Rieko Ishimura

Prevalence and distribution of coronary calcium in asymptomatic Japanese subjects in lung cancer screening computed tomography

BACKGROUND Coronary artery calcium (CAC) is associated with a risk of coronary heart disease. The prevalence and distribution of the CAC score have been examined in Western countries, but few studies have been performed in Asia, and especially in Japan. The goal of this study was to investigate CAC scores in an asymptomatic Japanese population. METHODS CAC score and risk factors were analyzed in 1834 asymptomatic subjects who underwent lung cancer screening computed tomography. RESULTS CAC was present in 26.9% of all the subjects, 29.8% of the males, and 17.1% of the females. In all age groups, the CAC score was higher in males. In multivariate analysis, male gender [odds ratio (OR) 2.461, 95% confidence interval (CI) 1.361-4.452, p=0.002], aging (OR 1.102, 95% CI 1.081-1.123, p<0.001), dyslipidemia (OR 1.740, 95% CI 1.216-2.490, p=0.002), and fasting glucose (OR 1.008, 95% CI 1.002-1.015, p=0.012) were significantly associated with a CAC score >100. CONCLUSION The results of this study provide a pattern of CAC distribution based on age and gender in asymptomatic Japanese subjects. This pattern was similar to that in Western countries, although the absolute CAC scores were lower. High CAC scores were associated with male gender, aging, dyslipidemia, and fasting glucose.

Non-contrast myocardial perfusion using a novel 4D magnetic resonance arterial spin labeling technique: Initial experience

The aim of this study is to develop a novel non-contrast 4-dimensional MR arterial spin labeling (4D-ASL) technique (3D acquisition and time) and to investigate myocardial perfusion on healthy volunteers without administration of contrast materials. A non-contrast 4D-ASL technique was developed using the time-spatial labeling inversion pulse (Time-SLIP) to obtain myocardium perfusion of eight volunteers at 1.5 T. The tagging slab was placed on the proximal ascending aorta to invert the blood magnetization and mid-ventricle 3D images at diastolic phase were acquired with multiple tagging delays. The time resolved 3D images with various inversion times (TI) were registered and segmented for the visualization of myocardial signal changes along the TI, and perfusion curves were generated to identify the perfusion peaks. Blood flow from basal to apical slices was observed in all volunteers. Peak flow at the mid-ventricle was observed 200-400 ms after the blood was tagged at the aortic root blood. After the perfusion peak, all signals returned to the base line. The 4D Time-SLIP technique permits non-contrast perfusion images with high temporal resolution, which may potentially differentiate normal from diseased myocardium.

Clinical application of an automatic slice-alignment method for cardiac MR imaging.

PURPOSE We evaluated the usefulness of an automatic slice-alignment method to simplify planning of cardiac magnetic resonance (MR) scans with a 3-tesla scanner. METHODS We obtained 2-dimensional (2D) axial multislice images using steady-state free precession (SSFP) sequences covering the whole heart at the end-diastole phase with electrocardiography (ECG) gating in 38 patients. We detected several anatomical feature points of the heart and calculated all planes required for cardiac imaging based on those points. We visually evaluated the acceptability of an acquired imaging plane and measured the angular differences of each view between the results obtained by this method and by a conventional manual pointing approach. RESULTS The average visual scores were 3.4 ± 1.0 for short-axis images, 3.2 ± 0.9 for 4-chamber images, 3.2 ± 0.8 for 2-chamber images, and 3.3 ± 0.8 for 3-chamber images; average angular differences were 5.8 ± 5.1 (short axis), 7.7 ± 5.7 (4-chamber), 11.5 ± 6.7 (2-chamber), and 9.1 ± 4.6 degrees (3-chamber). Processing time was within 1.8 s in all subjects. CONCLUSION The proposed method can provide planes within the clinically acceptable range and within a short time in cardiac imaging of patients with various cardiac shapes and diseases without the need for high level operator proficiency in performing the examination and interpreting results.

Evaluation of clinical datasets in fully automatic planning assist system for cardiac magnetic resonance imaging.

Background Planning assist systems for cardiac MR examinations are necessary for easier operation and shorter examination times. Slice alignment systems [1] have played an important role in achieving these objectives. We propose a new automatic planning assist system for couch adjustment, local shimming, and axial multislice imaging as the input to a slice alignment system [2]. The new system employs an atlas-based segmentation technique using single scout volume data. In the present study, the accuracy and robustness of the proposed method were evaluated based on more than 50 datasets including clinical data, and the results were compared against the degree of interobserver error in manual annotation.

