Biomedical subjects
Publications and source records attributed to J A Bello.
Computed tomography has become a prime method of examination after trauma. We report a case of traumatic leukoencephalopathy detected with high-field strength, heavily T2-weighted magnetic resonance imaging in a patient with minimal computed tomography findings.
Eleven obese young women with idiopathic pseudotumor cerebri were studied with high-field-strength (1.5 T) MR imaging to demonstrate increased water content in the brains of such patients. Heavily T2-weighted studies were obtained for 10 patients, and balanced (long TRs, short TEs, spin density, proton density) pulse sequences were obtained for four patients. We examined the studies of morphologically normal periventricular white matter and developed a white matter water index to determine if a slight increase in signal was present that could be ascribed to low levels of edema. Comparison was made to an age-matched control group. We also examined five patients with sodium MR imaging. Two of the 11 patients had focal areas of increased signal in their periventricular white matter. Presumably, these are areas of increased edema above the background that could not be detected on the CT scan. The white matter water index for the normal controls was an average of 0.479 (+/- 0.015), while that of the pseudotumor cerebri group was 0.520 (+/- 0.016). This indicates an increase in the white matter water signal. We believe this represents a diffuse low level of edema. These findings are consistent with previous estimates of the increase in brain water in patients with idiopathic pseudotumor cerebri. The patients with focally abnormal proton studies demonstrated similar abnormalities on their sodium studies.
A consecutive series of 14 patients with trigeminal schwannoma managed surgically at the Neurological Institute of New York since 1970 is reported. Nine women and five men (mean age 40 years) were diagnosed following a mean symptom duration of 33 months. Abnormalities of trigeminal nerve function were present in 11 patients on admission examination. Facial pain was a prominent feature in eight patients. Two patients, both with schwannomas arising from the trigeminal root, presented initially with typical trigeminal neuralgia. Additional cranial nerve palsies or cerebellar or pyramidal tract signs were noted in eight patients. The surgical approach to these tumors depends on their anatomical location. Four patients had tumors confined to the middle fossa, three patients had tumors limited to the posterior fossa, and seven patients had both supratentorial and infratentorial components of their tumors. Twenty operative procedures were performed on these patients, resulting in complete extirpation in six patients, nearly complete removal in seven patients, and partial removal in one patient. Adherence of the tumor to the lateral wall of the cavernous sinus or the brain stem precluded total removal. There was one postoperative death. In the immediate postoperative period, abnormalities of cranial nerves controlling the extraocular muscles were common. In general, these deficits were transient; however, some permanent loss of trigeminal nerve function occurred in nine patients. Two patients required tarsorrhaphy for neurotropic keratitis, and two patients underwent cerebrospinal fluid (CSF) shunting procedures for hydrocephalus or for a persistent CSF leak. The follow-up period ranged from 4 to 177 months (mean 47 months). The clinical features, anatomical considerations, and surgical approach to these rare tumors are discussed. A clinical review of 106 additional cases of trigeminal schwannoma, reported in the English literature since 1935, is also presented.
To distinguish opacification owing to inflammatory conditions (sinusitis) from that caused by nasomaxillary malignancy, computed tomography scans in 24 proved cases of sinusitis or tumor were reviewed for features related to sinus size, wall thickness, and character of bone erosion. An anatomic system was defined for classifying lesions according to the surface and type of bony involvement. In 12 cases of chronic maxillary sinusitis, the involved sinus was usually small and thick walled. The nasal surface of the involved sinus usually was eroded; often the orbital surface was eroded. The erosion was, however, short, irregular, and in the region of a normal dehiscence (semilunar hiatus or infraorbital canal) in all cases. The infratemporal surface was never eroded. In 12 cases of nasomaxillary neoplasia, the sinus was enlarged, one or more walls of the involved sinus being thinned and expanded. Bone erosion was present in all cases; erosion of the infratemporal surface was specific for neoplasia and significant as the usual site of recurrence.
Many parasellar lesions may mimic pituitary adenomas clinically, endocrinologically, and radiologically. Certain patterns do lead suspicion toward the correct diagnosis, whereas in other cases the diagnosis may be difficult. For most of these lesions, the treatment of choice is different from that for a pituitary tumor, so correct diagnosis is of paramount importance. The presenting signs and symptoms as well as radiologic manifestations of parasellar tumors and conditions are discussed.
The recent development of contiguous thin section (2 mm) imaging utilizing a high field (1.5 tesla magnetic resonance imaging) (MR) system has remarkably improved the precision of spinal cord diagnosis. Imaging was performed using three-dimensional data acquisition which generated twelve contiguous T1-weighted sections. Each section is reconstructed from a true 512 X 512 data matrix. Sixty patients with cervical cord lesions were evaluated with this technique and the results compared with conventional cervical myelography and CT scanning. The normal MRI anatomy of the cervical spinal cord on the thin-section technique shows the medullary gray and white matter. A description of this anatomy will be provided. In cases of syringohydromyelia MRA has demonstrated with accuracy the size and location of spinal cord cavities that were not detected by metrizamide CT scanning. Associated Arnold-Chiari malformations can be clearly delineated. Patients with spinal cord tumors were examined with both the T1-weighted thin-section technique and the T2-weighted multislice technique. Spinal cord cavities and cysts associated with tumors did not as a rule fill with metrizamide. High-field, thin-section studies outlined each of these lesions. The differentiation between intradural and extradural masses can be difficult on MRI and presents one of the limitations of this method in its current state as compared with metrizamide CT scanning. A complete discussion of the MRI findings of a number of pathological entities will be discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Multicystic benign lymphoepithelial lesions of the parotid gland (BLL) seen in patients with human immunodeficiency virus (HIV) can produce considerable cosmetic deformity as well as physical discomfort. We previously reported our preliminary results with low-dose radiotherapy in this disease, and all 8 patients were satisfied with the initial improvement in their appearance. We now report the long-term follow-up of those patients and additional patients. METHODS: Twelve HIV-positive patients with BLL were treated with 8-10 Gy of external radiation using 2-Gy daily fractions. Objective responses and subjective duration of patient-defined cosmetic control were recorded. RESULTS: All 12 patients (100%) had at least a 50% decrease in the size of their parotid masses. Five of 12 (42%) had a complete response and 7 (58%) had a partial response. Persisting complete response was achieved in only 1 patient, however, with relapse in the other 11 patients. Cosmetic palliation, as judged by the patients, was achieved for a median of 9.5 months. Eight patients were subsequently retreated with doses of 6-16 Gy (median and mode: 10 Gy). None (0%) of the 8 patients retreated achieved local control. CONCLUSIONS: Very low-dose radiation (8-10 Gy) provides reliable but temporary cosmetic palliation for BLL. Retreatment was unsatisfactory, and we are now investigating higher initial doses of radiation to prolong palliation and eliminate recurrences.
In an elderly woman a small thalamic infarct, documented by computed tomography and nuclear magnetic resonance imaging, caused proprioceptive loss contralaterally without impairment of other sensory modalities. This patient, the first so reported, demonstrates the anatomic separation of spinothalamic and dorsal column/medial lemniscus sensory modalities in the human thalamus.