Christoph Schaeffeler - Academia.edu (original) (raw)

Papers by Christoph Schaeffeler

Research paper thumbnail of 3.0T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging—A preliminary study

European Journal of Radiology, 2015

To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on ... more To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. MR images of n=25 asymptomatic ankles were acquired with and without axial traction (6kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1=best, 4=worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n=8) T2 and SSFP diffusion-weighted imaging (DWI; n=8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (P<0.05). Cartilage surfaces were best visualized on coronal T1-w images (P<0.05). Differences for cartilage matrix evaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P>0.05). T2 values were lower at the tibia than at the talus (P<0.001). Reproducibility was better for images with axial traction. Axial traction increased the joint space width, allowed for better visualization of cartilage surfaces and improved compartment discrimination and reproducibility of quantitative cartilage parameters.

Research paper thumbnail of ABER Position MR Arthrography of the Shoulder: Diagnostic Signs for Capsular Laxity in Patients with Atraumatic Multidirectional Instability

PURPOSE To retrospectively evaluate diagnostic signs for capsular laxity on ABER position MR arth... more PURPOSE To retrospectively evaluate diagnostic signs for capsular laxity on ABER position MR arthrography (MR-A) of the shoulder in patients with atraumatic multidirectional instability. METHOD AND MATERIALS Clinical data of patients with 275 consecutive MR-Arthrographies including T1w ABER position were reviewed. Patients with MDI were identified through typical clinical history and instability in two or more directions. Patients with traumatic instability, previous surgery, overhead athletes (including posterosuperior impingement), and age >45 years were excluded. The control group comprised patients with clinical stable shoulders. ABER position MR-A were independently assessed by three blinded radiologists for two defined signs (Figure): (1) Crescent sign: Presence of contrast agent between the anterior inferior glenohumeral ligament (AIGHL) and the humeral head (HH); (2) Triangle sign: Contrast filled triangular shaped space between AIGHL, HH, and glenoid. Centering of the HH...

Research paper thumbnail of View-Angle Tilting and Slice-Encoding Metal Artifact Correction for Artifact Reduction in MRI: Experimental Sequence Optimization for Orthopaedic Tumor Endoprostheses and Clinical Application

PLOS ONE, 2015

MRI plays a major role in follow-up of patients with malignant bone tumors. However, after limb s... more MRI plays a major role in follow-up of patients with malignant bone tumors. However, after limb salvage surgery, orthopaedic tumor endoprostheses might cause significant metal-induced susceptibility artifacts. To evaluate the benefit of view-angle tilting (VAT) and slice-encoding metal artifact correction (SEMAC) for MRI of large-sized orthopaedic tumor endoprostheses in an experimental model and to demonstrate clinical benefits for assessment of periprosthetic soft tissue abnormalities. In an experimental setting, tumor endoprostheses (n=4) were scanned at 1.5T with three versions of optimized high-bandwidth turbo-spin-echo pulse sequences: (i) standard, (ii) VAT and (iii) combined VAT and SEMAC (VAT&SEMAC). Pulse sequences included coronal short-tau-inversion-recovery (STIR), coronal T1-weighted (w), transverse T1-w and T2-w TSE sequences. For clinical evaluation, VAT&SEMAC was compared to conventional metal artifact-reducing MR sequences (conventional MR) in n=25 patients with metal implants and clinical suspicion of tumor recurrence or infection. Diameters of artifacts were measured quantitatively. Qualitative parameters were assessed on a five-point scale (1=best, 5=worst): "image distortion", "artificial signal changes at the edges" and "diagnostic confidence". Imaging findings were correlated with pathology. T-tests and Wilcoxon-signed rank tests were used for statistical analyses. The true size of the prostheses was overestimated on MRI (P<0.05). A significant reduction of artifacts was achieved by VAT (P<0.001) and VAT&SEMAC (P=0.003) compared to the standard group. Quantitative scores improved in the VAT and VAT&SEMAC group (P<0.05). On clinical MR images, artifact diameters were significantly reduced in the VAT&SEMAC-group as compared with the conventional-group…

Research paper thumbnail of Evaluation of 18F-Fluoride PET/MR and PET/CT in Patients with Foot Pain of Unclear Cause

Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2015

Our objective was to compare the quality and diagnostic performance of (18)F-fluoride PET/MR imag... more Our objective was to compare the quality and diagnostic performance of (18)F-fluoride PET/MR imaging with that of (18)F-fluoride PET/CT imaging in patients with foot pain of unclear cause. Twenty-two patients (9 men, 13 women; mean age, 48 ± 18 y; range, 20-78 y) were prospectively included in this study and underwent a single-injection dual-imaging protocol with (18)F-fluoride PET/CT and PET/MR. At a minimum, the PET/MR protocol included T1-weighted spin echo and proton-density fat-saturated sequences in 2 planes each with simultaneous acquisition of PET over 20 min. PET/CT included a native isotropic (0.6 mm) diagnostic CT scan (80 kV, 165 mAs) and a subsequent PET scan (2 min per bed position). By consensus, 2 masked interpreters randomly assessed both PET datasets for image quality (3-point scale) and for the presence of focal lesions with increased (18)F-fluoride uptake (maximum of 4 lesions). For each dataset (PET/CT vs. PET/MR), the diagnoses were defined using both PET and a...

Research paper thumbnail of Bone marrow oedema on MR imaging indicates ARCO stage 3 disease in patients with AVN of the femoral head

European Radiology, 2014

Objectives To test the hypothesis that bone marrow oedema (BME) observed on MRI in patients with ... more Objectives To test the hypothesis that bone marrow oedema (BME) observed on MRI in patients with avascular necrosis (AVN) of the femoral head represents an indicator of subchondral fracture. Methods Thirty-seven symptomatic hips of 27 consecutive patients (53 % women, mean age 49.2) with AVN of the femoral head and associated BME on magnetic resonance (MR) imaging were included. MR findings were correlated with computed tomography (CT) of the hip and confirmed by histopathological examination of the resected femoral head. Imaging studies were analysed by two radiologists with use of the ARCO classification. Results On MR imaging a fracture line could be identified in 19/37 (51 %) cases, which were classified as ARCO stage 3 (n=15) and stage 4 (n=4). The remaining 18/37 (49 %) cases were classified as ARCO stage 2. However, in all 37/37 (100 %) cases a subchondral fracture was identified on CT, indicating ARCO stage 3/4 disease. The extent of subchondral fractures and the femoral head collapse was graded higher on CT as compared to MRI (P<0.05). Histopathological analysis confirmed bone necrosis and subchondral fractures. Conclusions In patients with AVN, BME of the femoral head represents a secondary sign of subchondral fracture and thus indicates ARCO stage 3 disease.

Research paper thumbnail of Lesions of the Biceps Pulley: Diagnostic Accuracy of MR Arthrography of the Shoulder and Evaluation of Previously Described and New Diagnostic Signs

Radiology, 2012

To retrospectively determine the diagnostic accuracy of magnetic resonance (MR) arthrography of t... more To retrospectively determine the diagnostic accuracy of magnetic resonance (MR) arthrography of the shoulder in the evaluation of lesions of the biceps pulley and to evaluate previously described and new diagnostic signs. Institutional review board approval was obtained; the requirement for informed consent was waived. MR arthrograms of 80 consecutive patients (mean age, 34.2 years; 53 male, 27 female) with arthroscopically proved intact or torn pulley systems were assessed for the presence of a pulley lesion by three radiologists who were blinded to arthroscopic results. Criteria evaluated were displacement of the long head of the biceps tendon (LHBT) relative to the subscapularis tendon on oblique sagittal images (displacement sign), medial subluxation of the LHBT on transverse images, nonvisibility or discontinuity of the superior glenohumeral ligament (SGHL), presence of biceps tendinopathy, and rotator cuff tears adjacent to the rotator interval. There were 28 pulley lesions noted at arthroscopy. For observers 1, 2, and 3, respectively: MR arthrography showed a sensitivity of 89%, 86%, and 82% and a specificity of 96%, 98%, and 87% in the detection of pulley lesions. Nonvisibility or discontinuity of the SGHL was sensitive (79%, 89%, and 79%) and specific (83%, 79%, and 75%). With the displacement sign, sensitivity was 86%, 82%, and 75% and specificity was 96%, 98%, 90%. Tendinopathy of the LHBT on oblique sagittal images showed a sensitivity of 93%, 82%, 64%; specificity was 81%, 96%, and 85%. Subluxation of the LHBT was insensitive (36%, 50%, and 64%) but specific (100%, 98%, and 96%). MR arthrography is accurate in the detection of pulley lesions; the displacement sign, nonvisibility or discontinuity of the SGHL, and tendinopathy of the LHBT on oblique sagittal images are the most accurate criteria for the detection of pulley lesions.

