The purpose of this study was to assess in pediatric pulmonary artery (PA) reconstruction candidates the feasibility and added utility of preoperative chest computed tomography angiography (CTA) ...using dual-energy technique, from which perfused blood volume (PBV)/iodine maps can be generated as a surrogate of pulmonary perfusion. Pediatric PA reconstruction patients were prospectively recruited for a new dose-neutral dual-energy CTA protocol. For each case, the severity of anatomic PA obstruction was graded by two pediatric cardiovascular radiologists in consensus using a modified Qanadli index. PBV maps were qualitatively reviewed and auto-segmented using Siemens
syngo
.via software. Associations between Qanadli scores and PBV were assessed with Spearman correlation (r) and ROC analysis. Effective radiation doses were estimated from dose-length product and ICRP 103 k-factors, using cubic Hermite spline interpolation. 19 patients were recruited with mean (SD) age of 6.0 (5.1), 11 (57.9%) female, 11 (73.7%) anesthetized. Higher QS correlated with lower PBV, both on a whole lung (r = − 0.54, p < 0.001) and lobar (r = − 0.50, p < 0.001) basis. The lung with lowest absolute PBV was predictive of the lung with highest Qanadli score, with AUC of 0.70 (95% CI 0.47–0.93). Qualitatively, PBV maps were heterogeneous, corresponding to multifocal PA stenoses, with decreased iodine content in areas of most severe obstruction. In conclusion, dual-energy chest CTA is feasible for pediatric PA reconstruction candidates. PBV maps show deficits in regions of more severe anatomic obstruction and may serve as a novel biomarker in this population.
Purpose
To evaluate the capacity of perfusion CT imaging to distinguish between complete and incomplete responders after neoadjuvant chemoradiation therapy for rectal carcinoma, with particular ...attention to segmentation technique.
Materials and methods
17 patients were evaluated in this prospective IRB-approved study. For each patient, a perfusion CT acquisition was obtained prior to the initiation of chemoradiation, at 1–2 weeks after the start of chemoradiation, and at 12 weeks after the start of chemoradiation therapy. From each dataset, three perfusion parameters were measured, each in two different ways: a region of interest incorporating only “hot spots” of greatest enhancement and whole-tumor measurements.
Results
In univariate analysis, blood volume and permeability differed significantly between responders and non-responders. In logistic regression analysis evaluating predictors of the “complete response” outcome, only two predictors were retained as statistically significant: peak hot spot blood volume 1–2 weeks into therapy (OR 10.25,
p
= 0.0026) and hot spot permeability decline at 12 weeks after the initiation of therapy (OR 5.62,
p
= 0.03). The overall likelihood ratio test for this model supported the conclusion that hot spot blood volume and hot spot permeability decline were significant predictors of the complete pathologic response outcome (
p
< 0.0001).
Conclusion
In this pilot study, peak tumor blood volume and decline in tumor permeability, when measured in “hot spots” of greatest enhancement, were strong predictors of complete therapeutic response in rectal cancer after neoadjuvant therapy.
