Intra- and Inter-Observer Variability of Quantitative Parameters Used in Contrast-Enhanced Ultrasound of Kidneys of Healthy Cats

Abstract

Contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technique which allows qualitative and quantitative assessment of tissue perfusion. Although CEUS offers numerous advantages, a major challenge remains the variability in tissue perfusion quantification. This study aimed to assess intra- and inter-observer variability for quantification of renal perfusion. Two observers with different levels of expertise performed a quantitative analysis of 36 renal CEUS studies, twice. The CEUS data were collected from 12 healthy cats at 3 different time points with a 7-day interval. The inter- and intra-observer agreement was assessed by the intraclass correlation coefficient. Within and between observers, a good agreement was demonstrated for intensity-related parameters in the cortex, medulla, and interlobular artery. For some parameters, ICCinter was considerably lower than ICCintra, mostly when the ROI encompassed the entire kidney or medulla. With the exception of time to peak (TTP) and mean transit time (mTTI), time-related and slope-related parameters showed poor agreement among observers. In conclusion, it may be advised against having the quantitative assessment of renal perfusion performed by different observers, especially if their experience levels differ. The cortical mTTI seemed to be the most appropriate parameter as it showed a favorable inter-observer agreement and inter-period agreement.

Ultrasound-Based Technologies for the Evaluation of Testicles in the Dog: Keystones and Breakthroughs

“…These studies have examined normal and pathological aspects, differentiating between inflammatory, degenerative, and neoplastic lesions, while providing discrimination between benign or malignant conditions [ 106 , 119 , 151 ]. Some studies have also been performed on cats [ 86 , 152 , 153 ]. A limited number of studies have explored the application of CEUS in canine andrology, primarily focused on chronic testicular alterations [ 120 ].…”

Contrast-enhanced ultrasound features as a potential biomarker for the prediction of breast cancer recurrence

“…In addition, all CEUS scans were obtained with one unit from one vendor and analyzed by using one type of specialised software. CEUS imaging features can be influenced by different imaging protocols, US scanners, and software used, potentially limiting the generalizability of the results [20,23]. Additional prospective studies with longer follow-ups and larger samples are needed to confirm our results.…”

“…Additionally, in the present study, the blood velocity indicators (difference in WiR before and after NAC, obtained from ROI 2 normalized and 3 normalized ) significantly differed between the no-recurrence and recurrence groups. This may be because the walls of newly formed vessels inside the tumor are thinner, lacking a muscle layer and easily forming arteriovenous fistulas, which al-lows the contrast agent to diffuse quickly inside the tumor [17,26]. According to Kim et al, rapidly enhancing tumors on MRI are more commonly observed in fast-growing breast cancer and are related to a poor prognosis [18].…”

“…Higher PE and washout component values measured on preoperative breast MRI scans are reportedly associated with worse recurrence-free survival [14,19]. Dynamic contrast-enhanced MRI is mainly influenced by vessel permeability rather than angiogenesis of the tumor, whereas the contrast medium used in CEUS is a blood-pool agent that does not undergo diffusion [17]. CEUS with hardly any medical side effects (e. g., ionizing radiation) leads to fewer and less severe complications than the contrast agents of MRI or CT.…”

“…An important drawback of CEUS is its potentially high variability, which may lead to diagnostic uncertainty [17,20]. Drawing of ROIs is a manual process based on an observer's assessment and is thus subject to interobserver variability [21,22].…”