Isolated Cardiac Sarcoidosis Presenting with Stroke

https://e-kcj.org A 42-year-old man without past medical history presented to our hospital with temporary right sided hemiparalysis and dysarthria. Brain magnetic resonance imaging (MRI) showed multiple cerebrovascular infarctions (Figure 1). Electrocardiography showed sinus rhythm with frequent premature ventricular contractions (PVCs), but no atrial ventricular block. Echocardiography showed partial dyskinesis at the apical lesion and a significant left ventricular (LV) thrombus (Figure 2). Coronary computed tomography angiography (CTA) showed normal coronary arteries (Figure 3). The thrombus became small 4 weeks after anticoagulation therapy with warfarin, but it remained. Therefore, we could not conduct cardiac tissue biopsy because of the additional stroke risks. Gallium-67 scintigraphy showed no specific lesion (Figure 4). However, cardiac MRI showed multiple focal late gadolinium enhancement (LGE) in left ventricle (Figure 5B) where T2 star weighted image (T2WI) also showed pale high intensity (Figure 5A). It suggested active inflammation. Fasting 18F-fluorodeoxyglucose positron emission tomography (PET) after carbohydrate restriction showed multiple increased cardiac uptake lesions (Figure 6). However, apical lesions Korean Circ J. 2018 Mar;48(3):236-239 https://doi.org/10.4070/kcj.2017.0133 pISSN 1738-5520·eISSN 1738-5555

A Rare Case of Stress-Induced Cardiomyopathy due to Intracranial Aneurysm

Stress-induced cardiomyopathy (SICM) is characterized by transient systolic dysfunction of the apical and mid segments of the left ventricle without obstructive coronary artery disease. The precipitate causes are reported either an emotional or physically stressful event, which induces hyper-catecholamine secretion. It is extremely rare that SICM was induced by internal carotid artery (ICA) aneurysmal dilation. In this case report, we present an 86-year-old female patient with SICM induced by ICA aneurysm with panhypopituitarism, who on hormone replacement therapy had normalized asynergy.

Non-contrast myocardium blood flow: consideration of technical differences between 4D Time-SLIP using tagging aortic root and FAIR

Background A non-contrast 4D Time-Spatial Labeling Inversion Pulse (Time-SLIP) technique [1,2] (3D acquisition and time) has been developed to investigate myocardial bloodflow on healthy volunteers without administration of contrast materials. The technical differences are discussed between our 4D Time-SLIP using tagging aortic root and Flow-sensitive Alternating inversion recovery (FAIR) using a globally IR tagging pulse and control pulse in imaging plane [3,4].

Automatic slice-alignment method in cardiac magnetic resonance imaging for evaluation of the right ventricle in patients with pulmonary hypertension

We propose a new automatic slice-alignment method, which enables right ventricular scan planning in addition to the left ventricular scan planning developed in our previous work, to simplify right ventricular cardiac scan planning and assess its accuracy and the clinical acceptability of the acquired imaging planes in the evaluation of patients with pulmonary hypertension. Steady-state free precession (SSFP) sequences covering the whole heart in the end-diastolic phase with ECG gating were used to acquire 2D axial multislice images. To realize right ventricular scan planning, two morphological feature points are added to be detected and a total of eight morphological features of the heart were extracted from these series of images, and six left ventricular planes and four right ventricular planes were calculated simultaneously based on the extracted features. The subjects were 33 patients (25 with chronic thromboembolic pulmonary hypertension and 8 with idiopathic pulmonary arterial hypertension). The fou...

Automatic motion probe setting assist system for cardiac magnetic resonance imaging

Background Planning assist systems for cardiac MR examinations are necessary for easier operation and shorter examination times. This is also true for motion probe setting in whole-heart MR imaging. In previous reports, we proposed an automatic planning assist system for couch adjustment, local shimming, and axial multislice imaging using single scout volume data of the chest. This system employs an atlas-based segmentation technique, so it can detect not only the heart region but also various anatomical structures in the chest. In the present study, this technique was employed to detect the position of the top of the right hemidiaphragm for motion probe setting. The results were also compared against the degree of interobserver error in manual annotation. Methods An ECG-non-gated 3D fast field echo (FFE) single volume covering the entire chest area was acquired using a 1.5-T MRI scanner (Excelart VantageTM powered by Atlas, Toshiba Medical Systems) during a single breathhold with TR/TE = 3.7/1.3, FOV = 500x350x350 mm3 (coronal slab), and readout/phase/slice encode steps = 256/64/35 in an acquisition time of approximately 9 seconds. The acquired volume was then transformed to match a prepared model volume with manual annotation of the heart region and the position of the top of the right hemidiaphragm, permitting the motion probe region of the input data to be located. Accuracy was assessed by measuring the Euclidean distance between the position of the top of the right hemidiaphragm obtained by our

Effects of quality of dictionary in knowledge- based 6-plane automatic slice-alignment method for cardiac magnetic resonance imaging

Summary We have developed a new automatic slice-alignment method that employs a combination of knowledge-based algorithm and model based algorithm to determine six planes at the same time. We have also evaluated the effects of the quality of the dictionary used in this method. The results showed that the robustness of slice determination in the proposed method can be improved as compared to the model-based only algorithm by using an appropriate dictionary and can be further improved if a larger number of patient datasets is used. Background We have developed a new automatic slice-alignment method that employs a combination of knowledge-based algorithm and model based algorithm to determine six planes at the same time. We have also evaluated the effects of the quality of the dictionary used in this method.