Browsing by Subject "Aorta, Thoracic"

Now showing 1 - 6 of 6
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    Anomalous Origin of the Right Coronary Artery from the Pulmonary Artery in a Neonate with Turner Syndrome and Aortic Arch Hypoplasia.
    (Texas Heart Institute journal, 2019-06) Stefek, Bryan P; Imundo, Jason R; Clark, Joseph B
    Anomalous origin of the right coronary artery from the pulmonary artery, a rare congenital cardiac defect, is typically not diagnosed during infancy. On the other hand, Turner syndrome is usually diagnosed early, and it is classically associated with bicuspid aortic valve and aortic coarctation. Individuals with Turner syndrome are also at increased risk for coronary artery anomalies. We present a case of anomalous right coronary artery from the pulmonary artery in a week-old neonate who also had Turner syndrome, patent ductus arteriosus, transverse aortic arch hypoplasia, and impaired ventricular function. Prostaglandin therapy through the ductus increased the patient's myocardial perfusion. Four months after corrective surgery, she was doing well. We discuss the reperfusion phenomenon in our patient's case, as well as other considerations in this combination of congenital defects.
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    Development of a simplified spinal cord ischemia model in mice.
    (Journal of neuroscience methods, 2010-06) Wang, Z; Yang, W; Britz, GW; Lombard, FW; Warner, DS; Sheng, H
    Use of genetically manipulated mice facilitates understanding pathological mechanisms in many diseases and contributes to therapy development. However, there is no practical and clinically relevant mouse model available for spinal cord ischemia. This report introduces a simplified long-term outcome mouse model of spinal cord ischemia. Male C57Bl/6J mice were anesthetized with isoflurane and endotracheally intubated. The middle segment of the thoracic aorta was clamped for 0, 8, 10 or 12 min via left lateral thoracotomy. Rectal temperature was maintained at 37.0+/-0.5 degrees C. A laser Doppler probe was used to measure lumbar spinal cord blood flow during thoracic aorta cross-clamping. Open field locomotor function and rotarod performance were evaluated at 1h and 1, 3, 5, and 7 days post-injury. Surviving neurons in the lumbar ventral horn were counted at 7 days post-injury. Cross-clamping the middle segment of the thoracic aorta resulted in approximately 90% blood flow reduction in the lumbar spinal cord. Neurological deficit and neuronal cell death were associated with ischemia duration. Another set of mice were subjected to 10 min aortic clamping or sham surgery and neurological function was examined at 1h and 1, 3, 5, 7, 14, and 28 days. Four of 5 mice (80%) in the injured group survived 28 days and had significant neurological deficit. This study indicates that cross-clamping of the aorta via left thoracotomy is a simple and reliable method to induce spinal cord ischemia in mice allowing definition of long-term outcome.
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    Fibroblast growth factor 23 is not associated with and does not induce arterial calcification.
    (Kidney international, 2013-06) Scialla, Julia J; Lau, Wei Ling; Reilly, Muredach P; Isakova, Tamara; Yang, Hsueh-Ying; Crouthamel, Matthew H; Chavkin, Nicholas W; Rahman, Mahboob; Wahl, Patricia; Amaral, Ansel P; Hamano, Takayuki; Master, Stephen R; Nessel, Lisa; Chai, Boyang; Xie, Dawei; Kallem, Radhakrishna R; Chen, Jing; Lash, James P; Kusek, John W; Budoff, Matthew J; Giachelli, Cecilia M; Wolf, Myles; Chronic Renal Insufficiency Cohort Study Investigators
    Elevated fibroblast growth factor 23 (FGF23) is associated with cardiovascular disease in patients with chronic kidney disease. As a potential mediating mechanism, FGF23 induces left ventricular hypertrophy; however, its role in arterial calcification is less clear. In order to study this, we quantified coronary artery and thoracic aorta calcium by computed tomography in 1501 patients from the Chronic Renal Insufficiency Cohort (CRIC) study within a median of 376 days (interquartile range 331-420 days) of baseline. Baseline plasma FGF23 was not associated with the prevalence or severity of coronary artery calcium after multivariable adjustment. In contrast, higher serum phosphate levels were associated with prevalence and severity of coronary artery calcium, even after adjustment for FGF23. Neither FGF23 nor serum phosphate were consistently associated with thoracic aorta calcium. We could not detect mRNA expression of FGF23 or its coreceptor, klotho, in human or mouse vascular smooth muscle cells, or normal or calcified mouse aorta. Whereas elevated phosphate concentrations induced calcification in vitro, FGF23 had no effect on phosphate uptake or phosphate-induced calcification regardless of phosphate concentration or even in the presence of soluble klotho. Thus, in contrast to serum phosphate, FGF23 is not associated with arterial calcification and does not promote calcification experimentally. Hence, phosphate and FGF23 promote cardiovascular disease through distinct mechanisms.
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    Impact of beta-blockade premedication on image quality of ECG-gated thoracic aorta CT angiography.
