Standardized ultrasonography with cine-loop documentation : diagnostic variability in liver and kidney examinations

Abstract: Background: Ultrasound examination of the abdomen is often a first choice at radiology departments due to the lack of ionizing radiation. For diagnostic accuracy and economic benefits there has been a need for new routines in this area that incorporate the benefits of an radiographer or sonographer performing a multitude of ultrasound examinations following strictly standardized examination protocols and documentation forms made by cine-loops that will give the radiologist access to all relevant information needed for an accurate postexamination diagnosis.Aim: The overall objective of this thesis was to evaluate the diagnostic variability in examinations of the kidneys and liver that use a standardized ultrasound method along with video documentation of the entire examination and off-line review by radiologists. More specifically, we wanted to compare the agreement between readers and between operators.Design and method: This thesis is based on four quantitative studies using standardized protocols for kidney, liver and gallbladder examinations. In paper I, including 64 patients, and paper IV, including 98 patients, the patients were prospectively enrolled and the  examinations were retrospectively reviewed. The patients in papers I and IV were examined by one radiographer (sonographer) and one radiologist during the same session. In paper I, findings using the standardized ultrasound method were compared with traditional bedside assessments by a radiologist. In paper IV, the patients were examined using only the standardized method. In paper II, including 98 patients, and in paper III, including 115 patients, the patients were examined by one sonographer using the standardized method and the examinations were reviewed by two or three radiologists.Results: In paper I, no significant systematic differences were found between the findings using the standardized method and the traditional bedside assessment.Paper II showed good intra- and inter-observer agreement between three experienced radiologists when reviewing examinations conducted using the standardized method.In paper III we verified good inter-observer agreement between two radiologists reviewing ultrasound examinations using the standardized technique in patients who had undergone surgery for colorectal cancer. Intravenous contrast was used and the injection of contrast medium increased the visibility of liver lesions.In paper IV, we observed that using a standardized cine-loop technique, there was a slightly better inter-operator agreement than inter-reader agreement.Conclusion: The satisfactory agreement shown in all four studies suggests that the new workflow method using standardized ultrasound examinations and stored cine-loops, performed by a radiographer or sonographer and analyzed off-line by a radiologist, is a promising technique. The results are less affected when a radiologist examiner is replaced by a radiographer or sonographer than when the reviewer is replaced by a different radiologist.