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The purpose of this study was to obtain a survey about the present situation including the usage pattern, technical characteristics and the anticipated future of teleradiology in Switzerland. An internet-based questionnaire was made available to all members of the Swiss Society of Radiology. Questions concerning current teleradiology usage, the type of transmitted modalities, the technology employed, security, billing issues and the anticipated future of teleradiology were addressed. One hundred and two (22.67%) of 450 radiologists responded to the survey. Of the total, 41.2% (42) were teleradiology users, 35.3% (36) planned to use teleradiology in the near future and 24.5% (25) did not use or plan to use teleradiology. The mean number of examinations transmitted per month was 198 (range 1-2,000) and the mean distance was 33 km (range 1,250 km). An emergency service was considered the most important purpose (mean score 6.90; minimum 1, maximum 10) for the use of teleradiology, followed by image distribution (mean 6.74) and expert consultation (mean 6.61). The most commonly transmitted modality was computed tomography (mean 8.80), followed by conventional X-rays (8.40) and magnetic resonance imaging (8.32). The most commonly transmitted format was Digital Imaging and Communications in Medicine (DICOM) (66.7%), followed by bitmap/Joint Photographic Experts Group (jpg) (38.1%), using the DICOM send/receive protocol (52.4%), followed by the hypertext transfer protocol (26.2%) and e-mail (21.4%). For security a secure connection (54.8%) followed by encryption (14.3%) and anonymization (9.5%) was used. For the future, image distribution was rated the most important aspect of teleradiology (7.88), followed by emergency (7.22) and expert consultation (6.53). Development of legal regulations is considered most important (8.17), followed by data security guidelines (8.15). Most radiologists believe that insurance companies should pay for the costs of teleradiology (37.3%), followed by the radiologist (33.3%). In conclusion, in Switzerland a wide spectrum of teleradiology applications and technologies is in use. Guidelines and reimbursement issues remain to be solved.

OBJECTIVE. Our aim was to describe MRI and CT characteristics of primary lymphoma of bone during and after successful treatment.CONCLUSION. MRI showed a rapid decrease of tumor volume with complete disappearance of the soft-tissue component. Minor signal abnormalities of bone marrow without clinical relevance persisted for up to 2 years. CT showed bone remodeling within months with a persistent architecture similar to that of Paget's disease of the bone.

The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine.In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined).At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55).The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.

To evaluate proton magnetic resonance (MR) spectroscopy in the assessment of lipid content of the supraspinatus muscle in asymptomatic volunteers and patients with supraspinatus tendon lesions.Single-voxel proton MR spectroscopy was used to assess lipid content of the supraspinatus muscle in asymptomatic volunteers (n = 30) and patients with partial-thickness supraspinatus tendon tears (n = 30), newly diagnosed full-thickness supraspinatus tendon tears (n = 30), and chronic full-thickness supraspinatus tendon tears (n = 30). The apparent lipid content of the supraspinatus muscle measured with proton MR spectroscopy was related to its appearance on sagittal-oblique T1-weighted spin-echo MR images (grades 0-4). One-way analysis of variance was performed to test for significant differences, and the Tukey honestly significant difference procedure was performed for post hoc comparisons.Mean apparent lipid content was 13.7% (95% confidence interval [CI]: 11.5%, 15.8%) for asymptomatic volunteers, 29.5% (95% CI: 25.1%, 34.0%) for patients with partial-thickness tears, 48.6% (95% CI: 41.3%, 55.9%) for patients with full-thickness tears, and 66.1% (95% CI: 57.7%, 74.5%) for patients with chronic tears. Values were significantly different (analysis of variance, P.001; P.001-.002 for all post hoc pairwise comparisons). Mean apparent lipid content for the supraspinatus muscle was as follows: grade 0, 19.6% (95% CI: 16.7%, 22.6%); grade 1, 36.8% (95% CI: 33.2%, 40.4%); grade 2, 53.6% (95% CI: 43.1%, 64.2%); grade 3, 67.5% (95% CI: 52.6%, 82.3%); and grade 4, 79.2% (95% CI: 73.2%, 85.3%). With analysis of variance (P.001), all post hoc pairwise comparisons were significant (P/=.001) except between grades 2 and 3 (P =.112) and between grades 3 and 4 (P =.261). In 14 (25%) subjects who had grade 0 appearance on T1-weighted images, lipid content values were greater than the upper range of values in the volunteers.Proton MR spectroscopy is suitable in the assessment of apparent lipid content of rotator cuff muscles.

The objective of this study was to determine gray-scale and power Doppler sonographic findings in patients with arthrofibrosis associated with total knee arthroplasty. SUBJECTS AND METHODS. From a consecutive cohort of more than 3000 mobilebearing total knee arthroplasties, 44 cases (1.5%) with arthrofibrosis were identified, of which 38 were recruited for a clinical and sonographic investigation. A control group of 38 patients with a well-functioning total knee arthroplasty was matched. Synovial hypertrophy, presence of neovascularity, patellar tendon thickness, and extent of effusion were assessed.Synovial membrane thickness was significantly (p0.001) increased in the arthrofibrosis group (medial, 3.4 mm; lateral, 3.0 mm; suprapatellar, 3.1 mm) when compared with the control group (medial, 2.0 mm; lateral, 2.0 mm; suprapatellar, 1.9 mm). When a cutoff of 3.0 mm was used, sonography had a sensitivity of 84% and a specificity of 82% for detecting arthrofibrosis. Neovascularity (rated as grades 0-3) of the synovial membrane and Hoffa's fat pad was significantly (por= 0.003) more pronounced in the arthrofibrosis group (medial, 1.1; lateral, 1.2; suprapatellar, 1.0; Hoffa's fat pad, 1.1) than in the control group (medial, 0.1; lateral, 0.3; suprapatellar, 0.2; Hoffa's fat pad, 0.1). No significant difference was seen between study groups with regard to the amount of joint effusion at three locations and with regard to patellar tendon thickness.Synovial membrane thickening and neovascularity are characteristic sonographic findings for the diagnosis of arthrofibrosis associated with total knee arthroplasty.

To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography.Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software.Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv.CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

To evaluate different types of polymethylmethacrylate (PMMA) leakage and patient-related factors in relation to clinical midterm (1-24-month) outcome after vertebroplasty.Standardized four-view radiographs obtained during 363 vertebroplasties in 181 treatment sessions in 152 patients were reviewed (121 patients with osteoporotic fractures, 30 with malignant disease, and one with hemangioma). Four types of PMMA leakage and other potential predictors (patient age and sex, treated region, number of vertebral levels injected, preprocedural pain, PMMA volume per vertebra) were related to postprocedural pain response and midterm outcome after vertebroplasty. chi2 and Kruskal-Wallis tests were used for statistical analysis. The mean follow-up period was 8.8 months (range, 1-24 months).At the time of discharge after the procedure, pain was absent after 106 of the 181 sessions (58.5%), better after 50 (27.6%), and the same after 25 (13.8%). In 258 of the 363 treated vertebral levels, at least one type of leakage was found. None of the evaluated factors were related significantly to postprocedural pain response, including PMMA leakage. Pain response at midterm outcome was strongly related to postprocedural treatment success, however (P.001).Small to moderate amounts of PMMA may escape from the vertebral body with no significant effect on therapeutic success. Immediate postprocedural pain relief is the best predictor of midterm clinical outcome after vertebroplasty.

