Stroke, evolution of NMR imaging characteristics

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:6574166

Nicholson, R L; Carr, T; Kertesz, A; Black, S; Cooper, P; Stewart, S

This study evaluates the NMR imaging characteristics of stroke and temporal evolution of these features. Patients with acute stroke clinically had NMR imaging (prototype 0.15T resistive imager, Technicare, Inc.) acutely (n=37), at approximately 2 weeks (n=31) and 3 months (n=10). Patients with old (> 1 yr.) stroke were also imaged (n=7). Partial saturation sequences were used employing echo time (T/sub E/) of 30, 60 and 120 msec, as well as inversion recovery (TR) sequences. Partial saturation images displayed a homogeneous increase in signal at lesion sites in both bland and hemorrhagic infarcts, reflection prolongation of spin-spin relaxation (T/sub 2/) due to increased tissue water content, blood and edema being indistinguishable. IR images recovered low signal from bland infarcts due to prolongation of spinlattice relaxation (T/sub 1/) by tissue edema, hemorrhagic lesions and short (T/sub 1/) centrally (blood) with moderate or increased IR signal, and low signal peripherally (edema). On follow-up IR imaging, hematomas developed low signal centres, possibly reflection cavitation, with short T/sub 2/ rims, possibly indicating the presence of iron-laden macrophages. In 2 patients with hemorrhagic infarcts an area of increased signal (prolonged T/sub 2/) was seen on initial partial saturation images in the homologous portion of the other hemisphere (normal by CT). This may reflect a local alteration of blood volume or velocity. In 5 patients with old infarcts, a rim of prolonged T/sub 2/ was seen at the periphery of old lesions, possibly reflecting a local chronic increase in extravascular or intravascular water, slowing of blood velocity, or a zone of neuronal dropout. Detailed pathophysiologic correlation is required to understand the basis of these NMR findings.

• Research Organization: St. Joseph's Research Institute, London
• OSTI ID: 6574166
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
BLOOD FLOW
BODY
BRAIN
CAT SCANNING
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
CORRELATIONS
DIAGNOSTIC TECHNIQUES
EDEMA
EVALUATION
IMAGES
NERVOUS SYSTEM
NMR IMAGING
ORGANS
PATHOLOGICAL CHANGES
SIGNALS
SYMPTOMS
TOMOGRAPHY