Purpose: To determine the sensitivity of contrast material-enhanced transcranial color-coded sonography (c-TCCS) compared with that of contrast-enhanced transesophageal echocardiography (c-TEE) for detection of cardiac right-to-left shunt.
Materials and methods: Forty consecutive patients with stroke or transient ischemic attack were admitted to the hospital and were examined by using c-TCCS and c-TEE. High-intensity transient signals (HITS) were counted for 25 seconds after the end of the Valsalva maneuver, and the numbers of HITS were classified in one of four categories (zero HITS, one to 10 HITS, >10 HITS without curtain, and curtain). A statistically significant difference was calculated with the Fisher exact test.
Results: HITS were counted in 21 (52%) patients by using c-TCCS and c-TEE. With both tests, no HITS were counted in 15 (38%) patients. In two (5%) patients, no HITS were counted with c-TEE but three HITS in one patient and five HITS in the other were counted with c-TCCS. In two (5%) patients, no HITS were counted with c-TCCS, but a small patent foramen ovale (PFO) was seen at c-TEE. With c-TCCS, the sensitivity was 91% (21 of 23) and the specificity was 88% (15 of 17). In 23 patients examined with c-TCCS, 14 (61%) patients had category 1 PFO; seven (30%) patients, category 2 PFO; and two (9%) patients, category 3 PFO. Mean HITS count in patients with category 1 PFO was 4.4 and that for those with category 2 PFO was 27.6.
Conclusion: c-TCCS is a sensitive noninvasive method for detecting cardiac right-to-left shunt and is as sensitive as c-TEE.