[Diagnostic efficacy of gadodiamide-enhanced dynamic examination technique in comparison to conventional magnet resonance tomography in exacerbated chronic osteomyelitis]. / Diagnostische Effektivität der Gadodiamid-verstärkten dynamischen Untersuchungstechnik im Vergleich zur konventionellen Magnetresonanztomographie bei exazerbierter chronischer Osteomyelitis.

ABSTRACT

PURPOSE: To evaluate the diagnostic effectiveness of dynamic gadodiamide-enhanced MRI in discriminating reparative tissue formation from florid inflammation in patients with chronic osteomyelitis. MATERIALS AND METHODS: Subjects with chronic osteomyelitis and clinically suspected exacerbation were consecutively enrolled into a prospective trial. Following conventional contrast-enhanced MRI scanning, a dynamic contrast-enhanced SE sequence was carried out in all patients (acquisition interval 58 s, 11 repetitions with a total acquisition time of 11 minutes). The relative increase of the time-dependent signal intensity was assessed in representative circular regions of interest placed over bone marrow and surrounding soft tissues. As diagnostic reference standard, histologic and intraoperative findings were obtained independently from the result of the index test. The MRI studies were evaluated by two radiologists who were blinded to the findings of the reference test. RESULTS: 30 of 51 patients were subsequently scheduled for surgery (mean age 42.6 +/- 12.7 years, 27 males). 19 cases had a florid granulocytic infection, with 6 cases showing histologic signs of putrid liquefaction. Another 11 patients had chronic-granulating, fibrosing osteomyelitis. The course of the signal-time curves differed significantly between the different pathologic processes (multiple measures ANOVA, p < 0,001) in both bone marrow and soft tissue. The areas under the receiver operating characteristics (ROC) curves of the dynamic sequence as a performance measure to distinguish between acute and chronic infection were 0.73 (95 % confidence interval 0.41 - 1.00) and 0.82 (95 % confidence interval 0.59 - 1.00), respectively. Although no overall difference was found in diagnostic efficacy between conventional and dynamic MRI, the dynamic technique provided important additional information for equivocal conventional results. CONCLUSION: Dynamic contrast-enhanced MRI scanning is a safe and potentially valuable tool to discriminate between florid and chronic inflammation in documented osteomyelitis.