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Biomedical subjects

B H Braffman

Publications and source records attributed to B H Braffman.

15 recordsLinked to original sources

Imaging anatomy of the normal orbit.

Sectional imaging by CT and MRI now displays the gross anatomy of the orbit in vivo. Gross anatomy, axial and coronal CT, and MRI will be used to review the anatomic features of the orbit critical to image interpretation. Familiarity with the positions, relationships, and normal appearance of the major structures described and illustrated in this article will provide a solid basis for interpreting images of orbital pathology, as discussed in subsequent articles.

Humans↗

Emergency department screening for ectopic pregnancy: a prospective US study.

PURPOSE: To determine the effectiveness of pelvic sonography as a screening test for ectopic pregnancy. MATERIALS AND METHODS: Pelvic sonograms were prospectively analyzed in 1,427 consecutive patients with a serum level of the beta subunit of human chorionic gonadotropin of over 1,500 IU/L. RESULTS: Sonograms were diagnostic in 1,158 patients and indeterminate in 269. When indeterminate studies were considered falsely negative, the diagnostic accuracy was 81%. Twenty-four percent of patients with indeterminate studies were subsequently proved to have ectopic pregnancy. In ectopic pregnancy (n = 103), the most common finding was a complex adnexal mass (specificity = 92% [P < .001]). The sensitivity and specificity of screening sonography for ectopic pregnancy were 99% and 84%, respectively. CONCLUSION: Pelvic sonography is an effective screening test for ectopic pregnancy. Having a one in four chance of harboring an ectopic pregnancy, patients with indeterminate studies require close follow-up. The presence of a complex adnexal mass is a strong predictor of ectopic pregnancy.

Adult↗

MR imaging of tuberous sclerosis: pathogenesis of this phakomatosis, use of gadopentetate dimeglumine, and literature review.

Findings on cranial magnetic resonance (MR) images were correlated with known histopathologic findings in 42 patients with tuberous sclerosis (TS), 17 of whom received gadopentetate dimeglumine, to extend the range of signs on MR images. Four neuroradiologists recorded the number, sites, configurations, and relative signal intensities of intracranial abnormalities. White matter lesions, found in 39 patients (93%), showed four distinct patterns: (a) straight or curvilinear bands extending radially from the ventricle through the cerebral mantle toward the cortex, (b) wedge-shaped lesions, (c) nonspecific conglomerate foci, and (d) cerebellar radial bands. It is concluded that cortical tubers, white matter lesions, subependymal nodules, and sub-ependymal giant cell astrocytomas (SGCAs) may be enhanced after administration of gadopenetetate dimeglumine. Enhancement of a TS lesion does not indicate neoplastic transformation into SGCA. Imaging surveillance every 12 months appears indicated during the peak ages (8-18 years) of occurrence of SGCA. The appearance of white matter lesions supports the theory that the cerebral lesions of TS may be caused by disordered migration of dysgenetic cells.

Adolescent↗

Magnetic resonance imaging in Parkinson's disease and parkinsonian syndromes.

High field strength magnetic resonance imaging (MRI) provides a noninvasive means of evaluating patients with parkinsonism. Using strict clinical criteria, we began a prospective study of patients with Parkinson's disease (PD) and parkinsonian syndromes (PS) including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and atypical parkinsonism (ATYP). We detected moderate to severe putaminal hypointensity more frequently in PS than in PD and controls, although putaminal hypointensity did not distinguish between MSA, PSP, or ATYP. Signal intensity in the lateral substantia nigra did not differ significantly among patients with PD, PS, or controls and was therefore not a useful MRI marker. Pars compacta width was significantly narrower in both PD and PS. Subcortical and periventricular hyperintense foci were more abundant in PD and PS than controls. Atrophy of the brainstem occurred only in patients with PS.

Aging↗

MR imaging of Parkinson disease with spin-echo and gradient-echo sequences.

High-field MR with both spin-echo and gradient-echo sequences was performed in 21 patients with (idiopathic, drug-responsive) Parkinson disease. The use of gradient echoes allowed more sensitive detection than did spin echoes of susceptibility changes in the putamina and substantia nigra. No statistically significant difference in putaminal hypointensity on long TR/long TE spin-echo sequences or on T2*-weighted images using gradient-echo sequences was observed between Parkinson patients and controls. There was also no statistically significant difference in the frequency of restoration of the signal intensity of the substantia nigra between the two groups of patients. The width of the pars compacta of the substantia nigra in patients with Parkinson disease was 2.12 + 0.82 mm (mean +/- SD). This value in age- and gender-matched controls was 2.67 +/- 0.5. Comparing these two groups with an unpaired t test resulted in a p value less than or equal to .005. Our MR study with spin-echo and gradient-echo images in Parkinson and control patients was able to substantiate and elaborate on previously described MR features of Parkinson disease.

