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The purposes of this study was to determine the prevalence of the accessory anterolateral talar facet (AALTF); to evaluate the relationship between AALTF, focal abutting bone marrow edema (FABME), and sinus tarsi edema; and to study the prevalence of tarsal coalitions in patients with the AALTF utilizing ankle MR images. 5-T ankle MR images were reviewed for the presence of AALTF, FABME, sinus tarsi edema, tarsal coalition, and location and type of coalition (cartilaginous, fibrous, and osseous). Multivariate analysis was performed to examine the correlation between AALTF and the other variables. Three hundred ninety-one consecutive patients were included (age range 5–86 years; mean age 45 years). An AALTF was present in 3.6% (14/391) of patients. The AALTF prevalence was 2% in women and 6.6% in men. There was a significantly association between AALTF and FABME (9/14, p < 0.05), sinus tarsi edema (13/14, p < 0.05), and tarsal coalition (4/14, p < 0.05). AALTF is relatively often detected on MRI of the ankle and significantly associated with BME, sinus tarsi edema, and subtalar coalition. Patients with a tarsal coalition should be evaluated for the concurrent presence of an AALTF.

Despite being one of the most common indications for surgery, data on the types of meniscus tear that should be treated surgically are limited. Improving patient selection requires agreement on meniscus tear description. This study evaluates a simple MRI tear classification system for inter-observer agreement. Knee MRI examinations from 57 subjects from the Osteoarthritis Initiative cohort were reviewed by two sub-specialty trained, musculoskeletal radiologists. Based on two pulse sequences, each meniscus was classified by: tear or no tear; location of tear in anterior, middle or posterior third or multiple thirds; and displaced or non-displaced radial, horizontal, longitudinal or complex tear pattern. A tear was defined as signal abnormality extending to the surface on at least two images and displacement as more than 2 mm of extrusion or separation measured orthogonal to the tear plane. Kappa, weighted Kappa and percentage agreement were calculated. For the medial meniscus, Kappa and percentage agreement estimates were, respectively: the presence of tear, 0.79 and 89.5%; tear with displacement, 0.70 (weighted Kappa) and 66.0%; tear description, 0.47 and 61.4%; tear location, 0.64 and 79.0%. For the lateral meniscus, estimates were: the presence of tear, 0.75 and 89.5%; tear with displacement, 0.81 (weighted Kappa) and 86.0%; tear description, 0.56 and 78.9%; tear location, 0.74 and 87.7%. The strength of agreement between readers was moderate to substantial underscoring the challenge of meniscus tear classification.

Intraosseous foreign body granuloma formation related to migrated surgical material is a rarely reported condition with variable imaging appearance. In this case report, we describe a foreign body granuloma that occurred in a lumbar vertebral body one level above a prior surgical fusion. The lytic appearance mimicked a skeletal metastasis in a 65-year-old patient with recently diagnosed renal cell carcinoma. To the best of our knowledge, this is the first reported case of a lumbar vertebral foreign body granuloma occurring distant from the site of surgery, indistinguishable from skeletal metastasis on radiologic examination.

Following IRB approval, a cohort of 3-D rigid-body computational models was created from submillimeter MRIs of clinically diagnosed Adult Acquired Flatfoot Deformity patients and employed to investigate postoperative foot/ankle function and surgical effect during single-leg stance. Models were constrained through physiologic joint contact, passive soft-tissue tension, active muscle force, full body weight, and without idealized joints. Models were validated against patient-matched controls using clinically utilized radiographic angle and distance measures and plantar force distributions in the medial forefoot, lateral forefoot, and hindfoot. Each model further predicted changes in strain for the spring ligament, deltoid ligament, and plantar fascia, as well as joint contact loads for three midfoot joints, the talonavicular, navicular-1st cuneiform, and calcaneocuboid. Radiographic agreement ranged across measures, with average absolute deviations of

Adult acquired flatfoot deformity (AAFD) is a degenerative disease resulting in malalignment of the mid- and hindfoot secondary to posterior tibial tendon dysfunction and increasing implication of ligament pathologies. Despite the complex 3D nature of AAFD, 2D radiographs are still employed to diagnose and stage the disease. Computer modeling techniques allow for accurate 3D recreations of musculoskeletal systems for the investigation of biomechanical factors contributing to disease. Following Institutional Review Board approval, the lower limbs of six diagnosed AAFD sufferers were imaged with MRI, photographs, and X-ray. Next, a radiologist graded the MRI attenuation of eight soft-tissues implicated in AAFD. Six patient-specific rigid-body models were then created and loaded according to patient weight, graded soft-tissues, and extrinsic muscles. Model function was validated using clinically relevant kinematic measures in three planes. Agreement varied depending on the measure, with average absolute deviations of

