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Biomedical subjects

W T Djang

Publications and source records attributed to W T Djang.

At least 19 recordsLinked to original sources
PubMed1993

Quantitative cerebral anatomy in depression. A controlled magnetic resonance imaging study.

Magnetic resonance imaging was used to examine cerebral anatomy in 48 inpatients with severe depression who were referred for electroconvulsive therapy and in 76 normal control subjects. The magnetic resonance imaging measures included determinations of regional cerebral volumes and ratings of the frequency and severity of cortical atrophy, lateral ventricular enlargement, and subcortical hyperintensity. The mean total frontal lobe volume was found to be 7% smaller in the inpatients with severe depression (235.88 mL) than in the normal control subjects (254.32 mL)--a difference that was statistically significant even after adjusting for the effects of age, sex, education, and intracranial size. No group differences were observed in the volumes of the cerebral hemispheres, the temporal lobes, or the amygdala-hippocampal complex, nor in the frequency of cortical atrophy. Neither did the groups differ with respect to the total volumes of the lateral and third ventricles, nor in the frequency of lateral ventricular enlargement. Patients with depression had a significantly higher frequency of subcortical hyperintensity in the periventricular white matter, with an odds ratio of 5.32.

Adult↗
PubMed1992

Neuropsychological importance of subcortical white matter hyperintensity.

Subcortical hyperintensity on magnetic resonance imaging is a common incidental finding in healthy elderly subjects. The relationship of such changes to cognitive functioning remains unclear, however, because only a small number of studies have examined this issue with conflicting results. We therefore assessed 66 healthy adult volunteers (mean [+/- SD] age, 61.8 +/- 15.8 years) with magnetic resonance imaging scans rated for subcortical hyperintensity, and with two neuropsychological instruments selected a priori on the basis of previous reports in the literature. Findings were highly significant for both the Benton Facial Recognition Test and the Wechsler Adult Intelligence Scale-Revised Digit Symbol. However, in both cases, the majority of variance was accounted for by age and educational level. Effects of subcortical hyperintensity were not significant. We conclude that subcortical hyperintensity in healthy adults does not relate to cognitive functioning, at least with these two instruments.

Aged↗
PubMed1992

Quantitative cerebral anatomy of the aging human brain: a cross-sectional study using magnetic resonance imaging.

Seventy-six healthy adults underwent magnetic resonance imaging (1.5 T) to investigate the effects of age on regional cerebral volumes and on the frequency and severity of cortical atrophy, lateral ventricular enlargement, and subcortical hyperintensity. Increasing age was associated with (1) decreasing volumes of the cerebral hemispheres (0.23% per year), the frontal lobes (0.55% per year), the temporal lobes (0.28% per year), and the amygdala-hippocampal complex (0.30% per year); (2) increasing volumes of the third ventricle (2.8% per year) and the lateral ventricles (3.2% per year); and (3) increasing odds of cortical atrophy (8.9% per year), lateral ventricular enlargement (7.7% per year), and subcortical hyperintensity in the deep white matter (6.3% per year) and the pons (8.1% per year). Many elderly subjects did not exhibit cortical atrophy or lateral ventricular enlargement, however, indicating that such changes are not inevitable consequences of advancing age. These data should provide a useful clinical context within which to interpret changes in regional brain size associated with "abnormal" aging.

Adult↗
PubMed1991

Brain anatomic effects of electroconvulsive therapy. A prospective magnetic resonance imaging study.

To determine prospectively whether electroconvulsive therapy (ECT) produces structural brain changes, 35 inpatients with depression underwent magnetic resonance imaging before and twice after (at 2 to 3 days and at 6 months) completion of a course of brief-pulse, bilateral ECT. The magnetic resonance images were analyzed blindly for evidence of changes in brain structure using two approaches: measurement of regional brain volumes and a pairwise global comparison. Structural brain abnormalities were present in many patients before ECT. The course of ECT produced no acute or delayed (6-month) change in brain structure as measured by alterations of the total volumes of the lateral ventricles, the third ventricle, the frontal lobes, the temporal lobes, or the amygdala-hippocampal complex. In five subjects, the pairwise global comparisons revealed an apparent increase in subcortical hyperintensity, most likely secondary to progression of ongoing cerebrovascular disease during follow-up. Our results confirm and extend previous imaging studies that also found no relationship between ECT and brain damage.

