scholarly journals OP03.07: Magnetic resonance diffusion weighted imaging (DWI): reproducibility of apparent diffusion coefficient measurements for the normal fetal brain

2011 ◽  
Vol 38 (S1) ◽  
pp. 64-64
Author(s):  
A. C. Boyer ◽  
L. F. Gonçalves ◽  
W. Lee ◽  
A. Shetty ◽  
A. Krisko ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Fetal Brain ◽  
Diffusion Weighted ◽  
Apparent Diffusion

A History of Sarcoidosis and a New Brain Lesion

2021 ◽  
pp. 187-188
Author(s):  
Andrew McKeon ◽  
Julie E. Hammack
Keyword(s):  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Symptom Onset ◽  
Magnetic Resonance Image ◽  
Diffusion Weighted Imaging ◽  
Lymph Node Biopsy ◽  
Active Pulmonary Tuberculosis ◽  
Diffusion Weighted ◽  
Apparent Diffusion

A 59-year-old man with long-standing hypertension sought a second opinion for a left-sided posterior headache and aphasia of approximately 1 week’s duration. Eight months before neurologic symptom presentation, he was febrile with night sweats, weight loss, arthralgias, dyspnea, and wheezing. Bronchoscopy and hilar lymph node biopsy showed noncaseating granulomatous inflammation consistent with pulmonary sarcoidosis. Remotely, as a teenager, given exposure to a family member with active pulmonary tuberculosis infection, he had a purified protein derivative skin test, which was positive; he received 6 months of isoniazid treatment. On examination, he was aphasic but had an otherwise normal neurologic examination. Brain magnetic resonance image performed at hospital admission (1 week after symptom onset) showed extensive T2 signal abnormality in the left temporal neocortex, with vasogenic edema, and abnormal gyriform gadolinium enhancement. There was no restricted diffusion in the left temporal lobe on diffusion-weighted imaging, but an apparent diffusion coefficient map showed a gyriform hypointense pattern. Prior outside magnetic resonance image obtained 1 day into the patient’s symptoms showed similar findings on T2/fluid-attenuated inversion recovery and T1 postgadolinium images but also gyriform hyperintensity on diffusion-weighted imaging, with hypointensity on apparent diffusion coefficient map in the same region. The patient was diagnosed with subacute cerebral infarction in the context of cardioembolic disease secondary to hereditary hypertrophic cardiomyopathy. As a result of the findings and diagnosis, the patient received an implantable cardioverter-defibrillator and was treated with warfarin, aiming for an international normalized ratio of 2.0 to 3.0 to reduce the risk of recurrent cardioembolic disease. The patient had a subacute ischemic stroke mimicking a brain mass radiologically. The acuity of symptom onset could have been a key clinical clue in this case but was absent from the patient history. Patients with stroke typically have hyperacute symptom onset (over seconds to minutes). Autoimmune and inflammatory central nervous system disease symptoms tend to have subacute evolution (over days to weeks) or might be chronic (over months).

scholarly journals Classification of paediatric brain tumours by diffusion weighted imaging and machine learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jan Novak ◽  
Niloufar Zarinabad ◽  
Heather Rose ◽  
Theodoros Arvanitis ◽  
Lesley MacPherson ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Posterior Fossa ◽  
Brain Tumours ◽  
Diffusion Weighted Imaging ◽  
Regions Of Interest ◽  
Apparent Diffusion Coefficients ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Paediatric Brain Tumours

AbstractTo determine if apparent diffusion coefficients (ADC) can discriminate between posterior fossa brain tumours on a multicentre basis. A total of 124 paediatric patients with posterior fossa tumours (including 55 Medulloblastomas, 36 Pilocytic Astrocytomas and 26 Ependymomas) were scanned using diffusion weighted imaging across 12 different hospitals using a total of 18 different scanners. Apparent diffusion coefficient maps were produced and histogram data was extracted from tumour regions of interest. Total histograms and histogram metrics (mean, variance, skew, kurtosis and 10th, 20th and 50th quantiles) were used as data input for classifiers with accuracy determined by tenfold cross validation. Mean ADC values from the tumour regions of interest differed between tumour types, (ANOVA P < 0.001). A cut off value for mean ADC between Ependymomas and Medulloblastomas was found to be of 0.984 × 10−3 mm2 s−1 with sensitivity 80.8% and specificity 80.0%. Overall classification for the ADC histogram metrics were 85% using Naïve Bayes and 84% for Random Forest classifiers. The most commonly occurring posterior fossa paediatric brain tumours can be classified using Apparent Diffusion Coefficient histogram values to a high accuracy on a multicentre basis.

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