Using placebo data from a recently completed disease-modifying osteoarthritis (OA) drug trial, we seek to inform study design of future radiographic studies.Eligible patients aged ≥40 years, with body mass index (BMI) 25-40kg/m(2) and symptomatic knee OA diagnosed by modified Kellgren and Lawrence grade (KLG) 2 or 3 and pain/stiffness and/or use of medication for knee pain in the past year, were assessed by radiography using a modified Lyon-schuss (mL/S) protocol for joint space narrowing (JSN) (primary outcome variable) at baseline and weeks 48 and 96. Multifaceted quality control was conducted throughout. Repeat images were requested when the medial tibial plateau (MTP) was not aligned (inter-margin distance [IMD]1.5mm) or for other quality issues. Data are given mean ± standard deviation.Patients (74.9% female; 61.3 ± 9.1 years) had BMI 31.6 ± 4.1kg/m(2) at baseline; 222 (173 females) had KLG2, 264 (191 female) KLG3. A significant loss in joint space width (JSW) from baseline to week 48 (-0.13 ± 0.36mm) and to week 96 (-0.22 ± 0.45mm) was observed for all randomised placebo patients (p0.001 for both), and at both time points when stratified by KLG2 or KLG3. Standard deviations were small relative to mean changes, providing standardised response means for all placebo patients of 0.35 (week 48) and 0.48 (week 96).Using a tightly controlled radiographic technique, JSN is a viable outcome variable for determining disease progression in mild-to-moderate knee OA. The mL/S protocol is a sensitive and feasible method for OA studies aiming to assess rate of JSN in the knee.

It is important to determine the bone mass in normal premenopausal women because increasing numbers of conditions have been identified that result in premenopausal osteoporosis. The relationship between age and bone density was evaluated in 57 carefully characterized normal, premenopausal women using both single energy quantitative computed tomography (SEQCT) and dual energy (DEQCT). The mean bone density measurements were 172 mg/ml K2HPO4 SEQCT and 185 DEQCT. Bone density showed no statistically significant decline between age 18 and age 44. Single- and dual-energy data were highly correlated with each other (r = 0.89), and dual energy appeared to confer no advantage. There was an inverse relation between density and age of menarche. Bone density did not correlate with ideal body weight, percentage fat, or subcutaneous fat area.

STUDY DESIGN: Image analysis model development.OBJECTIVE: The objective of this study was to develop a novel clinical workflow tool that uses model-based shape recognition technology to allow efficient, semiautomated detailed annotation of each vertebra between T4 and L4 on plain lateral radiographs.SUMMARY OF BACKGROUND DATA: Identification of prevalent vertebral fractures, especially when not symptomatic, has been problematic despite their importance. There is a recognized need to increase the opportunities to detect vertebral fractures so that clinically beneficial therapeutic interventions can be initiated.METHODS: Radiographs obtained from 165 subjects in the Canadian Multicenter Osteoporosis Study (CaMos) were used to construct a vertebral shape model of the vertebral column from T4 to L4 using a statistical learning technique, as well as to estimate the accuracy and precision of this automated software tool for vertebral shape analysis. Radiographs showing scoliosis greater than 15 degrees were excluded.RESULTS: Vertebral contours defined by 95 points per vertebra, represented by 79,895 points in total, were assessed on 841 individual vertebrae. The mean absolute accuracy error calculated over each vertebra in each test image was 1.06 +/- 1.2 mm. This value corresponded to an average 3.4% of vertebral height. The mean precision error, reflecting interobserver variability, per vertebra of the resulting annotations was 0.61 +/- 0.73 mm. This value corresponded to an average 2.3% of vertebral height. Accuracy and precision error estimates did not differ notably by vertebral level.CONCLUSION: The results of the current study indicate that statistical modeling can provide a robust tool for the accurate and precise semiautomated annotation of vertebral body shape from T4 to L4 in patients who do not have scoliosis greater than 15 degrees . This method may prove useful as a clinical workflow tool to aid the physician in vertebral fracture assessment and might contribute to decision-making about pharmacologic treatment of osteoporosis.

OBJECTIVE. Accurate characterization of acetabular fractures can be difficult because of the complex acetabular anatomy and the many fracture patterns. In this article, the five most common acetabular fractures are reviewed: both-column, T-shaped, transverse, transverse with posterior wall, and isolated posterior wall. Fracture patterns on radiography are correlated with CT, including multiplanar reconstruction and 3D surface rendering.CONCLUSION. In the evaluation of the five most common acetabular fractures, assessment of the obturator ring, followed by the iliopectineal and ilioischial lines and iliac wing, for fracture allows accurate classification. CT is helpful in understanding the various fracture patterns.

To prospectively compare magnetic resonance (MR) imaging-defined abnormalities of osteoarthritis (OA) of the knee with radiographic severity measurements of OA of the knee and self-reported pain.This study was approved by the institutional review board of University of Michigan. Informed consent was obtained for this HIPAA-compliant study. Knee MR imaging was performed in 117 women (mean age, 46 years; range, 32-56 years) from a community-based arthritis study (n = 1053) with 30 women in each of four categories: (a) no pain and no OA of the knee, (b) no pain and OA of the knee, (c) pain and no OA of the knee, and (d) pain and OA of the knee. OA of the knee was defined from radiographs. Two hundred thirty-two eligible knees had Kellgren-Lawrence scores for OA of the knee as follows: grade 0, 115 (49.6%); grade 1, 33 (14.2%); grade 2, 66 (28.4%); grade 3, 17 (7.3%); and grade 4, one (0.4%). MR images were assessed for location and severity of defects of cartilage, bone marrow edema (BME), osteophytes, subchondral cysts, sclerosis, meniscal and/or ligamentous tears, joint effusion, synovial cysts, and synovitis. MR imaging findings were compared with radiographic severity of OA of the knee (Kellgren-Lawrence scale) and self-reported pain with analysis of variance, t tests, and contingency table analyses.Defects of cartilage (higher than grade IIA) were found in 75% of knees; BME was found in 57% of knees (1 cm, 41%;1 cm, 16%). Large BME lesions were common in the pain and OA of the knee group (P = .001); this group was significantly more likely to have defects of cartilage (P = .001); meniscal tears (P = .001); and osteophytes, subchondral cysts, sclerosis, joint effusion, and synovitis (P.001). Defects of cartilage, osteophytes, sclerosis, meniscal or ligamentous tears, joint effusion, and synovitis were strongly related to increasing Kellgren-Lawrence grade (P.001).In middle-aged women, there were significant associations between pain, radiographic severity of OA of the knee, and seven MR imaging-identified parameters.

