Chisato Kondo

Tetralogy of fallot with pulmonary atresia associated with chromosome 22q11 deletion

OBJECTIVES The purpose of this study was to clarify characteristics of tetralogy of Fallot and pulmonary atresia associated with chromosome 22q11 deletion. BACKGROUND DiGeorge syndrome and conotruncal anomaly facies syndrome are associated with chromosome 22q11 deletion (hemizygosity). Associated cardiac anomalies include tetralogy of Fallot, truncus arteriosus and interrupted aortic arch. METHODS Twenty-three patients with tetralogy of Fallot and pulmonary atresia were proved to have chromosome 22q11 deletion with fluorescent in situ hybridization using N25 probe (Oncor). Cardiovascular anomalies were compared with those in 26 patients with tetralogy of Fallot and pulmonary atresia without the deletion. Cardiovascular anomalies were studied with cardiac catheterization, cineangiography and echocardiography. RESULTS In patients with 22q11 deletion, additional anomalies of the aortic arch, ductus arteriosus and pulmonary artery were more common as follows: right aortic arch (70% with deletion vs. 23% without deletion), high aortic arch reaching third rib (43% vs. 15%), aberrant left subclavian artery (35% vs. 0%), absent ductus arteriosus (83% vs. 46%), major aortopulmonary collateral arteries (91% vs. 50%), absent confluent central pulmonary arteries (48% vs. 4%). CONCLUSIONS In patients with tetralogy of Fallot and pulmonary atresia, additional anomalies of the aortic arch, ductus arteriosus and pulmonary arteries are more common in patients with than in those without the 22q11 deletion.

Tetralogy of Fallot associated with chromosome 22q11 deletion

Abstract In summary, all patients with tetralogy and 22qH deletion had 1 to 4 additional conotruncal anomalies, such as high aortic arch, right aortic arch, infundibular septal defect, aberrant origin of the subclavian artery, major aortopulmonary collateral arteries, and anomalous ductus arteriosus causing isolation of either the left pulmonary artery or the subclavian artery.

Cardiac anomalies associated with a chromosome 22q11 deletion in patients with conotruncal anomaly face syndrome

Among 114 cardiac patients with conotruncal anomaly face syndrome and DiGeorge syndrome, 100 patients were found to have a chromosome 22q11 deletion. Those with the deletion included 73 patients with tetralogy of Fallot, 12 with ventricular septal defect, 5 with aortic arch anomalies without intracardiac anomaly, 4 with interrupted aortic arch, 2 with double-outlet right ventricle, 2 with truncus arteriosus, 1 with complete transposition, and 1 with atrial septal defect.

Comparison of Imaging Protocols for 18F-FDG PET/CT in Overweight Patients: Optimizing Scan Duration Versus Administered Dose

The quality of 18F-FDG PET/CT images of overweight patients is often degraded. We evaluated the effect of optimizing injected dose or acquisition time on the quality of images of overweight patients using lutetium oxyorthosilicate PET/CT with high-performance detector electronics. Methods: We initially retrospectively measured radioactivity concentrations and signal-to-noise ratios (SNRs) in the liver relative to body weight for 80 patients who had undergone 18F-FDG PET/CT according to our standard protocol (injected dose, 3.7 MBq/kg; acquisition time, 2 min/bed position). The patients were grouped (n = 20 per group) according to baseline body weight as G1 (≤59 kg), G2 (60–69 kg), G3 (70–84 kg), and G4 (≥85 kg). We compared the SNRs of G1 with those of G2, G3, and G4 and calculated the ratio squared as a factor to correct the acquisition parameters for overweight patients. We then prospectively enrolled 120 patients according to the same body weight criteria. We multiplied the correction factors to optimize injected doses or acquisition times and defined dose-adjusted groups (n = 20 per group) and time-adjusted groups (n = 20 per group). G2 dose was defined as 5.59 ± 0.19 MBq/kg, G3 dose as 7.29 ± 0.33 MBq/kg, and G4 dose as 8.88 ± 0.43 MBq/kg. G2 time was defined as 3 min/bed position, G3 time as 4 min/bed position, and G4 time as 5 min/bed position. Results: Although liver activities did not significantly differ among G1 through G4 irrespective of patient weight, SNR progressively decreased as patient weight increased. The liver activities of G2 dose, G3 dose, and G4 dose were, respectively, 1.4-, 1.9-, and 2.5-fold higher than those of the baseline counterparts. Nevertheless, the increased liver activities of G2 dose, G3 dose, and G4 dose did not significantly affect SNR, compared with the baseline groups. In contrast, the SNR of G4 time was significantly higher than that of G4. Conclusion: Our findings suggest that the quality of images acquired from heavier patients can be maintained only by scanning for longer periods. Increasing the dose per kilogram of body weight did not improve the quality of lutetium oxyorthosilicate PET/CT images.