SummaryMR imaging abnormalities, such as increasedsignal within normally hypointense structures,form and attachment abnormalities, fluid collec-tions in joints, tendon sheaths and bursa, or eventumors, such as Morton’s neuromas, are commonin asymptomatic volunteers. They may be ex-plained by normal physiology, anatomic variabil-ity, MR imaging artifacts, or true abnormalitieswithout clinical importance. Although it is notalways possible to differentiate such variants orartifacts from clinically relevant findings, it isimportant to know their potential cause andclinical importance and not to over-report themas abnormality requiring additional imaging ortreatment. Thorough knowledge of normal anat-omy is crucial in this situation.References [1] Arena L, Morehouse HT, Safir J. MR imagingartifactsthatsimulatedisease:Howtorecognizeandeliminate them. Radiographics 1995;15:1373–94.[2] Beltran J, Marty-Delfaut E, Bencardino J, Rosen-berg ZS, Steiner G, Aparisi F, et al. Chondrocalci-nosis of the hyaline cartilage of the knee: MRimaging manifestations. Skeletal Radiol 1998;27:369–74.[3] Boden SD, Davis DO, Dina TS, Stoller DW, BrownSD, Vailas JC, et al. A prospective and blindedinvestigation of magnetic resonance imaging of theknee: abnormal findings in asymptomatic subjects.Clin Orthop 1992;201:177–85.[4] Burke BJ, Escobedo EM, Wilson AJ, Hunter JC.Chondrocalcinosis mimicking a meniscal tear onMR imaging. AJR Am J Roentgenol 1998;170:69–70.[5] Cheung YY, Rosenberg ZS, Ramsinghani R,Beltran J, Jahss MH. Peroneus quartus muscle:MR imaging features. Radiology 1997;202:745–50.[6] Cho JM, Suh JS, Na JB, Cho JH, Kim Y, Yoo WK,et al. Variations in meniscofemoral ligaments atanatomical study and MR imaging. Skeletal Radiol1999;28:189–95.[7] Clarke RP. Symptomatic, lateral synovial fringe(plica)oftheelbowjoint.Arthroscopy1988;4:112–6.[8] Czervionke LF, Czervionke JM, Daniels DL,Haughton VM. Characteristic features of MR trun-cation artifacts. AJR Am J Roentgenol 1988;151:1219–28.[9] De Maeseneer M, Van Roy F, Lenchik L,Shahabpour M, Jacobson J, Ryu KN, et al. CTandMR arthrography of the normal and pathologicanterosuperior labrum and labral-bicipital complex.Radiographics 2000;20:S67–81.[10] Deutsch AL, Mink JH, Fox JM, Arnoczky SP,Rothman BJ, Stoller DW, et al. Peripheral meniscaltears: MR findings after conservative treatment orarthroscopic repair. Radiology 1990;176:485–8.[11] Edelson JG, Zuckerman J, Hershkovitz I. Osacromiale: anatomy and surgical implications. JBone Joint Surg Br 1993;75:551–5.[12] Ekstrom JE, Shuman WP, Mack LA. MR imagingofaccessorysoleusmuscle.JComputAssistTomogr1990;14:239–42.[13] Erickson SJ, Cox IH, Hyde JS, Carrera GF, StrandtJA, Estkowski LD. Effect of tendon orientation onMR imaging signal intensity: a manifestation of the‘‘magic angle’’ phenomenon. Radiology 1991;181:389–92.[14] Hauger O, Frank LR, Boutin RD, Lektrakul N,Chung CB, Haghighi P, et al. Characterization ofthe ‘‘red zone’’ of knee meniscus: MR imaging andhistologic correlation. Radiology 2000;217:193–200.[15] Herman LJ, Beltran J. Pitfalls in MR imaging of theknee. Radiology 1988;167:775–81.[16] Hilfiker P, Zanetti M, Debatin JF, McKinnon G,Hodler J. Fast spin-echo inversion-recovery imag-ing versus fast T2-weighted spin-echo imaging inbone marrow abnormalities. Invest Radiol 1995;30:110–4.[17] Kreitner KF, Botchen K, Rude J, Bittinger F,Krummenauer F, Thelen M. Superior labrum andlabral-bicipital complex: MR imaging with patho-logic-anatomic and histologic correlation. AJR AmJ Roentgenol 1998;170:599–605.[18] Kwak SM, Brown RR, Resnick D, Trudell D,Applegate GR, Haghighi P. Anatomy, anatomicvariations, and pathology of the 11- to 3-o’clockposition of the glenoid labrum: findings on MRarthrography and anatomic sections. AJR Am JRoentgenol 1998;171:235–8.[19] Link SC, Erickson SJ, Timins ME. MR imaging ofthe ankle and foot: normal structures and anatomicvariants that may simulate disease. AJR Am JRoentgenol 1993;161:607–12.[20] Lohman M, Kivisaari A, Vehmas T, Kallio P,Malmivaara A, Kivisaari L. MR imaging abnor-malities of foot and ankle in asymptomatic, phy-sically active individuals. Skeletal Radiol 2001;30:61–6.[21] Miller TT, Bucchieri JS, Joshi A, Staron RB,Feldman F. Pseudodefect of the talar dome: ananatomic pitfall of ankle MR imaging. Radiology1997;203:857–8.[22] Muhle C, Ahn JM, Yeh L, Bergman GA, BoutinRD, Schweitzer M, et al. Iliotibial band frictionsyndrome: MR imaging findings in 16 patients andMR arthrographic study of six cadaveric knees.Radiology 1999;212:103–10.[23] Noto AM, Cheung Y, Rosenberg ZS, Norman A,Leeds NE. MR imaging of the ankle: normalvariants. Radiology 1989;170:121–4.[24] Peh WC, Chan JH. The magic angle phenomenonin tendons: effect of varying the MR echo time. Br JRadiol 1998;71:31–6.204 C.W.A. Pfirrmann et al / Magn Reson Imaging Clin N Am 11 (2003) 193–205

To evaluate the clinical relevance of neovascularization diagnosed with power Doppler ultrasonography (US) in Achilles tendons in patients with chronic achillodynia.Forty consecutive patients (mean age, 52 years; age range, 30-72 years) were examined. US was performed bilaterally and repeated after 3 months. Shape and echogenicity were assessed with gray-scale US and vascularization with power Doppler US. All patients were treated conservatively. Clinical assessment was performed after 0, 3, and 6 months by using visual analogue scale (VAS) scores (0, no pain; 100, unbearable pain). The VAS scores were compared with the initial US findings, and analysis of variance was used for repeated measurements.Neovascularization was present in 30 of 55 painful tendons and in one of 25 asymptomatic tendons. The mean VAS scores at 0, 3, and 6 months, respectively, for tendons with neovascularization were 52, 26, and 20; those for tendons without neovascularization were 39, 19, and 18 (P =.15). Forty-eight painful and nine asymptomatic tendons were spindle shaped. The mean VAS scores at 0, 3, and 6 months, respectively, for the spindle-shaped tendons were 48, 25, and 20; those for normally shaped tendons were 33, 10, and 16 (P =.17). Thirty-five painful and four asymptomatic tendons were inhomogeneous. The mean VAS scores at 0, 3, and 6 months, respectively, for symptomatic inhomogeneous tendons were 54, 29, and 25; those for symptomatic homogeneous tendons were 32, 12, and 9 (P.001).Although neovascularization is a specific sign for pain, it does not indicate an unfavorable outcome. Conversely, tendon inhomogeneity seems to be associated with an unfavorable outcome.

