CTA Head
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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.
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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.
CA0385-CTA Head
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CA0385-CTA Head
Case ReportHistory
Exam
Prior Study
1. Hyperacute very focal intraluminal thrombus in a single mid insular M3 branch off the superior division Lt. MCA; stroke-age would likely be hyperacute.
CT perfusion
1. Focal area of minimally reduced CBV and CT density within the venocapillary pool in the mid left insula. This matches the territory of the acute branch thrombus on the noncontrast head CT.
2. The wider area of both prolonged TTP/MTT (compared to the CT) suggests that there is additional thrombus in the more proximal M3 trunk that is not currently hyperdense on CT.
CTA of the Neck
Negative CTA of the neck for any abnormality, which could serve as a potential source for emboli.
Findings
CTA of the head
There are often two superior division trunk arteries, one anterior and one posterior. The anterior trunk typically supplies the anterior insula, and adjacent frontal intrasylvian operculum, laterosylvian frontal operculum and lateral frontal cortex, which includes Broca’s area and the premotor cortex. The posterior trunk typically supplies the parietal cortex, which includes the supramarginal gyrus and the retrosylvian cortex. The artery to the central sulcus (frontoparietal cortex) can arise individually or be part of either the anterior or the posterior trunk.
In this case, there is occlusion of the posterior M3 trunk, which happens to include the artery to the central sulcus, which is CT-hyperdense in this case. This artery abruptly terminates 1 cm beyond its’ origin and accounts for the focal area of mid-insular hypoperfusion evident on the CT perfusion.
There is good pial collateral to most of the posterior intrasylvian trunk, but not for the artery to the central sulcus where there is approximately a 1 cm. pial collateral gap. This tissue will be a significant ischemic risk, while the collateralized branches in the posterior trunk are not.
The pial collateral gap area includes the lower the tongue portion of the primary motor cortex, which accounts for the patient’s current symptom of dysarthria.
Since CTA reveals a more proximal non hyperdense segment of thrombus, it is possible that this was an earlier thrombus (without symptoms-“silent stroke”) that subsequently underwent clot lysis with secondary embolization to the current hyperdense artery to the central sulcus, which did produce acute symptoms. This is not an uncommon occurrence, and often accounts for strokes in the same arterial circuit, but of different stroke-ages.
There is relatively little venous opacification as expected at this time to assess venous egress.
Impression
2. There is a single hyperdense artery to the central sulcus, which is hyperdense and does not fill in its’ initial segment. Retrograde pial collateral fills the distal part of this artery leaving a 1cm. area of pial collateral gap. This oligemic area includes the mid insula and adjacent intrasylvian cortex which corresponds to the lower motor cortex including the tongue region, which in this patient has produced dysarthria.
3. Since CTA reveals a more proximal non hyperdense segment of thrombus in the posterior superior division trunk, it is possible that the hyperacute (hyperdense) single arterial thrombus may be the result of clot lysis and secondary embolization.