We present a case of traumatic bamboo foreign body penetration through the posterior thigh extending cephalad into the pelvis sustained during skiing. The unsuspected bamboo foreign body was missed prospectively on the initial portable trauma radiograph of the pelvis, but was retrospectively quite apparent as a linear 12 x 2-cm radiolucent region overlying the left pelvis and hip region. On CT examination, the bamboo stick appeared as a round cylindrical air-filled structure of high density compared to soft tissue - the typical appearance of bamboo. Bamboo foreign bodies can be recognized radiographically by this typical appearance, since it is one of the few wood products that causes high attenuation relative to soft tissue on CT.

Acute megakaryocytic leukemia (AML M7) is a rare type of acute myelogenous leukemia in adults, commonly presenting with myelofibrosis. This report describes a case of a 32-yr-old male who presented with hypercalcemia and bony lytic lesions, in the absence of myelofibrosis. The diagnosis of AML M7 should be considered in a patient with pancytopenia, lytic lesions and hypercalcemia.

SummaryMonoclonal antibodies that bind and inhibit nerve growth factor (NGF) have demonstrated both, good analgesic efficacy and improvement in function in patients with osteoarthritis (OA). Despite initial promising data, trials in OA had been suspended by the Federal Food and Drug Administration (FDA) due to concerns over accelerated rates of OA progression. Imaging will play a crucial role in future clinical trials to define eligibility of potential participants and to monitor safety during the course of these studies. This will require baseline and frequent follow-up radiographs of both, the index joints and other large weight bearing joints to identify subjects at risk prior inclusion and on study so treatment can be discontinued.This imaging overview in the form of an atlas describes and illustrates potential exclusionary joint imaging findings at eligibility and potential adverse joint events on radiography and magnetic resonance imaging (MRI) in studies investigating a-NGF compounds. The overarching goal of this atlas is to facilitate trial design and to promote a common language and understanding between potential expert readers. This first section of the atlas will focus on knee joint specific findings that are relevant to a-NGF studies.

Neurofibromas are the most common tumors of the peripheral nerves. They may be solitary lesions, multiple localized lesions, or large plexiform masses often associated with neurofibromatosis. Relatively few reports discuss the sonographic features of PNST, specifically neurofibromas.1–7 The typical sonographic description is that of a well defined, homogeneous hypoechoic lesion, which can show posterior acoustic enhancement mimicking a cystic lesion.1,3,4 We present a case of neurofibromatosis in a 19 year old man, which was initially diagnosed by ultrasonography. We describe the ultrasonographic findings that we believe correspond to the so-called target sign on T2-weighted MR imaging examinations. The appearance on T2-weighted MR images is reported as increased signal intensity peripherally and decreased signal intensity centrally.8–10 A target sign appearance was seen sonographically in numerous lesions, demonstrating a hyperechoic central region and a hypoechoic periphery.

