cyst diagnosed by magnetic resonance imaging

Two rare cases of spinal cord herniation associated with intradural spinal arachnoid cyst are reported. A preoperative magnetic resonance imaging scan demonstrated the presence of spinal cord herniation, identified as a protrusion continuous with the spinal cord. Surgery upon the intradural spinal arachnoid cyst improved progressive neurological dysfunction. The authors postulate that spinal cord herniation occurred for the following reason: The pressure of the intradural arachnoid cyst on the dorsal aspect of the spinal cord caused thinning of the dura, leading to a tear and, thus, the development of an extradural arachnoid cyst. Along with the enlargement of intradural arachnoid cyst, the spinal cord herniated through the tear in the dura into the extradural arachnoid cyst.