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Biomedical subjects

R D Zimmerman

Publications and source records attributed to R D Zimmerman.

17 recordsLinked to original sources
PubMed1992

CT of 338 active professional boxers.

Computed tomography (CT) was performed in 338 active professional boxers. CT scans were abnormal in 25 boxers (7%). The most common CT abnormality was brain atrophy (22 cases). Focal lesions of low attenuation consistent with posttraumatic encephalomalacia were noted in only three boxers. Boxers with abnormal CT scans did not differ from those with borderline or normal CT scans in regard to age, win-loss record, number of bouts, or history of an abnormal electroencephalogram. Thirty-seven boxers with borderline CT scans (49%) and 17 with abnormal CT scans (68%) reported a previous technical knockout (TKO) or knockout (KO), compared with only 89 (37%) of the 238 boxers with normal CT scans (P < .01). Brain atrophy was noted more frequently in boxers with a large cavum septum pellucidum (CSP) than in those with a small or no CSP (P < .05). Boxers with abnormal or borderline CT scans who experienced a TKO or KO were slightly older than those with normal CT scans and a history of a TKO or KO (P < .05).

Adolescent↗
PubMed1992

Detection of residual or recurrent meningioma after surgery: value of enhanced vs unenhanced MR imaging.

The enhanced and unenhanced MR examinations obtained after surgery for meningioma in 38 patients were reviewed to determine the value of enhanced vs unenhanced MR imaging for the detection of residual or recurrent tumor. Enhanced images improved delineation of the extent of tumor in seven of 13 cases in which meningioma was identified on unenhanced images and allowed more definitive detection or exclusion of residual or recurrent meningioma in 18 of 21 cases with equivocal findings on unenhanced images. In addition, enhanced images were helpful for detecting small recurrences, identifying en plaque growth, and showing subtle progression on serial studies. Enhanced MR imaging also allowed detection of two morphologic patterns of dural enhancement adjacent to the surgical bed: (1) thin and smooth, which was seen in patients both with and without residual or recurrent tumor, and (2) thick and nodular, which was seen only in patients with findings indicative of, or at least suggestive of, residual or recurrent meningioma. Unenhanced images failed to detect, or poorly detected, these dural abnormalities. Unenhanced sequences were necessary for accurate interpretation of the enhanced images (e.g., identification or exclusion of hemorrhage). The combination of unenhanced and enhanced MR imaging is recommended for the detection of residual or recurrent meningioma after surgery.

Adult↗
PubMed1990

Intradural spinal arachnoid cyst. Case report.

An intradural spinal arachnoid cyst presenting with spinal cord compression is discussed. This case illustrates the value of magnetic resonance imaging in the diagnosis and follow-up of intradural spinal arachnoid cysts.

Adult↗
PubMed1979

Cysticercosis presenting as a mass lesion at foramen of Monro.

Cysticercosis is a parasitic infestation that commonly affects the central nervous system. This is a report of computed tomography findings in a patient with a noncalcified cyst causing asymmetric lateral ventricular obstruction at the foramen of Monro. The lesion was isodense and uniformly enhancing, an unusual finding possibly related to presentation early in the course of the disease. This disease should be considered in the differential diagnosis of the lesions at the foramen of Monro in patients with appropriate residence or travel history.

Adult↗
PubMed1979

Computed tomography in Herpes simplex encephalitis.

Eight patients with Herpes simplex encephalitis had computed cranial tomography (CT). In every case, areas of decreased attenuation were found in the temporal lobe(s); these areas extended to the insular cortex and often to the frontal or parietal lobes. This change developed between the third and the eleventh day of illness. It was present, sometimes only in retrospect, in patients who were alert as well as patients who were comatose. Compared to the isotopic brain scan, electroencephalogram, and cerebral angiogram, CT demonstrates changes that are indicative of H simplex early enough in the course of the illness to be therapeutically useful.

Adult↗
PubMed1979

Cranial CT findings in patients with meningomyelocele.

The association between meningomyelocele and various cranial abnormalities, particularly Chiari II malformation is well established. Cranial CT scans in 47 patients with meningomyelocele proved to be a safe and effective method of elucidating the type and extent of anatomic abnormalities associated with this disorder, and evaluating and following the degree of hydrocephalus seen in these patients. Of the 47 patients, 43 (92%) showed CT findings indicative of an abnormally low fourth ventricle, the hallmark finding in Chiari II malformation. In 67% the fourth ventricle was not visualized, and in 25% it was directly visualized in an abnormally caudal position. Other findings included hydrocephalus (85%), a striking and possibly unique heart-shaped psuedomass in the posterior fossa (58%), and abnormal configuration of the lateral ventricles ("vampire bat" configuration). Calvarial abnormalities, in particular lacunar skull, were also noted at CT.

Abnormalities, Multiple↗
PubMed1979

Reye syndrome: computed tomographic documentation of disordered intracerebral structure.