Research paper thumbnail of Magnetic resonance perfusion and diffusion imaging characteristics of transient bone marrow edema, avascular necrosis and subchondral insufficiency fractures of the proximal femur

European Journal of Radiology, 2014

To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients w... more To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients with transient bone marrow edema (TBME), avascular necrosis (AVN), or subchondral insufficiency fractures (SIF) of the proximal femur. 29 patients with painful hip and bone marrow edema pattern of the proximal femur on non-contrast MR imaging were examined using diffusion-weighted and dynamic gadolinium-enhanced sequences. Apparent diffusion coefficients (ADCs) and perfusion parameters were calculated for different regions of the proximal femur. Regional distribution and differences in ADC values and perfusion parameters were evaluated. Seven patients presented with TBME, 15 with AVN and seven with SIF of the proximal femur. Perfusion imaging showed significant differences for maximum enhancement values (Emax), slope (Eslope) and time to peak (TTP) between the three patient groups (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). In contrast, no significant differences for ADC values were calculated when comparing TBME, AVN, and SIF patients. Diffusion weighted imaging of bone marrow of the proximal femur did not show significant differences between patients with TBME, AVN or SIF. In contrast, MR perfusion imaging demonstrated significant differences for the different patient groups and may as a complementary imaging technique add information to the understanding of the pathophysiology of diseases associated with bone marrow edema.

Research paper thumbnail of Rupturen am Footprint der Rotatorenmanschette: Prävalenz und Morphologie in 305 MR-Arthrographien der Schulter mit klinischer Korrelation

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2010

Research paper thumbnail of MR-Arthrographie der Schulter bei Pulley-Läsionen: Diagnostische Leistung etablierter und neuer Befundkriterien

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2012

Research paper thumbnail of Ultraschallgesteuerte intraartikuläre Kontrastmittelapplikation für die MR-Arthrografie der Schulter

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2010

To evaluate ultrasound guidance for intraarticular contrast injection via an anterolateral approa... more To evaluate ultrasound guidance for intraarticular contrast injection via an anterolateral approach in comparison with fluoroscopic guidance. Contrast agent injection was performed in 40 consecutive patients, 20 under sonographic guidance and 20 under fluoroscopic guidance. None of the patients had previous shoulder surgery. The procedure time was measured and the efficiency of joint distension, incidence of extravasation and intraarticular air on the consecutive MR arthrograms were assessed by three blinded radiologists with musculoskeletal radiology experience. Statistical analysis was performed using the Kruskal-Wallis test. Intraarticular contrast injection was successfully accomplished in all 40 patients. Subsequent MR arthrograms did not show any significant difference between sonographic and fluoroscopic guidance with respect to diagnostic quality, joint distension (p=0.6665), intraarticular air bubbles (p=0.1567) and occurrence of contrast extravasation (p=0.8565). The mean duration of ultrasound-guided injection was 7:30 min compared to a shorter procedure time of 4:15 min for fluoroscopic guidance. In both groups, no procedural complications were observed. Ultrasound-guided injection for MR arthrography of the shoulder via an anterolateral approach represents a simple, safe, and effective technique which yields comparable results to those of injection under fluoroscopic guidance, but is slightly more time-consuming.

Research paper thumbnail of View-Angle Tilting (VAT) und Slice-encoding Metal Artifact Correction (SEMAC) zur MR Bildgebung orthopädischer Tumor-Prothesen

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013

Research paper thumbnail of MR Bildgebung des Gelenkknorpels am OSG: Bessere Beurteilbarkeit durch axiale Traktion?

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013

Research paper thumbnail of Reply to letter to the editor: “Is balloon osteoplasty attractive or questionable treatment for Hill-Sachs lesions?”

