Madan V. Kulkarni

Acute spinal cord injury : a study using physical examination and magnetic resonance imaging

Magnetic resonance imaging (MRI) was performed on 37 patients with acute spinal injury using T1− and T2-weighted images. Three different types of MRI signal patterns were detected in association with these spinal cord injuries. A classification was developed using these three patterns. Type I, seen in ten (27.0%) of the patients, demonstrated a decreased signal intensity consistent with acute intraspinal hemorrhage. Type II, seen in 16 (43.2%) of the patients, demonstrated a bright signal intensity consistent with acute cord edema. Type III, seen in three (8.1%) of the patients, demonstrated a mixed signal of hypointensity centrally and hyperintensity peripherally consistent with contusion. The remaining eight patients had normal cords by MRI. All 37 patients had an admitting neurologic assessment and classification of their spinal injury according to the Frankel classification and the Trauma Motor Index (TMI). At an average of 12.1 months postinjury, their neurologic function was reassessed. Patients with Type I patterns showed no improvement in their Frankel classification and minimal improvement in their TMI, 32.1 to 42.4. In comparison, all of the Type II and III patterns improved at least one Frankel classification. The Type II TMI increased from 70.8 to 91.9 and Type III from 37.3 to 75.7. This preliminary report indicates a distinct correlation between the pattern of spinal cord injury as identified by MRI and neurologic recovery. It appears that the ability of MRI to aid in examination of the condition of the spinal cord will offer a means of predicting neurologic recovery following acute spinal cord injury.

MR Imaging of Transverse/Sigmoid Dural Sinus and Jugular Vein Thrombosis

Magnetic resonance (MR) imaging was performed on six patients with thrombosis involving the transverse/sigmoid sinus and jugular bulb/vein. Venographic confirmation was obtained in five cases. Thrombi were characterized by increased intraluminal signal on all planes of section and pulse sequences. The change in signal intensity from first to second echo for thrombi was qualitatively less than that found with slow flow. Partial thrombosis in one case was seen as a ring pattern of central intermediate intensity corresponding to the thrombus, surrounded by a peripheral ring of signal void related to flowing blood. The MR findings closely correlated with venography in predicting thrombosis. Evidence of thrombi was not available from CT. Magnetic resonance is well suited for the diagnosis of occlusive disease of the dural venous sinus and jugular bulb.

Giant fibrovascular polyp of the esophagus.

Fibrovascular polyp (FVP) of the esophagus is a benign intraluminal tumor that consists primarily of loose connective tissue with numerous vessels and can attain vast dimensions. Symptoms are commonly dysphagia, vomiting, and weight loss. Small polyps can be removed endoscopically, but larger masses should be excised surgically because of the potential for hemorrhage. This case report illustrates the characteristic features of this unusual disease.

Evaluation of renal masses by MR imaging.

Magnetic resonance (MR) imaging was performed in 20 subjects, 10 of whom had benign or malignant renal masses, and 10 were normal volunteers. The purpose of the study was to evaluate the ability of MR to provide significant diagnostic information in the management of renal mass lesions. Ten normal patients were included to supply baseline data. Different pulse sequences were used and their contribution to the diagnosis was evaluated. The emphasis has been placed on evaluating MR against the pathological diagnosis rather than other imaging modalities.

Benign pleomorphic adenomas of the salivary glands: surface coil MR imaging versus CT.

High resolution magnetic resonance (MR) imaging of three salivary gland tumors was performed at 1.5 T and compared with CT. Two of the three tumors were well seen on CT. However, one required CT sialography to separate tumor from the remaining parotid parenchyma, and, in the other, soft tissue invasion could not be excluded on the basis of CT. Magnetic resonance imaging demonstrated sharp tumor margins with no evidence of invasion. All three tumors were pathologically proven benign pleomorphic adenomas confirming the MR findings. On T2 weighted images, the two large adenomas demonstrated inhomogeneity that was not observed on CT.

Craniocervical manifestations of neurofibromatosis: MR versus CT studies.

Craniocervical manifestations of neurofibromatosis on magnetic resonance (MR) imaging are described in three patients and compared with those on CT. Using MR, intracranial gliomas, schwannomas, and neurofibromas were detected as well as with CT. In addition, a brain stem lesion that was not visualized on CT and a cervical cord lesion that was not suspected clinically were diagnosed with MR. Taking into account the noninvasive nature of MR, we believe that this technique should be the primary imaging modality for screening and follow-up studies in patients with known or suspected neurofibromatosis.

Magnetic resonance imaging of the breast: Functional T1 and three-dimensional imaging

Thirty-two patients with breast abnormalities and 10 normal volunteers were examined with magnetic resonance imaging (MRI) utilizing a 0.5-Tesla superconducting magnet imaging system. Sagittal, coronal, and transverse breast imaging with the 50-cm body coil and with a specialized 16×8 cm breast coil allowed the evaluation of a single breast. Soft-tissue contrast was clearly apparent using proton density-weighted. T1 weighted, calculated T1 images. In addition, the feasibility and potential clinical utility of three-dimensional color imaging was evaluated using computer-based interactive algorithms for edge detection of the breast and for abnormal structures within the breast. MR scan data were correlated with conventional xeromammography, ultrasound, clinical, data, and pathological specimens. In vivo and in vitro breast imaging was evaluated in a feasibility study. It was concluded that MR imaging is a most sensitive modality for the identification of breast lesions, especially when the adjacent normal tissue is primarily fat. There does appear to be significant overlap in soft-tissue contrast when the adjacent breast parenchymal tissue is fibrocystic in nature. The T1 parameter may be a relatively specific measure for identifying a malignant breast mass.

Maxillary sinus hemangioma: MR and CT studies.

A maxillary sinus hemangioma was detected as an incidental finding during magnetic resonance imaging of the head. The CT findings are more characteristic for the diagnosis of this lesion. Preoperative diagnosis of maxillary sinus hemangioma is important since these lesions can frequently cause a large amount of hemorrhage during surgery.

Diagnosis of spinal arteriovenous malformation in a pregnant patient by MR imaging.

An intraspinal arteriovenous malformation (AVM) was diagnosed by magnetic resonance imaging in a pregnant patient. Serpentine areas of low signal intensity surrounded by cerebrospinal fluid were considered diagnostic of this surgically verified abnormality. In addition, T2 weighted images helped to determine the extent of the spinal canal occupied by the AVM.

Magnetic Resonance Imaging in Pediatrics

Magnetic resonance imaging has potentially broad applications in pediatric practice. Although further studies are needed to determine its exact role in comparison with the other imaging modalities, magnetic resonance has shown increased sensitivity in lesion detection in many disease processes. Since MR does not use ionizing radiation and does not require intravenous contrast to identify vascular structures, it becomes an ever more attractive imaging tool for pediatric diagnosis. Thus, the early results of MR imaging have shown promise and the future of MR appears exciting.