Preprocedural planning of transcatheter mitral valve interventions by multidetector CT: What the radiologist needs to know

Abstract

Mitral regurgitation is the most common valve disorder in the Western world, and although surgery is the established therapeutic gold standard, percutaneous transcatheter mitral interventions are gaining acceptance in selected patients who are inoperable or at an exceedingly high surgical risk. For such patients, multidetector computed tomography (MDCT) can provide a wealth of valuable morphological and functional information in the preoperative setting. Our aim is to give an overview of the MDCT image acquisition protocols, post-processing techniques, and imaging findings with which radiologists should be familiar to convey all relevant information to the Heart Team for successful treatment planning.

Keywords: Cardiac multidetector computed tomography; Mitral regurgitation; Transcatheter mitral valve repair; Transcatheter mitral valve replacement.

Fig. 1

Reduction of motion artefacts due to high R-R interval variability by means of ECG-editing (a, before ECG-editing; b, after ECG-editing).

Fig. 2

(a–c) MPR views for optimal evaluation of the mitral valve complex (a, 4-chamber view; b, 2-chamber view; c, short axis view at the level of the mitral annulus, aligned parallel to dashed lines in b). (d) Straightened and stretched CPR views of the circumflex artery (arrow).

Fig. 3

VR views of the mitral valve complex (a) and the circumflex artery coursing along the left atrio-ventricular groove (b, arrow).

Fig. 4

Sizing of mitral annulus on MPR short axis view using Blanke's D-shape model. TT = trigone-to-trigone distance, SL = septal-to-lateral distance, 2p = perimeter. Mitral cross-sectional area can also be directly measured.

Fig. 5

(a) Mild and (b) moderate MAC as shown by 4-chamber (upper) and short axis MPR views (lower).

Fig. 6

Severe MAC as shown by 4-chamber (a) and short axis MPR views (b). MIP (c) and VR (d) views show the overall extent of MAC reaching the mitral-aortic curtain and the aortic valve.

Fig. 7

MDCT appearance of CCMA in a patient with atrial fibrillation and severe MR; (a) precontrast axial image, (b) 4-chamber and (c) short axis MPR views, (d) MIP and (e) VR views.

Fig. 8

2-chamber MPR view showing myocardial shelf (red dashed lines) in a patient with severe left ventricular dilation.

Fig. 9

Preprocedural assessment of the circumflex artery. (a) VR shows the vessel course along the left atrio-ventricular groove (arrow), whereas CPR (b) and CPR-derived cross-sections along the vessel centerline (c) provide detailed and reproducible information about its patency and distance from the mitral annulus.

Fig. 10

MIP (a) and VR images (b, c) show retroaortic course of the circumflex artery (arrow) in a patient with bulky MAC extending to the mitral-aortic curtain and the aortic valve.

Fig. 11

MPR (a) and VR images (b) allow assessment of the CS (asterisk) course, patency, and distance to the mitral annulus (double headed arrow). The single headed arrow in b) points to the circumflex artery. As shown in b), the patient has a bypass graft (saphenous vein) to the distal right coronary artery.

Fig. 12

Measurement of the aorto-mitral angle (light blue) from the intersection between the mitral annulus trajectory (straight line) and the LVOT long axis (dashed line). Asterisks indicate mitral leaflets.

Fig. 13

Some incidental findings that could occur upon systematic review of preprocedural MDCT studies. (a) 71-year-old male with bilateral pleural effusion (red asterisks) and lung nodule (arrow). (b) 78-year-old male with history of renal clear cell carcinoma previously treated with left nephrectomy and MDCT finding of hypervascular left subdiaphragmatic nodule (blue asterisk). (c) 82-year-old female with unexpected MDCT finding of pulmonary embolism (dashed arrows).