    (Acta radiologica (Stockholm, Sweden : 1987), 2014-12) Entezari, Pegah; Collins, Jeremy; Chalian, Hamid; Tore, Huseyin Gurkan; Carr, James; Yaghmai, Vahid
    BACKGROUND: Thoracic aortic aneurysm is one of the most common aorta pathologies worldwide, which is commonly evaluated by computed tomography angiography (CTA). One of the routine methods to improve the image quality of CTA is heart rate reduction prior to study by beta-blockade administration. PURPOSE: To assess the effect of beta-blockade on image quality of the ascending aorta in electrocardiography (ECG)-gated dual-source CTA (DSCTA) images. MATERIAL AND METHODS: In this retrospective study, ECG-gated thoracic aorta CTA images of 40 patients without beta-blocker administration were compared with ECG-gated images of 40 patients with beta-blockade. Images of the aorta were analyzed objectively and subjectively at three levels: sinus of Valsalva (sinus), sinotubular junction (STJ), and mid ascending aorta (MAA). Quantitative sharpness index (SI) and signal-to-noise ratio (SNR) were calculated and two radiologists evaluated the image quality using a 3-point scale. RESULTS: Mean heart rate in beta-blocker and non-beta-blocker groups was 61.7 beats per minute (bpm) (range, 58.1-63.9 bpm) and 72.9 bpm (range, 69.3-84.1 bpm), respectively (P < 0.05). Aorta wall SI, SNR, and subjective grading were comparable between the two groups at all three levels (P > 0.05). CONCLUSION: Beta-blocker premedication may not be necessary for imaging of ascending aorta with ECG-gated DSCTA.
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    Optimization of reduced-dose MDCT of thoracic aorta using iterative reconstruction.
    (Journal of computer assisted tomography, 2014-01) Töre, Hüseyin Gürkan; Entezari, Pegah; Chalian, Hamid; Gonzalez-Guindalini, Fernanda Dias; Botelho, Marcos Paulo Ferreira; Yaghmai, Vahid
    OBJECTIVE: To evaluate the contribution of iterative reconstruction on image quality of reduced-dose multidetector computed tomography of the thoracic aorta. METHODS: A torso phantom was scanned using two tube potentials (80 and 120 kVp) and five different tube currents (110, 75, 40, 20, and 10 mAs). All images were reconstructed with both filtered back projection (FBP) and iterative reconstruction. Aortic attenuation, image noise within the thoracic aorta, signal-to-noise ratio, and sharpness of the aortic wall were quantified in the phantom for the two reconstruction algorithms. Data were analyzed using paired t test. A value of P < 0.05 was considered significant. RESULTS: The aortic attenuation was similar for FBP and iterative reconstruction (P > 0.05). Image noise level was lower (P < 0.0001), and image sharpness was higher (P = 0.046) with iterative reconstruction. Signal-to-noise ratios were higher with iterative reconstruction compared with those with FBP (P < 0.0001). Signal-to-noise ratio at 80 kVp with iterative reconstruction (9.8 ± 4.4) was similar to the signal-to-noise ratio at 120 kVp with FBP (8.4 ± 3.3) (P = 0.196). CONCLUSIONS: Less image noise and higher image sharpness may be achieved with iterative reconstruction in reduced-dose multidetector computed tomography of the thoracic aorta.
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    Utility of virtual monoenergetic images derived from a dual-layer detector-based spectral CT in the assessment of aortic anatomy and pathology: A retrospective case control study.
    (Clinical imaging, 2018-11) Chalian, Hamid; Kalisz, Kevin; Rassouli, Negin; Dhanantwari, Amar; Rajiah, Prabhakar
    OBJECTIVES:To evaluate the ability of the retrospectively generated virtual monoenergetic images (VMIs) from a dual-layer detector-based spectral computed tomography (SDCT) to augment aortic enhancement for the evaluation of aortic anatomy and pathology. METHODS:98 patients with suboptimal aortic enhancement (≤200 HU) were retrospectively identified from SDCT scans. VMI from 40 to 80 keV were generated. Attenuation, noise, SNR, and CNR were measured at seven levels in the aorta. Image quality was graded on a 5-point scale, 5 being the best. From the VMI, an ideal set was chosen with mean vascular attenuation above 200 HU while maintaining diagnostic quality. Image parameters and quality of this ideal-set were compared to the standard 120-kVp images. RESULTS:The mean attenuation of all seven measured anatomical regions was 156.6 ± 61.7 HU in the 120-kVp images. Attenuation of the VMI from 40 to 70 keV were higher than the 120-kVp image, measuring 439.2 ± 215.3 HU, 298.5 ± 140.6 HU, 213.4 ± 94.3 HU, and 164.7 ± 90.2 HU, for 40 keV, 50 keV, 60 keV, and 70 keV, respectively (p value <0.01 for 40, 50, 60 keV; 0.07 for 70 keV). SNR and CNR showed similar trends. The 50 keV VMI had the best image quality (4.48 ± 0.84 vs. 2.24 ± 0.92 on 120-kVp images, p < 0.001). Attenuation, CNR, and SNR increased by 90.6%, 85.0%, and 108.1% at 50 keV compared to 120-kVp. CONCLUSIONS:A contrast-enhanced CT study can be optimized for the assessment of the aorta by using low-energy VMI obtained using SDCT. At the optimal monoenergetic level, attenuation, SNR, CNR and image quality were significantly higher than that of conventional polyenergetic images.