CTA Head
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.
CA0364-CTA Head
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CA0364-CTA Head
Case ReportExam
Prior Study
1. Hyperdense thrombus is evident in the distal basilar artery extending into the left P1 PCA segment.
2. Multiple recent strokes (readily apparent cytogenic edema sites) involving Lt. PICA and both P4 segments of the PCA were evident on noncontrast CT placing these ischemic events outside the hyperacute treatment timeline. There is an evolving older (subacute phase) left PICA stroke. There is parenchymal hypdensity in the deep cerebellar watershed zones, which could be recent ischemia or chronic age-related ischemic demyelination. It is likely there has been recent thrombus in the intradural vertebral artery initially occluding the left PICA, which has then undergone clot lysis with distal secondary embolization to downstream arteries.
CT Perfusion
1. Known acute thrombus in distal basilar artery
2. Focal completed stroke is evident in Lt. PICA perfusion area and early stroke in the Lt. mesial occipital P4-PCA perfusion zone. Reperfusion (increased CBV & CBF) is evident in the Lt.occipital Ischemic zone.
CTA Neck
1. Focal left vertebral artery stenosis without intraluminal soft clot; estimated stenosis is 50% by NASCET & physiologic criteria. This stenosis could be related to an atherosclerotic plaque or from recanalization of a recent thrombus.
2. Occluded distal mesial cerebellar hemispheric branches off the smaller than expected Lt. PICA. The left PICA origin is present but reduced in size consistent with recanalization of a prior thrombus.
Findings
CTA of the head
There is partially obstructing thrombus within the distal basilar segment. Yet, both SCA’s are patent.
The proximal Lt. PCA is patent, but is partially restricted by the distal intraluminal basilar thrombus and remains small in size compared to the right PCA.
The distal Rt. PCA is collateralized through the patent P-com so that all Rt. PCA segments (P1-4) appear normal. There is no apparent pial collateral gap.
The proximal segment of the Lt. PICA is barely patent, and remains markedly reduced in size. All its’ distal branches opacify only faintly. They are likely filled by a combination of limited antegrade flow and from ipsilateral AICA collaterals. The right PICA is patent.
Both SCA arteries are patent.
Supratentorial arteries are NL.
There is relatively little venous opacification at this time to allow evaluation.
Impression
2. There is proximal stenosis of the Rt. PCA initial segment with limited filling of the distal Lt. PCA branches.
3. The circle of Willis is complete allowing the P-com’s to collateralize the right PCA’s. The distal P4 trunk arteries are well opacified on the right but are less so on the left (likely in process of clot lysis and recanalization). Arteries are patent bilaterally in the areas of post ischemic cytogenic edema.
4. Distal Lt. PICA distal branches are partially collateralized from ipsilateral AICA. The mesial left PICA cerebellar hemispheric arteries are not opacified at all.
