Right Ventricular Strain Analysis By Tissue Tracking Cardiac Magnetic Resonance Imaging In Pediatric Patients With End-Stage Renal Disease.

PURPOSE: To investigate right ventricular (RV) volume and mass by cardiac magnetic resonance (CMR) and the added value of tissue tracking strain analysis as markers of RV dysfunction in pediatric patients with end-stage renal disease (ESRD) and preserved RV ejection fraction. MATERIALS AND METHODS: Twenty-five children with ESRD and preserved RVEF (>50%) and 10 healthy control children were enrolled. Tissue tracking CMR was used to assess Global Longitudinal, circumferential (GCS), and radial short and long axes (GRS SAX and GRS LAX) RV strains in the patients group compared with controls. Correlations between strain parameters and other CMR parameters and clinical biomarkers were assessed. Binary logistic regression was used to test the independence of cofounders and detect their significance. RESULTS: RV end-diastolic volume and mass (RVMi) were significantly higher in patients (97.2±19.3 mL/m 2 and 26.6±7gr/m 2 ) than control (71±7.8 mL/m 2 and 11.9±2 gr/m 2 , P values 0.000). All RV global strain parameters were significantly impaired in patients compared with control (all P values <0.05). RV Global Longitudinal was significantly correlated to LVEF (r=-0.416, P =0.039), LVEDVi (r=0.481, P =0.015), LVMi (r=0.562, P =0.004), and systolic blood pressure index (r=0.586, P =0.002). RV GRS (LAX) was significantly correlated to LV GCS (r=-0.462, P =0.020) and LV GRS (SAX) (r=0.454, P =0.023). GRS (SAX) and GCS demonstrated the highest diagnostic accuracy (area under curve: 0.82 and 0.81) to detect strain impairment. Univariate binary logistic regression with patients versus control as dependent variables identified LVMi, RV end-diastolic volume, RVMi, weight, body surface area, RV GCS, RV GRS (LAX), RV GRS (SAX), LV GCS, and LV GRS (SAX) as significantly correlated to patients with ESRD. When adjusted to other cofounders in the multivariable model, only RVMi remained as an independent significant cofounder (Odds ratio:0.395, P =0.046). CONCLUSION: RV global strain, volume, and mass by CMR are markers of RV dysfunction in ESRD pediatric patients with preserved RVEF.

Impaired aortic strain and distensibility by cardiac MRI in children with chronic kidney disease.

Renal disease is associated with increased arterial stiffness. The aim was to investigate the effect of renal disease on regional aortic strain and distensibility in children with chronic kidney disease (CKD) by cardiac magnetic resonance imaging (MRI). The study included 30 children with CKD on hemodialysis, and ten healthy control subjects. Using cardiac MRI, maximal and minimal aortic areas were measured in axial cine steady state free precision images at the ascending aorta, proximal descending, and aorta at diaphragm. Regional strain and distensibility were calculated using previously validated formulas. Second reader aortic areas measurements were used to assess inter-observer agreement. Ascending aorta strain was significantly reduced in patients (38.4 ± 17.4%) compared to the control group (56.1 ± 17%), p-value 0.011. Ascending Aorta distensibility was significantly reduced in patients (9.1 ± 4.4 [× 10-3 mm Hg-1]) compared to the control group (13.9 ± 4.9 [× 10-3 mm Hg-1]), p-value 0.006. Strain and distensibility were reduced in proximal descending aorta and aorta at diaphragm but did not reach statistical significance. Only ascending aorta strain and distensibility had significant correlations with clinical and cardiac MRI parameters. Inter-observer agreement for strain and distensibility was almost perfect or strong in the three aortic regions. Aortic strain and distensibility by cardiac MRI are important imaging biomarkers for initial clinical evaluation and follow up of children with CKD.

Understanding the Aorta-Spine Relation in Idiopathic Scoliosis: Value of Noncontrast CT-Derived Curved Coronal Reformats and 3D Volume Images.

