Seijiro Inoue, Presenter: Nothing to Disclose

Toshinori Hirai MD, Abstract Co-Author: Nothing to Disclose

Koichi Kawanaka MD, Abstract Co-Author: Nothing to Disclose

Shinya Shiraishi MD, Abstract Co-Author: Nothing to Disclose

Morikatsu Yoshida, Abstract Co-Author: Nothing to Disclose

Hiroyuki Uetani, Abstract Co-Author: Nothing to Disclose

Yasuyuki Yamashita MD, Abstract Co-Author: Nothing to Disclose

To determine the radiologic features of hyperplastic hematopoietic bone marrow (HHBM) mimicking vertebral metastasis on MR and FDG positron emission tomography (PET) images and to evaluate the diagnostic value of CT and bone scintigraphy for differentiating the two entities.

We retrospectively reviewed radiologic images of 6 consecutive male patients (age 52-73 years; mean 63 years) with suspected vertebral metastasis on MRI and FDG PET scans confirmed as HHBM by CT-guided biopsy. MR, FDG PET, CT, and bone scintigraphy images were qualitatively and/or quantitatively evaluated and the maximum standard uptake value (SUVmax) of the lesions was calculated. Vertebral bone marrow on CT was qualitatively recorded as grade 1 (normal or subtle high attenuation) or grade 2 (osteolytic and/or sclerotic areas). Spinal findings on bone scintigraphy were qualitatively classified as high, normal, or low uptake. CT and bone scintigraphy findings on patients with HHBM were compared with 10 vertebral metastasis patients and the difference between the two modalities was statistically analyzed.

FDG PET showed slightly high uptake by all HHBM lesions; the mean ± S.D. for SUVmax was 2.75 ± 0.37 (range 2.3-3.4). All HHBM lesions were diffuse, patchy or nodular, and hypointense on T1- and T2-weighted images and tended to be continuous in some vertebrae. In one HHBM patient the apparent diffusion coefficient (ADC) of the lesion was 0.7 x10-3mm2/s. Grade 1 CT findings were recorded for all HHBM patients; grade 2 for 9 of 10 patients with vertebral metastasis (p < 0.01). In 4 HHBM patients bone scintigraphy showed normal uptake in the lesions; in 9 of 10 patients with vertebral metastasis uptake was abnormal (p < 0.01).

Although the differentiation of HHBM from vertebral metastasis is difficult on FDG PET and MRI scans, CT and bone scintigraphy are useful for their differentiation.

In patients with suspected vertebral metastases on FDG PET and MRI, CT and bone scintigraphy may be useful for differentiating HHBM from metastasis.

Inoue, S, Hirai, T, Kawanaka, K, Shiraishi, S, Yoshida, M, Uetani, H, Yamashita, Y, Hyperplastic Hematopoietic Bone Marrow Mimicking Vertebral Metastases on MRI and FDG-PET Studies: Diagnostic Value of CT and Bone Scintigraphy for Differentiating the Two Entities.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006326.html