Satoru Furuhashi

Diagnosis of anomalous origin of the right coronary artery using multislice computed tomography: evaluation of possible causes of myocardial ischemia.

Anomalous origin of the right coronary artery (RCA) is a rare condition, but may cause myocardial ischemia and sudden death. Multislice computed tomography, which allows three-dimensional visualization of the coronary artery with high spatial resolution, may be the most promising imaging modality for diagnosing this anomaly. We describe a patient with anomalous origin of the RCA arising from the left sinus of Valsalva. Volume rendering, and axial and curved multiplanar images showed stenosis in the proximal portion of the RCA that coursed between the aorta and the pulmonary artery, and an acute angled take-off of the RCA from the aorta. Three-dimensional virtual angioscopic images showed a hypoplastic RCA orifice and luminal narrowing in the proximal portion of the RCA. Multislice computed tomography was thought to be useful for detecting anomalous origin of the RCA and for evaluating possible causes of myocardial ischemia.

A giant left circumflex coronary artery – right atrium arteriovenous fistula detected by multislice spiral computed tomography

A 70-year-old man was referred to our hospital because of symptoms of congestive heart failure. The initial echocardiographic study revealed a dilated and poorly contractile left ventricle, a markedly dilated left circumflex coronary artery (LCx), and an enormously dilated anomalous vessel inferior to the right atrium (RA). Color Doppler flow mapping documented a turbulent flow in the LCx, draining into the RA through the anomalous vessel. An LCx-RA arteriovenous fistula was suspected. Multislice spiral computed tomography (MSCT) imaging was performed using a Somatom Volume Zoom (4-detector-row, Siemens, Stuttgart, Germany) with collimation 1.0 mm, table feed 1.5 mm/rotation, 140 kV, 320 mA, and gantry rotation time 500 ms. Our scan protocol and image reconstruction method have been reported previously. 1 Metoprolol (40 mg) was

Regression of an atherosclerotic coronary artery plaque demonstrated by multislice spiral computed tomography in a patient with stable angina pectoris.

Multislice spiral computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also atherosclerotic plaques in patients with coronary artery disease. In this report, we describe a patient with stable angina in whom the regression of the plaque was documented by serial MSCT examinations. In the patient, a 46-year-old man with stable angina, MSCT revealed a stenotic lesion at the proximal portion of the left anterior descending artery. Axial, curved multiplanar reconstruction and cross-sectional images consistently depicted a protruding computed tomography low-signal mass suggesting an atherosclerotic plaque. Intracoronary ultrasound (ICUS) also documented an eccentric soft plaque with an echo-lucent mass suggesting a lipid core. Lipid-lowering therapy with pravastatin was started. Follow-up MSCT performed 7 months later documented an increase in the luminal area while the external vessel area remained unchanged. The regression of the plaque was also confirmed by a follow-up ICUS study. MSCT was thought to be feasible for serial evaluation of the plaque size and texture.

Assessment of coronary artery abnormalities in a patient with Kawasaki disease by multislice computed tomography

The high spatial resolution of multislice computed tomography (MSCT) permits direct visualization of the coronary artery system. In this report, we describe coronary artery abnormalities in a young adult with Kawasaki disease. MSCT detected a giant coronary artery aneurysm, coronary artery stenosis in the first diagonal artery, and a multi-layered structure in the right coronary artery and the left circumflex artery. These findings corresponded well to those obtained by coronary angiography. MSCT has the potential to be the standard diagnostic tool for the follow-up evaluation of coronary artery disease in adolescents and young adults with Kawasaki disease.

Radiological assessment following thermoradiation therapy for primary pleural synovial sarcoma: case report

Primary pleural synovial sarcoma is a rare disease with poor outcomes. Although hyperthermia therapy as part of a combined treatment regimen can offer improved local tumor control, only two reports of hyperthermia therapy for synovial sarcoma have appeared in the literature, and these sarcomas were not of pleuropulmonary origin. This report of an advanced inoperable primary pleural synovial sarcoma is the first to address the use of hyperthermia therapy in combination with chemoradiotherapy for this disease, together with radiological assessment following that therapy. Computed tomography performed after thermoradiation showed a decrease in tumor size and a characteristic unenhanced low-density area in the tumor suggesting that tumor necrosis resulted from the therapy. These image findings were helpful in assessing the tumor response to thermoradiation. We believe that hyperthermia therapy combined with chemoradiotherapy should be regarded as an option for advanced primary pleural synovial sarcoma. This would give computed tomography important role in evaluating this approach.