The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees.MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured.Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees.Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

To assess the effect of prone, supine, and upright weight-bearing body positions on visibility, position, shape, and size of Morton neuroma during magnetic resonance (MR) imaging.Eighteen patients with 20 Morton neuromas underwent MR imaging of the forefoot in prone (plantar flexion of the foot), supine (dorsiflexion of the foot), and upright weight-bearing positions. Visibility (3 = good, 2 = moderate, 1 = poor), position relative to the metatarsal bone, shape, and transverse diameter of Morton neuroma were assessed on transverse T1-weighted MR images. Associations between different body positions and variables of interest were calculated with Wilcoxon signed rank test, chi2 test, and paired Student t test.In the prone position, visibility of all 20 Morton neuromas was rated with a score of 3; visibility in the supine and weight-bearing positions was inferior (mean score, 2.4). All 20 (100%) Morton neuromas changed their position relative to the metatarsal bone between prone and supine and between prone and weight-bearing positions. When compared with the prone position, there was a difference in the shape of all 20 Morton neuromas in the weight-bearing position (P.001). Between prone (mean transverse diameter of Morton neuroma, 8 mm) and supine (mean transverse diameter of Morton neuroma, 6 mm) positions, the transverse diameter of Morton neuroma significantly decreased by 2 mm (P =.03); between prone and weight-bearing positions, the decrease of the mean transverse diameter was also significant (difference, 2 mm; P =.03).Morton neuroma appears significantly different during MR imaging in prone, supine, or weight-bearing positions. The transverse diameter of Morton neuroma is significantly larger on images obtained in the prone position than it is on images obtained in the supine and upright weight-bearing positions. Visibility of Morton neuroma is best on MR images obtained in the prone position.

To evaluate the diagnostic performance of magnetic resonance (MR) arthrography in the detection of articular cartilage lesions in patients suspected of having femoroacetabular impingement and/or labral abnormalities.Forty-two MR arthrograms obtained in 40 patients with a clinical diagnosis of femoroacetabular impingement and/or labral defect were retrospectively analyzed. Two readers independently interpreted the images for cartilage lesion location, depiction, and characteristics. Within 6 months after MR arthrography, each patient underwent open hip surgery, during which the entire cartilage of the hip joint was inspected. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. kappa values were calculated to quantify the level of interobserver agreement.At surgery, most (37 [88%] of 42) cartilage defects were identified in the anterosuperior part of the acetabulum. In 23 (55%), 12 (29%), 10 (24%), and 10 (24%) hips, lesions were found in the posterosuperior acetabulum, anteroinferior acetabulum, posteroinferior acetabulum, and femoral head, respectively. The sensitivities and specificities of MR arthrographic detection of cartilage damage in all regions combined were 79% (73 of 92 regions) and 77% (91 of 118 regions), respectively, for reader 1 and 50% (46 of 92 regions) and 84% (99 of 118 regions), respectively, for reader 2. At interobserver comparison, agreement was fair (kappa = 0.31) for detection of cartilage lesions in the femoral head and poor (kappaor= 0.2) for detection of lesions in all acetabular regions.Cartilage lesions are common in young and middle-aged patients with femoroacetabular impingement and/or labral abnormalities and are most frequently found in the anterosuperior part of the acetabulum. 2003

To determine the prevalence of articular cartilage lesions in patients with subacromial impingement syndrome and to assess the diagnostic effectiveness of magnetic resonance (MR) arthrography in detecting such cartilage abnormalities.MR arthrographic images obtained in 52 consecutive patients (mean age, 45.8 years; age range, 17-73 years; 26 male and 26 female patients) were retrospectively evaluated for glenohumeral cartilage lesions. Two experienced musculoskeletal radiologists who were blinded to the arthroscopy report independently analyzed the articular cartilage. Humeral and glenoidal cartilage were assessed separately. The lesions were graded as either subtle or marked. Arthroscopic findings were the standard of reference. Sensitivity, specificity, accuracy, and interobserver agreement were calculated.At arthroscopy, humeral cartilage lesions were found in 15 patients (frequency, 29%). Four lesions were subtle, and 11 were marked. Cartilage lesions of the glenoid were less frequent (eight patients; frequency, 15%): Three were subtle, and five were marked. For reader 1 and reader 2, respectively, sensitivity of MR arthrography for humeral cartilage lesions was 53% and 100%, specificity was 87% and 51%, and accuracy was 77% and 65%; sensitivity for glenoidal cartilage lesions was 75% and 75%, specificity was 66% and 63%, and accuracy was 67% and 65%. Interobserver agreement for the grading of cartilage lesions with MR arthrography was fair (humeral lesions, kappa = 0.20; glenoidal lesions, kappa = 0.27).Glenohumeral cartilage lesions are found in up to one third of patients referred for MR arthrography for subacromial impingement syndrome. The performance of MR arthrography in the detection of glenohumeral cartilage lesions is moderate.

The objective of our study was to evaluate the usefulness of FDG positron emission tomography (PET) for the differentiation of degenerative and infectious endplate abnormalities in the lumbar spine that were detected on MR imaging.FDG PET was performed prospectively in 30 consecutive patients with substantial endplate abnormalities (craniocaudal diameter of bone marrow abnormalities,or = 25% of vertebral height) found during MR imaging of the lumbar spine. Both the MR and PET images were evaluated by two experienced musculoskeletal radiologists and two experienced nuclear physicians. The diagnosis of either degeneration with different types of endplate abnormalities or disk-space infection was determined. Clinical follow-up and, in selected cases, bone biopsies with cultures were used as the standard of reference.On the MR images, 25 of the 38 degenerated levels were classified as Modic type I, 13 levels as type II, and none as type III. Five disk-space infections were diagnosed in four patients. MR imaging findings were false-positive at one disk level with type I abnormalities and false-negative at two levels with infection. PET did not show FDG uptake in the intervertebral spaces of any patient with degenerative disease. FDG PET findings were true-positive in all five levels with disk-space infection. The sensitivity and specificity for MR imaging in detecting disk-space infection were 50% and 96%, and were 100% and 100% for FDG PET, respectively (not significant, McNemar test, p = 0.5).Our findings suggest that FDG PET may prove useful for differentiation of degenerative and infectious endplate abnormalities detected on MR imaging. Even in active (Modic type I) degenerative endplate abnormalities in our series, PET did not show increased FDG uptake.

PURPOSE: To compare short inversion time inversion-recovery (STIR) and T1-weighted contrast material–enhanced fat-suppressed spin-echo magnetic resonance (MR) sequences for depiction of bone marrow abnormalities of the foot and ankle. MATERIALS AND METHODS: Fifty-one consecutive patients with bone marrow abnormalities depicted on turbo STIR images were examined with additional T1-weighted contrast-enhanced (0.1 mmol/kg gadopentetate dimeglumine) MR imaging with fat suppression. Volume and signal difference–to-noise ratio (SDNR) were measured. An additional qualitative analysis was performed by two experienced musculoskeletal radiologists to correlate the presence or absence of ill-defined edema-like zones, well-defined zones, and cystlike zones. Diagnoses determined with MR findings with each sequence were compared with the results of a review panel. Correlation coefficients (r2) and paired t tests were calculated for all measurements. Agreement percentages and κ values were calculated for inter- and intr...