International Orthopaedics, 2012

Research paper thumbnail of Balloon osteoplasty—a new technique for minimally invasive reduction and stabilisation of Hill–Sachs lesions of the humeral head: a cadaver study

International Orthopaedics, 2012

Purpose Traumatic shoulder dislocation may be complicated by concomitant bony injury of the gleno... more Purpose Traumatic shoulder dislocation may be complicated by concomitant bony injury of the glenoid rim or the humeral head. In Hill-Sachs lesions, reconstruction techniques vary widely and range from open reduction to tendon transposition or humeral head derotation. These operations are extensive and have questionable outcomes. With the expertise from vertebral compression fracture reduction by kyphoplasty, we examined in a cadaver feasibility study whether reduction of the Hill-Sachs lesion via hydraulic lift might be an anatomical and minimally invasive treatment option. We postulated that the use a of a balloon-assisted kyphoplasty reduction could achieve almost anatomical correction of the defect. Methods We created Hill-Sachs lesions in six humeral specimens and performed a computed tomography (CT) scan before and after reduction with the kyphoplasty system. The entry point at the greater tuberosity and balloon positioning was visualised by fluoroscopy. The size of the Hill-Sachs lesion before and after reduction was measured using CT scans in the axial orientation. Results Using the balloon kyphoplasty system, we achieved a statistically significant reduction (80 % ) of the Hill-Sachs lesion.

Research paper thumbnail of MR arthrography including abduction and external rotation images in the assessment of atraumatic multidirectional instability of the shoulder

European Radiology, 2014

To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atrauma... more To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atraumatic multidirectional instability (MDI) of the shoulder on MR arthrography (MR-A) including abduction/external rotation (ABER) images. Twenty-one MR-A including ABER position of 20 patients with clinically diagnosed MDI and 17 patients without instability were assessed by three radiologists. On ABER images, presence of a layer of contrast between the humeral head (HH) and the anteroinferior glenohumeral ligament (AIGHL) (crescent sign) and a triangular-shaped space between the HH, AIGHL and glenoid (triangle sign) were evaluated; centring of the HH was measured. Anterosuperior herniation of the rotator interval (RI) capsule and glenoid version were determined on standard imaging planes. The crescent sign had a sensitivity of 57 %/62 %/48 % (observers 1/2/3) and specificity of 100 %/100 %/94 % in the diagnosis of MDI. The triangle sign had a sensitivity of 48 %/57 %/48 % and specificity of 94 %/94 %/100 %. The combination of both signs had a sensitivity of 86 %/90 %/81 % and specificity of 94 %/94 %/94 %. A positive triangle sign was significantly associated with decentring of the HH. Measurements of RI herniation, RI width and glenoid were not significantly different between both groups. Combined assessment of redundancy signs on ABER position MR-A allows for accurate differentiation between patients with atraumatic MDI and patients with clinically stable shoulders; measurements on standard imaging planes appear inappropriate. MR arthrography has the possibility to accurately identify patients with atraumatic MDI. Imaging of the shoulder in abduction and external rotation provides additive information. Capsular enlargement of the shoulder can be diagnosed on MR arthrography.

Research paper thumbnail of Traumatic instability of the elbow - anatomy, pathomechanisms and presentation on imaging

European Radiology, 2013

Traumatic instability of the elbow is a common problem among patients presenting to emergency dep... more Traumatic instability of the elbow is a common problem among patients presenting to emergency departments. As recurrent instability is more common than previously thought and the knowledge of the most frequent underlying causes increases, treatment of elbow instability is becoming increasingly sophisticated. Therefore, it is mandatory for the radiologist to be familiar with the important osseous and soft-tissue stabilisers of the elbow joint and to know the pathomechanisms that lead to a spectrum of joint instability. This article discusses the relevant anatomy in elbow stability with respect to imaging and function, states the mechanisms leading to elbow dislocation and displays the types of traumatic instability of the elbow on radiography, computed tomography, and magnetic resonance imaging. • Expert imaging helps the management of traumatic instability of the elbow • The lateral ulnar collateral ligament is the cornerstone for elbow stability • Soft-tissue disruption is important in posterolateral rotatory instability • Identification of small coronoid process fragments is essential for optimal surgical therapy.

