NMR-neuropathologic correlation in stroke.

Abstract

True, three-dimensional proton nuclear magnetic resonance imaging at 0.147 tesla was performed postmortem on 2 patients embodying various stroke syndromes, including chronic (4 and 15 years) infarction, subacute (within 1 week) bland infarction, acute (2 days) hemorrhagic Infarction, and hematoma secondary to ruptured aneurysm. A third patient, with subcortical arteriosclerotic encephalopathy, so-called Binswanger's disease, was examined antemortem using a 0.6 tesla scanner. Nuclear magnetic resonance images were reconstructed at levels matching the pathologic specimens. Qualitative and, when available, quantitative comparisons between the results of nuclear magnetic resonance imaging and pathology were carried out. Areas of qualitatively prolonged Tl and T2 relaxation times on nuclear magnetic resonance imaging were more extensive than the corresponding areas of chronic infarction noted pathologically and were determined to be infarcts plus the adjacent areas of Wallerian degeneration. Hemorrhagic infarction, without evidence of blood on computed tomography, was found to have mildly prolonged Tl and T2 relaxation times, between those of normal brain and chronic infarction; a 10-day-old hematoma had a very short Tl, slightly shorter than that of white matter, and a mildly prolonged T2, with values between those of white and gray matter. T HERE have now been several reports regarding the use of nuclear magnetic resonance imaging (NMRI, also referred to as magnetic resonance imaging, MRI) in the evaluation of various stroke syndromes.1 " 5 Acute (within hours to 2 days) and chronic (within weeks) infarcts have been noted to have prolonged Tl and T2 relaxation times.24 "* NMRI studies in hemorrhagic infarction have been based on plain (i.e., not contrast-enhanced) computed tomography (CT) showing bright, speckled areas in areas of superimposed infarction. NMRI in such cases has shown Tl and T2 relaxation times between the short Tl of hemorrhage and the long Tl and T2 of infarction.1 ' 37 Acute hemorrhages have had short Tl and T2 relaxation times, 47 while chronic hemorrhages have had short Tl and long T2 relaxation times. 37 In the few reported instances, subarachnoid hemorrhage (SAH) detected by x-ray CT has gone undetected by NMRI, only rarely showing as a region of shortened Tl relaxation time 3 or as a region of long T2 relaxation time 7 corresponding to subarachnoid clot. Reports of areas of prolonged T2 relaxation time (bright areas on T2-weighted spin-echo images) surrounding areas of chronic infarction, as documented From the Departments of Neurology

Computed Tomography, Magnetic Resonance Imaging and Pathological Correlations in a Case of Binswanger's Disease

“…21 Post-mortem MR examination has recently been established as an appropriate tool for the investigation of MR-pathological correlations. 12 ' 22 " 24 The results in our case showing wide areas of prolonged Tl and T2 relaxation times in the white matter confirm previous MR-pathological correlations in patients with BD submitted to MR ante-mortem." 12 indeed uncommon when compared to the MR picture of white matter damage often encountered in hypertensive elderly subjects suffering from cerebrovascular symptoms but without a clinical picture of vascular dementia.…”

“…12 ' 22 " 24 The results in our case showing wide areas of prolonged Tl and T2 relaxation times in the white matter confirm previous MR-pathological correlations in patients with BD submitted to MR ante-mortem." 12 indeed uncommon when compared to the MR picture of white matter damage often encountered in hypertensive elderly subjects suffering from cerebrovascular symptoms but without a clinical picture of vascular dementia. 25 The latter is characterized by patchy or punctate areas of altered MR signal which correspond to pathological changes of arteriosclerosis, dilated perivascular spaces and vascular ectasia, referred to as etat crible\ 23 -26 a picture quite dissimilar to that observed in our case, or to small cystic or non-cystic infarcts.…”

“…8 Valuable information has come from computed tomography (CT) and magnetic resonance imaging (MRI) which show wide areas of degeneration of the cerebral white matter in pathologically proven cases of BD. [9][10][11][12] A patient with a clinical picture of vascular dementia and CT evidence of diffuse white matter disease recently came to autopsy in our department. A post-mortem MR study was carried out before the histopathological examination.…”

Measurements of acute cerebral infarction: lesion size by computed tomography.

“…5 With magnetic resonance imaging, greater sensitivity is possible, but imaging may be less specific. 22 We suggest that clinical and anatomic measures of cerebral infarction are fundamentally complementary and that neither measurement approach can be adequately evaluated independent of the other. tance in design of the CT assessment methods and the stroke scale (neurologic examination and scale).…”

Clinical use of nuclear magnetic resonance imaging in stroke.

“…4 Recently, a "halo" of moderately prolonged T2 surrounding an area of more prolonged T2 in chronic infarction has been noted, 16 representing Wallerian degeneration. 17 MRI appears at present to be as good as, and in many cases better than, CT for the evaluation of ischemic infarction. For early lesion detection MRI is clearly better than CT because MRI is known to show well-demarcated areas of prolonged Tl and T2 relaxation times.…”