左心室心尖閉鎖の解明：心尖部閉鎖の評価のためのマルチモダリティイメージング

Left ventricular (LV) apical obliteration represents a convergent imaging phenotype arising from diverse cardiac conditions, including thrombotic, hypertrophic, infiltrative, congenital, and neoplastic diseases. These conditions, despite sharing overlapping morphological features, require profoundly different management strategies. In this context, an accurate characterization of the LV apex is a cornerstone point, and can be performed through various techniques. Advances in multimodality imaging have substantially improved diagnostic precision, allowing clinicians to differentiate true obliteration from mimicking conditions such as hypertrabeculation, apical hypertrophy, or subendocardial fibrosis. This review provides a comprehensive overview of the anatomical variability of the LV apex and its implications for imaging interpretation. We appraise the role of echocardiography, including contrast-enhanced and speckle-tracking studies-alongside cardiac magnetic resonance (CMR), computed tomography (CT), and selective nuclear imaging in the evaluation of apical pathology. For each principal cause of apical obliteration-LV thrombus, apical hypertrophic cardiomyopathy, left ventricular non-compaction, endomyocardial fibrosis, cardiac amyloidosis, and intracardiac tumors-we outline key diagnostic clues, imaging red flags, and distinguishing tissue characteristics. Special emphasis is given to the incremental value of CMR for tissue characterization, thrombus detection, and fibrosis mapping, as well as to the interpretative challenges posed by apical foreshortening, near-field artefacts, and suboptimal acoustic windows. A practical, stepwise imaging framework is proposed to guide clinicians through the differential diagnosis of apical obliteration using an integrated multimodality approach. Future directions include the incorporation of 4D flow, advanced mapping techniques, and artificial intelligence-powered analysis to refine apical phenotyping and identify early disease signatures. Recognizing the full spectrum of apical pathology and its imaging manifestations is essential to prevent misdiagnosis, enable timely therapeutic decisions, and improve risk stratification.