Can routine MRI spine T1 sequences be used for prediction of decreased bone density?

Background Bone marrow signal is ideally evaluated with magnetic resonance imaging (MRI) due to its high tissue contrast. While advanced MRI quantitative methods can be used for estimating bone density, there are no readily available parameters on routine clinical MRI sequences of the lumbar spine. Purpose To evaluate whether T1 signal intensity (SI) ratio of lumbar vertebral body (VB)/cerebrospinal fluid (CSF) may predict decreased bone density. Material and Methods A retrospective study was conducted. After use of inclusion/exclusion criteria, 36 patients who had an MRI scan of the lumbar spine and a DEXA scan performed as a part of annual health visit were selected. T1 SI of the lumbar vertebral bodies and adjacent CSF were recorded. Ratio of T1 SI of L1–L4 (VB)/CSF was calculated. The corresponding bone-density values on DEXA scan measured as g/cm2 were obtained. Pearson's r correlation statistic was used to determine the correlation between these variables. Results T1 VB/T1 CSF SI ratio was between 1.308 and 2.927 (mean = 2.028). Mean T1 SI value of vertebral bodies (L1–L4) was 264.9 and mean CSF SI value was 131.9. Bone density in g/cm2 was between 0.851 and 1.398 (mean = 1.081). Pearson correlation coefficient was r = −0.619 ( P=0.0001), which shows a negative moderate correlation between the T1 VB/T1 CSF SI ratio and bone density. Conclusion A high T1 VB/T1 CSF SI ratio on routine MRI sequences may indicate decreased bone density. This ratio may be of substantial benefit in unsuspected osteoporosis/osteopenia on routine MRI lumbar spine imaging.

Dental implants: a potential cause of bone marrow edema in the jaw—preliminary report

Background Different magnetic resonance imaging (MRI) sequences are frequently used to examine bone marrow in the jaw, including short tau inversion recovery (STIR). MRI is a sensitive method for detecting bone marrow lesions. Currently, pantomography and computed tomography (CT) are used frequently for preoperative dental implant treatment. However, no study has evaluated bone marrow edema around dental implants using MRI. This study aimed to assess bone marrow edema in the jaw around dental implants using brain magnetic resonance images. Methods This retrospective cohort study was approved by our university ethics committee (EC19-011). A total of 17 patients (170 sites) who underwent brain MRI between April 2010 and March 2016 were analyzed. All subjects underwent scanning more than 3 years after implant placement. This study investigated two bone marrow signals (with implant site and without implant site). These two groups were then compared using Fisher’s exact test. The Mann–Whitney U test was used to analyze bone marrow signal intensity as the dependent variable and the long and short-axis diameters of the implant as the independent variables. Results The were 22/31 sites (71%) and 38/139 sites (27%) of bone marrow edema in the dental implants and without dental implants groups, respectively (p < 0.001). Furthermore, there was a significant correlation between bone marrow signal intensity and the short-axis diameter of the implant (p < 0.001). Conclusion The signal intensity in the bone marrow sites in the jaw with dental implants was significantly higher than that in the sites without dental implants. The present study findings suggest that dental implants are a potential cause of bone marrow edema in the jaw.

The Prediction of Lymphohematopoietic Diseases by Incidentally-Detected Diffuse Signal Alterations of Bone Marrow on MRI

Objective: Advanced imaging techniques are increasingly used in the diagnostic workup of patients. The clinical significance of incidentally-detected signal alterations of the bone marrow on magnetic resonance imaging has not been widely studied. The purpose of this study was to determine whether bone marrow signal changing on magnetic resonance imaging could predict a hematologic disease. Materials and Methods: Thirty patients who were referred to Hematology department due to bone marrow signal alteration on magnetic resonance imaging between the years of 2011 and 2018 were evaluated. Results: There were 8 males and 22 females with a median age of 53 (range, 31–86) years at the time of presentation to the Hematology clinic. The magnetic resonance imaging studies had been taken because the patients had complaints of pain in extremities or lumbago (80%). The patients had been followed for median 4.5 months (0-71.7). Six (20%) cases had a bone marrow biopsy at presentation and a diagnosis was established in 5 (16.6%) of them (1 patient was diagnosed acute myeloid leukemia, 4 patients were diagnosed multiple myeloma). Marrow biopsy was done in 11 of the cases during follow-up median 3.8 months (1.3-11.5) after presentation. A diagnosis was made in 9 cases (5 patients were diagnosed multiple myeloma, 2 patients were diagnosed follicular lymphoma, 1 patient was diagnosed waldenstrom macroglobulinemia). Thirteen cases never had a biopsy. These cases had been followed for 1.3 months (0-71.7). None of them showed clinical abnormalities related to a lymphohematopoietic disorder and/or diagnosed with such a disorder. Only 1 patient was diagnosed with osteomalacia at follow-up. Conclusion: Incidentally-detected signal alterations of the bone marrow on magnetic resonance imaging should trigger investigations for a marrow problem. Most of the diagnosis patients were multiple myeloma. Extremity pain and findings like anemia may be associated with lymphohematological malignancies.

