Non-Invasive Imaging in Pulmonary Hypertension　― Comprehensive Assessment Using Dual-Layer Spectral Computed Tomography ―

A 33-year-old woman with pulmonary hypertension underwent computed tomography (CT) imaging using a dual-layer spectral detector CT (IQon Spectral CT; Philips Healthcare, Best; The Netherlands). A comprehensive assessment scan protocol (Supplementary Table) was used. During early (1^st) phase imaging, high-resolution pulmonary CT angiography revealed multiple chronic thrombus in the bilateral distal pulmonary arteries (Figure A). Pulmonary perfusion imaging revealed the functional consequences by delineating multiple segmental perfusion defects in the areas corresponding to the thrombus (Figure B, Supplementary Movie, Supplementary Figure). Delayed (2^nd) phase cardiac CT revealed right ventricular insertion point late iodine enhancement (LIE), which is indicative of focal myocardial fibrosis (Figure C). In addition, myocardial extracellular volume (ECV) fraction in the affected segments was elevated to 35–48% (normal range, 23–28%), suggesting severe right ventricular dysfunction (Figure D). The patient was eventually diagnosed with chronic thromboembolic pulmonary hypertension.

Figure.

(A) High-resolution pulmonary computed tomography (CT) angiography revealed multiple chronic thrombus in the pulmonary arteries. (B) Pulmonary perfusion imaging revealed functional consequences by delineating multiple segmental perfusion defects in the areas corresponding to the thrombus. (C) Delayed phase cardiac CT revealed right ventricular insertion point late iodine enhancement. (D) Myocardial extracellular volume fraction in the affected segments was elevated to 35–48%.

Dual-layer spectral detector CT enables comprehensive evaluation of these patients using high-resolution pulmonary CT angiography and pulmonary perfusion imaging with myocardial LIE imaging, and ECV analysis.¹ We believe that this technology offers a practical and useful approach for the non-invasive “one-stop shop” evaluation of pulmonary hypertension.

Disclosures

K.T. is a member of Circulation Journal’s Editorial Team.

Supplementary Files

Supplementary Movie. Pulmonary perfusion imaging by CT.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-20-1007

Reference

• 1.   Oda S, Emoto T, Nakaura T, Kidoh M, Utsunomiya D, Funama Y, et al. Myocardial late iodine enhancement and extracellular volume quantification with dual-layer spectral detector dual-energy cardiac CT. Radiol Cardiothorac Imaging 2019; 1: ryct.2019180003.