Naomi Winn

Diagnostic Utility of Magnetic Resonance Imaging and Radiography in Juvenile Spondyloarthritis: Evaluation of the Sacroiliac Joints in Controls and Affected Subjects

Objective. To compare the utility of radiography and magnetic resonance imaging (MRI) for the diagnosis of juvenile-onset spondyloarthritis in pediatric patients presenting with low back and/or sacroiliac (SI) pain of potentially inflammatory etiology. Methods. Radiographs and MRI studies of the SI joints in 26 patients with juvenile spondyloarthritis (JSpA) and 35 controls were assessed independently by 2 radiologists, with discrepancies arbitrated by a third. Radiographs and MRI were blinded and read in separate batches in random order. Results. Erosion was common and was the most useful diagnostic feature on radiography [positive likelihood ratio (LR) = 3.5] and was especially diagnostic of SpA on MRI (LR = 6.7). Subchondral sclerosis was common but was the least specific feature for both modalities. Joint space narrowing had some utility on radiography (LR = 2.0) and MRI (LR = 2.7) but was uncommon and had poor reader reliability. Bone marrow edema (LR = 3.1) and subarticular fat infiltration (LR = 4.5), detectable only on MRI, were both useful features. Global diagnostic impression of MRI (LR = 9.4) had very high utility for the diagnosis of JSpA, exceeding radiography (LR = 4.4) because of superior specificity. In addition, global diagnosis of SpA is much more reliably made on MRI (κ = 0.80) compared to radiography (κ = 0.30). Conclusion. Specificity and reliability of MRI of the SI joints are superior to radiography for the diagnosis of juvenile-onset SpA and, where available, MRI should replace radiography as the first line of investigation.

Sonoelastography in the musculoskeletal system: Current role and future directions

Ultrasound is an essential modality within musculoskeletal imaging, with the recent addition of elastography. The elastic properties of tissues are different from the acoustic impedance used to create B mode imaging and the flow properties used within Doppler imaging, hence elastography provides a different form of tissue assessment. The current role of ultrasound elastography in the musculoskeletal system will be reviewed, in particular with reference to muscles, tendons, ligaments, joints and soft tissue tumours. The different ultrasound elastography methods currently available will be described, in particular strain elastography and shear wave elastography. Future directions of ultrasound elastography in the musculoskeletal system will also be discussed.

Development and Preliminary Validation of a Digital Overlay-based Learning Module for Semiquantitative Evaluation of Magnetic Resonance Imaging Lesions in Osteoarthritis of the Hip

Objective. To develop and validate a knowledge transfer (KT) module aimed at enhancing feasibility and reliability of semiquantitative assessment of bone marrow lesions (BML) and synovitis-effusion using the Hip Inflammation Magnetic Resonance Imaging Scoring System (HIMRISS). Methods. Three radiologists naive to the HIMRISS method reviewed the manuscript describing the method and then scored MRI scans from 16 patients with hip OA obtained at baseline and 8 weeks after intraarticular injection of corticosteroid. Readers then reviewed a KT module comprising an instructional presentation and 8 reference DICOM (digital imaging and communications in medicine) cases scored by 3 readers with expertise in the HIMRISS method, and then used electronic overlay software to score scans from 23 patients with OA. The same format was followed with a second group of 3 readers naive to HIMRISS using a KT module revised to incorporate the overlay with a Web-based DICOM viewer to enhance feasibility. Interobserver reliability was assessed with the intraclass correlation coefficient (ICC). Results. In both exercises, reliability for baseline scores was excellent for femoral BML, very good for acetabular BML, and good for synovitis-effusion (overall ICC = 0.91, 0.89, 0.62, respectively) even without prior calibration using the KT module. However, reliability for detecting change was substantially worse than for expert readers, especially for acetabular BML and synovitis-effusion (overall ICC = 0.59 vs 0.19, and 0.42 vs 0.25, respectively). Reliability improved for detection of change in these lesions, especially after reader calibration with the revised KT module. Conclusion. Development and validation of a systematic method for KT may enhance external validation of certain imaging instruments.