Amygdala↗
PubMed1990

Brain magnetic resonance imaging findings in ECT-induced delirium.

A prolonged (interictal) but reversible delirium was induced by electroconvulsive therapy (ECT) in 10 of 87 (11%) elderly depressed patients. Brain magnetic resonance imaging (MRI) revealed several structural abnormalities, particularly basal ganglia and moderate to severe subcortical white-matter lesions, in the patients who developed delirium. These findings are consistent with several lines of data that have implicated the basal ganglia and subcortical white matter in the development of delirium from other causes and suggest that lesions in these areas may predispose one to developing an interictal delirium during a course of ECT.

Aged↗
PubMed1990

MR imaging in patients with temporal lobe seizures: correlation of results with pathologic findings.

Thirty-nine consecutive patients with medically intractable complex partial seizures were studied with electroencephalography and MR imaging to localize an epileptogenic focus for temporal lobectomy. The patients were divided into three groups on the basis of pathologic findings after lobectomy: Group 1 comprised 13 patients with neoplasms, hamartomas, or cysts; group 2 comprised 13 patients with moderate and severe mesial temporal sclerosis (one patient was included in both groups 1 and 2); and group 3 comprised 14 patients who underwent aspiration lobectomy, which yielded limited tissue for pathologic study so no pathologic diagnosis was made. The majority of the patients in group 3 were assumed to have mesial temporal sclerosis. Abnormal MR signal in the temporal lobe on T2-weighted images was graded as minimal increase (1+), intermediate or moderate increase (2+), and very significant increase (3+). An abnormal signal was demonstrated in 26 (67%) of the 39 patients. In group 1, the tumor/cyst subgroup, an abnormal signal was seen in all 13 patients. Most had 3+ signal. There was increased signal in eight (62%) of 13 patients in group 2 and in six (43%) of 14 patients in group 3. This study suggests that MR can detect almost all tumors and a significant number of mesial temporal sclerosis lesions in individuals with complex partial seizures. On the basis of this small series, individuals who exhibit significant signal (3+) can be expected to have neoplasms, hamartomas, or cysts, and patients who exhibit minimal signal (1+) will usually have mesial temporal sclerosis.

Adult↗
PubMed1989

Significant extracranial carotid stenosis: detection on routine cerebral MR images.

Severe stenosis of the cervical internal carotid artery was detected on magnetic resonance images in three patients from a series of eight with abnormality of flow. In contrast to complete loss of "flow void" in the horizontal carotid within the petrous bone seen in patients with complete occlusion, these three patients had partial flow void in which there was a central area of signal void in the artery, surrounded by circumferential increase in signal in the outer third of the artery. This was seen on axial views at right angles to the long axis of the artery below the petrous bone and on "in-plane" sections through the horizontal carotid canal. An animal model with 70% and 90% carotid stenosis and carotid occlusion was created. The model with 70% stenosis showed no significant change. The 90% stenosis model showed partial flow void in the center of the lumen with peripheral signal exactly as seen in the human patients.

Adult↗
PubMed1989

White matter hyperintensity on magnetic resonance imaging: clinical and neuroanatomic correlates in the depressed elderly.

In a prospective study of depressed elderly patients referred for electroconvulsive therapy (ECT), subcortical white matter hyperintensity (WMH) was seen in all 51 patients 60 years or older who received magnetic resonance imaging (MRI) prior to treatment. In over half of the patients the WMH was formally rated as at least moderately severe, and it was commonly associated with other structural brain changes. The majority (80%) of patients had late-age-onset depression, suggesting that structural brain changes may interact with aging to facilitate the emergency of depression in late life.

Aged↗
PubMed1989

Criteria for termination of phase II chemotherapy for patients with progressive or recurrent brain tumor.