Four patients with well documented Reye syndrome were examined with noncontrast computed tomography. Acute findings are those of diffuse cerebral edema with low density in deep white matter, increased gray-white matter differentiation, and evidence of secondary ventricular compression. The diffuse nature of the changes is unlike the more focal pattern often seen in true viral encephalitis. Residual changes after severe diseases are those of nonspecific cerebral degeneration and are most pronounced in the frontal lobes. Atrophic ventricular dilatation was observed in two cases. Computed tomography findings correlate with all known pathologic studies and with the subsequent clinical courses in the patients examined.

Brain↗
PubMed1977

Ring blush associated with intracerebral hematoma.

Seven cases of ring blush following spontaneous and post-traumatic, subacute and chronic intracerebral hematoma are presented. As such a hematoma ages, a ring blush may be seen following contrast-agent enhancement. Serial CT demonstrates disappearance of the ring blush from two to six months after the first scan. The CT appearance of the ring blush is not specific for hematoma, but its peripheral location and lack of mass effect may be considered suggestive of hematoma with appropriate clinical findings. The characteristic serial changes permit correct diagnosis without surgical intervention in most cases.

Adolescent↗
PubMed1977

The tentorium in axial section. I. Normal CT appearance and non-neoplastic pathology.

Bands of increased density representing the free edges and lateral margins of the tentorium were routinely identified on 100 sequential, normal, contrast-enhanced axial CT scans of good quality. Because the tentorium has a complex shape, the exact configuration of these bands varies with the level and the angle of the CT section. Comparison of CT scans with anatomic specimens permits an understanding of these varying configurations, and provides a means to estimate the position of the tentorium on non-contrast CT studies. The CT manifestations of diverse non-neoplastic diseases including subarachnoid hemorrhage, arteriovenous malformation, venous sinus thrombosis and Dandy-Walker malformation may be understood, in part, in terms of the configuration and density of these tentorial bands.

Cerebellar Diseases↗
PubMed1977

The tentorium in axial section. II. Lesion localization.

Most juxtatentorial lesions may be localized accurately on contrast-enhanced axial section CT scans by use of the opacified tentorial bands. Lesions that lie lateral edge of the diverging bands are supratentorial. Lesions that lie medial to the V-shaped tentorial bands are infratentorial and/or incisural. Flattening of the tentorial border of a lesion helps to identify its location. Use of the tentorial bands identifies transincisural extension of meningioma reliably, but does distinguish well between true transtentorial growth of meningioma and marked upward bulging of the tentorium from purely infratentorial meningioma.

Brain Neoplasms↗
PubMed1977

Scleral thickening: a CT sign of orbital pseudotumor.

Orbital pseudotumor is a benign inflammatory lesion of the orbit. Computed tomography is a new method for evaluation of orbits. Scleral uveal rim thickening with contrast enhancement was found in eight of 15 patients with pseudotumor (53%). Similar rim thickening was seen in one postoperative patient and two cases of recent trauma. Therefore, the sign presumably represents inflammation. It was not seen in 47 cases of thyroid disease and 66 cases of neoplasm.

Bone Diseases↗
PubMedDate not supplied

MR imaging of acute intracranial hemorrhage: findings on sequential spin-echo and gradient-echo images in a dog model.

Seven intraparenchymal hematomas (four venous and three arterial) were placed in the brains of six dogs in order to study the MR appearance of acute hemorrhage and to evaluate the effects of several variables on the signal intensity of the hematoma. MR imaging at 0.6 and 1.5 T was performed by using standard short and long TR spin-echo and low-flip-angle gradient-echo sequences. Sequential examinations were performed during the first week following hematoma creation. MR findings were compared with CT and postmortem examinations. Three patterns of signal intensity were observed, which varied according to the size (small vs large) and location (parenchymal vs intraventricular) of the hematomas. The small parenchymal hematomas did not undergo evolutionary changes. On short TR scans they were isointense at both field strengths, and therefore not detectable; on long TR scans these hematomas were of variable intensity at 1.5 T and were hyperintense at 0.6 T. On gradient-echo scans, they were hypointense at all times at both field strengths. The large parenchymal hematomas underwent evolutionary changes typical of those seen in clinical imaging. On short TR scans they were initially isointense and became hyperintense 1-3 days later. Long TR scans demonstrated initial hyperintensity, followed by the development of hypointensity within 12 hr in the venous hematomas and within 60 hr in the arterial hematoma. The intensity changes on long TR scans were seen at both 0.6 and 1.5 T, but occurred sooner and to a greater degree at 1.5 T. Gradient-echo imaging of these large lesions demonstrated hypointensity at all times at both field strengths. The intraventricular hemorrhages demonstrated more rapid development of hyperintensity on short TR scans and slower and less pronounced development of hypointensity on long TR scans compared with the parenchymal clots in the same animal. Gradient-echo imaging of the intraventricular hemorrhages demonstrated hypointensity at all times at both field strengths. A multifactorial hypothesis is proposed to explain the differences in intensity between venous, arterial, and intraventricular blood. Gradient-echo sequences should prove to be highly useful in detecting and delineating hemorrhages and are recommended for the MR protocol of patients with acute neurologic ictus and suspected hemorrhage.

