Shinsuke Shimoyama

The differences between bisecting and off‐center cuts of the aortic root: The three‐dimensional anatomy of the aortic root reconstructed from the living heart

It is axiomatic that the diameter of the virtual basal ring of the aortic root, which is elliptical rather than circular, will differ when assessed using between bisecting as opposed to off‐center cuts. Such differences, however, which pertain directly to echocardiographic assessments of the so‐called valvar annulus, have yet to be systematically explored.

Diversity and Determinants of the Three-dimensional Anatomical Axis of the Heart as Revealed Using Multidetector-row Computed Tomography

The location of the heart within the thorax varies significantly between individuals. The resultant diversity of the anatomical cardiac long axis, however, and its determinants, have yet to be systematically investigated. We enrolled 100 consecutive patients undergoing coronary arterial computed tomographic angiography, decomposing the vector of the anatomical cardiac long axis by projecting it to horizontal, frontal, and sagittal planes. The projected vectors on each plane were then converted into three rotation angles using coordinate transformation. We then measured the extent of aortic wedging, using the vertical distance between the inferior margins of the non‐adjacent aortic sinus and the epicardium. We took the aortic root rotation angle to be zero when an “en face” view of the right coronary aortic sinus was obtained in the frontal view, defining leftward rotation to be positive. The mean horizontal, frontal, and sagittal rotation angles were 48.7° ± 9.5°, 52.3° ± 12.0°, and 34.0° ± 11.2°, respectively. The mean extent of aortic wedging, and the aortic root rotation angle, were 42.7 ± 9.8 mm, and 5.3° ± 16.4°. Horizontal rotation of the anatomical axis was associated with leftward and ventral rotation, and vice versa. Multivariate analysis showed aortic root rotation to be associated with horizontal cardiac rotation, while aortic wedging is associated with frontal and sagittal cardiac rotation. We have quantified the marked individual variation observed in the anatomical axis of the living heart, identifying the different mechanisms involved in producing the marked three‐dimensional diversity of the living heart. Anat Rec, 300:1083–1092, 2017.

Tailored Duration of Contrast Material Injection in High-pitch Computed Tomographic Aortography With a Double-level Test Bolus Method

Objectives To achieve the efficient usage of contrast material (CM) in high-pitch CT aortography, an appropriate duration of the CM injection is crucial. We used a modification of the double-level test bolus method for determination of proper injection duration with the aim of evaluating the image quality of tailored-duration CM injection compared with that of a fixed duration. Materials and Methods The institutional review board approved retrospective review of 80 consecutive subjects who had undergone high-pitch 70-kVp CT aortography with a modified double-level test bolus method. The interval between peak enhancement at the aortic root and femoral artery was derived from the time/attenuation curves. A total of 40 subjects underwent CT aortography with individually set duration time from the results. The remaining subjects underwent CT aortography with a fixed-duration time. The density values at several parts of the aorta were assessed. The differences in image quality and CM amount used for each method were assessed by Welch test. Results The injection duration was almost 50% shorter (median, 15 seconds; range, 11–25 seconds) when individually tailored. The mean CM amount was reduced by 50% (46.2–23.9 mL, P < 0.01). The range of mean CT attenuation throughout the aorta was not significantly different between the 2 methods (316–327 HU and 305–321 HU, P > 0.05, respectively). Conclusions The modified double-level test bolus method in high-pitch CT aortography can significantly reduce the amount of CM without adversely affecting image quality.

Optimal reconstruction of left ventricular outflow tract obstruction before surgical myectomy in a case with hypertrophic obstructive cardiomyopathy

We present optimally reconstructed three‐dimensional computed tomography images of left ventricular outflow obstruction, comprehensive left ventriculography, and comparable intraoperative transesophageal echocardiography, as well as serial operative pictures, to facilitate the understanding of live‐heart anatomy of hypertrophic obstructive cardiomyopathy. As shown in this case, detailed morphological analysis around the left ventricular outflow tract using preoperative computed tomography would be feasible and useful. The present case highlights the importance of obtaining complete three‐dimensional information present in the acquired computed tomography dataset because computed tomography is not entirely noninvasive or free of radiation exposure and contrast material.

Advantages of 70-kV CT Angiography for the Visualization of the Adamkiewicz Artery: Comparison with 120-kV Imaging

BACKGROUND AND PURPOSE: Preprocedural identification of the Adamkiewicz artery is crucial in patients with aortic diseases. This study aimed to compare 70-kV CTA with conventional 120-kV CTA for the identification of the Adamkiewicz artery, examining differences in radiation dose and image quality. MATERIALS AND METHODS: We retrospectively analyzed 2 equal groups of 60 patients who had undergone 70-kV or 120-kV CTA to detect the Adamkiewicz artery before aortic repair. Size-specific dose estimate, the CT number of the aorta, and the contrast-to-noise ratio of the anterior spinal artery to the spinal cord were recorded. Furthermore, detectability of the Adamkiewicz artery was evaluated by using a 4-point continuity score (3, definite to 0, undetectable). RESULTS: There was significantly lower radiation exposure with 70-kV CTA than 120-kV CTA (median size-specific dose estimate, 23.1 versus 61.3 mGy, respectively; P < .001). CT number and contrast-to-noise ratio were both significantly higher in the 70-kV CTA group than the 120-kV group (999.1 HU compared with 508.7 HU, and 5.6 compared with 3.4, respectively; P < .001 for both). Detectability of the Adamkiewicz artery was not impaired in the 70-kV CTA group (90.0% versus 83.3% in the 120-kV group, P = .28). Moreover, the Adamkiewicz artery was detected with greater confidence with 70-kV CTA, reflected by a significantly superior continuity score (median, 3) compared with 120-kV CTA (median, 2; P = .001). CONCLUSIONS: Seventy-kilovolt CTA has substantial advantages for the identification of the Adamkiewicz artery before aortic repair, with a significantly lower radiation exposure and superior image quality than 120-kV CTA.

