CT, MRI, and NMR Spectroscopy in Alzheimer Disease*
Robert E. Becker, Ezio Giacobini in Alzheimer Disease, 2020
In summary, a large percentage of normal elderly will have at least small areas of hyperintensity visible on MRI. These changes are most commonly seen in the periventricular area on the T2 weighted image and there is no evidence that the small lesions have a significant effect on cognition. The small lesions are not typically seen with CT. Approximately 10% of normal elderly will have large white matter lesions on MRI with an area of more than 2.5 cm2. Lesions of this size can be seen with CT and may have subtle to severe effects on cognition. Hypertension, chronic hypotension, and ischemic cerebrovascular disease are all risk factors for white matter lesions. For this reason they are extremely common in patients with multi-infarct dementia, occurring in close to 100% of patients in two major studies. Large white matter lesions are common in patients with AD and the occurrence and progression of these lesions in AD cannot be used to rule in or rule out AD.
Neuroanatomy and Brain Perfusion in Functional Somatic Syndromes
Peter Manu in The Psychopathology of Functional Somatic Syndromes, 2020
Magnetic resonance abnormalities were identified in 78 percent of patients with chronic fatigue syndrome and 21 percent of the healthy control subjects. The abnormalities consisted of punctate hyperintensities in the subcortical white matter. Larger hyperintense areas were also occasionally seen, but the frequency of these abnormalities was not reported. The location of hyperintense signals correlated with the patients’ symptoms in only 8 percent of the cases; seven patients with unspecified visual complaints had abnormalities in the occipital cortex, one patient with ataxia had cerebellar high-intensity signals, and one patient with ataxia had a contralateral internal capsule hyperintensity. The authors noted that “the clinical significance of these ‘incidental’ areas of high signal intensity in the white matter is not known” (Buchwald et al., 1992, p. 109).
Imaging in IBD
Peter Sagar, Andrew G. Hill, Charles H. Knowles, Stefan Post, Willem A. Bemelman, Patricia L. Roberts, Susan Galandiuk, John R.T. Monson, Michael R.B. Keighley, Norman S. Williams in Keighley & Williams’ Surgery of the Anus, Rectum and Colon, 2019
Bowel wall thickening is another important characteristic of active CD, although it is not specific for activity, since this may be the result of either oedema and/or fibre deposition. A small-bowel wall thickness of more than 3 mm should be considered abnormal.110 The degree of bowel wall thickening correlates with CD severity assessed by endoscopy and/or pathology and is not always associated to late fibrotic stages of the disease.106,111,112 In fact, in the early stages, mural thickening is predominantly due to inflammatory cell infiltration and oedema. Histologically, oedema results in cell separation, increasing the space between the fibroblasts and smooth muscle fibre cells of the submucosa. When moderate to severe, oedema can be identified at MRI as a mural bright signal on T2-wedged sequences. Thus, the absence of wall hyperintensity does not exclude active disease. The addition of selective saturation of fat signal on T2-wedged sequences increases the sensitivity for the identification of oedema in the intestinal wall and perienteric fat and also facilitates the identification of small amounts of perienteric fluid. Fat saturated and non-fat saturated T2 sequences are also required to discern whether the presence of high mural signal intensity results from oedema or is secondary to intramural fat deposition, which is found in longstanding disease. The former demonstrates persistent high signal intensity with both sequences, whereas fat saturation will reduce wall signal intensity that is due to fat.113
Physiological and pathological covariates of persistent concussion-related fatigue: results from two regression methodologies
Published in Brain Injury, 2019
Tatyana Mollayeva, David Stock, Angela Colantonio
Table 1 describes the study sample, overall, and by sex. Twenty-eight (35%) participants were single/widowed or divorced, and 49 (61%) had post-secondary degrees. Forty-eight (60%) had dependent children in the household. The median TSI was 760 days (interquartile range, 481–1106 days); 37 (46%) participants sustained mTBI/concussion more than two years ago. The major mechanisms of injury were being struck by/against an object or crushed by an object (40%), falls from the same level (17.5%), motor vehicle accidents (13.8%), and being struck by another person(11%). Thirty participants (37.5%) had documented LOC and/or PTA. Previous head injuries were documented in the files of 22 participants(27.5%). All participants underwent structured MRI or CT imaging. None exhibited trauma-related brain changes. Scattered foci of hyperintensity were detected in 23 participants (28.8%). Cervical spinal abnormalities (all degenerative changes) were detected in 52 participants (65%) by MRI or CT imaging. Thirty-five participants (43.8%) had documented tension with employer or insurer at the time of assessment and 55 (68.8%) participants had documented family difficulties.
Acute hemichorea in a young type 1 diabetic
Published in International Journal of Neuroscience, 2020
Jeremy B Lin, Andrew A Sng, Furene S Wang, Ai Peng Tan, Velda X Han
Diabetic striatopathy is usually seen in the elderly Asian women with uncontrolled type 2 diabetes [2]. The classic MRI finding includes contralateral corpus striatum hyperintensity on T1-weighted image, hypo or isotense on T2-weighted image and lack of restrictions on diffusion images [3]. The MRI abnormalities usually resolves in few months. However persistent hyperintensity up to years have been reported [2,3]. Movement disorder generally resolves within 24–48 h of normoglycemia, however may persist for longer duration. There are a few hypotheses for this condition. Firstly, depletion of gamma-aminobutyric acid (GABA) related to non-ketotic hyperglycemia [2]. Secondly, cellular acidosis and regional hypometabolism due to disruption of blood brain barrier [2,3]. Thirdly, transient and incomplete striatal ischemia [2].
Signal Alteration in the Optic Nerve Head on 3D T2-weighted MRI: a Potential Neuroimaging Sign of Glaucomatous Optic Neuropathy
Published in Current Eye Research, 2018
Jong Yeon Lee, Hyo Jeong Kwon, Su Jin Park, Chungkwon Yoo, Yong Yeon Kim, Eung Yeop Kim
All participants underwent 3D sagittal T2-weighted MRI with a 12-channel coil at a 3T scanner (Verio, Siemens, Forchheim, Germany). The parameters for the 3D T2-weighted imaging were as follows: repetition time/echo time, 3200 ms/434 ms; sampling perfection with application-optimized contrasts by using different flip-angle-evolutions (SPACE); echo spacing, 3.4 ms; turbo factor 141; slice thickness, 1 mm without gap; 256 × 256 matrix; field of view, 250 mm (interpolated voxel size, 0.49 × 0.49 × 1 mm3); 160 slices, number of signals acquired, 1; parallel acquisition reduction factor, 2; total acquisition time, 3 minutes and 23 seconds). They were asked to fix their gaze on the virtual place ahead with eyes closed to avoid any deliberate eye movements during the examination. The image data were transferred to Osirix Lite (version 7.0.3, Pixmeo, Switzerland). Two reviewers (EYK and JYL) blinded to the information of the subjects independently determined the presence or absence of a signal alteration in the ONH region using the 3D multiplanar reformat of the Osirix Lite. The signal alteration in the ONH region was classified into the two grades: (a) mild (focal hyperintensity with incomplete loss of hypointense continuity) and (b) prominent signal alteration (definite hyperintensity with complete loss of hypointense continuity) (Figure 1.). Any discrepancies between the two reviewers were resolved by consensus, which was used for the statistical analysis.
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