A restriction fragment length polymorphism at the murine c-myb locus.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to B Mock.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
HIPDM-SPECT brain imaging was performed in four patients with intractable complex partial seizures (CPS). Three patients had an epileptogenic focus in one temporal lobe and underwent anterior temporal lobectomy. Interictal HIPDM-SPECT demonstrated decreased regional cerebral perfusion (rCP) in the epileptogenic area in only one patient, but ictal studies showed increased rCP in the epileptic foci of all three patients. In the fourth patient, interictal HIPDM-SPECT showed increased rCP in the area of epileptogenic focus; when antiepileptic medication was taken, rCP decreased. HIPDM-SPECT brain imaging is useful for localizing epileptogenic foci in CPS.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
HIPDM-Single photon emission computed tomography brain imaging was performed during interictal and ictal stages in three patients with complex partial seizures and secondarily generalized tonic-clonic seizures. In all three patients, interictal studies demonstrated decreased regional cerebral perfusion (rCP) and ictal studies showed increased rCP in the epileptogenic region. The demonstration of focal hyperperfusion by SPECT performed during secondarily generalized tonic-clonic seizures suggests that rCP in the epileptic focus remains higher than in other cerebral regions during immediate postictal stages, even in secondarily generalized seizures.
BACKGROUND AND PURPOSE: Recent technological advances in MR instrumentation allow acquisition of whole-brain diffusion-weighted MR scans to be obtained with b values greater than 1,000. Our purpose was to determine whether high-b-value diffusion-weighted MR imaging improved contrast and detection of signal changes in acute and chronic brain infarction. METHODS: We prospectively evaluated the MR scans of 30 subjects with a history of possible brain infarction on a 1.5-T MR imager with 40 mT/meter gradients (slew rate 150 T/m/s) by use of the following single-shot echo-planar diffusion-weighted MR sequences: 1) 7,999/ 71.4/1 (TR/TE/excitations, b = 1,000; 2) 999/ 88.1/3, b = 2,500; and 3) 7,999/ 92.1/4, b = 3,000. Diffusion-weighted MR imaging was performed in three orthogonal directions during all sequences. All subjects were scanned with fast fluid-attenuated inversion recovery (FLAIR) (10,006/145/2,200/1 [TR/TE/TI/excitations]) and fast spin-echo T2-weighted (3,650/95/3 [TR/TE/excitations], echo train length, 8). The diagnosis of brain infarction was established by clinical criteria. RESULTS: Twenty women and 10 men with a mean age of 67.7 years were enrolled in the study. One subject was excluded owing to poor image quality. Twelve of 29 subjects had a clinical diagnosis of acute infarction. All 12 had lesions that were hyperintense on diffusion-weighted images at all three b values; five were cortical and seven subcortical. There was increased contrast of all lesions on high-b-value scans (b = 2,500 and 3,000). Lesions that were hypointense on diffusion-weighted images were identified and evaluated at the three different b values. At b = 1,000, there were 19 hypointense lesions, whereas at b = 2,500 and 3,000 there were 48 and 55 lesions, respectively. On FLAIR and T2-weighted images, these low-signal lesions were predominantly chronic, subcortical, ischemic lesions and lacunar infarcts, but four chronic cortical infarcts, one porencephalic cyst, and one primary brain tumor were also found. Low-signal lesions were also noted to have increased contrast on high-b-value diffusion-weighted scans. CONCLUSION: High-b-value diffusion-weighted MR imaging (b = 2,500 or b = 3,000) had no impact on diagnosis of acute infarction. High-b-value diffusion-weighted MR imaging (b = 2,500) combined with diffusion-weighted MR imaging at b = 1,000 improves tissue characterization by increasing the spectrum of observed imaging abnormalities in patients with suspected brain infarction.