A 58-year-old man with a history of hypertension presents with dyspnea and chest discomfort. Echocardiography shows asymmetric left ventricular hypertrophy with an ejection fraction that is difficult to assess accurately due to geometric distortion. Cardiac MRI is ordered. The structure marked **A** in the 4-chamber view is the primary focus of assessment. Which of the following is the MOST important diagnostic advantage of cardiac MRI for evaluating this structure in suspected hypertrophic cardiomyopathy?