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A360 eligibility and safety findings relevant for aNGF clinical trials. More than 400 images were reviewed to define the most relevant and characteristic imaging findings. Diagnoses of exclusion for eligibility due to potentially increased risk of RPOA are subchondral insufficiency fractures (SIF), atrophic OA and severe malalignment of the knee in the medial-lateral direction. Diagnoses relevant for safety after enrolment (i.e. joint safety findings), i.e. RPOA, SIF, osteonecrosis and pathologic fractures will also be discussed. Several of these diagnoses have non-specific findings on the radiograph or cannot be detected radiographically in early stages. Thus, in cases of inconclusive or suspicious radiography, an additional MRI examination may be acquired to rule out or confirm some of these diagnoses. Results: Early and late signs of diagnoses relevant for eligibility will be presented. Fig 3A. Radiograph of the hip joint shows superior JSN (arrows) without relevant osteophytes present. Fig 3B. Follow up image 12 months later shows near-complete destruction of the femoral head (arrows) and subsequent migration of the femur superiorly consistent with RPOA. Conclusions: Expert readers in aNGF programs need to be aware of relevant imaging findings. These include early signs of diagnoses relevant for RPOA on radiography, and other potential X-ray and MRI diagnoses relevant for eligibility and safety during aNGF studies. 591 PROLONGED JOINT RESIDENCY OF TRIAMCINOLONE ACETONIDE AFTER AN INTRA-ARTICULAR INJECTION OF FX006, A SUSTAINED RELEASE FORMULATION FOR THE TREATMENT OF OSTEOARTHRITIS N. Bodick y, J. Lufkin y, C. Willwerth y, J. Hauben y, A. Kumar y, P. Boen y, J. Bolognese z, C. Schoonmaker z, M. Clayman y. y Flexion Therapeutics, Burlington, MA, USA; zCytel Inc, Cambridge, MA, USA Purpose: Although available intra-articular (IA) corticosteroids are well established in the treatment of painful osteoarthritis (OA), limitations include short duration of pain relief (1-4 weeks), an effect consistent with the transient residency of these compounds in the joint and high plasma corticosteroid concentrations immediately following injection. FX006 is a novel IA sustained-release injectable formulation of 25% triamcinolone acetonide (TCA) in poly(lactic-co-glycolic acid) microspheres intended to prolong therapeutic concentrations of TCA in the joint and limit systemic exposure. In a previously described 6-week long clinical study, FX006 at 40 mg demonstrated maintenance of synovial concentrations of TCA consistent with pharmacologic activity for a period of at least 6 weeks, when levels of TCA produced by an equivalent dose of TCA IR were below the limit of quantitation. The current study extended these data on joint residency by measuring synovial fluid levels of TCA at later time points. Methods: In this multi-center, open-label study, patients with OA of the knee received a single IA injection of FX006 containing 10 or 40mg TCA, or 40mg of a standard, immediate-release suspension of TCA (TCA IR). A total of 50 patients were enrolled (FX006 10 mg: 10 patients, FX006 40 mg: 30 patients, TCA IR: 10 patients). Synovial fluid and plasma samples were obtained at baseline (pre-dose) and at the planned Final Visit at either Week 12, 16, or 20, depending on cohort assignment and availability of fluid in the knee. Concentrations of TCA were measured in plasma or in filtered synovial fluid samples using High Performance Liquid Chromatographic methods with Tandem Mass Spectrometry Detection and Automated Extraction, validated for the determination of TCA in human plasma and synovial fluid respectively. The quantitation limits of both assays were 50 to 50000 pg/mL. Results: In the FX006 10 mg group, 8 patients had synovial fluid available for analysis at Week 12. In the FX006 40 mg group, 6 patients had synovial fluid available for analysis at Week 12, 8 patients at Week 16 and 11 patients at Week 20. In the TCA IR group, 5 patients had synovial fluid available for analysis at Week 12. The concentrations of TCA achieved by 40mg FX006 in the synovial fluid atWeek 12 were 924 pg/mL, at Week 16, the IA concentrations of TCAwere 224 pg/mL and by Week 20 they were below the lower limit of quantitation (Figure; geometric means from the earlier 6-week study and the current study are merged). The IA concentration of TCA in patients receiving 40 mg of TCA IR at Week 12 was below the lower limit of quantitation. FX006 maintained a gradient between synovial and systemic plasma concentrations of TCA for 16 weeks.

Adult Acquired Flatfoot Deformity (AAFD) is a degenerative disease characterized by chronic changes in the joint alignment of the bones of the foot leading to significant pain and dysfunction. The hallmark of this disease is the functional loss in posterior tibialis tendon (PTT) strength though mechanical degradation of passive support structures of the foot have also been implicated, namely the spring ligament, talocalcaneal interosseous ligaments, fibers of the anterior deltoid, and the long and short plantar ligaments. [1] Clinically, AAFD patients present with midfoot collapse, forefoot abduction, and valgus tilting of the hindfoot and the magnitudes of these deformities are most often graded using plane radiographs in the mediolateral (ML), oblique anteroposterior (AP) and posteroanterior (PA) views. [1–3] The objective of this study was to develop a population of patient-matched rigid-body kinematic models using a standardized methodology that can be used to predict pathologic foot function with agreement between patient and model assessed through clinically relevant radiographic joint angles.Copyright © 2013 by ASME

Objective To determine if inhibition of inducible nitric oxide synthase (iNOS) with cindunistat hydrochloride maleate slows progression of osteoarthritis (OA) Methods This 2-year, multinational, double-blind, placebo-controlled trial enrolled patients with symptomatic knee OA (Kellgren and Lawrence Grade (KLG) 2 or 3). Standard OA therapies were permitted throughout. Patients were randomly assigned to cindunistat (50 or 200 mg/day) or placebo. Randomisation was stratified by KLG. Radiographs to assess joint space narrowing (JSN) were acquired using the modified Lyon-schuss protocol at baseline, week 48 and 96. Results Of 1457 patients (50 mg/day, n=485; 200 mg/day, n=486; placebo, n=486), 1048 (71.9%) completed the study. Patients were predominantly women; 56% had KLG3. The primary analysis did not demonstrate superiority of cindunistat versus placebo for rate of change in JSN. In KLG2 patients, JSN after 48 weeks was lower with cindunistat 50 mg/day versus placebo (p=0.032). Least-squares mean±SE JSN with cindunistat 50 mg/day ( −0.048±0.028 mm) and 200 mg/day (−0.062±0.028 mm) were 59.9% (95% CI 6.8% to 106.9%) and 48.7% (95% CI -8.4% to 93.9%) of placebo, improvement was not maintained at 96 weeks. No improvement was observed for KLG3 patients at either time-point. Cindunistat did not improve joint pain or function, but was generally well tolerated. Conclusions Cindunistat (50 or 200 mg/day) did not slow the rate of JSN versus placebo. After 48-weeks, KLG2 patients showed less JSN; however, the improvement was not sustained at 96-weeks. iNOS inhibition did not slow OA progression in KLG3 patients. Clinical trial listing NCT00565812

