EFFICACY OF TRANSCRANIAL DOPPLER BUBBLE STUDY COMPARED TO TRANSTHORACIC ECHO BUBBLE STUDY AS A SCREENING METHOD FOR PULMONARY ARTERIOVENOUS MALFORMATION IN PATIENTS WITH HEREDITARY HEMORRHAGIC TELANGIECTASIA S. Chheang, J. Tobis, J. Child, R. Gevorgyan, M. Kuo, G. Duckwiler, J. McWilliams Department of Radiology; University of California, Los Angeles Introduction Materials & Methods Results Discussion• Affecting approximately 1 in 5-8000 people, • 9 nonconsecutive patients with known or •Despite our small sample size, the utility of Hereditary Hemorrhagic Telangiectasia suspected HHT received TCD and TTE TCD TCD grade TCD is indicated by its comparable sensitivity grade at with (HHT) is an autosomal dominant disease bubble studies. Chest CT was performed in 6 rest Valsalva TTE CT Chest to TTE. leading to the abnormal vessel of these patients. PATIENT 1 0 3 negative negative development. PATIENT 2 1 1 negative not done •Valsalva maneuver is • TTE bubble study was performed by an PATIENT 3 0 1 negative not done• Approximately 30-50% of patients with HHT experienced cardiologist at UCLA PATIENT 4 0 0 negative not done have pulmonary arteriovenous • At UCLA, results of TTE are reported as negative, •Compared to TTE or TEE, TCD has notable PATIENT 5 1 3 negative negative small shunt, or definite shunt. malformations (AVMs). Approximately 9- benefits, including: PATIENT 6 1 2 definite shunt negative 14% of these patients can have disease • Not a tomographic study, like TTE or TEE, so • TCD bubble study was performed with Power PATIENT 7 4 4 small shunt positive interpretation is easier complicated by brain abscess or stroke. • Sedation is not needed M-mode Transcranial Doppler (Terumo 150 PATIENT 8 4 4 negative negative • Procedure is well tolerated PMD) PATIENT 9 0 4 small shunt negative• HHT type 1 (HHT1) is caused by a • Head frame with mounted sonars over temporal • Valsalva maneuver can be performed while bearing down against a calibrated manometer: mutation in the endoglin gene (9q34); HHT acoustic windows monitors the flow in middle cerebral •Table 1. Results of TCD grade, both at rest and with • easier to perform for patients type 2 is caused by a mutation in the activin arteries (MCA) bilaterally. Valsalva, TTE, and Ct Chest. • Better quantify the shunt using the Spencer logarithmic • Injection of a mixture of 8 cc of agitated saline, 0.5 cc scale receptor-like kinase gene (12q1). Studies of air, and 1 cc of blood at rest. The solution was suggest that pulmonary AVMs are more rapidly passed between 2 10-ml syringes connected Figure 1. Effect of Valsalva maneuver on TCD grade. • Causes of false negative TCD common in HHT1 than HHT2. together through a 3-way stopcock. 5 include: • Injection was repeated during calibrated Valsalva 4 strain (40 mm Hg) with manometer for visual feedback TCD grade• AVMs are usually silent at the time of AVM- 3 TCD grade at rest TCD grade with valsalva • Causes of false positive TCD 2 induced stroke or brain abscess. Because 1 include: neither AVM size nor patient symptom 0 severity can adequately assess the risk of 1 2 3 4 5 6 7 8 9 Patient paradoxical emboli, all pulmonary AVMs should be treated. •Figure 1. Effect of Valsalva maneuver on TCD grade. In 4/9 cases, Valsalva maneuver did not change the TCD grade. In 3/9 cases, Valsalva maneuver increased the grade by at• All patients with either known or suspected least 2 logs. HHT should therefore be screened for pulmonary AVM, but the optimal screening method remains in question.• Studies have shown the increased Conclusion sensitivity of transcranial doppler (TCD) bubble study compared to transthoracic • Using the Spencer Logarithmic Scale, a grade echo (TTE) bubble study in the detection •TCD bubble study is a viable alternative to of 0-5 is given to the number of microbubbles of patent foramen ovale. TTE bubble study for the detection of right to visualized in both MCAs within one minute left shunt in patients with known or suspected after injection.• A recent study by Manawadu et al showed HHT. Grade 0 0 mB* that TCD had the same sensitivity but Grade 1 1-10 mB improved specificity compared to TTE in Grade 2 11-30 mB detecting right to left shunt in HHT Grade 3 31-100 mB patients.. Grade 4 101-300 mB Grade 5 >300 mB (Grade 3-5 indicates a positive result) Literature Cited Purpose • • Spencer M et al (J NEUROIMAGING 2004;14:342-349) Manawadu D et al (Stroke 2011;42:00-00, online publication) • Van H et al (JACC 2010; 3:343-348) Grade 0 Grade 1 Grade 2 • Govani F and Shovlin C (European Journal of Human• We hypothesize that TCD bubble study may Genetics 2009; 17: 860-871 have comparable sensitivity to that of TTE • Shovlin C et al (Thorax 2008; 63: 259-266) bubble study for the detection of right-to-left Grade 0 • Stendel C et al (Anesthesiology 2000; 93: 971-975) shunting from pulmonary AVMs in patients • Gamboa P et al (AJR 2000; 175: 853-858) with HHT. Grade 3 Grade 4 Grade 5 •Figure 2. Noncontrast CT of PATIENT 7 shows subcentimeter AVM in the right upper lobe.