Acute Disease↗
PubMedDate not supplied

Detection of acute intracerebral hemorrhage on MR imaging: ineffectiveness of prolonged interecho interval pulse sequences.

MR imaging at 0.6 T was performed in 22 patients with acute (less than 7 days) intracranial hemorrhage to determine the efficacy of prolongation of the interecho interval, which has been demonstrated to enhance T2 shortening in vitro, as a method to improve the detection of hemorrhage in clinical imaging. The protocol included 750/33 (TR/TE), 2150/60,120 (short interecho interval of 60 msec), and 2150/120 (long interecho interval of 120 msec) sequences. Visual comparisons of the 2150/120 images obtained with the short and long interecho intervals demonstrated no difference in the degree of hypointensity in 21 of 22 cases. Quantitative comparisons demonstrated no statistically significant difference in the degree of maximal hypointensity, in the ease of detectability of hypointensity, or in the overall image contrast in 16 of 22 cases. We conclude that prolongation of the interecho interval is not a clinically useful technique to improve the detection of acute hemorrhage.

Acute Disease↗
PubMedDate not supplied

Computed tomography and magnetic resonance imaging comparisons in boxers.

The efficacy of computed tomography (CT) and magnetic resonance imaging (MRI) in identifying traumatic injuries of the brain was compared in a referred population of 21 amateur and professional boxers. Three boxers displayed CT scans with equivocal findings that were verified as artifacts by MRI. Eleven boxers had both CT and MRI scans with normal findings, and 7 boxers had both CT and MRI scans with abnormal findings. There were no instances where abnormalities demonstrated on CT scanning were not detected by MRI. However, some abnormalities detected on MRI were not detected on CT scans. These included a subdural hematoma, white-matter changes, and a focal contusion. Magnetic resonance imaging appears to be the neuroradiodiagnostic test of choice compared with CT.

Adult↗
PubMedDate not supplied

Differentiation between meningeal fibrosis and chronic subdural hematoma after ventricular shunting: value of enhanced CT and MR scans.

Unenhanced CT in four patients with long-standing ventricular shunts demonstrated bilateral low-density extraaxial collections that were indistinguishable from chronic subdural hematomas. After administration of contrast material, however, there was marked enhancement of the collections as well as prominent paratentorial and parafalcial enhancement. MR imaging, performed in three patients, demonstrated the extent and paradural location of the collections better than CT did, but, as with unenhanced CT, the collections could not be distinguished from chronic subdural hematomas. On follow-up CT and MR, there was no change in the size, enhancement, or intensity of the collections. Histologic examination of biopsies from two patients demonstrated fibrosis of the meninges characterized by granulation tissue and collagen deposition. Meningeal fibrosis is a rare postshunt phenomenon that may mimic chronic subdural hematoma on unenhanced CT and MR. Recognition of this entity is important, particularly if therapeutic intervention is being considered. Therefore, an enhanced CT or enhanced MR scan should be obtained in chronically shunted patients to differentiate between a drainable chronic subdural hematoma and meningeal fibrosis.

Adult↗
PubMedDate not supplied

Large Virchow-Robin spaces: MR-clinical correlation.

High-field MR scans frequently show Virchow-Robin spaces, which conform to the path of the penetrating arteries as they enter either the basal ganglia or the cortical gray matter over the high convexities. A retrospective review of 816 MR scans was undertaken to determine the clinical significance and associations (if any) of this finding. The Virchow-Robin spaces were graded, as were the nonspecific white-matter lesions. The presence of atrophy, infarction, hydrocephalus, and miscellaneous disease was noted. Large Virchow-Robin spaces were identified in 314 cases. A study sample was created consisting of a positive group containing all the larger grade 2 and 3 Virchow-Robin spaces (67 patients) and a negative or control group of 109 randomly selected patients from the original 502 who did not have large Virchow-Robin spaces. The charts of this study sample were reviewed and the following patient variables were noted: age, gender, incidental white-matter lesions, infarction, dementia, hypertension, and atrophy. For each variable, the proportion of patients who were positive for that variable was calculated for each of the two groups and compared across groups by using a Fisher exact test. Multiple logistic regression analysis was used to determine whether any of these variables were jointly associated with being "positive" or "negative" for large Virchow-Robin spaces. Some variables were strongly associated with being positive for large Virchow-Robin spaces: age, hypertension, dementia, and incidental white-matter lesions. Logistic regression analysis revealed that when all of these variables are considered jointly, only age remains significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