Adult Acquired Flatfoot Deformity (AAFD) is a degenerative disease characterized by chronic changes in the joint alignment of the bones of the foot leading to significant pain and dysfunction. The early stages of the disease are thought to involve primarily the mechanical degradation of the soft-tissue support structures of the foot, namely the spring ligament, talocalcaneal interosseous ligaments, fibers of the anterior deltoid, and the long and short plantar ligaments, as well as a functional loss in posterior tibialis tendon (PTT) strength. [1] These changes manifest clinically as midfoot collapse, forefoot abduction, and valgus tilting hindfoot. [1–3] Various surgical corrections exist for Stage II AAFD to restore more normal biomechanical function to the foot. Treatment selection is most often based on clinical outcomes and surgeon preference. However, the optimal procedure(s) for an individual patient is unknown. Computer Aided Design (CAD) approaches offer advantages for evaluating foot function as well as the ability to predict pre-operatively the outcome of corrective procedures. This study developed a 3D patient specific computer model of the lower leg from a diagnosed Stage II flatfoot patient and evaluated its ability to predict foot function pre- and post-operatively through agreement with clinically relevant radiographic joint angles.Copyright © 2012 by ASME

A case of calcific tendinitis of the gluteus medius is presented. This report describes a patient with a history of breast cancer who had the combination of amorphous calcifications in the gluteus medius tendon and the MR finding of conspicuous bone marrow edema in the adjacent greater trochanter, prompting concern for metastatic disease. We present images from radiography, bone scanning, CT, and MR imaging. The unusual combination of findings in these studies should be considered conclusive for calcific tendinitis, and should not be confused with malignancy.

The bone marrow edema (BME) pattern of signal intensity changes on magnetic resonance (MR) images (decreased on T1-weighted and increased on T2-weighted) is a nonspecific finding encountered with several entities, including transient osteoporosis of the hip, transient BME syndrome, osteonecrosis, trauma, infection, and infiltrative neoplasm. Transient osteoporosis, an unusual but distinct syndrome characterized by self-limited pain and radiographically evident osteopenia, can be distinguished from other causes of the BME pattern, particularly osteonecrosis, on the basis of clinical findings and the development of radiographically evident focal osteopenia within 8 weeks after the onset of pain. This is an important distinction, since all patients with transient osteoporosis recover completely, without intervention. The term transient BME syndrome can be used to describe any patient in whom a reversible BME pattern is seen on MR images. Although the transient BME syndrome is also self-limited and quite likely related to transient osteoporosis, the authors believe that to avoid confusion, this nonspecific term should be reserved only for patients who do not develop radiographically evident osteopenia.

The seat belt syndrome consists of skeletal, soft-tissue, and visceral injuries associated with use of two- and three-point restraints in patients involved in motor vehicle accidents. Skin abrasions of the neck, chest, and abdomen--the classic seat belt sign--indicate internal injury in 30% of cases. Neck abrasions are associated with injuries to the carotid artery, larynx, and cervical spine; chest abrasions, with fractures of the sternum, ribs, and clavicles and injuries to the heart and thoracic aorta; and abdominal abrasions, with mesenteric tears, bowel perforation and hematoma, Chance fractures, and injuries to the abdominal aorta. The seat belt sign should prompt a diligent search for related injuries.

Calcium hydroxyapatite crystal deposition disease is characterized by the presence of basic calcium phosphate crystals--predominantly hydroxyapatite--in the periarticular soft tissues, especially the tendons. The entity is best recognized as "calcific tendinitis" at its most frequent site about the shoulder, but the disease involves numerous other sites and may be more appropriately termed calcific periarthritis. This article illustrates typical and atypical radiographic features of hydroxyapatite deposition, as well as some unusual manifestations of the disease. A brief review of various theories on the pathogenesis of the disease and a section on differential diagnosis is included.

OBJECTIVE. We have found variability in the sonographic appearance of peripheral nerve sheath tumors. The purpose of this study was to characterize the sonographic appearances of pathologically proven peripheral nerve sheath tumors.CONCLUSION. Peripheral nerve sheath tumors are often hypoechoic with posterior acoustic enhancement and so may simulate a ganglion cyst. The presence of intrinsic blood flow on color Doppler sonography and peripheral nerve continuity suggests the diagnosis of peripheral nerve sheath tumor. Sonography cannot reliably distinguish neurofibromas from schwannomas.