BackgroundChronic overload is considered the main cause of patellar tendinitis, but it has been postulated that impingement of the inferior patellar pole against the patellar tendon during knee flexion could be responsible.HypothesisThe role of the patellar pole in patellar tendinitis can be determined by dynamic magnetic resonance imaging.Study DesignCase-control study.MethodsWe compared 19 knees with patellar tendinitis and 32 asymptomatic knees of age-matched subjects using an open-configuration magnetic resonance imaging system. Dynamic sagittal images were obtained from full extension to 100° of flexion with and without activation of the quadriceps muscle. The following measurements were made from the images: tendon-patella angle, anteroposterior diameter of the tendon, signal difference-to-noise ratio, the shape of the inferior patellar pole, and the location of the patellar tendon insertion.ResultsThe tendon-patella angle was not significantly different between groups at any flexion angle, with or without quadriceps muscle activation. The insertion site of the patellar tendon differed significantly but not the shape of the inferior pole of the patella. The volume and the signal difference-to-noise ratio of zones of increased intratendinous signal as well as the anteroposterior diameter of the proximal patellar tendon were increased in symptomatic knees.ConclusionsThe relationship between the patella and the patellar tendon was identical in both groups; therefore, chronic overload seems to be a major cause of patellar tendinitis.

MR imaging abnormalities, such as increased signal within normally hypointense structures, form and attachment abnormalities, fluid collections in joints, tendon sheaths and bursa, or even tumors, such as Morton's neuromas, are common in asymptomatic volunteers. They may be explained by normal physiology, anatomic variability, MR imaging artifacts, or true abnormalities without clinical importance. Although it is not always possible to differentiate such variants or artifacts from clinically relevant findings, it is important to know their potential cause and clinical importance and not to over-report them as abnormality requiring additional imaging or treatment. Thorough knowledge of normal anatomy is crucial in this situation.

Pfirrmann CWA, Huser M, Szekely G, et al. Evaluation of complex joint motion with computer based analysis of fluoroscopic sequences. Invest Radiol 2002;37:73-76. RATIONALE AND OBJECTIVES. To develop a computer-assisted analysis of complex joint motion based on standard fluoroscopic sequences. MATERIALS AND METHODS. Fluoroscopic sequences of 10 normal shoulders and 20 patients after total shoulder arthroplasty were recorded during abduction and adduction. The analysis of the shoulder motion was based on automated tracking of selected components (models) of the shoulder joint. After processing the digitized images with an edge-detection procedure, visible edges were defined as base models. These models were tracked frame by frame. Several automated postprocessing evaluation procedures were developed and tested. RESULTS. The amounts of rotation and translation of the glenohumeral joint can be quantified and related. The mean translation parallel to the glenoid in the normal shoulder joints was 2.8 mm and 1.9 mm in joints after shoulder arthroplasty. The mean translation perpendicular to the glenoid was 0.9 mm and 0.8 mm, respectively. In complex motion patterns (ie, combined glenohumeral and thoracoscapular motion), electronic stabilization of an object (ie, stabilization of scapula) and, thus, separate analysis of each component. CONCLUSION. Computer assisted analysis allows automated evaluation of complex joint motion based on standard fluoroscopic sequences.

Study design A longitudinal magnetic resonance imaging investigation of lumbar disc degeneration in asymptomatic individuals was conducted. Objective To investigate risk factors for the development or deterioration of lumbar disc degeneration. Summary of background data Numerous studies have explored the significance of certain risk factors for the development or progression of disc degeneration, but no comprehensive longitudinal magnetic resonance imaging-based study has been reported that simultaneously considers clinical, morphologic, physical, psychosocial, and occupational risk factors. Methods In the 5-year follow-up evaluation of 41 asymptomatic individuals, the risk factors for the development of lumbar disc degeneration and its progression were investigated. All 41 individuals had a magnetic resonance imaging scan at baseline and at the minimum 5-year follow-up assessment using the same scanner and protocol. The magnetic resonance images were analyzed independently by two radiologists with regard to disc degeneration. Various predictor variables were assessed both at baseline and follow-up, with special emphasis on physical job characteristics, sports activities, and magnetic resonance image-based morphologic findings. Results Of the 41 individuals, 17 (41%) exhibited a deterioration of the disc status. In 10 individuals, the progression of disc degeneration was one grade or more. Only a weak correlation existed between progressive disc degeneration and low back pain development during a 5-year follow-up period. Multiple logistic regression analysis demonstrated that the extent of disc herniation (odds ratio [OR], 12.63; confidence interval [CI], 1.24-128.49), the lack of sports activities (OR, 2.71; CI, 1.04-7.07), and night shift work (OR, 23.01; CI, 1.26-421.31) were significant predictors for disc degeneration during follow-up evaluation when control was used for the number of degenerated discs at baseline, gender, age, and body mass index. Conclusions The results indicate that the extent of disc herniation, the lack of sports activities, and night shift work are significant risk factors for the development of lumbar disc degeneration and its progression.

Awise old physician once told me that he would never agree to do a book review because reviewing someone’s book is a bit like reviewing their spouse. There is no “constructive criticism” that is welcome. For a scholarly publication such as Skeletal Radiology, letters to the Editor can pose a similar risk. As pointed out by Wikipedia (http://en.wikipedia.org/wiki/Letter_to_the_ editor), “In academic publishing, letters to the editor of an academic journal are usually open postpublication reviews of a paper, often critical of some aspect of the original paper. ” Such letters are likely to be critical of the author, the reviewers who accepted the paper, and, by implication, the editors who selected it. Letters are not subject to the same standards of evidence and peer review as a scientific publication; they can therefore be seen as a “cheap shot” taken at someone’s hard work. Despite growth in recent years, the world of musculoskeletal diagnosis is a small one; it is highly likely that the authors of a letter and the authors of the paper it addresses will be known to each other. For these reasons, Skeletal Radiology has, with very rare exceptions, declined the publication of letters to the editor. And yet, letters can also add a certain amount of liveliness to a publication. The letter writer might have arcane knowledge to share, and the author gets the satisfaction of knowing that someone somewhere has read and thought about what he or she has written. Should we change our policy and accept letters? The Editors request your feedback on this issue.

To provide normal values of the cervical spinal canal and spinal cord dimensions in several planes with respect to spinal level, age, sex, and body height.This study was approved by the institutional review board; all individuals provided signed informed consent. In a prospective multicenter study, two blinded raters independently examined cervical spine magnetic resonance (MR) images of 140 healthy volunteers who were white. The midsagittal diameters and areas of spinal canal and spinal cord, respectively, were measured at the midvertebral levels of C1, C3, and C6. A multivariate general linear model described the influence of sex, body height, age, and spinal level on the measured values.There were differences for sex, spinal level, interaction between sex and level, and body height, while age had significant yet limited influence. Normative ranges for the sagittal diameters and areas of spinal canal and spinal cord were defined at C1, C3, and C6 levels for men and women. In addition to a calculation of normative ranges for a specific sex, spinal level, age, and body height data, data for three different height subgroups at 45 years of age were extracted. These results show a range of the spinal canal dimensions at C1 (from 10.7 to 19.7 mm), C3 (from 9.4 to 17.2 mm), and C6 (from 9.2 to 16.8 mm) levels.The dimensions of the cervical spinal canal and cord in healthy individuals are associated with spinal level, sex, age, and height. Online supplemental material is available for this article.

