MR Diffusion
Claim CME CreditPOINT OF CARE INFORMATION
This CME activity consists of the student reviewing the video of the professor reviewing the case as well as the associated DICOM image set related to the case in question.
Learning Objectives
As a result of participation in this activity, participants should be able to:
- Provide improved patient care.
- Greater knowledge of the imaging characteristics of the patient's disease.
- Understand a better approach to interpretation of studies.
Faculty Disclosure
Mehmet Albayram, MD, Ivan Davis, MD, Mariam Hanna, MD, Anthony Mancuso, MD, Ronald Quisling, MD, Dhanashree Rajderkar, MD, Priya Sharma, MD, Roberta Slater, MD and Joann Stamm, MBA have disclosed that they have no relevant financial relationships. No one else is a position to control content have any financial relationship to disclose.
CME Advisory Committee Disclosure:
Conflict of interest information for the CME Advisory Committee members can be found on the following website: https://cme.ufl.edu/disclosure/.
Continuing Medical Education Credit
Accreditation: The University of Florida College of Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
Credit: The University of Florida College of Medicine designates this enduring material for a maximum of 0.5 AMA PRA Category 1 Credits. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
CA0414-MR Diffusion
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CA0414-MR Diffusion
Case ReportExam
Prior Study
There is evidence of a left high-cervical ICA dissection. There is very subtle edema in the left hippocampus.
MRA Head and Neck
There are changes consistent with left high-cervical and vertical intrapetrous ICA dissection. There is a short segment with non-filling of the genu segment of the ICA likely representing occlusion. However, the left ICA becomes patent in the horizontal, intrapetrous segment and beyond reflecting patent EC-IC collateralization.
Focal areas of absent MRA signal (consistent with down-stream thromboemboli) were evident in the proximal right ACA, the proximal left PCA, and the left MCA at the M2 trunk division (affecting flow into both the superior and inferior MCA perfusion zones).
Findings
MR diffusion
There is abnormal diffusion (positive on DWI but barely positive on the ADC) within the left hippocampus. The mesial temporal cortex remains normal. This appearance, therefore, is consistent with a recent seizure event with secondary post ictal hippocampal injury. Since the uncal and parahippocampal cortex and the lateral thalamic parenchyma are uninvolved, embolic stroke in the left anterior choroidal artery (which supplies these areas) is an unlikely explanation for these diffusion findings.
The remainder of the brain demonstrates no additional post ischemic abnormality including all the perfusion zones for those arteries with evidence of proximal intraluminal thromboembolic clot on MRA (Rt. ACA, Lt. PCA, & Lt. MCA bifurcation into superior & inferior divisions.
Impression
2. Positive diffusion is confined to the left hippocampus, sparing the adjacent mesial temporal cortex and the lateral thalamus. These findings are consistent with post-ictal effects of a recent seizure, rather than post ischemic changes related to thromboemboli in the anterior choroidal artery. A grand mal seizure is a likely precipitating cause for the left, high-cervical, ICA dissection; there is no underlying vasculopathy to provide an alternative explanation.
