Martin Stenzel MD, Presenter: Nothing to Disclose

Hermann Girschick MD, PhD, Abstract Co-Author: Nothing to Disclose

Christiane Zimmer MD, Abstract Co-Author: Nothing to Disclose

Meinrad Johannes Beer MD, Abstract Co-Author: Nothing to Disclose

The chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease of childhood and adolescence which is often diagnosed with considerable delay due to clinical nonspecific findings. When MR imaging in these patient is done, often clinically silent inflammatory foci are found, this makes  whole body imaging necessary to evaluate disease activity and monitor therapeutic effects.

Over a 5 year period 32 children and adolescents (11 male, 21 female, aged 2.1 to 17.1 years) with a biopsy proven (negative for bacteria) CRMO had sequential MR imaging while on therapy. MRI protocol included non-enhanced TSE T1w, post contrast (Gd-DTPA) fat saturated TSE T1w and TIRM sequences. By consensus MRI examinations were systematically evaluated for the following criteria: 1. Quantity, 2. Distribution, 3. Signal strength, 4. Size, 5. Location of lesions and 6. periosteal, articular and muscular changes of the adjacent structures. Signal was semiquantitatively categorized as 1. profound, 2. moderate, 3.minimal, and 4. discreet.  

In a cohort of 32 patients with the diagnosis of CRMO in whole body MRI a total of 184 lesions were detected. The most often affected skeletal region were the pelvis and the lower extremities (90 out of 184 lesions, i. e. 49%). Lesions were detected in TIRM most easily (n=38 profound, n=41 moderate, n=23 minimal, n=13 discreet, n=115 total). Post gadolinium fat suppressed sequences showed the lesions nearly as good (n=29 profound, n=42 moderate, n=23 minimal, n=22 discreet, n=116 total). The size of the lesions was in the range of 2 to 180 mm. In the follow-up examinations (latest 4 years after diagnosis) more than 90% of lesions showed total regression. During therapy with NSAID lesions disappeared, reappeared and new lesions were detected.  

Chronic recurrent multifocal osteomyelitis shows from a few to multiple inflammatory foci in MRI, this necessitates acquisition of whole body MR images. Our series of 32 children and adolescents showed many clinically silent lesions. Since the therapeutic effect with NSAID needs to be monitored, whole body MRI is a useful tool. MRI not only shows the inflammatory osseous foci, but accompanying arthritis and myositis as well.

In cases of CRMO whole body MRI shows the exact extent of the disease before treatment. MRI is a useful tool to monitor treatment since it shows clinically silent lesions.

Stenzel, M, Girschick, H, Zimmer, C, Beer, M, Whole Body MRI in Chronic Recurrent Multifocal Osteomyelitis (CRMO).  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6018484.html