Sports-related and overuse conditions may cause painful abnormalities that include muscle and tendon tears, tendon avulsion, bone remodeling, and stress fracture. Adductor insertion avulsion syndrome (AIAS), or thigh splints, is a stress-related avulsive injury of the adductor muscles that occurs at the posteromedial midfemoral diaphysis (Fig. 1). 1,2 Repetitive avulsive stresses in AIRS may result in a spectrum of findings, which include traction periostitis, osseous stress reaction, and stress fracture. 1 1 Bone scan findings in AIAS include linear uptake along the medial shaft of the femur. 3-5 The findings associated with AIAS on magnetic resonance (MR) imaging have been described recently 1,2 They include bone marrow edema, adjacent enhancing periostitis, and stress fracture of the posteromedial femoral diaphysis. 1,2 Musculoskeletal sonography is commonly used to evaluate muscle and tendon injury. 6 To our knowledge, the sonographic findings of AIAS have not been described. We present the sonographic findings in a patient with clinical and MR imaging evidence of AIAS.

Diffuse idiopathic skeletal hyperostosis is an ossifying diathesis that commonly affects the vertebral skeleton. Spinal ankylosis can occur, predisposing the spine to abnormal stresses and fracture. Fracture through an ankylosed segment with continued motion at the site of fracture can result in pseudoarthrosis. Pseudoarthrosis can also develop at the junction of the fused and mobile spine secondary to chronic abnormal stresses. This complication is manifest radiographically by single-level intervertebral disc space destruction, vertebral endplate erosions, marked vertebral sclerosis, and large osteophytes. The radiographic manifestations can mimic infective spondylitis or neuropathic changes.

OBJECTIVE. We describe the sonographic imaging characteristics of ankle ganglia with pathologic correlation in 10 patients.CONCLUSION. Foot and ankle ganglia exhibit a spectrum of sonographic appearances from round and completely anechoic masses to hypoechoic, multilobulated, multiseptated masses with dependent debris. All the ganglionic cysts examined in our study showed posterior acoustic enhancement without solid nodules on sonography.

OBJECTIVE. Intraarticular osteoid osteoma often has subtle radiographic findings and nonspecific clinical features; further diagnostic workup of unexplained joint pain may involve musculoskeletal sonography. We describe the sonographic features of intraarticular osteoid osteoma in three consecutive patients with radiographic, CT, and MR imaging correlation.CONCLUSION. The sonographic findings of painful cortical irregularity and focal synovitis should raise the possibility of intraarticular osteoid osteoma, prompting the search for characteristic findings on correlative imaging studies.

Ultrasonography (US) allows detection of a variety of soft-tissue foreign bodies, including wood splinters, glass, metal, and plastic, along with evaluation of their associated soft-tissue complications. Cases were obtained from the authors' clinical experience over the past 1.5 years. Surgical correlation allowed confirmation of the presence of a foreign body and associated soft-tissue complications in all cases. All of the foreign bodies were echogenic when imaged with US. A surrounding hypoechoic rim and posterior acoustic shadowing or reverberation aided detection in several cases. Associated soft-tissue complications included a complete laceration of the posterior tibial tendon and septic flexor digitorum tenosynovitis. US allows accurate and efficient detection of radiolucent soft-tissue foreign bodies and aids assessment of their associated complications. For radiopaque foreign bodies, US can provide more precise localization and improved assessment of the surrounding soft tissues. US has emerged as the study of choice for detection and localization of radiolucent soft-tissue foreign bodies and can aid assessment of their associated complications.

Received March 23, 2001, from the Department of Radiology, University of Michigan Hospitals, Ann Arbor, Michigan. Revision requested April 30, 2001. Revised manuscript accepted for publication June 4, 2001. Address correspondence and reprint requests to David A. Jamadar, MB, BS, Radiology, TC 2910, University of Michigan Hospitals, 1500 E Medical Center Dr, Ann Arbor, MI 48109-0326. onography is now used to evaluate many disorders of the musculoskeletal system.1 One such example is evaluation of the median nerve in carpal tunnel syndrome.2 Sonographic findings such as median nerve enlargement immediately proximal to the carpal tunnel and bowing of the flexor retinaculum have been described in these patients.2 A correct diagnosis relies on accurate identification of the median nerve and an understanding of the osseous landmarks delineating the carpal tunnel. The presence of multiple closely approximated linear echogenic structures at the volar wrist makes identification of the median nerve difficult; differentiation from the palmaris longus tendon and other tendons may occasionally prove challenging. We present a technique that allows reliable identification of the median nerve at several locations in the distal forearm and wrist by using the real-time capability of sonography. Median nerve pathologic characteristics are also described.

Initial experience with the use of dynamic sonography of the elbow for diagnosing ulnar nerve dislocation and snapping triceps syndrome is reported. Cases of three consecutive patients who underwent sonographic evaluation of the elbow and subsequent open elbow surgery for symptomatic ulnar nerve dislocation were reviewed. Dynamic sonography of the elbow was used to aid in the accurate diagnosis of and differentiation between ulnar nerve dislocation and snapping of the medial triceps muscle.