We report six patients with progressive primary tumors of the brain who had prolonged periods with stable contrast-enhancing CT lesions following initial responses to chemotherapy. Chemotherapy was discontinued after 21 to 36 months, despite the persistence of apparent disease in each patient. PET using (F-18) fluorodeoxyglucose was performed in three patients, revealing hypometabolic lesions. All six patients are alive and well, with no clinical or radiographic evidence of progressive disease at 24 to 57+ months following termination of treatment. The usual criteria for terminating phase II chemotherapy in patients with a recurrent brain tumor are evidence of progressive disease or unacceptable toxicity. However, chemotherapeutic success mandates that these criteria be expanded to include patients whose response following the initiation of phase II treatment is followed by prolonged (greater than 1 year) radiographic and clinical stability. Complete response, ie, disappearance of all evidence of disease, is unusual in patients with recurrent primary brain tumors, even with highly effective therapy. Continued improvement in the therapy of patients with these tumors will allow wider application of these criteria.

Adolescent↗
PubMed1989

Efficacy of MR vs CT in epilepsy.

We studied 59 seizure patients with CT, MR, and EEG to determine the efficacy of each in the detection of an epileptogenic focus. EEG was most sensitive (67%), MR was next (53%), and CT was least sensitive (42%). MR detected an abnormality in five patients (8%) in whom CT was negative. EEG was positive in each of these patients. CT failed to demonstrate any focal lesion not detected by MR. MR and CT detected focal abnormalities in seven patients (12%) who had negative EEGs. Five of the seven patients had brain tumors. Eighteen of the 26 patients who underwent surgery had positive CT and MR; 14 of these patients had tumors. The remaining eight patients who had surgery all had temporal lobectomies for intractable seizures; none had tumors. In the complex partial seizure subgroup of 34 patients, MR was positive in 44%, CT was positive in 29%, and EEG was positive in 80%. We consider MR to be the imaging procedure of choice for the detection of an epileptogenic focus in seizure patients. When indicated, CT may be performed as a second procedure to try to distinguish neoplasm from thrombosed vascular malformations and other lesions.

Brain Neoplasms↗
PubMed1989

CSF TRAP: a procedure to improve laboratory testing with myelography.

CSF TRAP (Transport and Rapid Accessioning for Additional Procedures) is a procedure that provides storage of and rapid access to cerebrospinal fluid (CSF) specimens and allows clinicians to review initial findings before ordering low-yield CSF studies. The cost-effectiveness of routinely using the CSF TRAP procedure with myelography is examined in a study group of 819 patients, 74% with disc diseases, spinal stenosis, spondylolisthesis, or pain syndromes, 10% with cancer, and 16% with neuropathies and miscellaneous conditions. Routine studies on CSF obtained during myelography provided little additional clinical information, except for patients with cancer (of 80 patients with cancer, the results of cytological examination of the CSF were positive in 12) and patients with multiple sclerosis, for whom oligoclonal band and IgG analysis provided supportive diagnostic data. The utilization of the CSF TRAP procedure with elimination of unnecessary culture and cytological studies on patients with disc diseases, spinal stenosis, spondylolisthesis, and pain syndromes, reduces myelographic CSF procedures by 20%, for a savings exceeding $14,000. The CSF TRAP procedure allows for a more cost-efficient analysis of CSF obtained using myelography, while providing fluid for analysis in patients with unexpected findings.

Adult↗
PubMed1988

Leukoencephalopathy in elderly depressed patients referred for ECT.

Using brain magnetic resonance imaging (MRI) and high-resolution computed tomography (CT), we identified changes in the subcortical white matter in 44 of 67 elderly depressed inpatients (66%) referred for electroconvulsive therapy (ECT). This "leukoencephalopathy" was frequently associated with other structural brain changes, including cortical atrophy, lateral ventricular enlargement, and lacunar infarctions of the basal ganglia and thalamus. Many (58%) of the patients had developed late-onset depressive disorders, and the majority (86%) had been refractory to and/or intolerant of antidepressant drug therapy. Nevertheless, all but 1 of the 44 patients subsequently responded to a course of ECT, which in general was well tolerated. Although the precise etiology of the leukoencephalopathy remains unclear, clinical data suggest that it may result from arteriosclerotic disease of the medullary arteries that supply the subcortical brain regions. Several lines of evidence suggest that leukoencephalopathy may have implications for the pathophysiology of depressive illness, at least in some elderly patients.