To assess patient discomfort during (a) intraarticular contrast material injection (arthrography) and (b) magnetic resonance (MR) imaging in patients referred for MR arthrography of the shoulder and to compare the relative discomfort associated with each part of the examination.With use of a visual analogue scale (VAS) and relative ratings, 202 consecutive patients referred for MR arthrography of the shoulder rated the expected discomfort and that actually experienced during both arthrography and MR imaging. The Student t test was used for statistical analysis.The average VAS score (0 = "did not feel anything," 100 = "unbearable") was 16.1 +/- 16.4 (SD) for arthrography and 20.2 +/- 25.0 for MR imaging. This difference was statistically significant (P =.036, paired t test). The discomfort experienced during arthrography was as expected in 90 (44.6%) patients, less than expected in 110 (54.4%), and worse than expected in two (1.0%). MR imaging-related discomfort was as expected in 114 (56.4%) patients, less than expected in 66 (32.7%), and worse in 22 (10.9%). Arthrography was rated worse than MR imaging by 53 (26.2%) patients, equal to MR imaging by 69 (34.2%), and less uncomfortable than MR imaging by 80 (39.6%).Arthrography-related discomfort was well tolerated, often less severe than anticipated, and rated less severe than MR imaging-related discomfort.

To evaluate the effect of slight off-lateral positioning of the wrist on measurements of the palmar tilt of the distal radius on lateral views and to determine how this effect can be corrected quantitatively.Seven cadaveric forearms in neutral and various oblique positions (5 degrees, 10 degrees, 15 degrees, 20 degrees ) of supination and pronation were examined with lateral radiography. The palmar tilt of the distal radius measured on the radiographs was correlated with each position of the wrist and the distance between the position of the palmar cortex of the pisiform bone (P) and a reference point (point 0), which was defined as the midpoint within the interval between palmar cortices of the distal scaphoid pole and of the capitate head (P0 distance). The same measurements were performed on 11 wrists during arthrography.The apparent palmar tilt of the distal radius increased with supination of the forearm. Regression analysis with the P0 distance as independent and palmar tilt as dependent variables resulted in a slope of 0.95 in the seven cadaveric wrists and of 0.92 in the 11 wrist arthrograms. The squares of the correlation coefficients (R(2)) were 0.89 in cadaveric wrists and 0.69 in 11 wrist arthrograms.Differences in the palmar tilt produced by off-lateral projections of the wrist can be estimated from the measured difference of the P0 distance. A 1-mm difference in the P0 distance corresponds to a difference in the palmar tilt of approximately 1 degrees.

Study design A reliability study was conducted. Objectives To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system. Summary of background data A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations. The reliability of the assessment has a crucial influence on the validity of the data. Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse. Methods A grading system for lumbar disc degeneration was developed on the basis of the literature. An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations. The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years). All scans were analyzed independently by three observers. Intra- and interobserver reliabilities were assessed by calculating kappa statistics. Results There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs. The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 0.84-0.90) and interobserver (kappa range, 0.69-0.81). Complete agreement was obtained, on the average, in 83.8% of all the discs. A difference of one grade occurred in 15.9% and a difference of two or more grades in 1.3% of all the cases. Conclusion Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.

The purpose of this study was to assess qualitatively and quantitatively the MR arthrographic variability of the arthroscopically normal glenoid labrum. Form and signal abnormalities of arthroscopically normal labral parts were analyzed on axial and coronal MR arthrograms of 55 consecutive patients (mean age 43.8 years, age range 21–76 years) referred mainly for suspected rotator cuff lesions. Length and width of the labrum were measured. One hundred twenty-one of 241 (50 %) arthroscopically normal labral parts demonstrated normal (low) signal intensity and normal form on MR arthrograms. Increased linear or globular signal intensity was present in 74 of 241 (31 %) normal labral parts, deformed or fragmented labra in 28 (12 %), complete separation of the labrum from the glenoid in 4 (2 %), a cleft in 5 (2 %), attenuation in 4 (2 %), and complete absence in 5 (2 %), respectively. The mean size of the normal labrum varied between 3.8 × 3.3 mm at the subscapularis bursa level (anteriorly) and 6.1 × 5.6 mm at the inferior portion of the glenoid (anteriorly). The size was not significantly different between arthroscopically normal and abnormal labral parts (p = 0.13–0.83). Since the MR appearance of the arthroscopically normal glenoid labrum varies considerably concerning signal intensity, form, and size, only major tears or detachments of the labrum should be diagnosed.

To investigate the predictive value of magnetic resonance (MR) imaging of abnormalities of the lumbar intervertebral disks, particularly with adjacent endplate changes, to predict symptomatic disk derangement, with discography as the standard.Fifty patients aged 28-50 years with chronic low back pain and without radicular leg pain underwent prospective clinical examination and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging. Subsequently, patients underwent lumbar discography with a pain provocation test (116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity zone, and endplate abnormalities. Results of pain provocation at discography were rated independently of the image findings as concordant or as nonconcordant or painless. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the clinical relevance of MR abnormalities.Normal disks on MR images were generally not painful at provocative discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV, 63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%) were not helpful in the identification of symptomatic disk derangement. When only moderate and severe type I and type II endplate abnormalities were considered abnormal, all injected disks caused concordant pain with provocation (sensitivity, 38%; specificity, 100%; PPV, 100%).Moderate and severe endplate abnormalities appear be useful in the prediction of painful disk derangement in patients with symptomatic low back pain.

Objective. To assess the shape of the posterior glenoid rim in patients with recurrent (atraumatic) posterior instability. Design and patients.CT examinations of 15 shoulders with recurrent (atraumatic) posterior instability were reviewed in masked fashion with regard to abnormalities of the glenoid shape, specifically of its posterior rim. The glenoid version was also assessed. The findings were compared with the findings in 15 shoulders with recurrent anterior shoulder instability and 15 shoulders without instability. For all patients, surgical correlation was available. Results.Fourteen of the 15 (93%) shoulders with recurrent (atraumatic) posterior shoulder instability had a deficiency of the posteroinferior glenoid rim. In patients with recurrent anterior instability or stable shoulders such deficiencies were less common (60% and 73%, respectively). The craniocaudal length of the deficiencies was largest in patients with posterior instability. When a posteroinferior deficiency with a craniocaudal length of 12 mm or more was defined as abnormal, sensitivity and specificity for diagnosing recurrent (atraumatic) posterior instability were 86.7% and 83.3%, respectively. There was a statistically significant difference in glenoid version between shoulders with posterior instability and stable shoulders (P=0.01). Conclusion.Recurrent (atraumatic) posterior shoulder instability should be considered in patients with a bony deficiency of the posteroinferior glenoid rim with a craniocaudal length of more than 12 mm.

To determine the effect of magnetic resonance (MR) imaging results on diagnostic thinking and therapeutic decisions by orthopedic surgeons in cases of a possible Morton neuroma.Orthopedic surgeons completed a questionnaire before and after MR imaging for 54 feet in 49 patients thought to have Morton neuroma. Clinical diagnosis (Morton neuroma, differential diagnosis), location, diagnostic confidence, and therapeutic decisions were noted before and after MR imaging. The influence of the size of the neuroma on therapeutic decisions was analyzed. MR imaging diagnoses were compared with surgical results for 23 revised intermetatarsal spaces.After MR imaging, the clinical diagnosis of Morton neuroma was withdrawn in 15 of 54 (28%) feet. In 14 of 39 maintained diagnoses, the location or number of neuromas was changed after MR imaging. Confidence levels for Morton neuroma increased substantially after MR imaging. In 31 (57%) feet, a change in treatment plan resulted after MR imaging. Diameters of neuromas on MR images were significantly larger (P = .003) in surgically treated feet than in conservatively treated feet. MR imaging diagnoses were correct in all 23 revised intermetatarsal spaces.MR imaging has a major effect on diagnostic thinking and therapeutic decisions by orthopedic surgeons when Morton neuroma is suspected, especially because MR imaging helps in localization and size assessment of Morton neuromas.

