The objective of this study was to evaluate the performance of digital subtraction angiography (DSA)–like bone subtraction with 2 different registration methods for the identification of bone marrow edema pattern (BMEP) in patients with lytic bone lesions, using magnetic resonance imaging as the criterion standard.
Fifty-five patients with a lytic bone lesion were included in this prospective study with approval from the ethics committee. All patients underwent magnetic resonance imaging and low-dose computed tomographic (CT) perfusion after signing an informed consent. Two CT volumes were used for bone subtraction, which was performed with 2 different algorithms (rigid and nonrigid). Enhancement at the nonlytic bone marrow was considered as a sign of BMEP. Two readers evaluated the images blindly. The presence of BMEP on bone-subtracted CT images was evaluated subjectively and quantitatively. Image quality was assessed. Magnetic resonance imaging was used as the criterion standard.
Using a rigid registration method, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT with DSA-like bone subtraction BMEP was 77%, 100%, 100%, 68%, and 85%, respectively. The interobserver agreement was good (κ, 0.782). Image quality was better using a nonrigid registration. With this algorithm, artifacts interfered with image interpretation in only 5% of cases. However, there was a noticeable drop in sensitivity and negative predictive value when a nonrigid algorithm was used: 56% and 52%, respectively. The interobserver agreement was average with a nonrigid subtraction algorithm.
Computed tomography with DSA-like bone subtraction is sensitive and highly specific for the identification of BMEP associated with lytic bone lesions. Rigid registering should be preferred, but nonrigid algorithms can be used as a second option when artifacts interfere with image interpretation.
From the *Service D’imagerie Guilloz, Hôpital Central, Nancy; †Université de Lorraine, Vandoeuvre-lès-Nancy, France; and ‡Toshiba Medical Visualization Systems Europe, Edinburgh, United Kingdom.
Received for publication August 12, 2013; and accepted for publication, after revision, September 16, 2013.
Conflicts of interest and sources of funding: Supported by the French Society of Radiology (Societé Francaise de Radiologie) through a research grant.
Authors P.T. and A.B. participate on a nonremunerated research contract with Toshiba Medical Systems, the developer of the software used for this technique. The author M.R. was an employee of Toshiba Medical Systems and worked in the development of the bone subtraction algorithms used. This author had no control of patient inclusion, has not performed data analysis, or participated in any way that might present a conflict of interest. The authors G.H., S.L., and M.L. have no potential conflicts of interest to disclose.
Reprints: Pedro Augusto Gondim Teixeira, MD, Service d’imagerie Guilloz, Hôpital central, CHU-Nancy, 29 Av. Marechal Lattre de Tassigny, CO 60034 - 54035, Nancy France; E-mail: email@example.com.