Development of Cardiac Computed Tomography for Evaluation of Aortic Valve Stenosis

Figure 1. Motion artifact improvement in the right coronary artery using a new motion correction algorithm. From left to right: images without motion correction algorithm (A), with the 1st generation motion correction (B), and with the 2nd generation motion correction (C). Motion artifact is gradually reduced by using the new motion correction algorism (yellow arrow).

Figure 2. Usefulness of the 2nd generation motion correction algorithm in a case with severe motion artifacts for aortic valve calcification score analysis. Comparison of images of a severely calcified aortic valve (AV) (white arrows) with and without severe motion artifacts is shown. These were calcified AV images from the same patient without the second-generation motion correction algorithm (SSF2) (A) and with SSF2 (B). The Agatston calcium score of the AV was measured using both images. The score decreased from 2875 (C) in the image without SSF2-corrected image to 2214 (D) in the image with SSF2, mainly due to the presence of motion artifacts. Using the new motion correction algorism, motion artifact of aortic valve calcification is reduced (upper yellow arrow) and the calcification score is also reduced (lower yellow arrow).

Figure 3. Usefulness of the 2nd generation motion correction algorithm in a case with severe motion artifacts for the measurement of the size of aortic annulus. The size of aortic annulus is usually measured on the systolic image before transcatheter aortic valve implantation (TAVI) at 30% of the R-R waves interval. These are the images of aortic annulus in the same patient, without the 2nd generation motion correction algorithm (A) and with (B). The 2nd generation motion correction algorithm is useful to decrease the motion artifacts of aortic annulus (white arrows) for the accurate measurement of the size of aortic annulus to decide the artificial valve in TAVI. The new motion correction algorism reduces motion artifact-induced blurring of the aortic valve annulus (yellow arrow).

Figure 4. Thoracic aortic coarctation in a case with severe aortic valve stenosis. These were maximum-intensity projection images of computed tomography in a case with severe aortic valve stenosis and aortic coarctation. Panel (A) shows severe aortic valve calcifications on a short axial image of the aortic valve. Panel (B) shows coarctation of the aortic arch and severe aortic valve calcifications. Yellow arrows indicate a highly calcified aortic valve. A white arrow indicates aortic coarctation.

Figure 5. Extracellular volume analysis of left ventricular myocardium in a case with severe aortic valve stenosis. Extracellular volume (ECV) of left ventricular myocardium (LVM) on computed tomography (CT) in this patient with severe aortic valve (AV) stenosis was 39.37% (A), and this patient was admitted because of congestive heart failure 12 months after the transcatheter AV implantation(TAVI). ECV was measured using a specific software (Ziostation 2, Ziosoft, Tokyo, Japan). Short axial, 2-chamber, and 4-chamber views of late enhancement LVM were shown in Figure (B–D). The dotted lines over the LV in the long-axis images (C,D), indicate the slices of the short-axial images used for analysis (The red dotted line indicates the currently displayed short axis image) (B).

Figure 6. Myocardial longitudinal strain analysis in a patient with severe aortic stenosis. Myocardial longitudinal strain (LS) analysis was performed using specific software (Ziostation REVORAS v5.3.0.0, Ziosoft, Tokyo, Japan) in a case with severe aortic stenosis. Peak global LS of the left ventricular myocardium was measured using longitudinal views (Panel A) and decreased to −7.4 (Panel B), and this patient was admitted because of congestive heart failure 13 months after the transcatheter aortic valve replacement.

Figure 7. Severe calcification of aortic annulus in a case with severe aortic stenosis. An yellow arrow indicates severe calcification contiguous from the aortic annulus to the lower part of the aortic valve.

Figure 8. Compute tomography blood flow analysis around sinus of Valsalva in a case after transcatheter aortic valve replacement. (A): The computed tomography (CT) flow analysis of this case after transcatheter aortic valve replacement shows a marked decrease in blood flow (dark blue lesion) in the right coronary cusp (RCC) of sinus of Valsalva (SOV) (red circles mean each cusp of SOV, LCC means left coronary cusp). (B): A huge thrombus was detected in the RCC of SOV on CT in the same patient (yellow arrow).

Figure 9. Summary of utility of cardiac computed tomography for evaluation of aortic valve stenosis. AS: aortic valve stenosis, AV: aortic valve, LFLG: low flow low gradient, CR: contractile reserve, CT: computed tomography, AVR: aortic valve replacement, TAVI: transcatheter aortic valve implantation, CAD: coronary artery disease, PCI: percutaneous coronary artery intervention, CABG: coronary artery bypass grafting, CA: cardiac amyloidosis.