Serial observation of electrocardiographic responses to corticosteroid therapy in a patient with right ventricular-predominant cardiac sarcoidosis

Predominant or isolated right ventricular involvement in cardiac sarcoidosis is uncommon, but should always be considered in a case of right ventricular hypertrophy combined with ventricular arrhythmia and/or conduction disturbance. Although improvement in right ventricular hypertrophy and atrioventricular conduction disturbance following corticosteroid therapy has been reported, the detailed serial electrocardiographic responses during corticosteroid therapy, as well as temporal changes in the electrocardiographic, biochemical, and morphological responses, have not been reported. We describe the clinical course and supportive imaging findings of reversible right ventricular hypertrophy and cardiac conduction disturbance in a case of right ventricular-predominant cardiac sarcoidosis.

A case of acute heart failure due to myocardial infiltration of mycosis fungoides

Mycosis fungoides (MF) has been reported to be the most common cutaneous lymphoma with a good prognosis and myocardial infiltration is clinically rare. We hereby report a case of rapidly progressing acute heart failure due to myocardial infiltration by MF. Perfusion cardiac magnetic resonance imaging (MRI) demonstrated a massive perfusion defect in the left ventricle (LV) where multiple nodular enhancement areas by delayed enhancement MRI could be documented in the postero-lateral wall of the LV, which resulted in a deterioration of the LV function and mitral regurgitation. Autopsy confirmed the myocardial infiltration by the MF, which corresponded with the MRI findings. <Learning objective: Symptomatic heart failure patients with myocardial infiltration by mycosis fungoides (MF) have a poor prognosis because they could not undergo chemotherapy for primary disease. Therefore, early diagnosis is important for improvement of prognosis. The routine assessment of the cardiac involvement by cardiac magnetic resonance imaging as well as transthoracic echocardiography should be performed for an early recognition of myocardial infiltration even in asymptomatic MF patients.>.

The lesion characteristics assessed by LGE‐MRI after the cryoballoon ablation and conventional radiofrequency ablation

Rhythm outcomes after the pulmonary vein isolation (PVI) using the cryoballoon (CB) are reported to be excellent. However, the lesions after CB ablation have not been well discussed. We sought to characterize and compare the lesion formation after CB ablation with that after radiofrequency (RF) ablation.

The first case of “locked-in leaflet” after transcatheter aortic valve replacement in a patient with bicuspid aortic stenosis

This case report is about an 85‐year‐old woman with bicuspid aortic stenosis (AS). Although preoperative multimodality imaging showed challenging anatomical aspects, transcatheter aortic valve replacement (TAVR) was selected to be performed as a less invasive alternative treatment approach, owing to her comorbidity. Postoperative transesophageal echocardiography and multidetector‐row computed tomography revealed the presence of “locked‐in leaflet” caused by stent distortion due to pinching by calcified native leaflets, with nodular calcification preventing the full expansion of the valve, which resulted in moderate perivalvular leakage. This is the first reported case of bicuspid AS treated with TAVR that eventually resulted in “locked‐in leaflet.”

Relationship between the membranous septum and the virtual basal ring of the aortic root in candidates for transcatheter implantation of the aortic valve: Variation in the Membranous Septum in TAVI

Knowledge of the anatomy of the membranous septum, as a surrogate to the location of the atrioventricular conduction axis, is a prerequisite for those undertaking transcatheter implantation of the aortic valve (TAVI). Equally important is its relationship of the virtual basal ring. This feature, however, has yet to be adequately described in the living heart. We analyzed computed tomographic angiographic datasets from 107 candidates (84.1 ± 5.2 years, 68% women) for TAVI. Using multiplanar reconstructions, we measured the height and width of the membranous septum, and the distances of its superior and inferior margins from the virtual basal ring plane. We also assessed the extent of wedging of the aortic root between the mitral valve and the ventricular septum. Mean heights and widths of the membranous septum were 6.6 ± 2.0, and 10.2 ± 3.1 mm, respectively, with its size significantly associated with that of the aortic root (P < 0.05). Its superior and inferior margins were 4.5 ± 2.3 and 2.1 ± 2.1 mm, respectively, from the plane of the basal ring. The inferior distance, the surrogate for the adjacency of the atrioventricular conduction axis, was ≤ 5mm in 91% of the patients. Deeper wedging of the aortic root was independently correlated with a shorter inferior distance (β = 0.0569, P = 0.0258). The membranous septum is appreciably closer to the virtual basal ring than previously appreciated. These findings impact on estimations of the risk of damage to the atrioventricular conduction axis during TAVI. Clin. Anat. 31:525–534, 2018.