BACKGROUND: Investigating axial position and longitudinal bending of the aorta in relation to spine curvature in adolescent idiopathic scoliosis patients could help surgeons in planning of spine surgeries. METHODS: Noncontrast computed tomography (CT) scans of 27 consecutive patients with adolescent idiopathic scoliosis (19 right and 8 left curves) and 16 control subjects were retrospectively reviewed. Using semiautomated software, centerline was drawn along the descending aorta, and curved reformat was generated. Aorta tortuosity index (TI) was calculated as (centerline length/straight line distance) - 1 × 100. The spine centerline was drawn from T1 to L5, and curve index (CI) was similarly calculated. The aorta centerline angle was measured. Apical vertebral-rotation angle and multilevel aorto-vertebral angles were measured on axial CT. Three-dimensional volume-rendered images of the aorta were generated using a manual region grow function. RESULTS: Mean (± standard deviation) Cobb's angle was 63.8 ± 34.6°. The spine CI of patients (9.7 ± 7.11) was significantly higher than controls (0.28 ± 0.22), P = .00001. Aorta TI in scoliosis was significantly higher than controls (6.4 ± 7.2 versus 0.6 ± 0.5, P = .0001). The aorta centerline angle was steeper in scoliosis than controls (140 ± 26.8° versus 170 ± 3.6°). Correlations were excellent between the aorta TI and each of Cobb's angle, spine CI, and vertebral rotation angle (r = 0.851 to 0.867, all P < .001). Aorto-vertebral angles were significantly different between right scoliosis and left scoliosis patients and control groups at T6, T7, T8, L2, and L3 levels. CONCLUSIONS: Aortic curvature increases in proportion to the degree of scoliosis. The aorta follows the concavity of scoliosis in right and left curves. In the axial CT plane, the aorta in both right and left scoliosis is maximally rotated away from its normal position at T7 and is closest to its normal position at T11 to T12. CLINICAL RELEVANCE: Quantitative evaluation of aortic curvature combined with preoperative reconstructed CT images could be beneficial for surgeons in planning of spine surgeries.

Left superior vena cava: cross-sectional imaging overview.

Persistent left-sided superior vena cava (PLSVC) is the commonest systemic venous anomaly in the thorax with a reported prevalence of up to 0.5% in otherwise normal population and up to 10% in patients with congenital heart disease (CHD). In the absence of associated CHD, it is usually asymptomatic, discovered incidentally. It may complicate catheter or pacemaker lead placement. PLSVC typically drains into the right atrium through the coronary sinus. In children with CHD, the presence of a PLSVC may affect the choice of certain surgical procedures. PLSVC is significantly more common in association with situs ambiguous than with situs solitus or inversus, up to 60-70%. In patients with situs ambiguous, the drainage of LSVC is variable, more commonly directly into the atria rather than through the coronary sinus (CS). Rarely, there is a PLSVC draining into the CS with absent right SVC. PLSVC draining into the right atrium via the CS will not usually cause blood shunting between the right and the left sides. However, shunting occurs when PLSVC is associated with unroofed CS, or when it directly drains into the left atrium. With an increased use of CT and MRI for chest and cardiac imaging, PLSVC is being more encountered by radiologists than before. In this article, we will discuss the embryology of PLSVC, its anatomic course and drainage pathways, as well as its clinical relevance and relation to congenital heart disease and viscero-atrial situs.

The effect of age and gender on tortuosity of the descending thoracic Aorta.

BACKGROUND: To study the effect of age and gender on tortuosity of the descending thoracic aorta, and to evaluate inter-observer agreement of tortuosity index (TI) measurements. METHODS: Contrast-enhanced CT scans of 182 patients were analyzed by an experienced radiologist using routine 3D imaging software. The descending aorta was defined by proximal and distal endpoints. The software generated centerline length, and straight line distance between the 2 endpoints were measured. TI was calculated as: [centerline length / straight line distance -1] * 100. Impact of age on TI of the descending aorta was assessed using linear regression in both genders. To assess inter-observer agreement; TI measurements of 50 cases were repeated by 3 other independent readers. RESULTS: The mean (±SD) TI was 8.3 ± 2.6 in men and 8.9 ± 3 in women, with no significant difference between the 2 genders, p = 0.208. Moderate positive correlation was observed between TI and age (r = 0.566, p < 0.00001 and r = 0.569, p < 0.00001 in men and women, respectively). The 10-year-percent change was higher in women than men (13.3% and 9.5%, respectively). Inter-observer agreement for TI was good, intra-class correlation coefficient was 0.84 (95% CI: 0.76-0.89, p < 0.0001). Centerline length was poorly correlated to age (r = 0.248, p = 0.048 in men and r = 0.369, p < 0.001 in women). Body-surface-area-indexed centerline length was not significantly correlated to age (p = 0.948). CONCLUSIONS: Tortuosity of the descending aorta increases with age in both genders. TI has acceptable inter-observer agreement and was better correlated to age than centerline length measurements.