M. H. Brem

Longitudinal evaluation of the occurrence of MRI-detectable bone marrow edema in osteoarthritis of the knee

Background: Bone marrow edema (BME) is a condition detectable with magnetic resonance imaging (MRI) and is present in different stages of osteoarthritis (OA). Its pathogenesis is still not completely known. Purpose: To evaluate the longitudinal occurrence and persistence of BME in early OA of the knee. Material and Methods: Twenty-three patients (eight females, 15 males; mean age 55.5±10.3 years) were scanned with a 1.5T MR imaging unit (sagittal fat-suppressed intermediate-weighted fast spin echo; 4-mm section thickness, 1-mm intersection gap, 256x192 matrix, 120-mm field of view). Images were obtained in all 23 patients at two time points (TPs) and in 12 patients at three TPs. Images were evaluated by two readers independently; discrepancies in image grading were reviewed and evaluated in consensus. A four-point image-grading scale was used (absence of BME to severe BME). Four main anatomical regions were evaluated (medial femur, lateral femur, medial tibia, lateral tibia), which were subcategorized into anterior, central, and posterior regions. Results: One hundred five areas of BME in the 23 patients were found at all three TPs. In 16 areas, the BME was consistent at the same location over time, in seven locations the BME became larger, in six areas the BME became smaller, and in 16 locations it could not be detected in follow-up MRIs. In one case, the BME was smaller at TP2 but increased at TP3. In eight cases, only at the last time point could a BME be detected. Conclusion: BME is not a static phenomenon but changes over time. Correlation to physical activity and local inflammatory reaction should be evaluated.

Magnetic resonance image segmentation using semi-automated software for quantification of knee articular cartilage-initial evaluation of a technique for paired scans

PurposeSoftware-based image analysis is important for studies of cartilage changes in knee osteoarthritis (OA). This study describes an evaluation of a semi-automated cartilage segmentation software tool capable of quantifying paired images for potential use in longitudinal studies of knee OA. We describe the methodology behind the analysis and demonstrate its use by determination of test–retest analysis precision of duplicate knee magnetic resonance imaging (MRI) data sets.MethodsTest–retest knee MR images of 12 subjects with a range of knee health were evaluated from the Osteoarthritis Initiative (OAI) pilot MR study. Each subject was removed from the magnet between the two scans. The 3D DESS (sagittal, 0.456xa0mmu2009×u20090.365xa0mm, 0.7xa0mm slice thickness, TR 16.5xa0ms, TE 4.7xa0ms) images were obtained on a 3-T Siemens Trio MR system with a USA Instruments quadrature transmit–receive extremity coil. Segmentation of one 3D-image series was first performed and then the corresponding retest series was segmented by viewing both image series concurrently in two adjacent windows. After manual registration of the series, the first segmentation cartilage outline served as an initial estimate for the second segmentation. We evaluated morphometric measures of the bone and cartilage surface area (tAB and AC), cartilage volume (VC), and mean thickness (ThC.me) for medial/lateral tibia (MT/LT), total femur (F) and patella (P). Test–retest reproducibility was assessed using the root-mean square coefficient of variation (RMS CV%).ResultsFor the paired analyses, RMS CV % ranged from 0.9% to 1.2% for VC, from 0.3% to 0.7% for AC, from 0.6% to 2.7% for tAB and 0.8% to 1.5% for ThC.me.ConclusionPaired image analysis improved the measurement precision of cartilage segmentation. Our results are in agreement with other publications supporting the use of paired analysis for longitudinal studies of knee OA.

Longitudinal in vivo reproducibility of cartilage volume and surface in osteoarthritis of the knee

ObjectiveThe aim of this study was to evaluate the longitudinal reproducibility of cartilage volume and surface area measurements in moderate osteoarthritis (OA) of the knee.Materials and methodsWe analysed 5 MRI (GE 1.5T, sagittal 3D SPGR) data sets of patients with osteoarthritis (OA) of the knee (Kellgren Lawrence grade I–II). Two scans were performed: one baseline scan and one follow-up scan 3xa0months later (96u2009±u200910xa0days). For segmentation, 3D Slicer 2.5 software was used. Two segmentations were performed by two readers independently who were blinded to the scan dates. Tibial and femoral cartilage volume and surface were determined. Longitudinal and cross-sectional precision errors were calculated using the standard deviation (SD) and coefficient of variation (CV%=100×[SD/mean]) from the repeated measurements in each patient. The in vivo reproducibility was then calculated as the root mean square of these individual reproducibility errors.ResultsThe cross-sectional root mean squared coefficient of variation (RMSE-CV) was 1.2, 2.2 and 2.4% for surface area measurements (femur, medial and lateral tibia respectively) and 1.4, 1.8 and 1.3% for the corresponding cartilage volumes. Longitudinal RMSE-CV was 3.3, 3.1 and 3.7% for the surface area measurements (femur, medial and lateral tibia respectively) and 2.3, 3.3 and 2.4% for femur, medial and lateral tibia cartilage volumes.ConclusionThe longitudinal in vivo reproducibility of cartilage surface and volume measurements in the knee using this segmentation method is excellent. To the best of our knowledge we measured, for the first time, the longitudinal reproducibility of cartilage volume and surface area in participants with mild to moderate OA.

[Molecular imaging: future uses in arthritides].