Validation of a Knowledge Transfer Tool According to the OMERACT Filter: Does Web-based Real-time Iterative Calibration Enhance the Evaluation of Bone Marrow Lesions in Hip Osteoarthritis?

Objective. To assess reliability and feasibility of using a Web-based interface and interactive online calibration tool for magnetic resonance imaging (MRI) scoring of bone marrow lesions (BML) in osteoarthritis (OA), applied to the Hip MR Inflammation Scoring System (HIMRISS). Methods. Seven readers new to HIMRISS (3 radiologists, 4 rheumatologists) scored coronal short-tau inversion recovery MRI from a hip OA observational study obtained pre- and 8-week poststeroid injection (n = 40 × 2 scans × 2 hips = 160 hips). By crossover design, Group B (4 readers) scored 20 patients (40 hips) using conventional spreadsheet-based methods and then another 20 using a Web-based interface and an online real-time iterative calibration (RETIC) training module. Group A (3 readers) reversed the order, scoring the first 20 subjects by the new method and the final 20 conventionally. Outcomes included ICC and reader survey. Results. Interobserver reliability for BML status was high by both spreadsheet and Web-based methods (0.84–0.90), regardless of the order in which scoring was performed. Reliability of change scores was moderate and improved with training. Improvement was greater in readers who began with the spreadsheet method and then used the Web-based method than in those who began with the Web-based method, especially at the acetabulum. Readers found Web-based/RETIC scoring more user-friendly and nearly 50% faster than traditional spreadsheet methods. Conclusion. HIMRISS offers reliable BML scoring in OA, whether by conventional spreadsheet-based scoring or by a Web-based interface with interactive feedback. The new method allowed faster readings, provided a consistent training environment that helped inexperienced readers achieve reliability equivalent to that of conventional methods, and was preferred by the readers.

Validation of a Knowledge Transfer Tool for the Knee Inflammation MRI Scoring System for Bone Marrow Lesions According to the OMERACT Filter: Data from the Osteoarthritis Initiative

Objective. To assess feasibility and reliability of scoring bone marrow lesions (BML) on knee magnetic resonance imaging (MRI) in osteoarthritis using the Outcome Measures in Rheumatology Knee Inflammation MRI Scoring System (KIMRISS), with a Web-based interface and online training with real-time iterative calibration. Methods. Six readers new to the KIMRISS (3 radiologists, 3 rheumatologists) scored sagittal T2-weighted fat-saturated MRI in 20 subjects randomly selected from the Osteoarthritis Initiative data, at baseline and 1-year followup. In the KIMRISS, the reader moves a transparent overlay grid within a Web-based interface to fit bones, then clicks or touches each region containing BML per slice, to score 1 if BML is present. Regional and total scores are automatically calculated. Outcomes include the interreader intraclass correlation coefficients (ICC) and the smallest detectable change (SDC). Results. Scoring took 3–12 min per scan and all readers rated the process as moderately to very user friendly. Despite a low BML burden (average score 2.8% of maximum possible) and small changes, interobserver reliability was moderate to high for BML status and change in the femur and tibia (ICC 0.78–0.88). Four readers also scored the patella reliably, whereas 2 readers were outliers, likely because of image artifacts. SDC of 1.5–5.6 represented 0.7% of the maximum possible score. Conclusion. We confirmed feasibility of knee BML scoring by new readers using interactive training and a Web-based touch-sensitive overlay system, finding high reliability and sensitivity to change. Further work will include adjustments to training materials regarding patellar scoring, and study in therapeutic trial datasets with higher burden of BML and larger changes.

Radiofrequency thermo-ablation of PVNS in the knee: initial results

IntroductionPigmented villonodular synovitis (PVNS) is normally treated by arthroscopic or open surgical excision. We present our initial experience with radiofrequency thermo-ablation (RF ablation) of PVNS located in an inaccessible location in the knee.MaterialsReview of all patients with histologically proven PVNS treated with RF ablation and with at least 2-year follow-up.ResultsThree patients met inclusion criteria and were treated with RF ablation. Two of the patients were treated successfully by one ablation procedure. One of the three patients had a recurrence which was also treated successfully by repeat RF ablation. There were no complications and all patients returned to their previous occupations following RF ablation.ConclusionIn this study we demonstrated the feasibility of performing RF ablation to treat PVNS in relatively inaccessible locations with curative intent. We have also discussed various post-ablation imaging appearances which can confound the assessment for residual/recurrent disease.