Detection of coronary artery stenosis in children with Kawasaki disease. Usefulness of pharmacologic stress 201Tl myocardial tomography.

This study determined the feasibility and accuracy of quantitative 201Tl myocardial single-photon emission computed tomography (SPECT) after dipyridamole infusion to detect coronary obstructive lesions in children with Kawasaki disease. 201Tl distribution after dipyridamole infusion was measured in 23 normal children, and with these normal values, quantitative analysis of SPECT was performed in 49 patients. Thirty-four patients had coronary stenosis 90% or greater on angiograms. Side effects resulting from systemic vasodilation were observed in about 70%. Angina pectoris and ischemic ST changes were observed only in patients with coronary stenosis. These symptoms disappeared after aminophylline infusion. Results of visual and quantitative analysis of SPECT were compared. SPECT data were shown on two-dimensional polar maps, and the extent and severity scores were calculated. The sensitivity of SPECT for detection of overall coronary stenosis was 91% (visual analysis) and 88% (quantitative analysis). The specificity of SPECT was 60% visually and 93% quantitatively. The sensitivity of quantitative analysis to detect individual coronary stenosis was similar to that of visual analysis. However, the specificity of visual analysis to detect individual coronary artery stenosis was significantly less than that of quantitative analysis. From these data, we conclude that quantitative analysis of myocardial SPECT after dipyridamole infusion is a safe and accurate diagnostic method for identifying coronary stenosis in children with Kawasaki disease.

Real-time volumetric imaging of human heart without electrocardiographic gating by 256-detector row computed tomography: initial experience.

Objective: The feasibility of human cardiac imaging using a prototype 256-detector row cone-beam computed tomography (256CBCT) scanner without electrocardiographic gating was examined. Methods: Two healthy male volunteers were examined by contrast-enhanced 256CBCT. The number of detectors was 912 × 256, each measuring approximately 0.5 mm × 0.5 mm at the center of rotation. The craniocaudal coverage was approximately 100 mm after reconstruction by the Feldkamp-Davis-Kress algorithm. The effective time resolution was 500 milliseconds using a half-scan algorithm. Results: Serial enhancement of the left ventricular myocardium was detected. The right and left coronary arteries at proximal and distal segments were depicted without significant blurring. Although the left ventricular wall motion on cine images was not smooth over time, it was possible to measure ventricular volume and ejection fraction. Conclusions: Using the 256CBCT, it was possible to visualize the coronary arteries, myocardial perfusion, and ventricular contraction simultaneously during a single acquisition.

Left Ventricular Dysfunction on Exercise Long Term After Total Repair of Tetralogy of Fallot

BACKGROUND Excellent results regarding mortality are well recognized in the long-term period after intracardiac repair of tetralogy of Fallot. However, it is still unclear how postoperative sequelae affect cardiac performance during exercise. METHODS AND RESULTS Twenty-nine patients with tetralogy of Fallot were studied 16 +/- 2 years after intracardiac repair by use of radionuclide first-pass ventriculography with an ultra-high-sensitive gamma camera at rest and at peak exercise on a semi-upright bicycle ergometer. The results were compared with those from 10 age- and sex-matched control subjects. Left and right ventricular ejection fraction and absolute ventricular volume were measured at rest and peak exercise. Regional right ventricular wall motion and diastolic function of the left ventricle were also assessed. Cardiac output of tetralogy was normally preserved both at rest and during exercise. Nevertheless, the incremental response of left ventricular ejection fraction during exercise was depressed in the patients. Left ventricular ejection fraction during exercise was inversely correlated with the right ventricular end-diastolic volume and the severity of pulmonary regurgitation. Regional wall motion at the right ventricular outflow tract was not decreased in the patients. Left ventricular diastolic function was not impaired in the patients compared with control subjects. CONCLUSIONS Latent left ventricular dysfunction during exercise is related to an enlarged right ventricle due to pulmonary regurgitation after intracardiac repair of tetralogy. Careful follow-up is required in patients having significant pulmonary regurgitation.

