[Validity of the Test Bolus Tracking Technique in Head CT Angiography: Validation of Accuracy Using 4D CT Data in Patients with Subarachnoid Hemorrhage].

PURPOSE: This study aimed to evaluate the validity of the test bolus tracking (TBT) method for head computed tomography (CT) angiography (CTA) using four-dimensional (4D) CT data in patients with subarachnoid hemorrhage (SAH).

METHODS

We analyzed 39 patients who developed SAH and underwent 4D CT. Based on the imaging protocol, patients were classified into a test-injection (TI) group and a TBT group. Time-enhancement curves (TECs) of the M1 segment of the middle cerebral artery were measured. Validation was performed by assessing the concordance between the TEC peak time and the peak scan timing set on 4D CT (peak concordance rate).

RESULTS

The median TEC peak time for all patients was 10.7 s (range: 9.2-17.1 s). The peak concordance rate was 100% in the TI group and 76% in the TBT group. In TBT cases where the peaks did not match, the scan start was determined prematurely using bolus tracking during the test injection. Univariate analysis comparing the TBT group with the TI group showed that the TBT group had a lower concordance rate and shorter examination time (P<0.05).

CONCLUSION

The results of this study suggest that, if the TBT method can accurately determine the peak time of the test injection, it is a valid technique for head CTA.