1155 he identification of soft-tissue foreign bodies is not always a straightforward pursuit. Although routine radiography is the preferred imaging modality for the initial workup, several types of soft-tissue foreign bodies are not radiopaque and therefore remain undetected. Because a retained foreign body may cause infection and inflammation, detection and removal are imperative [1]. Sonography is playing an increasing role in the diagnostic process, not only for the detection of nonopaque foreign bodies but also for the accurate localization of all types of soft-tissue foreign bodies. Accurate localization can be valuable in minimizing surgical exploration, or, alternatively, real-time sonographic visualization can guide percutaneous removal of a soft-tissue foreign body [2]. Sonography can also be used to evaluate associated softtissue abscess, neurovascular abnormality, and tendon disorders. This pictorial essay will define the imaging characteristics of various soft-tissue foreign bodies, comparing their appearances on sonography and radiography. Familiarity with the imaging appearances of soft-tissue foreign bodies is critical for an accurate diagnosis.

The objective of this study was to assess the ability of sonography to reveal Baker's cysts using MR imaging as a gold standard.The study group consisted of 36 consecutive knees in 36 patients evaluated with both MR imaging and sonography. Inclusion criteria included axial proton density-weighted or T2-weighted MR images, a sonography report that documented the evaluation of the popliteal region of the knee, and sonographic and MR images that were available for review. The MR images were retrospectively reviewed for the presence of Baker's cyst (fluid signal between the semimembranosus and medial gastrocnemius tendons). Sonography reports were compared with the MR imaging results. The sonographic images were also retrospectively reviewed to determine whether any characteristic findings on sonography were significantly associated with the presence of Baker's cyst on MR imaging.Retrospective review of MR images revealed 21 Baker's cysts, one myxoid liposarcoma, one meniscal cyst, and 13 examinations with normal findings. The sonography reports revealed that the 21 Baker's cysts were correctly diagnosed, whereas the meniscal cyst and myxoid liposarcoma were misdiagnosed as Baker's cysts. Retrospective review of sonographic images showed a 100% sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the diagnosis of Baker's cyst when hypoechoic or anechoic fluid was present between the semimembranosus and medial gastrocnemius tendons. No other sonographic characteristics were significant.Identification of fluid between the semimembranosus and medial gastrocnemius tendons in communication with a posterior knee cyst indicates Baker's cyst with 100% accuracy.

OBJECTIVE. The purpose of this article is to describe the sonographic findings of muscle infarction in patients with diabetes with MR imaging, CT, and pathologic correlation.CONCLUSION. Sonographic findings of diabetic muscle infarction include internal linear echogenic structures coursing through the lesion; an absence of internal motion or swirling of fluid with transducer pressure; and a lack of a predominately anechoic area. We believe that these sonographic characteristics may help differentiate diabetic muscle infarction from abscess or necrotic tumor. Additional study involving direct sonographic comparison of these entities is needed to establish the role of sonography in diagnosis of diabetic muscle infarction.

Purpose To determine and illustrate the causes of unproductive arthrocentesis of the knee. Patients and methods Consecutive patients were studied who had inflammatory (rheumatoid or psoriatic) arthritis affecting the knees and experienced unproductive arthrocentesis during a randomized, controlled trial. Magnetic resonance imaging (MRI) was used, supplemented first by intravenous gadolinium contrast and subsequently by manual mixing of the diffused contrast to outline the furthest possible penetration of contrast within the joint cavity. Results In 4 out of 5 patients studied, failed arthrocentesis was due to combinations of inspirated joint fluid too viscous to be withdrawn or to mix with contrast, adipose tissue, and lipoma arborescens (thickened synovium with fat replacement). One MRI exam was normal. More free synovial fluid was imaged on the lateral side. Conclusions Failure to aspirate synovial fluid from the knee is explicable in anatomic terms; in particular, fluid viscosity and lipoma arborescens play a role in chronic effusions. Although surface anatomic landmarks for knee arthrocentesis may be more visible medially, the lateral approach is more likely to yield fluid for synovial analysis in difficult cases. Internal medicine trainees should be taught the lateral approach.

In routine MRI of the knee, less attention frequently is paid to the patellofemoral joint and its surrounding structures than to the menisci and ligaments. This article reviews MRI of common abnormalities of the anterior aspect of the knee. Chondromalacia patellae, pathological softening of the patellar cartilage, can be diagnosed with reasonable accuracy with MRI using standard sequences. Abnormalities of alignment can be assessed grossly on static images, but more sophisticated evaluation of patellofemoral tracking requires the kinematic technique. Other traumatic or overuse injuries involving the extensor mechanism of the knee, such as the quadriceps and patellar tendons, are also reviewed briefly.

After plain radiography has been performed, magnetic resonance (MR) imaging is considered the modality of choice for the evaluation of suspected musculoskeletal lesions because of its exquisite sensitivity to changes in the signal intensity of marrow and soft tissue. That sensitivity, however, may lead to an overestimation of the aggressiveness and extent of some benign bone lesions, particularly in children. Such lesions include chondroblastoma, osteoid osteoma, eosinophilic granuloma, and stress fractures. Potentially misleading MR features commonly seen include prominent marrow edema, soft-tissue edema, and apparent mass effect adjacent to the bone lesion. Features that these lesions have in common that may explain the MR findings include associated inflammatory reactions caused by the lesions and their occurrence in childhood, when the periosteum is more loosely attached. Knowledge of the potential pitfalls encountered with MR imaging may help explain the discrepancy between the radiographic and MR appearances of these benign lesions and avoid misplaced reliance on MR imaging for a diagnosis. Radiography remains the single most valuable modality in determining a differential diagnosis for bone lesions.

