CT Hip In a 2002 study, Cyteval et al [84] prospectively reviewed helical noncontrast CT scans of 65 painful prosthetic hips with diagnosis confirmed by surgery. Infection was present in 12. Fluid collections in muscles and perimuscular fat demonstrated a 41% sensitivity and a 100% specificity for infection (PPV 100%, NPV 88%, accuracy 89%). Joint distension was 83% sensitive and 96% specific with a PPV of 83%, NPV of 96%, and accuracy of 94%. Thus, fluid collections in muscles and perimuscular fat had a 100% PPV, and absence of joint distention had a 96% NPV for infection. In the same study, periostitis was 100% specific but only 16% sensitive for infection. (PPV 100%, NPV 84%, accuracy 85%) [84]. A more recent study by Isern-Kebschull et al [85] confirmed that findings on Imaging After Total Hip Arthroplasty noncontrast multidetector CT could differentiate delayed periprosthetic joint infection from aseptic loosening or granulomas. Intravenous (IV) contrast may be of help in defining abscess [23]. FDG-PET/CT Skull Base to Mid-Thigh Reported results for diagnosing periprosthetic hip infection have been inconsistent. In some investigations, the test has been both sensitive (81%-95%) and specific (89%-94%) for infection [82,86-90]. The results of other investigations; however, have been less satisfactory, with sensitivity and specificity ranging from 64% to 100% and 38% to 68% [91-93]. Delank et al [94] reported that although a negative FDG-PET excludes infection, a positive result could not accurately differentiate infection from aseptic inflammation. Kiran et al [92] performed preoperative FDG-PET/CT on 130 painful cemented hip arthroplasties and reported a sensitivity of 95% and a specificity of 38% for periprosthetic infection. In this investigation, the false-positive rate of FDG PET/CT compared with culture alone was 77%. Comparisons of FDG-PET with conventional nuclear medicine studies have been contradictory.
Imaging after Total Hip Arthroplasty PCAs. CT Hip In a 2002 study, Cyteval et al [84] prospectively reviewed helical noncontrast CT scans of 65 painful prosthetic hips with diagnosis confirmed by surgery. Infection was present in 12. Fluid collections in muscles and perimuscular fat demonstrated a 41% sensitivity and a 100% specificity for infection (PPV 100%, NPV 88%, accuracy 89%). Joint distension was 83% sensitive and 96% specific with a PPV of 83%, NPV of 96%, and accuracy of 94%. Thus, fluid collections in muscles and perimuscular fat had a 100% PPV, and absence of joint distention had a 96% NPV for infection. In the same study, periostitis was 100% specific but only 16% sensitive for infection. (PPV 100%, NPV 84%, accuracy 85%) [84]. A more recent study by Isern-Kebschull et al [85] confirmed that findings on Imaging After Total Hip Arthroplasty noncontrast multidetector CT could differentiate delayed periprosthetic joint infection from aseptic loosening or granulomas. Intravenous (IV) contrast may be of help in defining abscess [23]. FDG-PET/CT Skull Base to Mid-Thigh Reported results for diagnosing periprosthetic hip infection have been inconsistent. In some investigations, the test has been both sensitive (81%-95%) and specific (89%-94%) for infection [82,86-90]. The results of other investigations; however, have been less satisfactory, with sensitivity and specificity ranging from 64% to 100% and 38% to 68% [91-93]. Delank et al [94] reported that although a negative FDG-PET excludes infection, a positive result could not accurately differentiate infection from aseptic inflammation. Kiran et al [92] performed preoperative FDG-PET/CT on 130 painful cemented hip arthroplasties and reported a sensitivity of 95% and a specificity of 38% for periprosthetic infection. In this investigation, the false-positive rate of FDG PET/CT compared with culture alone was 77%. Comparisons of FDG-PET with conventional nuclear medicine studies have been contradictory.