This study aimed to evaluate effective dose and size-specific dose estimate (SSDE) of computed tomography angiography (CTA) examination using an anthropomorphic phantom. We included three CTA examination protocols to evaluate the intra- and extra-cranial arteries, pulmonary artery (CTPA), and abdominal vessels. Patient SSDEs were measured retrospectively to estimate patient dose, relative to the bodyweight of the patient and volume CT dose index (CTDIvol). Our findings revealed that the highest dose was absorbed by the left lobe of the thyroid gland during intra-/extra-cranial CTA and CTPA, that is, 14.11 ± 0.24 mGy and 16.20 ± 3.95 mGy, respectively. However, the highest absorbed dose in abdominal/pelvic CTA was the gonads (8.98 ± 0.30 mGy), while other radiosensitive organs in intra- and extra-cranial CTA, CTPA, and abdominal/pelvic CTA did not demonstrate significant differences between organs/structures with p value 0.88, 0.11, and 0.54, respectively. The estimated effective dose in intra-/extra-cranial CTA was lower in patients (0.80 ± 0.60 mSv) than in the phantom (0.83 mSv), but it was the opposite for CTPA, with the effective dose being higher in patients (7.54 ± 3.09 mSv) than in the phantom (6.68 mSv). Similar to the effective dose, only CTPA SSDEs were significantly higher in men than in women (19.74 ± 4.79 mGy versus 7.9 mGy). Effective dose and SSDE are clinically relevant parameters that can help estimate a more accurate patient dose based on a patient's size.
A 10-month-old boy was referred for tachypnea and heart murmur. An echocardiogram showed unexplained left heart dilation without evidence of an intracardiac shunt. A 64-slice computed tomographic contrast-enhanced angiography showed a large tortuous anomalous artery arising from the descending thoracic aorta and supplying the lower lobe of the left lung. The venous return into the left atrium was normal. The affected lobe had normal lung parenchyma, and its bronchial tree was connected normally with the left main bronchus. Hence, it was not a sequestrated lobe. The boy underwent surgical lobectomy of the left lower lobe and improved. Anomalous arterial supply of a lobe without sequestration of its bronchial tree is a rare pathologic entity. It also is a very rare cause of congestive heart failure in children. Computed tomographic angiography was a useful tool for evaluation of the intrathoracic anomalous vessel in this case.
Findings are reviewed of isolated Patent Ductus Arteriosus after infancy as seen in 181 patients studied at the University Hospital, Kuala Lumpur, during the period 1967 to 1975. The ages of patients ranged from nine months to 54 years. Eighty-two patients underwent cardiac catheterization. More than 50% of patients were above ten years of age; the sex ratio was 1 male: 2.93 females. Thirty-two per cent of the patients had significant effort dyspnoea or were in heart failure. The complications noted were elevated pulmonary vascular resistance, Eisenmenger syndrome, bacterial endocarditis and cardiac failure.
miRNAs are important regulators of cellular senescence yet the extent of their involvement remains to be investigated. We sought to identify miRNAs that are involved in cytokine-induced premature senescence (CIPS) in endothelial cells. CIPS was established in young human pulmonary microvascular endothelial cells (HMVEC-Ls) following treatment with a sublethal dose (20ng/ml) of tumor necrosis factor alpha (TNF-α) for 15days. In parallel, HMVEC-Ls were grown and routinely passaged until the onset of replicative senescence (RS). Differential expression analysis following miRNA microarray profiling revealed an overlapped of eight deregulated miRNAs in both the miRNA profiles of RS and TNF-α-induced premature senescence cells. Amongst the deregulated miRNAs were members of the miR 17-92 cluster which are known regulators of angiogenesis. The role of hsa-miR-20b in TNF-α-induced premature senescence, a paralog member of the miR 17-92 cluster, was further investigated. Biotin-labeled hsa-miR-20b captured the enriched transcripts of retinoblastoma-like 1 (RBL1), indicating that RBL1 is a target of hsa-miR-20b. Knockdown of hsa-miR-20b attenuated premature senescence in the TNF-α-treated HMVEC-Ls as evidenced by increased cell proliferation, increased RBL1 mRNA expression level but decreased protein expression of p16INK4a, a cellular senescence marker. These findings provide an early insight into the role of hsa-miR-20b in endothelial senescence.