Patient reported experiences of CT guided lung biopsy: a prospective cohort study

BackgroundCT guided lung biopsy is a commonly performed procedure to obtain tissue for a histological diagnosis in cases of suspected lung cancer.MethodsThis is a prospective cohort study to obtain information directly from patients about their experiences of the biopsy procedure, thus obtaining a more accurate picture of complications compared with previously performed retrospective reviews. Patients participated in a post-procedure telephone interview and information was gathered about any procedural complications and personal experiences. We also compared the patient reported complications with those obtained from a retrospective review of hospital databases, analogous to previously performed retrospective studies.ResultsIn our patient group, reported procedural complication rates were 10% pneumothorax rate (4% requiring a chest drain) and 10% haemoptysis. Post-procedural pain and shortness of breath showed positive correlation, with one patient experiencing prolonged pain. No statistical difference was found between the patient reported complication rates and those obtained from retrospective review of the hospital database.ConclusionsOur study demonstrates CT guided lung biopsy is a safe procedure and is generally well tolerated. Some patients may experience significant and lasting pain and therefore should be counselled about this pre-procedure.

Interventional articular and para-articular knee procedures

The knee is a common area of the body to undergo interventional procedures. This article discusses image-guided interventional issues specific to the knee area. The soft tissues in and around the knee are frequently affected by sport-related injuries and often need image-guided intervention. This article details the specific technical issues related to intervention in these soft tissues, including the iliotibial tract, fat pads, patellar tendon and other tendons, bursae and the meniscus. Most often, simple procedures such as injection and aspiration are performed without image guidance. Rarely image-guided diagnostic arthrography and therapeutic joint injections are necessary. The technique, indications and diagnostic considerations for arthrography are discussed in this article. Primary bone and soft-tissue tumours may involve the knee and adjacent soft tissues. Image-guided biopsies are frequently necessary for these lesions; this article details the technical issues related to image-guided biopsy around the knee. A number of newer ablation treatments are now available, including cryoablation, high-frequency ultrasound and microwave ablation. Radiofrequency ablation, however, still remains the most commonly employed ablation technique. The indications, technical and therapeutic considerations related to the application of this technique around the knee are discussed here. Finally, we briefly discuss some newer, but as of yet, unproven image-guided interventions for osteochondral lesions and Brodies abscess.

Imaging of the Knee and Surrounding Structures Following Tumor Surgery

Abstract Limb salvage is a key goal of tumor management around the knee, with surgical, medical, and radiologic treatment options. Primary bone and soft tissue sarcomas are optimally treated in specialist tertiary centers; however, metastatic disease is encountered in all aspects of radiologic practice, with overlap in the management strategies. Both specialist and generalist radiologists therefore need to be familiar with the expected normal appearances following these therapies and be able to recognize potential complications. This review article describes the techniques available for imaging the knee following treatment of bone and soft tissue tumors, with particular reference to artifact reduction. The therapeutic options for managing bone and soft tissue lesion are discussed, with emphasis on imaging appearances. Surgical, medical, and radiologic treatments are described. Complications and their imaging appearances are reviewed including local recurrence of tumor, infection, complications related to metallic implants, postradiation changes, and amputation. Normal imaging appearances and complications following radiologic treatment (namely radiofrequency ablation) of bone and soft tissue tumors are presented.

Spine Trauma: Radiographic and CT Pitfalls

Imaging evaluation of the spine can be challenging. Awareness of the limitations of the different imaging modalities allows one to take a considered approach to their interpretation. The modalities of radiography, computed tomography, and magnetic resonance imaging are often complementary to each other in the information they provide. There are many pitfalls to be avoided. Familiarity with normal radiological anatomy, an awareness of technical factors which can lead to confusion in interpretation, and knowledge of normal ossification and normal variants will minimize the risk of over- or, indeed more seriously, underreporting radiological findings.