Adult↗

Multiple sclerosis: serial study of gadolinium-enhanced MR imaging.

Thirteen patients with definite multiple sclerosis (MS), studied 16-24 months previously with magnetic resonance (MR) imaging with and without enhancement by intravenously administered gadolinium diethylenetriaminepentaacetic acid (DTPA) dimeglumine, were reexamined with a similar protocol. Assessment of enhancement and clinical activity in both studies revealed that enhancement was observed in 13 of 14 cases in which clinical activity had changed within 4 weeks of the study and thus appeared more sensitive than clinical examination in determining active disease. The 3-minute postinjection, short repetition time image (TR) was the most efficient for depicting enhancement. Enhancing lesions (active plaques) arose from previously hyper- or isointense regions on long TR images. Previously active lesions reverted to areas of iso- or hyperintensity on long TR images. Serial comparison of long TR images in this population reveals a decrease in high-intensity lesions on long TR images in some cases and an increase in others. The findings of high-intensity regions on long TR images and previously enhancing lesions both becoming isointense suggests that transient inflammatory changes with concomitant edema without demyelination and/or with significant remyelination may occur in some MS lesions. MS lesions are dynamic; both active and inactive lesions may show dramatic change on longitudinal MR imaging studies.

Adult↗

Brain MR: pathologic correlation with gross and histopathology. 1. Lacunar infarction and Virchow-Robin spaces.

MR imaging was performed on 36 formalin-fixed brain specimens. For three of these specimens, in vivo MR studies had also been performed before death. Changes that take place in the MR appearance of the brain after fixation are discussed. Gross and microscopic pathology revealed 14 lacunar infarctions in seven cases and enlarged Virchow-Robin spaces (état criblé) in four. Both types of lesion were seen in specimens from predominantly elderly, hypertensive patients. Eight lacunae were in the deep gray-matter nuclei (four in the putamen with variable involvement of the internal capsule and caudate nuclei, two in the thalami, and two in the dentate nuclei), five were in the supratentorial white matter, and one was in the brainstem. Enlarged Virchow-Robin spaces were identified in the basal ganglia. All lesions were detected on MR. CT failed to disclose the brainstem and dentate lacunae and the enlarged Virchow-Robin spaces. On MR, all lacunae were slitlike or ovoid, except one that was round. They were less than 1 cm in greatest diameter in all but two cases. The lacunae were hyperintense relative to brain parenchyma on both long TR sequences (short and long TEs) in all cases except that of a chronic infarct that underwent cystic change and was isointense relative to CSF on all pulse sequences. In contrast, dilated Virchow-Robin spaces were isointense relative to CSF in vivo or to fluid in the subarachnoid space in the postmortem state on all pulse sequences in all four cases. They were round or linear, and in general were smaller than the lacunae, although some overlap in size did occur. They were seen at the level immediately above the bifurcation of the internal carotid into the middle and anterior cerebral arteries and were seen on successive axial sections in the putamen (most prominent along its lateral margin) and in the internal capsule. MR studies of gross and microscopic pathology of lacunae and dilated Virchow-Robin spaces are useful in correlating MR and pathologic findings. However, changes resulting from the fixation process must be considered when postmortem and in vivo MR findings are correlated.

Adult↗

Brain MR: pathologic correlation with gross and histopathology. 2. Hyperintense white-matter foci in the elderly.

MR was performed on 23 formalin-fixed brain specimens of patients 60 years old or older at the time of death. In two of these subjects MR had also been performed in vivo prior to death. Fifteen hyperintense white-matter foci were found on long TR MR images in seven brains. These lesions were correlated with gross and microscopic pathology. Six lesions were infarctions, two were small foci of gliosis or noncavitated infarcts, two were plaques of demyelination, one was a minute brain cyst, and one was a congenital diverticulum of the lateral ventricle; in three foci the abnormality was not found. We identified no MR criteria to distinguish noncystic infarction from either gliosis or demyelination. However, MR was able to distinguish all these lesions from fluid-containing spaces-including cystic infarction, brain cyst, and ventricular diverticulum-since the lesions in the latter group may be isointense relative to CSF in vivo or to fluid in the subarachnoid space in the postmortem fixed state on all pulse sequences. The relationship of a ventricular diverticulum and a brain cyst to the ventricle or subarachnoid space serves as an additional differentiating feature on MR. In cases in which CT was also performed, it revealed corresponding hypodensities in two infarctions, but failed to reveal the foci of gliosis (or noncavital infarction), demyelination, or brain cyst. These data suggest that subtle changes of gliosis and demyelination, presumably from chronic vascular insufficiency, and/or frank infarction account for the majority of hyperintense white-matter lesions seen in MR in elderly patients. Distinguishing among the various lesions is difficult, but subtle differences are present when MR is correlated with histopathology.