THU0518 ACCURACY OF DUAL-ENERGY COMPUTED TOMOGRAPHY FOR THE DETECTION OF BONE MARROW EDEMA IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS

Background:An important applications of the Dual energy computed tomography DECT in the field of musculoskeletal radiology is the detection of bone marrow edema (BME), using a post-processing software to remove calcium in trabecular bone by using a “virtual non-calcium (VNCa)” subtraction process DECT have been successfully employed in the evaluation of the extent of BME in patients with sacroiliitis (1)Objectives:The aims of this study were i)to evaluate the discriminating capacity of DECT versus MRI in the detection of BME of the sacroiliac joints in patients with axial-SpA and to define the optimal cutoff; ii) to define of inter-observer agreement between radiologistsMethods:All patients underwent a pelvic DECT examination, within 30 days of the MRI imaging, (Somatom Force; Siemens Healthineers, Enlangen, Germany). Each exam was evaluated by two operators: an experienced radiologist and a radiologist in training. The dedicated software also allows the precise calculation of the attenuation values in the region of interest (ROI). On the reformatted color-coded dual-energy virtual non-calcium images bone marrow signal is depicted in green and corresponding to high signal intensity on T2-weighted fat suppression MR images (Fig. 1). With the consent of the two operators, three ROIs were manually positioned for each side of the sacroiliac joints in the subchondral region of the proximal, middle and distal thirds of each joint head, respectively. The interobserver agreement analysis was carried out in the semi-quantitative evaluation of the scores assigned in CT. The accuracy of DECT for the detection of BME compared to MRI was analyzed using the Receiver Operating Characteristics (ROC) curve methodFigure 1.Patient with SpA A. Short tau inversion recovery MR image demonstrating extensive BME in both iliac and sacral subchondral bone, indicating active sacroiliitis. B. CT Semicoronal multiplanar reformatted grayscale image shows signs of structural change. C. Semicoronal multiplanar reformatted color-coded dual-energyVNCaimage reveals bone marrow signal involving both sacroliliac joints, corresponds toBMEon the MR imageResults:56 axial-SpA patients have been evaluated, 30 males and 26 females, a mean age of 48.6 ± 12.3 years, a mean disease duration of 5.5 ± 2.9 years, a mean C-reactive protein level of 3.0 ± 2.5 mg/dl. The inter-rater agreement of readers showed a high statistical significance greater than 0.80, in particular the weighted kappa is 0.815, with a standard error of 0.04 and a 95% variability coefficient between 0.73 and 0.89. Sensitivity, specificity, and positive likelihood ratio in the identification of BME at DECT were 95.8%, 83.3% and 6.67, respectively. The differences in mean CT number (HU) among the four levels of edema category were significant (p<0.0001). The AUC was 0.905 in the differentiation of the presence of BME from no edema (Fig. 2). A cutoff value of –14.8 HU yielded overall sensitivity of 82.86% and specificity of 90.48%, with an LR+ of 8.70, in the detection of BMEFigure 2.Graph shows ROC curves from CT numbers (in Hounsfield units) derived from DECT images in the detection of sacroiliitis with and without BME. AUC was 0.905Conclusion:We confirm the potential of DECT for the detection of BME of the sacroiliac joints in patients affected by SpA. This new method appears to be very useful, not only in the diagnostic phase, but also for the monitoring of patients.References:[1]Carotti M, Salaffi F, Beci G, Giovagnoni A. The application of dual-energy computed tomography in the diagnosis of musculoskeletal disorders: a review of current concepts and applications. Radiol Med. 2019;124(11):1175-1183.Disclosure of Interests:None declared

Malignant Marrow Bone Tumors

Chapter 59 discusses malignant bone marrow tumors. Musculoskeletal radiologists are frequently confronted with bone marrow signal alterations on MRI that may represent physiologic variations or benign or malignant lesions. Although statistically most of these bone marrow signal abnormalities will be benign, distinguishing malignant from benign bone marrow entities is critical to patient management. This differentiation is not always possible on imaging, however, and biopsy may be necessary. This chapter will provide a practical approach to interpretation of diffuse and focal bone marrow abnormalities with an emphasis on malignant bone marrow lesions. With particular MRI criteria discussed, the reader will gain confidence in identifying malignant lesions and know for which lesions to recommend biopsy.

Genome-wide meta-analysis identifies genetic locus on chromosome 9 associated with Modic changes

BackgroundLow back pain (LBP) is a common disabling condition. Lumbar disc degeneration (LDD) may be a contributing factor for LBP. Modic change (MC), a distinct phenotype of LDD, is presented as a pathological bone marrow signal change adjacent to vertebral endplate on MRI. It is strongly associated with LBP and has heritability around 30%. Our objective was to identify genetic loci associated with MC using a genome-wide meta-analysis.MethodsPresence of MC was evaluated in lumbar MRI in the Northern Finland Birth Cohort 1966 (n=1182) and TwinsUK (n=647). Genome-wide association analyses were carried out using linear regression model. Inverse-variance weighting approach was used in the meta-analysis.ResultsA locus associated with MC (p<5e-8) was found on chromosome 9 with the lead SNP rs1934268 in an intron of the PTPRD gene. It is located in the binding region of BCL11A, SPI1 and PBX3 transcription factors. The SNP was nominally associated with LBP in TwinsUK (p=0.001) but not associated in the UK Biobank (p=0.914). Suggestive signals (p<1e-5) were identified near XKR4, SCIN, MGMT, DLG2, ZNF184 and OPRK1.ConclusionPTPRD is a novel candidate gene for MC that may act via the development of cartilage or nervous system; further work is needed to define the mechanisms underlying the pathways leading to development of MC. This is the first genome-wide meta-analysis of MC, and the results pave the way for further studies on the genetic factors underlying the various features of spine degeneration and LBP.