Value of color Doppler ultrasonography in the evaluation of orbital vascular flow in end-stage renal disease patients undergoing hemodialysis

WOS: 000226031800011PubMed ID: 15690616Purpose: To evaluate choroidal and retinal vascular flow dynamics by means of color Doppler ultrasonography in patients with end-stage renal disease undergoing hemodialysis and to compare these findings with healthy controls. Material and Methods: Color Doppler ultrasonography and spectral analysis of nasal and temporal posterior ciliary and central retinal artery flow of both eyes were performed in 20 patients (40 eyes) and 22 controls (44 eyes) to assess peak systolic flow velocity, end-diastolic flow velocity, and resistive indices (RI). Patients with hypertension, diabetes mellitus, and any cardiac pathology were not included in the study. A general ophthalmologic examination was performed in all patients and controls. Results: The average peak-systolic and end-diastolic blood flow velocities of nasal (12.88+/-4.91/6.88+/-3.26) and temporal (15.22+/-9.59/6.41+/-3.97) posterior ciliary artery and central retinal artery (14.94+/-8.38/6.7+/-4.13) in patients were significantly higher than the corresponding values of the controls. The RI values of nasal (0.52+/-0.10) and temporal (0.58+/-0.12) posterior ciliary artery and central retinal artery (0.55+/-0.11) in patients with end-stage renal disease undergoing hemodialysis were significantly lower than in the controls. Conclusion: Choroidal and retinal blood flow velocities are higher and RI values for all three vessels lower in patients with end-stage renal disease undergoing hemodialysis compared to healthy controls. These alterations may be related to either increased choroidal blood flow or vasoconstriction of the proximal vessels

Precision analysis of a quantitative CT liver surface nodularity score

To evaluate precision of a software-based liver surface nodularity (LSN) score derived from CT images. An anthropomorphic CT phantom was constructed with simulated liver containing smooth and nodular segments at the surface and simulated visceral and subcutaneous fat components. The phantom was scanned multiple times on a single CT scanner with adjustment of image acquisition and reconstruction parameters (N = 34) and on 22 different CT scanners from 4 manufacturers at 12 imaging centers. LSN scores were obtained using a software-based method. Repeatability and reproducibility were evaluated by intraclass correlation (ICC) and coefficient of variation. Using abdominal CT images from 68 patients with various stages of chronic liver disease, inter-observer agreement and test-retest repeatability among 12 readers assessing LSN by software- vs. visual-based scoring methods were evaluated by ICC. There was excellent repeatability of LSN scores (ICC:0.79-0.99) using the CT phantom and routine image acquisition and reconstruction parameters (kVp 100-140, mA 200-400, and auto-mA, section thickness 1.25-5.0 mm, field of view 35-50 cm, and smooth or standard kernels). There was excellent reproducibility (smooth ICC: 0.97; 95% CI 0.95, 0.99; CV: 7%; nodular ICC: 0.94; 95% CI 0.89, 0.97; CV: 8%) for LSN scores derived from CT images from 22 different scanners. Inter-observer agreement for the software-based LSN scoring method was excellent (ICC: 0.84; 95% CI 0.79, 0.88; CV: 28%) vs. good for the visual-based method (ICC: 0.61; 95% CI 0.51, 0.69; CV: 43%). Test-retest repeatability for the software-based LSN scoring method was excellent (ICC: 0.82; 95% CI 0.79, 0.84; CV: 12%). The software-based LSN score is a quantitative CT imaging biomarker with excellent repeatability, reproducibility, inter-observer agreement, and test-retest repeatability