Aged↗

Intracranial visual pathway gliomas in children with neurofibromatosis.

The association between neurofibromatosis and visual pathway gliomas is well documented. The introduction of computed tomography and magnetic resonance imaging has heralded a new era in the understanding of visual pathway gliomas. Both of these noninvasive neuroinvestigative techniques have demonstrated extensive abnormalities throughout the visual pathway in children with visual pathway gliomas, especially in those with neurofibromatosis. The clinical significance of these abnormal areas of brain, especially in asymptomatic patients, is unknown. In an attempt to clarify the incidence, natural history, and clinical course of patients with neurofibromatosis and visual pathway lesions, we reviewed our experience with 24 patients managed consecutively at Children's Hospital of Philadelphia over the past 12 years. The patients in this series were compared to 29 children with visual pathway gliomas without neurofibromatosis who were evaluated at our institution over the same period of time. Visual pathway gliomas in children with neurofibromatosis differ from those in children without neurofibromatosis. In general, lesions tended to be more extensive in patients with neurofibromatosis and the clinical course of these patients is more variable. Twelve of the 24 patients with neurofibromatosis in our series had symptoms of progressive disease at the time of diagnosis and underwent treatment with variable results. Twelve children with neurofibromatosis and visual pathway lesions had static lesions at the time of diagnosis and, to date, 3 have developed progressive disease. From our review we can make some recommendations concerning the management of children with neurofibromatosis and visual pathway gliomas, but many questions remain unanswered. Sequential follow-up of a large cohort of both asymptomatic and symptomatic children with neurofibromatosis and visual pathway lesions is needed to more definitively outline the best management approach for these patients.

Adolescent↗

MR imaging of a carcinoid tumor metastatic to the orbit.

This is a report of the magnetic resonance study in a case of orbital metastasis from a carcinoid tumor. A rather unusual feature of this lesion was its relatively short T2 as compared with other metastatic orbital lesions.

Aged↗

Human malignant melanomas with varying degrees of melanin content in nude mice: MR imaging, histopathology, and electron paramagnetic resonance.

The etiology of the paramagnetic relaxation enhancement seen in malignant melanoma on proton magnetic resonance (MR) images has been the subject of many recent investigations and has been ascribed to iron from associated hemorrhage or chelated metal ions, rather than directly due to melanin. The purpose of this study was to correlate proton relaxation times on MR images in malignant melanomas with histopathologic features (i.e., degree of pigmentation, iron deposition, and necrosis), water content, and electron paramagnetic resonance (EPR) spectra to elucidate the etiology of the relaxation behavior demonstrated by these neoplasms. Cultured cells derived from human malignant melanoma metastases were implanted subcutaneously into nude mice. Twelve separate lesions were evaluated in 10 mice. Magnetic resonance imaging was performed in vivo at 1.9 T using spin echo and inversion recovery acquisitions for the purposes of calculating T1, T2, and proton density [N(H)]. Histopathologic examination was performed on specimens resected immediately after imaging, using hematoxylin/eosin, Prussian blue, and Fontana stains to assess tumor necrosis, and iron and melanin content. Dry/wet weight ratios and EPR spectra were also obtained on resected specimens. Our results indicate that T1 shortening correlates with increasing melanin content and not with increasing iron deposition, EPR-active metallic cations, necrosis, or water content. In fact, a presumably unrelated statistical correlation was found between increased iron and T1 prolongation. The T2 relaxation times did not correlate with the presence of any single factor other than proton density. Although the unique relaxation behavior of nonhemorrhagic malignant melanoma in vivo cannot be traced to a single cause, our data suggest that, contrary to previous investigations, it is strongly influenced by the presence of melanin rather than iron or other naturally occurring paramagnetic ions.

Animals↗