Multislice Computed Tomography for Detection of Patients With Aortic Valve Stenosis and Quantification of Severity
Gudrun M. Feuchtner, MD*,*,
Wolfgang Dichtl, MD ,
Guy J. Friedrich, MD,
Mathias Frick, MD,
Hannes Alber, MD,
Thomas Schachner, MD ,
Johannes Bonatti, MD,
Ammar Mallouhi, MD*,
Thomas Frede, MD*,
Otmar Pachinger, MD,
Dieter zur Nedden, MD* and
Silvana Müller, MD
* Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck, Austria
Clinical Department of Cardiology, Innsbruck Medical University, Innsbruck, Austria
Clinical Department of Cardiac Surgery, Innsbruck Medical University, Innsbruck, Austria
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Figure 1 Mid-late systolic multislice computed tomography image reconstruction with retrospective electrocardiogram-gating: within mid-late systole (ejection phase: 2 and 3), aortic valve is opened. Image reconstruction window (R) was positioned within mid-late systole approximately corresponding to T-wave. The time point of reconstruction window was estimated by subtracting the time of isovolumetric contraction (1) (0.05 s) from overall duration of cardiac cycle dependent on heart rate. bpm = beats/min.
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Figure 2 Three-dimensional multislice computed tomography image reconstruction: left coronal oblique long axis (A), left sagittal oblique short axis (B), and cross-sectional transversal (C) in a patient with severe aortic stenosis and heavy calcifications (C). Black arrow pointing at aortic valve orifice (O). White arrow denotes the eccentric systolic jet (J) created from accelerated blood flow (white) through aortic valve orifice. AA = ascending aorta; LV = left ventricle. The white line indicates the plane of image C at which aortic valve area was circled with a digital calliper and computed in cm2.
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Figure 3 Quantification of aortic valve area (AVA) ("planimetry"): AVA was reconstructed at three cross-sectional transversal levels (A to C). The smallest AVA value was taken for effective AVA. AA = ascending aorta; LV = left ventricle.
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Figure 4 Aortic valve stenosis, diastole versus systole, bicuspid versus tricuspid valve: by using retrospective electrocardiogram-gating, split diastolic and systolic multislice computed tomography image reconstruction is feasible. The aortic valve of four patients with aortic stenosis is shown closed during diastole at panels A, C, E, and H (left) and open during systole at panels B, D, F, and G (right) allowing planimetry of aortic valve area (AVA) (tricuspid [A to D] valve in two patients vs. bicuspid [E to H] valve morphology in two patients). Note the characteristic "fish-mouth" feature of bicuspid aortic valve within systole (H). White arrows pointing at valve calcifications; black arrows denote AVA (F). Different post-processing techniques were applied: multiplanar reformation (A to F and H) and slab volume rendering technique (G); LCC = left coronary cusp; R = right coronary ostium; RCC = right coronary cusp. For accompanying videos for panels A and B, and panel G, please see the Appendix.
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Figure 5 Linear regression analysis illustrates a good correlation of aortic valve area (AVA) (in cm2) derived by multislice computed tomography (MSCT) (r = 0.89; p < 0.001) compared to transthoracic echocardiography (TTE).
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Figure 6 Bland-Altman plot demonstrates a good intermodality agreement between multislice computed tomography (MSCT) and transthoracic echocardiography (TTE) with a slight overestimation of aortic valve area (AVA) by MSCT (+0.04 cm2).
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Figure 7 Aortic valve with volume rendering technique (VRT) (A) versus multiplanar reformation (B): aortic valve area appeared split and was calculated by the addition of both area 1 (A1) and area 2 (A2). White arrow denotes aortic valve calcification, which can be displayed better with VRT. LCC = left coronary cusp; NCC = non-coronary cusp; RCC = right coronary cusp.
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