Aged↗
PubMed1988

Efficient pulse sequence for multisection dual-repetition time MR image acquisition.

A magnetic resonance imaging pulse sequence was developed in which multisection spin-echo image data are simultaneously acquired for two repetition time (TR) intervals (TR1 and TR2) in one imaging sequence. In a conventional multisection image at a single TR, the number of sections is limited to TR/TS, where TS is the readout time. With this new sequence, the number of sections that can be imaged at both TRs in one acquisition is equal to (TR1 + TR2)/(TS1 + TS2), where TS1 and TS2 may be different for the two TRs. Imaging time is equal to that for a single image at a TR of TR1 + TR2. Clinical images were obtained with the new sequence from 15 patients and compared with images acquired at the same TR/TE by means of standard multisection single-TR methods. Relative image quality was assessed by three radiologists in 37 comparisons. In general, the dual-TR results at the long TR were judged equivalent to those from a single-TR image. Dual-TR results at the short TR had a modest reduction in contrast, but in none of 15 cases were any pathologic features missed.

Magnetic Resonance Imaging↗
PubMed1988

Effects of ECT on brain structure: a pilot prospective magnetic resonance imaging study.

The authors describe a pilot prospective investigation of the effects of ECT on brain structure using magnetic resonance imaging (MRI). In nine patients with major depression, a course of ECT produced no acute changes in brain structure according to blind raters' assessments of cortical atrophy and global comparison of pre- and post-ECT studies. There were also no significant changes in the ventricle-brain ratios. Pre-ECT brain abnormalities were common in these patients yet were also unaffected by ECT. Future MRI studies of ECT should include more subjects and should address long-term changes and subtle brain abnormalities.

Adult↗
PubMed1988

Transient late magnetic resonance imaging changes suggesting progression of brain stem glioma: implications for entry criteria for phase II trials.

An 8-year-old boy was treated with irradiation (66 Gy) for a brain stem glioma. Five months after the completion of radiotherapy, magnetic resonance imaging demonstrated apparent tumor progression despite the patient's neurological improvement. The child continued to improve, with subsequent radiographic evidence of tumor regression, without additional therapeutic intervention. The evaluations of response and recurrence of brain tumors as well as entry criteria for Phase II studies are discussed.

Antineoplastic Agents↗
PubMed1988

Neuroimaging of scuba diving injuries to the CNS.

Diving accidents related to barotrauma constitute a unique subset of ischemic insults to the CNS. Victims may demonstrate components of arterial gas embolism, which has a propensity for cerebral involvement, and/or decompression sickness, with primarily spinal cord involvement. Fourteen patients with diving-related barotrauma were studied with MR imaging of the brain and spinal cord and with CT of the brain. In four patients with presumed cerebral gas embolism, cranial MR was abnormal in three patients while CT was abnormal in only one. Twelve patients had decompression sickness and spinal cord symptoms. MR documented spinal cord abnormalities in three patients. However, scans obtained early in our study were frequently limited by technical constraints. MR of the brain is more sensitive than conventional CT scanning techniques in detecting and characterizing foci of cerebral ischemia caused by embolic barotrauma to the CNS. Although spinal MR may be less successful in the localization of spinal cord lesions related to decompression sickness, these lesions were previously undetectable by other neuroimaging methods.

Adolescent↗
PubMed1987

Intracerebral malignant melanoma: high-field-strength MR imaging.

Thirteen patients with intracerebral malignant melanoma underwent high-field-strength (1.5-T) magnetic resonance (MR) imaging. The images were correlated with computed tomography (CT) scans (n = 7) and surgical specimens (n = 7). Most commonly, these lesions were hyperintense to normal white matter on T1-weighted images and hypointense to normal white matter on T2-weighted images. Hemorrhage in the lesion may have a greater influence on this unique appearance than does melanin. The increased tissue sensitivity of MR imaging allowed for 22% greater lesion detection than did CT.

Adult↗