Abstract Objective To evaluates a semi-automated method for Thoracic Aortic Aneurysm (TAA) measurement using ECG-gated Dual Source CT Angiogram (DSCTA). Methods This retrospective HIPAA compliant ...study was approved by our IRB. Transaxial maximum diameters of outer wall to outer wall were studied in fifty patients at seven anatomic locations of the thoracic aorta: annulus, sinus, sinotubular junction (STJ), mid ascending aorta (MAA) at the level of right pulmonary artery, proximal aortic arch (PROX) immediately proximal to innominate artery, distal aortic arch (DIST) immediately distal to left subclavian artery, and descending aorta (DESC) at the level of diaphragm. Measurements were performed using a manual method and semi-automated software. All readers repeated their measurements. Inter-method, intra-observer and inter-observer agreements were evaluated according to intraclass correlation coefficient (ICC) and Bland–Altman plot. The number of cases with manual contouring or center line adjustment for the semi-automated method and also the post-processing time for each method were recorded. Results The mean difference between semi-automated and manual methods was less than 1.3 mm at all seven points. Strong inter-method, inter-observer and intra-observer agreement was recorded at all levels (ICC ≥ 0.9). The maximum rate of manual adjustment of center line and contour was at the level of annulus. The average time for manual post-processing of the aorta was 19 ± 0.3 min, while it took 8.26 ± 2.1 min to do the measurements with the semi-automated tool (Vitrea version 6.0.0.1 software). The center line was edited manually at all levels, with most corrections at the level of annulus (60%), while the contour was adjusted at all levels with highest and lowest number of corrections at the levels of annulus and DESC (75% and 0.07% of the cases), respectively. Conclusion Compared to the commonly used manual method, semi-automated measurement of vessel dimensions is feasible in the thoracic aorta with the advantage of reduced post-processing time.
Various types of viable stem cells have been reported to result in modest improvement in cardiac function after acute myocardial infarction. The mechanisms for improvement from different stem cell ...populations remain unknown.
To determine whether irradiated (nonviable) embryonic stem cells (iESCs) improve postischemic cardiac function without adverse consequences.
After coronary artery ligation-induced cardiac infarction, either conditioned media or male murine or male human iESCs were injected into the penumbra of ischemic myocardial tissue of female mice or female rhesus macaque monkeys, respectively. Murine and human iESCs, despite irradiation doses that prevented proliferation and induced cell death, significantly improved cardiac function and decreased infarct size compared with untreated or media-treated controls. Fluorescent in situ hybridization of the Y chromosome revealed disappearance of iESCs within the myocardium, whereas 5-bromo-2'-deoxyuridine assays revealed de novo in vivo cardiomyocyte DNA synthesis. Microarray gene expression profiling demonstrated an early increase in metabolism, DNA proliferation, and chromatin remodeling pathways, and a decrease in fibrosis and inflammatory gene expression compared with media-treated controls.
As a result of irradiation before injection, ex vivo and in vivo iESC existence is transient, yet iESCs provide a significant improvement in cardiac function after acute myocardial infarction. The mechanism(s) of action of iESCs seems to be related to cell-cell exchange, paracrine factors, and a scaffolding effect between iESCs and neighboring host cardiomyocytes.
Seropositivity of anti–Helicobacter pylori antibody (HP+) was examined among Japanese Brazilians. The study was announced through 18 Japanese community culture associations in São Paulo, Curitiba, ...Mogi das Cruzes, and Mirandopolis in 2001. Among 969 participants, 963 individuals aged 33–69 years were analyzed. The overall HP+% was 48.1% (95% confidence interval, 44.9–51.3%). There was no difference in HP+% between 399 males and 564 females (49.6% and 47.0%, respectively). The HP+% increased with age; 35.3% for those aged 33–39 years, 46.2% for those aged 40–49 years, 46.5% for those aged 50–59 years, and 56.9% for those aged 60–69 years, but no differences were observed among the generations (Issei, Nisei, and Sansei) for each 10–year age group. Mogi das Cruzes, a rural area, showed a higher HP+%. Length of education was inversely associated with the positivity; the odds ratio (OR) relative to those with eight years or less of schooling was 0.61 (0.42–0.89) for those with 12 years or more. The associations with smoking and alcohol drinking were not significant. Fruit intake was associated with the HP+%; the OR relative to everyday intake was 1.38 (1.05–1.83) for less frequent intake, while intake frequencies of green tea, miso soup, and pickled vegetables (tsukemono) were not. Multivariate analysis including sex, 10–year age group, residence, education, and fruit intake showed that all factors except sex were significant. This is the largest study of HP infection among Japanese Brazilians, and the results indicated a similar pattern of age–specific infection rate to that for Japanese in Japan.
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