Data Management Solution for Large-Volume Computed Tomography in an Existing Picture Archiving and Communication System (PACS)

Multidetector row computed tomography (MDCT) creates massive amounts of data, which can overload a picture archiving and communication system (PACS). To solve this problem, we designed a new data storage and image interpretation system in an existing PACS. Two MDCT image datasets, a thick- and a thin-section dataset, and a single-detector CT thick-section dataset were reconstructed. The thin-section dataset was archived in existing PACS disk space reserved for temporary storage, and the system overwrote the source data to preserve available disk space. The thick-section datasets were archived permanently. Multiplanar reformation (MPR) images were reconstructed from the stored thin-section datasets on the PACS workstation. In regular interpretations by eight radiologists during the same week, the volume of images and the times taken for interpretation of thick-section images with (246 CT examinations) or without (170 CT examinations) thin-section images were recorded, and the diagnostic usefulness of the thin-section images was evaluated. Thin-section datasets and MPR images were used in 79% and 18% of cases, respectively. The radiologists’ assessments of this system were useful, though the volume of images and times taken to archive, retrieve, and interpret thick-section images together with thin-section images were significantly greater than the times taken without thin-section images. The limitations were compensated for by the usefulness of thin-section images. This data storage and image interpretation system improves the storage and availability of the thin-section datasets of MDCT and can prevent overloading problems in an existing PACS for the moment.

Inguinal bladder hernia: multi-planar reformation and 3-D reconstruction computed tomography images useful for diagnosis.

We present a case of inguinal bladder hernia that was preoperatively diagnosed with the aid of multi-planar reformation (MPR) and 3-D reconstruction computed tomography (CT) (Figs 1,2) and confirmed with surgery. While CT is a useful tool, reported CT findings are not consistently observed. To make the diagnosis with certainty, an oblique sagittal MPR CT image which is reconstructed along the inguinal canal by volume data (1 mm slice thickness) was completed and shows clear visualization of the continuity from the bladder to the hernia (arrow). 3-D reconstruction CT imaging by volume rendering shows the herniated bladder situated lateral to the inferior epigastric artery (arrow). This is useful in demonstrating its exact location and its relationship with the surrounding structures such as the inferior epigastric vessels, as shown in our case.

A Computer-Assisted System for Diagnostic Workstations: Automated Bone Labeling for CT Images

Although accurate information on thoracolumbar bone structure is essential when computed tomography (CT) images are examined, there is no automated method of labeling all the vertebrae and ribs on a CT scan. We are developing a computer-aided diagnosis system that labels ribs and thoracolumbar vertebrae automatically and have evaluated its accuracy. A candidate bone was extracted from the CT image volume data by pixel thresholding and connectivity analysis. All non-bony anatomical structures were removed using a linear discriminate of distribution of CT values and anatomical characteristics. The vertebrae were separated from the ribs on the basis of their distances from the centers of the vertebral bodies. Finally, the thoracic cage and lumbar vertebrae were extracted, and each vertebra was labeled with its own anatomical number by histogram analysis along the craniocaudal midline. The ribs were labeled in a similar manner, based on location data. Twenty-three cases were used for accuracy comparison between our method and the radiologist’s. The automated labeling of the thoracolumbar vertebrae was concordant with the judgments of the radiologist in all cases, and all but the first and second ribs were labeled correctly. These two ribs were frequently misidentified, presumably because of pericostal anatomical clutter or high densities of contrast material in the injected veins. We are confident that this system can contribute usefully as part of a picture archiving and communication system workstation, though further technical improvement is required for identification of the upper ribs.

Visualization of a coronary collateral channel by multislice spiral computed tomography

motion artifacts which occur during the rapid filling and atrial contraction periods, and allows for a better image quality as compared to the conventional technique which utilizes the R-R interval as a reference. The data were transferred to a computer workstation for post-processing (3D Virtuoso, Siemens, Germany). The scan was completed within 15min and post-processing, including manual reconstruction of volume rendering and curved multiplanar images, required 20min with the use of our image reconstruction method. Figure 1A demonstrates complete occlusion at the proximal portion of the RCA with retrograde contrast enhancement of the distal segments and the right ventricular branch. Figure 1B shows a volume-rendering image of the distal portions of the RCA and the LCx. A well-developed collateral channel connecting the distal portion of the LCx and the atrioventricular node branch of the RCA was visualized. A curved multiplanar reconstruction image also depicted a collateral channel (Fig. 1C). With its excellent spatial resolution, MSCT not only permits visualization of the major coronary artery segments, but also has the potential to detect well-developed collateral channels in patients with complete coronary artery occlusion when artifact-free images are obtained.