Automated sonographic evaluation of testicular perfusion

• Published in: Physics in medicine & biology Vol. 51; no. 14; pp. 3419 - 3432
• Main Authors: Thierman, Jonathan S, Clement, Gregory T, Kalish, Leslie A, O'Kane, Patrick L, Frauscher, Ferdinand, Paltiel, Harriet J
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 21.07.2006
• Subjects: Algorithms; Animals; Automation; Computer Simulation; Contrast Media - pharmacology; Echoencephalography - methods; Image Processing, Computer-Assisted; Male; Models, Statistical; Perfusion; Rabbits; Scattering, Radiation; Testis - pathology
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/51/14/010

Contrast-enhanced ultrasound (US) imaging is potentially applicable to the investigation of vascular disorders of the testis. We investigated the ability of two automated computer algorithms to analyse contrast-enhanced pulse inversion US data in a rabbit model of unilateral testicular ischaemia and to correctly determine relative testicular perfusion: nonlinear curve fitting of the US backscatter intensity as a function of time; and spectral analysis of the intensity time trace. We compared (i) five metrics based on the algorithmic data to testicular perfusion ratios obtained with radiolabelled microspheres, a reference standard; (ii) qualitative assessment of the US images by two independent readers blinded to the side of the experimental and control testes to the radiolabelled microsphere perfusion ratios; and (iii) results of the algorithmically-derived metrics to the qualitative assessments of the two readers. For the curve fit method, the algorithmically-derived metrics agreed with the reference standard in 54% to 68% of all cases. For the spectral method, the results agreed in 70% of all cases. The two readers agreed with the reference standard in 40% and 35% of all cases, respectively. These results suggest that automated methods of analysis may provide useful information in the assessment of testicular perfusion.