Objective. The objective of this study was to illustrate the magnetic resonance (MR) image appearance of the structures of the posteromedial ”corner” of the knee with particular emphasis on the anatomy and differentiation between the medial collateral ligament and the posterior oblique ligament. Design. Six cadaveric knee specimens underwent MR imaging, before and following instillation of intra-articular contrast material. The knees were sectioned in the axial, coronal, and coronal oblique planes and the gross morphology of the posteromedial corner and surrounding structures was studied and correlated with the MR images. Patients. The human cadaveric specimens were from two female and four male patients (age at death, 72–86 years; average, 78 years). Results and conclusions. The contrast-enhanced sequences and the coronal oblique images allowed for improved visualization of the structures.

Evaluation of the feasibility of virtual magnetic resonance (MR) arthroscopy was performed on 10 patients referred for MR arthrography of the shoulder, the elbow, or the knee. A fast spoiled contrast-enhanced three-dimensional gradient-echo sequence was combined with image postprocessing to render arthroscopic views. Virtual MR arthroscopy was successfully demonstrated in all 10 joints. Determination of added diagnostic benefit will require further study.

Our purpose was to evaluate the diagnostic efficacy of a gradient-echo sequence optimized for cartilage imaging in patellar cartilage abnormalities and to compare it to a standard turbo-spin-echo sequence. Fifty-eight consecutive patients who underwent, within 3 months both MRI and arthroscopy or surgery, were included in the investigation. Two radiologists specializing in musculoskeletal imaging independently assessed axial three-dimensional double-echo steady state (3D-DESS) gradient-echo images and sagittal proton- and T2-weighted turbo-spin-echo images with regard to retropatellar cartilage abnormalities. Possible findings were: 0: normal, 1: cartilage softening, and 2: lesion of the articular surface. Inter- and intraobserver variability was assessed. For cartilage softening, the axial 3D-DESS sequence had a sensitivity of 73%, a specificity of 75%, and an accuracy of 70%. The corresponding results for the sagittal turbo-spin-echo sequence were 53%, 65%, and 62%. For surface lesions, the results for the 3D-DESS sequence were 43%, 92%, and 83% and for the turbo-spin-echo sequence were 60%, 92%, and 86%. Intra- and interobserver agreement was moderate (k = 0.59 and 0.45 [DESS], 0.6 and 0.46 [turbo -spin-echo]). We conclude that the 3D-DESS sequence is moderately accurate in detecting patellar cartilage abnormalities. Compared with the sagittal turbo-spin-echo sequence, the axial 3D-DESS sequence is superior in diagnosing cartilage softening but not surface lesions.

The objective of this pictorial essay is to illustrate the MR appearance of the common peroneal nerve and the appearance of masses that have been associated with peroneal nerve entrapment. Four human cadaveric knees underwent axial MRI utilizing a T1-weighted SE sequence. One knee was dissected by an orthopedic surgeon and three knees were transversely sectioned, and the gross morphology of the common peroneal nerve and the perineural structures was evaluated and correlated with the MR images.

Low back pain is a very common but benign and, in general, self-limiting disease indicating that only a small proportion of patients will require sophisticated imaging studies. Recent studies have highlighted the fact that a simple relationship of structural abnormalities to low back pain is impossible because similar alterations can be found in symptomatic as well as in asymptomatic individuals. These findings question our current criteria for the diagnosis of low back pain disorders with regard to their discriminative power in differentiating diseased and nondiseased individuals. Structural abnormalities demonstrated by imaging studies should therefore only be interpreted in the light of the clinical findings. This review shows that only a few studies contribute to our understanding of the clinical efficacy of imaging studies in the evaluation of low back pain disorders. There is an absolute need for comprehensive, well conducted studies on the impact of specific imaging modalities on diagnosis and treatment of lumbar spinal disease.

RATIONALE AND OBJECTIVES Compartmental anatomy of the forearm is complex and controversial. The purpose of this investigation was to demonstrate via magnetic resonance the anatomy of forearm compartments and their preferential ways of communication in a human cadaveric model. METHODS Twelve forearm spaces (11 muscles and one intermuscular) were injected with a solution containing gadopentetate dimeglumine. The extent and distribution of leakage were evaluated on axial fat-suppressed T1-weighted spin-echo images. The findings were related to known descriptions of compartmental anatomy of the forearm. RESULTS Contrast leakage occurred mostly into the intermuscular space and into the muscles adjacent to the injected muscle. A frank communication within the classically described three forearm compartments (volar, radial, and dorsal) was not present. The interosseous membrane was not an absolute barrier between flexor and extensor compartments. CONCLUSION The classic description of three forearm compartments may not be sufficient to explain distribution of soft tissue abnormalities.

Objective. To evaluate the diagnostic value of the MR imaging syndrome before and after performance of provocative exercises in patients with dynamic carpal tunnel syndrome. Design. Fat-suppressed proton-density and T2-weighted spin-echo images of the wrist were obtained prior to and after provocative, standardized exercises. Images were interpreted in masked fashion with regard to six MR criteria of carpal tunnel syndrome: (a) bowing of the transverse ligament, (b) and (c) deformation of the median nerve at the pisiform and hamate levels respectively, (d) signal abnormality of the median nerve, (e) presence of fluid in the wrist joints and/or carpal tunnel, and (f) presence of synovial swelling. Patients. Twenty-one wrists in 20 patients with subjective complaints of carpal tunnel syndrome and equivocal or negative clinical findings and negative electrodiagnostic examinations were included (age range 21–61 years, mean 37 years, 2 men and 18 women). The diagnosis of dynamic carpal tunnel syndrome was made and confirmed by surgery in 18 of the 21 symptomatic wrists. The control group consisted of 15 asymptomatic wrists in volunteers (age range 22–60 years, mean 35 years, 8 men and 7 women). Results and conclusions. Sensitivities and specificities of the six MR criteria were 90.5–100%, and 6.7–86.7%, respectively, both before and after exercise. Likelihood ratios proved statistically significant differences between the symptomatic and asymptomatic wrists (P

The objective of our study was to prospectively compare the diagnostic performance of MR arthrography and conventional MRI with surgical correlation in the same patient for detecting labrum and articular cartilage defects.Twenty-eight patients (mean age, 31.8 years) underwent MR arthrography, conventional MRI, and subsequent hip surgery, which served as the reference standard. Labrum and cartilage defects were evaluated at MRI by two independent readers. A McNemar test and kappa statistics were used for statistical analysis.At surgery, 31 labral tears were identified. MR arthrography had an advantage over conventional MRI for detecting labral tears at the anterosuperior quadrant (sensitivity of MR arthrography, 81% and 69% for readers 1 and 2, respectively; sensitivity of conventional MRI, 50% for both readers); this difference in performance between MR arthrography and conventional MRI was statistically significant for reader 1 (p = 0.02) but not for reader 2 (p = 0.2). Interobserver agreement for labral tears was higher for MR arthrography (κ = 0.81) than for conventional MRI (κ = 0.63). Surgery showed 31 acetabular cartilage defects and nine femoral cartilage defects. MR arthrography had an advantage over conventional MRI for detecting acetabular cartilage defects (sensitivity of MR arthrography, 71% and 92% for readers 1 and 2, respectively; sensitivity of conventional MRI, 58% and 83%), whereas there was no advantage to using MR arthrography for detecting femoral cartilage defects with statistically significant difference for the acetabular cartilage or femoral cartilage. Interobserver agreement was slightly higher for MR arthrography (κ = 0.50) than for conventional MRI (κ = 0.40) for assessing the acetabular cartilage and was almost identical for the femoral cartilage (κ = 0.62 and 0.63, respectively).MR arthrography was superior to conventional MRI for detecting labral tears and acetabular cartilage defects and showed a higher interobserver agreement. For femoral cartilage lesions, both modalities yielded comparable results.

