Purpose or Case Report: POC-US aims at shortening the scanning and interpretation time being easy to use by clinicians and allied health professionals at the time of patients’ physical examination. Our purposes are: 1. To compare POC-US to detailed US and MRI in evaluating hemophilic arthropathy. 2. To point out limitations of POC-US that can decrease its accuracy. 3. To propose strategies to refine protocols.
Methods & Materials: 7 knees, 8 ankles and 7 elbows of 23 hemophilic boys (7-18 y; median, 13) followed at Beijing Children’s Hospital, China underwent POC-US (performed by a nurse trained in POC-US), detailed gray scale/color Doppler US (5-17 MHz linear probes, performed by experienced sonographers),3 T MRI (PD, Gradient Echo, T2 fat sat and WATSc) and physical examination. (Hemophilia Joint Health Score [HJHS] performed by a physiotherapist). Scoring of US and MRI images was achieved by consensus by a panel of experienced imagers based on International Prophylaxis Study Group systems.
Results: Median HJHS scores were 10.5/7/10.5 for knees, ankles, elbows. Whereas synovial hypertrophy and hemosiderin were diagnosed in 19 (83%) cases by MRI and detailed US, respectively. they were missed (false-negatives, FN) in 8/23 (35%) and 5/23 (22%) cases by POC-US. Mild to moderate joint effusion was detected in 6/23 (26%) cases by both MRI and detailed US, and in 4/23 (17%) by POC-US. One false-positive (FP) case was misdiagnosed by POC-US when mild effusion was mis-interpreted as hemosiderin.
Detection of osteochondral changes was limited by POC-US: out of 17/23 (74%) cases with cartilage loss and erosions diagnosed by MRI and detailed US, POC US missed 4 and 7 cases (FN), respectively.
Conclusions: Diagnostic accuracy of POC for assessing hemophilic arthropathy is overall limited. Challenges of POC-US include limited imaging planes, focused training, lack of optimized technical parameters and difficulties for interpreting a reduced number of images. Adding imaging planes, color Doppler, increasing level of training and availability of images are suggested ways to improve the accuracy of the technique.