ZusammenfassungDie molekulare Bildgebung gehört dank immenser Fortschritte bzgl. Technologie, Genetik und Biochemie in jüngster Vergangenheit zu den sehr viel versprechenden neuen Methoden der Bildgebung in der Radiologie. Die Darstellung pathophysiologischer Vorgänge auf molekularer Ebene in Initialstadien von Erkrankungen eröffnen ganz neue und noch weitgehend unerforschte Optionen bei der Behandlung von Erkrankungen, die mit herkömmlichen Methoden erst in weit fortgeschrittenen Stadien erkannt werden können. Gegenwärtig wird intensiv an Methoden zur Darstellung dieser verschiedenen zellulären Vorgänge durch Kontrastmittel auf molekularer Basis gearbeitet. In diesem Übersichtsartikel soll veranschaulicht werden, wie die molekulare Bildgebung bei Arthritiden derzeit und zukünftig zu verbesserter Früherkennung, Diagnostik und durch Monitoring der verschiedenen Behandlungsregime zu optimierter Therapie beitragen kann.AbstractMolecular imaging is an upcoming field in radiology as a result of great advances in imaging technology, genetics, and biochemistry in the recent past. Early-stage imaging of molecular pathological changes in cells opens the gates to new methods in medical treatment of diseases that otherwise would only be detected in advanced stages.Methods of imaging biochemical pathways with molecular agents are currently an issue of intensive research. This article reviews current modalities of molecular imaging in arthritis that should offer future perspective on early disease detection, diagnosis, and monitoring of treatment efficiency and how they can pave the way to optimized therapy.

Molekulare Bildgebung: Künftige Anwendungen bei Arthritiden@@@Molecular imaging: future uses in arthritides

ZusammenfassungDie molekulare Bildgebung gehört dank immenser Fortschritte bzgl. Technologie, Genetik und Biochemie in jüngster Vergangenheit zu den sehr viel versprechenden neuen Methoden der Bildgebung in der Radiologie. Die Darstellung pathophysiologischer Vorgänge auf molekularer Ebene in Initialstadien von Erkrankungen eröffnen ganz neue und noch weitgehend unerforschte Optionen bei der Behandlung von Erkrankungen, die mit herkömmlichen Methoden erst in weit fortgeschrittenen Stadien erkannt werden können. Gegenwärtig wird intensiv an Methoden zur Darstellung dieser verschiedenen zellulären Vorgänge durch Kontrastmittel auf molekularer Basis gearbeitet. In diesem Übersichtsartikel soll veranschaulicht werden, wie die molekulare Bildgebung bei Arthritiden derzeit und zukünftig zu verbesserter Früherkennung, Diagnostik und durch Monitoring der verschiedenen Behandlungsregime zu optimierter Therapie beitragen kann.AbstractMolecular imaging is an upcoming field in radiology as a result of great advances in imaging technology, genetics, and biochemistry in the recent past. Early-stage imaging of molecular pathological changes in cells opens the gates to new methods in medical treatment of diseases that otherwise would only be detected in advanced stages.Methods of imaging biochemical pathways with molecular agents are currently an issue of intensive research. This article reviews current modalities of molecular imaging in arthritis that should offer future perspective on early disease detection, diagnosis, and monitoring of treatment efficiency and how they can pave the way to optimized therapy.

Molekulare Bildgebung: Künftige Anwendungen bei Arthritiden

ZusammenfassungDie molekulare Bildgebung gehört dank immenser Fortschritte bzgl. Technologie, Genetik und Biochemie in jüngster Vergangenheit zu den sehr viel versprechenden neuen Methoden der Bildgebung in der Radiologie. Die Darstellung pathophysiologischer Vorgänge auf molekularer Ebene in Initialstadien von Erkrankungen eröffnen ganz neue und noch weitgehend unerforschte Optionen bei der Behandlung von Erkrankungen, die mit herkömmlichen Methoden erst in weit fortgeschrittenen Stadien erkannt werden können. Gegenwärtig wird intensiv an Methoden zur Darstellung dieser verschiedenen zellulären Vorgänge durch Kontrastmittel auf molekularer Basis gearbeitet. In diesem Übersichtsartikel soll veranschaulicht werden, wie die molekulare Bildgebung bei Arthritiden derzeit und zukünftig zu verbesserter Früherkennung, Diagnostik und durch Monitoring der verschiedenen Behandlungsregime zu optimierter Therapie beitragen kann.AbstractMolecular imaging is an upcoming field in radiology as a result of great advances in imaging technology, genetics, and biochemistry in the recent past. Early-stage imaging of molecular pathological changes in cells opens the gates to new methods in medical treatment of diseases that otherwise would only be detected in advanced stages.Methods of imaging biochemical pathways with molecular agents are currently an issue of intensive research. This article reviews current modalities of molecular imaging in arthritis that should offer future perspective on early disease detection, diagnosis, and monitoring of treatment efficiency and how they can pave the way to optimized therapy.

P267 SEMI AUTOMATED PAIRED IMAGE CARTILAGE SEGMENTATION A METHOD FOR THE EVALUATION OF MR IMAGES

M.H. Brem1, P.M. Schlechtweg2, G. Neumann2, R. Jackson3, J. Yu3, C. Eaton4, H. Yoshioka2, P. Lang2, J. Duryea2 1Friedrich Alexander University Erlangen-Nuremberg, Dept. of Surgery/Orthopedic Surgery, Erlangen, Germany, 2Brigham and Womens’ Hospital, Dept. of Radiology, Boston, MA, Boston, MA, 3The Ohio State University, Dept. Endocrinology, Diabetes and Metabolism and Radiology, Columbus, OH, 4Memorial Hospital of Rhode Island, Center for Primary Care and Prevention and Brown Medical School, Providence, RI