Research paper thumbnail of Tears at the rotator cuff footprint: Prevalence and imaging characteristics in 305 MR arthrograms of the shoulder

European Radiology, 2011

To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the r... more To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the rotator cuff (RC) footprint with MR arthrography (MR-A) of the shoulder. MR arthrograms obtained in 305 patients were retrospectively reviewed. Partial articular-sided supraspinatus tendon avulsions (PASTA), concealed interstitial delaminations (CID), reverse PASTA lesions and full-thickness tears (FT) at the humeral tendon insertion were depicted. Anatomical locations were determined and depths of tears were classified. 112/305 patients showed RC tears, including 63 patients with 68 footprint tears. 34 PASTA lesions were detected with 20/34 involving the anterior supraspinatus (SSP) tendon and 17/34 PASTA lesions were grade I lesions. Most CID lesions (14/23) occurred at the posterior SSP and 20/23 were classified as grade I or II. 9 FT and 2 reverse PASTA lesions were found. Statistical analysis revealed no difference in anatomical location (p = 0.903) and no correlation with overhead sports activity (p = 0.300) or history of trauma (p = 0.928). There were significantly more PASTA lesions in patients &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 40 years of age (p = 0.029). Most RC tears detected with MR-A involve the SSP footprint and are articular-sided with predominance in younger patients, but concealed lesions are not as uncommon as previously thought.

Research paper thumbnail of A 37-year-old Man with a Painless Growing Mass of the Thorax

Clinical Orthopaedics and Related Research®, 2010

Research paper thumbnail of Detection of synovitis in the hands of patients with rheumatologic disorders: Diagnostic performance of optical imaging in comparison with magnetic resonance imaging

Arthritis & Rheumatism, 2012

Methods. Forty-five patients (30 women [67%], mean ؎ SD age 52.6 ؎ 13.4 years) in whom there was ... more Methods. Forty-five patients (30 women [67%], mean ؎ SD age 52.6 ؎ 13.4 years) in whom there was a clinical suspicion of an inflammatory arthropathy were examined with a commercially available device for ICGenhanced optical imaging as well as by contrastenhanced 3T MRI as the standard of reference. Three independent readers graded the degree of synovitis in the carpal, metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of both hands (1,350 joints), using a 4-point ordinate scale (0 ‫؍‬ no synovitis, 1 ‫؍‬ mild, 2 ‫؍‬ moderate, 3 ‫؍‬ severe). Statistical analyses were performed using a logistic generalized estimating equation approach. Agreement of optical imaging ratings made by the different readers was estimated with a weighted kappa coefficient.

Research paper thumbnail of Primary extrahepatic alveolar echinococcosis of the lumbar spine and the psoas muscle

Annals of Clinical Microbiology and Antimicrobials, 2011

Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but i... more Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but important zoonosis especially in tempered zones of middle Europe and Northern America with endemic character in many countries. Due to the long incubation period, various clinical manifestations, critical prognosis, and outcome AE presents a serious and severe disease. The primary focus of infection is usually the liver. Although secondary affection of visceral organs is possible extrahepatic AE is highly uncommon. Moreover, the involvement of bone and muscle presents with an even lower incidence. In the literature numerous cases on hepatic AE have been reported. However, extrahepatic AE involving bones and/or muscles was described very rarely. We report a case of an 80-year-old man with primary extrahepatic alveolar Echinococcosis of the lumbar spine and the psoas muscle. The etiology, diagnosis, differential diagnoses, treatment options and outcome of this rare disease are discussed in context with the current literature.

Research paper thumbnail of 3.0T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging—A preliminary study

European Journal of Radiology, 2015

To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on ... more To determine the impact of axial traction during high resolution 3.0T MR imaging of the ankle on morphological assessment of articular cartilage and quantitative cartilage imaging parameters. MR images of n=25 asymptomatic ankles were acquired with and without axial traction (6kg). Coronal and sagittal T1-weighted (w) turbo spin echo (TSE) sequences with a driven equilibrium pulse and sagittal fat-saturated intermediate-w (IMfs) TSE sequences were acquired for morphological evaluation on a four-point scale (1=best, 4=worst). For quantitative assessment of cartilage degradation segmentation was performed on 2D multislice-multiecho (MSME) SE T2, steady-state free-precession (SSFP; n=8) T2 and SSFP diffusion-weighted imaging (DWI; n=8) images. Wilcoxon-tests and paired t-tests were used for statistical analysis. With axial traction, joint space width increased significantly and delineation of cartilage surfaces was rated superior (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Cartilage surfaces were best visualized on coronal T1-w images (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). Differences for cartilage matrix evaluation were smaller. Subchondral bone evaluation, motion artifacts and image quality were not significantly different between the acquisition methods (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05). T2 values were lower at the tibia than at the talus (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Reproducibility was better for images with axial traction. Axial traction increased the joint space width, allowed for better visualization of cartilage surfaces and improved compartment discrimination and reproducibility of quantitative cartilage parameters.

