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Paper 3
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
A 7 year old girl presents with ataxia, diplopia and facial droop. On clinical examination she is found to have cranial nerve VI and VII palsies. A CT brain shows a mass enlarging the pons and flattening the floor of the fourth ventricle. There is resultant mild hydrocephalus. MRI brain reveals the lesion has low T1 and heterogeneously high T2 signal relative to cortical grey matter. There is minimal enhancement and the affected area does not restrict on diffusion weighted imaging.
MRI before Myomectomy
Published in Rooma Sinha, Arnold P. Advincula, Kurian Joseph, FIBROID UTERUS Surgical Challenges in Minimal Access Surgery, 2020
Diffusion-weighted imaging (DWI) is currently indispensable in radiology. Diffusion refers to the random movement of molecules in a substance: the Brownian motion. DWI is a very fast technique where the diffusion behavior of hydrogen molecules is determined under different field strengths. DWI is an ultrafast T2W sequence. Because it is a fast sequence, the images that are acquired are of poor resolution but they are very sensitive to the molecular (hydrogen) motion.
Urinary system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Delayed imaging improves lesion detection and may show renal venous anatomy, thrombus and tumour extension in the peri-nephric fat [23]. Diffusion-weighted imaging may have the potential to improve lesion characterisation [24].
Intimate partner violence and brain imaging in women: A neuroimaging literature review
Published in Brain Injury, 2023
Jirapat Likitlersuang, David H. Salat, Catherine B. Fortier, Katherine M. Iverson, Kimberly B. Werner, Tara Galovski, Regina E. McGlinchey
Diffusion-weighted imaging is another domain of MRI that can be used to create the contrast image of the diffusion of water molecules within the brain tissue. The diffusion tensor imaging (DTI) is one of the DWI sequences that can evaluate the white matter tractography (3D modeling) of nerve fibers as well as microstructural tissue properties. Specifically, the degree in anisotropy or degree of directionality of water molecules movement within the brain can be extracted. Fractional anisotropy (FA) is a scalar value from 0 to 1 and in diffusion imaging described the fiber density, axonal diameter, and myelination in the brain white matter. A value of one indicates fluid flow in one direction without any restriction (anisotropic), while a value closer to zero indicates leaky axon and unrestricted flow in all directions (isotropic). In other words, the reduced FA value may indicate an alteration of the integrity of the white matter tracts (Figure 2).
Diagnostic accuracy of diffusion-weighted imaging in differentiating glioma recurrence from posttreatment-related changes: a meta-analysis
Published in Expert Review of Anticancer Therapy, 2022
Xiaoli Du, Qian He, Boli Zhang, Na Li, Xuewen Zeng, Wenbo Li
Diffusion weighted imaging (DWI) is the only method that can measure the diffusion of water molecules in living tissues at early disease stages. In recent years, the recurrence of glioma has been identified by quantitative analysis of the average apparent diffusion coefficient (ADC) value [6], cumulative ADC square analysis [7] and parameter response diagram [8]. Meta-analyses of DWI have been conducted to differentiate glioma recurrence and the posttreatment response. For example, Zhang H et al. included 9 Chinese and English studies until October 2014, comprising 284 patients, proving the advantage of DWI in distinguishing glioma recurrence and radioactive encephalitis [9]. Tsakiris C et al. included 24 English studies published before October 2019, comprising 900 patients, proving that DWI was superior in terms of sensitivity and specificity for perfusion weighted imaging (PWI) in distinguishing glioma recurrence and pseudoprogression [10]. Our study is a meta-analysis on DWI to differentiate between postoperative recurrence of glioma and posttreatment-related changes, guide clinical treatment and improve patient prognosis.
Genetic diseases mimicking multiple sclerosis
Published in Postgraduate Medicine, 2021
Chueh Lin Hsu, Piotr Iwanowski, Chueh Hsuan Hsu, Wojciech Kozubski
Progressive cystic degeneration is often visualized under brain MRI. The lateral ventricles are commonly enlarged due to white matter loss. Stripes and dots are present in the cystic white matter, and they align to the spared tissue strands [129,130]. Interestingly, adult-onset VWD patients rarely present with the complete vanishing of the white matter, rather, some cavitations are seen on FLAIR sequence [131]. Diffusion restriction covering the white matter lesions is demonstrated under diffusion weighted imaging (DWI) [131–133]. Cavitary lesions can also be shown in patients with primary progressive MS [134]. However, in such cases, there is currently no report of the observations on diffusion restriction under DWI [135] and the cavities found in MS are found mostly periventricular, in comparison to the anterior predominance in VWD [130].