Proton relaxation in acute and subacute ischemic brain edema

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Advances in Neurology; (USA)

OSTI ID:6511076

Boisvert, D P; Handa, Y; Allen, P S ^[1]

---

1. Univ. of Alberta, Edmonton (Canada)

The relation between regional ischemic brain edema and tissue proton relaxation rates (R1 = 1/T1; R2 = 1/T2) were studied in 16 macaque monkeys subjected to MCA occlusion. In vivo R2 measurements were obtained from multiple spin-echo (eight echoes) images taken at 2-, 3-, 4-, and 72-hr postischemia. In vitro R1 and R2 values were determined for corresponding regions after sacrifice at 4 hr (n = 8) or at 72-hr postischemia in seven surviving animals. The water content of the white and gray matter tissue samples was measured by the wet/dry method. Four animals (25%) showed ipsilateral regions of increased signal intensity as early as 2 hr after MCA occlusion. All seven animals imaged at 72 hr displayed such regions. Despite the absence of measured changes in tissue water content, significant decreases in R2, but not in R1, occurred at 4 hr. At this stage, R2 values correlated more closely than R1 with individual variations in water content. At 72 hr, marked decreases in both R1 and R2 were measured in ischemic deep gray matter and white matter. Cortical gray matter was unchanged. In edematous gray and white matter, both R1 and R2 correlated closely with tissue water content, but R2 was consistently 10 to 20 times more sensitive than R1. Biexponential R2 decay was observed at 4 and 72 hr, but only in the white matter region that became severely edematous at 72 hr.

• OSTI ID: 6511076
• Journal Information: Advances in Neurology; (USA), Vol. 52; ISSN 0091-3952
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
NMR IMAGING
NERVOUS SYSTEM DISEASES
DIAGNOSIS
EDEMA
MONKEYS
NUCLEAR MAGNETIC RESONANCE
SPIN ECHO
ANIMALS
BODY
CENTRAL NERVOUS SYSTEM
DIAGNOSTIC TECHNIQUES
DISEASES
MAGNETIC RESONANCE
MAMMALS
NERVOUS SYSTEM
ORGANS
PATHOLOGICAL CHANGES
PRIMATES
RESONANCE
SYMPTOMS
VERTEBRATES
550600* - Medicine