Reliability of contrast echocardiography to rule out pulmonary arteriovenous malformations and avoid CT irradiation in pediatric patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: The overall risk of cancer is higher in people exposed to computed tomography (CT) scans in childhood or adolescence compared to adults. Transthoracic contrast echocardiography (TTCE) has recently been used to screen for pulmonary arteriovenous malformations (PAVMs) in children with hereditary hemorrhagic telangiectasia (HHT), but the value of TTCE to rule out PAVMs and avoid chest CT radiation has yet to be discussed.

METHODS: Between 2003 and 2013, 92 pediatric patients with ≥3 Curaçao criteria and/or genetic mutation underwent TTCE and chest CT on the same day. We used the classification proposed by Barzilai for TTCE quantification of shunting. We considered CT findings as negative when no PAVMs or only one microscopic PAVM was detected.

RESULTS: Mean age was 11.2 ± 4.1 years. The shunt was grade 0 on TTCE in 27.3%, grade 1 in 17%, grade 2 in 29.6%, grade 3 in 23.9%, and grade 4 in 2.2%. We found PAVMs on chest CT in 52.2%. All the patients with a grade 0 or 1 had a negative CT. The sensitivity and specificity of TTCE for the detection of PAVMs were 100% and 95.1%, respectively. The negative predictive value (NPV) was 100% and the positive predictive value (PPV) was 96%.

CONCLUSIONS: A low-grade classification (Barzilai 0 or 1) could presumably exclude the presence of PAVMs and allow CT irradiation to be avoided in children and adolescents. The screening algorithm using TTCE first would allow more than 40% of the pediatric patients screened for PAVMs to be spared the radiation dose of CT.