MR measurement of blood flow in the true and false channel in chronic aortic dissection

Velocity encoded (VEC) cine MR imaging is a new noninvasive technique for the quantification of blood flow velocity in the cardiovascular system. Six patients with type B aortic dissection underwent VEC cine MR imaging at 1.5 T. This technique provides cine MR magnitude and VEC phase images at approximately 16 equally spaced intervals during an average cardiac cycle. A region of interest encompassing a vascular structure, i.e., false channel, provides a spatially averaged velocity for the time interval at which the image was acquired. Interpretation of velocity values from the 16 intervals during the cardiac cycle provides a temporally average velocity. Velocity mapping across the aortic lumen in these six cases showed average spatial and temporal velocity of 13.4 +/- 1.49 cm/s in the true channel and 3.1 +/- 0.84 cm/s in the false channel (p less than 0.05). The peak systolic velocity (temporal peak) was 43.6 +/- 7.20 cm/s in the true channel and 14.3 +/- 2.30 cm/s in the false channel (p less than 0.05). The flow volume per cardiac cycle was not significantly different between the ture (23.1 +/- 5.04 ml/cycle) and false channel (27.1 +/- 10.14 ml/cycle). There was substantial retrograde flow in the false channel of two patients. The intraobserver and interobserver variability was less than 10% (r = 0.98 to 0.99) for the measurement of flow parameters in both the true and the false channel. We conclude that VEC cine MR imaging demonstrates substantial differences in the hemodynamic pattern in the true and false channel in aortic dissection.

Sympathetic Denervation and Reinnervation After Arterial Switch Operation for Complete Transposition

BACKGROUND Sympathetic cardiopulmonary nerves arise from the cervical sympathetic trunks and the stellate ganglia and subsequently course along the origin of the great arteries and the coronary arteries to innervate the ventricles. Therefore, the sympathetic nerves may be obligatorily interrupted by the arterial switch operation (ASO) for complete transposition of the great arteries. METHODS AND RESULTS To demonstrate and characterize the possible sympathetic denervation, 51 patients after ASO, 4.8 years old (range, 1 month to 10.1 years), underwent [123I]metaiodobenzylguanidine (MIBG) imaging of the sympathetic nerve terminal. MIBG uptake to the heart was graded by quantitative analysis using the heart-to-mediastinum (H/M) ratio of MIBG uptake. A quantitative criterion for absent uptake of MIBG was set to 1.48 in the H/M ratio. Four patients < 1 month after ASO showed complete absence of MIBG uptake, which had been observed preoperatively. In contrast, 47 patients late after ASO (range, 15 months to 10.1 years) showed various degrees of uptake of MIBG. Patients operated on at < or =55 days of age showed positive MIBG uptake much more frequently than those operated on at later ages. Heart rate and rate-pressure product at peak exercise on a treadmill exercise test were significantly greater in patients with positive uptake than in those with absent uptake of MIBG. CONCLUSIONS Cardiac sympathetic nerves were denervated early after and reinnervated late after ASO. Neonatal ASO may be favorable to facilitate sympathetic reinnervation, which may affect exercise tolerance late after surgery.

Volumetric cine imaging for cardiovascular circulation using prototype 256-detector row computed tomography scanner (4-dimensional computed tomography): a preliminary study with a porcine model.

This is a preliminary demonstration of volumetric cine imaging of cardiovascular circulation in domestic pigs using a prototype 256-detector row computed tomography (CT) scanner. The scan range is approximately 120 mm in the craniocaudal direction, with a 0.5-mm slice thickness. The thin sections can be used to create cine loops in multiple planes. Thus, the 256-detector row CT scanner overcomes some of the limitations of present helical CT methods.