心臓核医学の右心系疾患への応用—右室二腔症，右室内巨大球状血栓，多発性肺梗塞による右室肥大及び三尖弁閉鎖不全，右室右房梗塞症例

Clinical application of radionuclide cardiac study to the right heart diseases

　心臓核医学は，近年めざましく発展し，主として虚血性心疾患の非侵襲的な検査法として確立されている。最近では，種々の右心系疾患の診断や右心機能評価に有用であったという報告も散見される。著者らも4例の稀な右心系疾患（右室二腔症，右室内巨大球状血栓，多発性肺梗塞に伴う右室肥大と三尖弁閉鎖不全，右室右房梗塞）を経験し，それらに心臓核医学法を施行する機会を得たので，その有用性について報告する。

We experienced the four cases of rare right heart diseases : those are two-chambered right ventricle, ball thrombus in right ventricle, right ventricular hypertrophy and tricuspid valve regurgitation due to multiple pulmonary infarction, and right ventricular and right atrial infarction. The preoperative or ante mortem diagnosis of these diseases is difficult, especially by use of a noninvasive technique. This report shows the usefulness of radionuclide cardiac study for diagnosis of these cases. In the two-chambered right ventricle, abnormal muscle bundle was visualized by ²⁰¹Tlcl and was observed as the filling defect by ^99mTc-HSA radionuclide angiography. The ball thrombus showed the fillingdefect of ^99mTc-HSA in the right ventricle but was not extracted by ²⁰¹Tlcl in the site of the defect area. In the multiple pulmonary infarction, the right ventricular free wall was visualized by ²⁰¹Tlcl, and during right ventricular systole, regurgitation from right atrium to inferior vena cava was noticed by means of ^99mTc-HSA radionuclide angiography. These findings suggested right ventricular hypertrophy and tricuspid valve regurgitation. In the right ventricular and right atrial infarction, right ventricular ejection fraction and right atrial fractional emptying were lower than those of normal controls.