The purpose of this study was to compare abnormalities detected on conventional shoulder radiography with improvement in pain and shoulder function after subacromial injections.We conducted a prospective outcomes study including 98 consecutive patients after fluoroscopy-guided subacromial injections who returned outcome questionnaires and who underwent routine shoulder radiography. Numeric pain rating scale (NRS) data were collected before and, along with patient global impression of change (PGIC) data, at 1 week and 1 month after injection. Outcome differences were assessed using the Student t test and Mann-Whitney U test. Logistic regression analysis was done, including radiographic variables compared with the outcome improvement. The odds ratios with 95% CIs were identified for the significant predictors.A significant difference in overall improvement was found depending on the posterior acromial slope. Patients with a slope of more than 36° had significantly lower NRS and PGIC scores at 1 week and 1 month (p0.025) compared with those with a slope of 36° or less, with 86.4% of patients with a slope of more than 36° reporting significant improvement at 1 month. This was the only variable linked with improvement in the logistic regression analysis, with an odds ratio of 2.16 (95% CI, 1.11-4.22). Patients with calcific tendinitis had significantly lower NRS scores at both 1 week and 1 month (p = 0.03 and 0.05, respectively) and PGIC scores at 1 week (p = 0.05).A posterior acromial slope of more than 36° and the presence of calcific tendinitis on conventional shoulder radiography are associated with better outcomes. Patients with a slope of more than 36° showed the best improvement.

Purpose We tested the hypothesis that whiplash trauma leads to changes of the signal intensity of cervical discs in T2-weighted images. Methods and materials 50 whiplash patients (18–65 years) were examined within 48 h after motor vehicle accident, and again after 3 and 6 months and compared to 50 age- and sex-matched controls. Signal intensity in ROI's of the discs at the levels C2/3 to C7/T1 and the adjacent vertebral bodies were measured on sagittal T2 weighted MR images and normalized using the average of ROI's in fat tissue. The contrast between discs and both adjacent vertebrae was calculated and disc degeneration was graded by the Pfirrmann-grading system. Results Whiplash trauma did not have a significant effect on the normalized signals from discs and vertebrae, on the contrast between discs and adjacent vertebrae, or on the Pfirrmann grading. However, the contrast between discs and adjacent vertebrae and the Pfirrmann grading showed a strong correlation. In healthy volunteers, the contrast between discs and adjacent vertebrae and Pfirrmann grading increased with age and was dependent on the disc level. Conclusion We could not find any trauma related changes of cervical disc signal intensities. Normalized signals of discs and Pfirrmann grading changed with age and varied between disc levels with the used MR sequence.

MR imaging is the method of choice in evaluating a large number of soft-tissue abnormalities; however, it has certain draw-backs, some of which may make other imaging methods more suitable. MR imaging is more expensive than alternative imaging methods; it may not be affordable for screening purposes and for diagnoses obtainable by less expensive imaging methods. In addition, immediate scheduling is not always possible for MR imaging, and an MR scanner may not be available close to the patient's home, which may be important for imaging follow-up. These factors support the use of other imaging modalities, with sonography frequently being the appropriate choice. In some situations, mainly in the presence of certain biomedical implants and devices, MR imaging is contraindicated. Additionally, under some circumstances patient access may be difficult during MR imaging; sonography and CT therefore are preferable (as for imaging guided biopsy). Moreover, some artifacts, such as motion artifacts, may have less relevance in other imaging methods (such as sonography), which may be important in noncooperative patients and children. MR imaging may not be specific in tumors and infection; this deficiency is shared with most alternative imaging methods, with the exception of scintigraphy in selected indications. Lastly, standard radiography and CT commonly are superior to MR imaging in diagnosing calcification and abnormalities of cortical bone. Consequently, in selected cases and for screening purposes, methods other than MR imaging should be considered for depicting soft-tissue structures.

To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21–76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0°–10° valgus); (2) abnormal valgus (>10°); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11° valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of

Objective: To determine the optimal intra-articular iodine concentration for C-arm flat-panel computed tomography (FPCT) arthrography using advanced joint phantoms and to evaluate its application in human cadaveric wrists and elbows. Multi-detector (MD) CT served as the standard of reference. Materials and methods: Joint phantoms and 10 human cadaveric wrist and elbow joints were scanned with C-arm FPCT (5-s, 8-s, and 20-s runs) and standard MDCT using different and optimal concentrations of iodinated contrast material. CT numbers of contrast material, tissue, and noise were measured and contrast-to-noise ratios (CNR) calculated for quantitative analysis. Image and depiction of cartilage, bone, and soft tissues were rated. Radiation doses were compared. Results: In FPCT, iodine concentrations positively correlated with CT numbers and noise of contrast material and with radiation dose (r = 0.713-0.996, p

To evaluate prospectively the performance of noncalcium images reconstructed from dual-energy (DE) computed tomography (CT) for the diagnosis of bone marrow lesions in patients with acute ankle joint trauma in comparison with magnetic resonance (MR) images.The study had local ethics board approval, and written informed consent was obtained. Thirty consecutive patients (15 women; mean age, 34 years±11.8 [standard deviation]) underwent dual-source DE CT (80 kVp and 140 kVp with tin filter) and MR imaging within 1 day following acute ankle trauma. DE CT data were postprocessed by using a three-material decomposition algorithm for generating noncalcium images. MR and noncalcium images were graded by two blinded, independent readers using a four-point system (1=distinct bone marrow lesion, 4=no lesion); CT numbers in noncalcium images were calculated by a third reader. MR imaging interpretations served as the reference standard.Interreader agreement for qualitative grading of DE CT images was substantial (κ=0.66). The respective sensitivity, specificity, positive predictive value, and negative predictive value of DE CT for depicting distinct bone marrow lesions for both readers were 90.0% each, 80.5% and 81.6%, 25.4% and 26.5%, and 99.1% each. In regions without abnormality, CT numbers in noncalcium images gradually increased from proximal to distal location (P.001). Significant differences in CT numbers were found in regions positive for bone marrow lesions compared with those that were negative (P.001). CT numbers for the diagnosis of distinct bone marrow lesions according to MR imaging revealed areas under the receiver operating characteristic curve of 0.973, 0.813, and 0.758 for ankle mortise, talar dome, and talar body/head, respectively.Compared with MR images, distinct traumatic bone marrow lesions of the ankle joint can be diagnosed on noncalcium images reconstructed from DE CT with high sensitivity and excellent negative predictive value, but with moderate specificity and low positive predictive value.

Objectives To determine whether data obtained from patients returning postal questionnaires accurately reflect how patients receiving imaging-guided lumbar facet injections respond. Methods Seventy-eight patients receiving lumbar facet joint injections who returned an outcomes questionnaire (responders) were age and gender matched with 78 patients who did not return the postal questionnaire (non-responders) after facet joint injections. Baseline numerical rating scale (NRS) pain data were collected. NRS and Patients’ Global Impression of Change (PGIC) data were collected 1 month after injection by postal questionnaire or telephone interview. Differences in NRS scores were calculated using the unpaired t-test. One level injection patients were compared to patients having ≥2 levels injected using the paired and unpaired t-test. The proportion of patients reporting significant improvement in each group was calculated. Results NRS scores were significantly improved compared to baseline (p = 0.0001). Thirty-eight percent of responders were significantly improved compared to 50 % of non-responders. Patients having ≥2 levels injected reported significantly higher baseline NRS scores, but by 1 month there was no difference in NRS scores between groups. Conclusions Patients returning postal questionnaires report a less favourable outcome. Telephone interview patients having injections at more than one level have better outcomes. Main messages • Patients returning postal questionnaires report worse outcomes after facet injection. • Method of data collection should be considered when reporting treatment outcomes. • Patients receiving facet injections at more than one level report greater levels of pain reduction.

