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Paper 4
Published in Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw, The Final FRCR, 2020
Amanda Rabone, Benedict Thomson, Nicky Dineen, Vincent Helyar, Aidan Shaw
There can be overlap between the radiological appearances in neurodegenerative disease. Multisystem atrophy is classically associated with the ‘hot cross bun’ sign due to pontine T2 hyperintensity. Hyperintensity can also be seen in the cerebellum and cerebellar peduncles. Typically there is low signal in the basal ganglia, specifically the putamen, with a peripheral rim of T2 hyperintensity. Atrophy of the pons, cerebellum and midbrain is also reported.
MRI before Myomectomy
Published in Rooma Sinha, Arnold P. Advincula, Kurian Joseph, FIBROID UTERUS Surgical Challenges in Minimal Access Surgery, 2020
T1W images depict excellent anatomy. These images more or less resemble CT scan images. Only a few structures are hyperintense (bright) on a T1W image: fat, blood, gadolinium (MR contrast), melanin, protein-containing structures, or lesions. Hyperintensity on T1W images can also be seen in specific MRI artifacts and accumulation diseases. Most of the fluids (except blood) appear hypointense on T1W images.
CT, MRI, and NMR Spectroscopy in Alzheimer Disease*
Published in Robert E. Becker, Ezio Giacobini, Alzheimer Disease, 2020
Liane J. Leedom, Bruce L. Miller
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.
Interactions between estradiol, diabetes, and brain aging and the risk for cognitive impairment
Published in Climacteric, 2021
C. E. Hugenschmidt, T. Duran, M. A. Espeland
The Early vs. Late Intervention Trial of Estradiol (ELITE) enrolled postmenopausal women who were within 6 years of, or ≥10 years after, their menopausal transition into a randomized controlled trial of oral estrogen therapy9,25. The Kronos Early Estrogen Prevention Study (KEEPS) was a randomized, controlled clinical trial of oral and transdermal HT in women who were within 6–36 months of their last menstrual period26,27. Neither the ELITE nor the KEEPS found beneficial or harmful effects between women assigned to HT versus placebo, across subgroups and regimens. However, relative to placebo, white matter hyperintensity volumes were increased among women assigned to the KEEPS HT regimens26. In addition, assignment to oral CEE was associated with significantly increased ventricular volumes at the end of the 4-year trial. However, this was attenuated after 3 years of post-trial follow-up, and, at that last time point, women who had been assigned to transdermal estrogen had significantly greater prefrontal cortex volumes than those who had been assigned to placebo.
Noninvasive thyroid histotripsy treatment: proof of concept study in a porcine model
Published in International Journal of Hyperthermia, 2021
John F. Swietlik, Scott C. Mauch, Emily A. Knott, Annie Zlevor, Katherine C. Longo, Xiaofei Zhang, Zhen Xu, Paul F. Laeseke, Fred T. Lee, Timothy J. Ziemlewicz
MRI images demonstrated well demarcated treatment zones, with thin transitions from treated to non-treated tissue (Figure 2). The treatment zones exhibited T2 hypointensity centrally, with areas of T2 hyperintensity around the treatment secondary to edema. T1 hyperintensity was present within the treatments, likely due to blood products from fractured red blood cells from histotripsy. Post-contrast images revealed a rim of T1 hypointensity outlining the treatments with non-enhancement within the treatment zone, suggestive of tissue necrosis. No diffusion restriction was seen in any of the treatment zones. All treatments demonstrated peripheral perfusional changes, including T1 arterial phase hypoenhancement. In two of eight treatments there was mild T2 hyperintensity in the musculature overlying the treatment zone, consistent with edema. This occurred in two separate animals, during the creation of one sphere and one ovoid treatment zone. The area of edema was located immediately superficial to the treatment zone. Both of the areas of muscle edema demonstrated relatively normal enhancement on post-contrast images. No abnormal MR signal was identified within the overlying subcutaneous fat or skin, or within any organ adjacent to the treatments.
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].