Twenty-five temporomandibular joints (TMJs) were studied in 20 patients who had undergone meniscoplasty. In all patients, preoperative magnetic resonance (MR) images showed anteriorly dislocated disks; all patients underwent a similar postoperative MR examination an average of 6 months after surgery. The results of these studies were correlated with clinical results of surgery, which were classified as poor, fair, good, or excellent at follow-up MR imaging. In 10 TMJs (eight patients [40%]) the clinical results were excellent or good; in 15 TMJs (12 patients [60%]), fair or poor. The position of the disk relative to its preoperative position was a good discriminator in determination of the clinical success of meniscoplasty. After surgery, in all patients with good or excellent results, the disks appeared to be in a normal or an improved position compared with that prior to surgery; in those with poor or fair results, the TMJs had anteriorly dislocated disks that showed no improvement.

Computed tomography (CT) and magnetic resonance (MR) imaging are extremely useful in the accurate diagnosis of anterior knee pain, a common complaint arising from numerous causes (including fracture, chondromalacia patellae, and alignment and tracking abnormalities). Plain CT is effective for evaluating intraosseous lesions of the knee. Although CT arthrography provides excellent visualization of the patellar articular cartilage, the technique is expensive and invasive. Cine CT is an excellent method for assessing patellofemoral tracking and alignment. Kinematic MR imaging can also perform this function. In addition, MR imaging can provide valuable information concerning the status of patellar cartilage. Although MR imaging can accurately show high-grade chondromalacia patellae, it is less accurate in the detection of low-grade disease. The authors believe that MR imaging and plain radiography offer radiologists the greatest latitude in making a specific diagnosis of the cause of anterior knee pain; however, CT is a useful alternative.

Computed tomography (CT) was used to study fat distribution in three groups of women of comparable age: 39 healthy volunteers, 15 patients with anorexia nervosa, and seven with Cushing syndrome. Patients with anorexia nervosa had a fivefold decrease in subcutaneous fat and only a twofold decrease in intraabdominal fat compared with the values for the volunteers. Patients with Cushing syndrome had less than a twofold increase in subcutaneous fat and greater than a fivefold increase in intraabdominal fat compared with values for the healthy subjects. These findings suggest that fat in different body compartments responds differently to disease processes and that CT can be used to measure these changes.

Objective : To assess whether the presence of subchondral bone marrow abnormalities (bone marrow edema (BME)) and cartilage defects, determined by magnetic resonance imaging (MRI), would explain the difference between painful osteoarthritis of the knee (OAK) compared with painless OAK or pain without OAK. Method : Four groups of women (30 per group), aged 35–55 years, were recruited from the southeast Michigan Osteoarthritis cohort (group 1: painful OAK; group 2: painless OAK; group 3: knee pain without OAK; and group 4: no OAK or knee pain). OAK was defined by a Kellgren–Lawrence score of 2 or greater, while pain was based on self-report. BME and cartilage defects were identified from MRI. Results : BME lesions were identified in 56% of all knees. BME lesions were four times (95% CI=1.7, 8.7) more likely to occur in the painless OAK group as compared with the group with pain, but no OAK. BME lesions >1cm were more frequent (OR=5.0; 95% CI=1.4, 10.5) in the painful OAK group than all other groups. While the frequency of BME lesions was similar in the painless OAK and painful OAK groups, there were more lesions, >1cm, in the painful OAK group.About 75% of all knees had evidence of some cartilage defect, of which 35% were full-thickness defects. Full-thickness cartilage defects occurred frequently in painful OAK. One-third of knees with full-thickness defects and 47% of knees with cartilage defects involving bone had BME >1cm. Women with radiographic OA, full-thickness articular cartilage defects, and adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than other groups (OR=3.2; 95% CI=1.3, 7.6). Conclusion : The finding on MRI of subchondral BME cannot satisfactorily explain the presence or absence of knee pain. However, women with BME and full-thickness articular cartilage defects accompanied by adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than painless OAK.

Five cases of calcific tendinitis with radiographic evidence of cortical bone erosion are presented. All five cases arose at unusual sites: two at the pectoralis major insertion on the proximal humerus, two at the insertion of the gluteus maximus, and one at the insertion of the adductor magnus. Biopsy was performed in four cases and revealed areas of histiocytic infiltration, amorphous spherules of calcification, and areas of giant cell reaction extending into the cortex. To our knowledge, calcific tendinitis presenting with radiographic evidence of bone erosion has not been reported previously.

We present a case of hemispherical spondylosclerosis (HSS) in a middle-aged woman with low back pain. The plain radiographic findings, CT and MR appearance, and pathological examination are described, and the difficulties encountered in differentiating HSS from malignancy and infection are discussed.

This paper presents examples of non-neoplastic lesions of the spine that produce focal or diffuse signal alterations on MR images, and that may, therefore, be confused with metastases or primary neoplasms. Examples include endplate changes associated with degenerative disk disease, hemispherical spondylosclerosis, osteoporotic compression fractures, Paget's disease, focal and diffuse fatty infiltration, osteomyelitis, and changes associated with various arthritides. Distinguishing signal intensity characteristics on T1 and T2 weighted images and distinctive morphology are emphasized.