OBJECTIVES: : To show the feasibility of flat-panel computed tomography (FPCT) arthrography and quantitatively and qualitatively compare different FPCT protocols with standard multidetector computed tomography (MDCT). MATERIALS AND METHODS: : First, a phantom simulating joint space with increasing iodine concentrations was scanned using a standard MDCT and 3 different FPCT protocols. Quantitative analyses were performed by measuring CT numbers of iodine dilutions, radiation dose, and image noise as well as signal-to-noise ratio and contrast-to-noise ratio. Second, FPCT arthrographies of 4 animal joint specimens were performed and analyzed qualitatively by 2 independent readers who evaluated image artifacts, image noise, overall image quality and anatomic depiction of bone, cartilage, and soft tissue. Kappa values were calculated for inter-reader agreement. Pearson's correlation coefficient (r) and Wilcoxon signed-ranks test with Bonferroni corrections for multiple comparisons were used to compare MDCT and FPCT. RESULTS: : In phantoms, all CT scans showed a linear correlation between increasing iodine concentrations and mean HU values of contrast media and radiation dose, respectively (r = 0.98-0.99, P < 0.01). Dose-length product remained constant for MDCT scans. Signal-to-noise ratio for phantom water linearly decreased in all FPCT scans with increasing iodine concentrations. Contrast-to-noise ratio curves showed reduced slope at iodine concentrations higher than 75 mg/mL. FPCT arthrography after intra-articular administration of 5 to 6 mL of a 25% dilution of iopromide (Ultravist 300 mg/mL, Bayer HealthCare, Berlin, Germany) was successfully performed in all 4 animal joint specimens. Kappa values for inter-reader agreement of qualitative image analyses were 0.62 to 0.91. Image and depiction quality of 20-s FPCT scans were similar or superior compared with standard MDCT (P < 0.005). CONCLUSION: : FPCT arthrography is feasible and may allow similar image quality compared with standard MDCT arthrography.

Objective: To describe a posterolateral fluoroscopy-guided injection technique into the posterior subtalar joint and to report patient outcomes 1month post-injection. Materials and methods: Twenty-three consecutive adult patients who underwent fluoroscopy-guided injection into the posterior subtalar joint using a direct posterolateral approach and who returned an outcomes-based postal questionnaire after receiving this injection were included. Numerical pain rating scale (NRS) data were collected prior to injection. NRS and Patient's Global Impression of Change (PGIC) scales were completed 1day, 1week, and 1month after injection. The proportion of patients who improved was calculated for each time period. Baseline NRS data were compared to each time point using the Wilcoxon test to assess differences. Spearman's correlation coefficient was used to compare the 20min NRS score with all follow-up NRS scores. All available images were reviewed for the presence of subtalar osteoarthritis (OA). Patient charts were reviewed to identify characteristics of patients referred for subtalar injections. Risk ratios were calculated comparing presence of OA or other abnormalities with improvement. Results: A posterolateral approach for fluoroscopy-guided injections into the subtalar joint is described. There was a significant reduction in the mean NRS score at all time periods compared to baseline (p ≤ 0.004). One-third of patients (7/21) reported clinically relevant improvement at 1month. Conclusions: Fluoroscopy-guided puncture of the posterior subtalar joint using a posterolateral approach is possible. Clinically significant improvement is reported in 33% of patients after 1month

This editorial and the “Perspective” on scientific journals and impact factors by W. Hendee, Bernstein, and Levine are the outcome of the Annual Editors’ Forum, which was hosted by the Imaging Institute of the Cleveland Clinic on August 20, 2011. In attendance at the forum were editors from Europe, Canada, and the United States representing 13 scientific journals concerned with medical imaging. One of the items on the agenda was the influence of the Impact Factor (IF) on the make-up of the journal. In our view, as lucidly outlined by Hendee et al., the IF has been brandished out of proportion as a signal of a journal’s worthiness. The IF is a metric that measures the citations of a journal’s articles over a 2-year period. The ranking of a journal is based on the 2-year IF. One of us (J.H.) gave a presentation on the influence of the IF on European radiology departments. Based on responses to a questionnaire survey, Hodler reported that promotions committees placed more emphasis on work published in journals with higher IFs and that a rise in a journal’s IF could influence the probability that a work would be submitted to Skeletal Radiology. To evaluate this position, we would like to share with you some metrics as they pertain to Skeletal Radiology with regard to citations, impact factor rank, and time. Based upon the 2-year IF, Skeletal Radiology is ranked 70 of 111 imaging journals. However, it ranks 38th based on the number of citations and 10th based on the cited half-life of articles, which is 8.8 years. These facts require interpretation. In a fast moving scientific field, it is probable that citations within 2 years capture the importance of an article. However, in our field, because of the relative rarity of the conditions, knowledge grows by the gradual accretion of information over a much longer time. In recognition of this, the journal has had a dedicated case report section since its inception. Case reports can be a sacrificial lamb on the altar of the IF because by their nature, they represent rarities, unlikely to be cited promptly after publication. It is often assumed that the higher the IF, the better the science. This is certainly an oversimplification. In their “Perspective” article, Hendee et al. have shown how the IF can be manipulated. To this we would add that the number of citations is merely an indicator of the degree to which a topic is “au courant”, not the accuracy or value of a paper. Completely false papers may receive a large number of citations as others debunk them. Scientific validity is a test of time and not a 2-year citation count. For these reasons and because of the narrowness of what it measures, we believe that the IF is of limited value for a journal such as Skeletal Radiology. The quality of a publication can not be evaluated based upon the IF of the journal in which it is published. M. Sundaram (*) The Cleveland Clinic Foundation, Cleveland, OH, USA e-mail: sundarm@ccf.org

To develop a list of radiologic criteria for describing lumbar spinal stenosis, to learn from experts which parameters they consider to be most important, and to assess the strength of agreement among experts on the most relevant criteria.An expert panel of 41 radiologists (musculoskeletal experts and neuroradiologists from Europe and the United States) was formed. A three-round Delphi survey was conducted. Twenty-seven of the 41 nominated experts agreed to participate; 21 completed all three rounds. In the first round, experts were asked to complete a list of suggested parameters and cutoff values to describe lumbar spinal stenosis. In the second round, panelists rated the diagnostic relevance of each parameter (visual analog scale, 0-10). In the third round, panelists were provided with the group results (median and range) and their own answers and had the opportunity to adapt their judgments from round 2. To assess the degree of consensus among experts, the Cronbach α was calculated.The qualitative criteria disk protrusion and perineural intraforaminal fat were rated as the most important diagnostic indicators, with median scores of 9 (range, 2-10). The highest rated quantitative criterion was the anteroposterior diameter of the osseous canal, with a median score of 8; however, there was a wide range of scores (range, 0-10). The median Cronbach α of all panelists within the group was 0.81 after the third round.Results of the survey suggest that there are no broadly accepted quantitative criteria and only partially accepted qualitative criteria for the diagnosis of lumbar spinal stenosis. The latter include disk protrusion, lack of perineural intraforaminal fat, hypertrophic facet joint degeneration, absent fluid around the cauda equine, and hypertrophy of the ligamentum flavum.