CT Perfusion
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.
CA0470-CT Perfusion
View Images
CA0470-CT Perfusion
Case ReportExam
Prior Study
1. Hyperacute basilar and left intradural vertebral artery thromboses with multicentric both arterial and watershed strokes involving multiple posterior fossa arteries, as described above.
2. There is early mass effect including compression of the 4th ventricle, effacement of prepontine cisterns, and clear evidence of early upward transtentorial herniation.
3. Focal lesion within the deep central left cerebellum is likely a site of hemorrhagic conversion with very acute hematoma.
Findings
CT perfusion
There is prolonged TTP but absent MTT/CBV/CBF in the Lt. P3 PCA zone (site of old stroke).
There is prolonged TTP with virtually absent CBV and CBF and little evidence of any MTT signal in the deep cerebellar hemispheres bilaterally; changes are worse on the left than right.
The completed left P3 stroke with an encephalomalacic defect in the temporal lobe has CT perfusion features of dense ischemic core (including absent MTT), but of course, this is not the case. This points out the need to define all site of encephalomalacia, focal atrophy, or lacunar defects on the noncontrast head CT prior to interpreting the CT-perfusion to avoid over-calling active stroke areas.
There is suggestion of a left pontine stroke. CT perfusion is relatively insensitive to brain stem strokes, because of the bone artifacts associated with the skull base.
There is also CT perfusion evidence of dense ischemic changes in both SCA territories.
The included initial CTA head demonstrates patency of the left intradural vertebral artery and of the caudal basilar artery at this time. There is distal basilar thrombosis.
Impression
2. Absent MTT signal (out of scale sign) indicates virtually no transcapillary blood flow to generate MTT data. This is can occur with either sequestered infarction, or hemorrhagic transformation, or both. Differentiation between these two stroke complications is best exhibited on the MR susceptibility sequence.
3. CTA head (included with our CT perfusion protocol) demonstrates patency of the left intradural vertebral artery and of the caudal basilar artery at this time, despite the CT-hyperdensity seen on the noncontrast CT head .
4. There is an old infarct with an encephalomalacic defect in the left temporal lobe (PCA-P3 segment perfusion zone).