Research paper thumbnail of ABER Position MR Arthrography of the Shoulder: Diagnostic Signs for Capsular Laxity in Patients with Atraumatic Multidirectional Instability

PURPOSE To retrospectively evaluate diagnostic signs for capsular laxity on ABER position MR arth... more PURPOSE To retrospectively evaluate diagnostic signs for capsular laxity on ABER position MR arthrography (MR-A) of the shoulder in patients with atraumatic multidirectional instability. METHOD AND MATERIALS Clinical data of patients with 275 consecutive MR-Arthrographies including T1w ABER position were reviewed. Patients with MDI were identified through typical clinical history and instability in two or more directions. Patients with traumatic instability, previous surgery, overhead athletes (including posterosuperior impingement), and age >45 years were excluded. The control group comprised patients with clinical stable shoulders. ABER position MR-A were independently assessed by three blinded radiologists for two defined signs (Figure): (1) Crescent sign: Presence of contrast agent between the anterior inferior glenohumeral ligament (AIGHL) and the humeral head (HH); (2) Triangle sign: Contrast filled triangular shaped space between AIGHL, HH, and glenoid. Centering of the HH...

Research paper thumbnail of View-Angle Tilting and Slice-Encoding Metal Artifact Correction for Artifact Reduction in MRI: Experimental Sequence Optimization for Orthopaedic Tumor Endoprostheses and Clinical Application

PLOS ONE, 2015

MRI plays a major role in follow-up of patients with malignant bone tumors. However, after limb s... more MRI plays a major role in follow-up of patients with malignant bone tumors. However, after limb salvage surgery, orthopaedic tumor endoprostheses might cause significant metal-induced susceptibility artifacts. To evaluate the benefit of view-angle tilting (VAT) and slice-encoding metal artifact correction (SEMAC) for MRI of large-sized orthopaedic tumor endoprostheses in an experimental model and to demonstrate clinical benefits for assessment of periprosthetic soft tissue abnormalities. In an experimental setting, tumor endoprostheses (n=4) were scanned at 1.5T with three versions of optimized high-bandwidth turbo-spin-echo pulse sequences: (i) standard, (ii) VAT and (iii) combined VAT and SEMAC (VAT&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;SEMAC). Pulse sequences included coronal short-tau-inversion-recovery (STIR), coronal T1-weighted (w), transverse T1-w and T2-w TSE sequences. For clinical evaluation, VAT&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;SEMAC was compared to conventional metal artifact-reducing MR sequences (conventional MR) in n=25 patients with metal implants and clinical suspicion of tumor recurrence or infection. Diameters of artifacts were measured quantitatively. Qualitative parameters were assessed on a five-point scale (1=best, 5=worst): &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;image distortion&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;artificial signal changes at the edges&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;diagnostic confidence&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;. Imaging findings were correlated with pathology. T-tests and Wilcoxon-signed rank tests were used for statistical analyses. The true size of the prostheses was overestimated on MRI (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). A significant reduction of artifacts was achieved by VAT (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and VAT&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;SEMAC (P=0.003) compared to the standard group. Quantitative scores improved in the VAT and VAT&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;SEMAC group (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). On clinical MR images, artifact diameters were significantly reduced in the VAT&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;SEMAC-group as compared with the conventional-group…

Research paper thumbnail of Evaluation of 18F-Fluoride PET/MR and PET/CT in Patients with Foot Pain of Unclear Cause

Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2015

Our objective was to compare the quality and diagnostic performance of (18)F-fluoride PET/MR imag... more Our objective was to compare the quality and diagnostic performance of (18)F-fluoride PET/MR imaging with that of (18)F-fluoride PET/CT imaging in patients with foot pain of unclear cause. Twenty-two patients (9 men, 13 women; mean age, 48 ± 18 y; range, 20-78 y) were prospectively included in this study and underwent a single-injection dual-imaging protocol with (18)F-fluoride PET/CT and PET/MR. At a minimum, the PET/MR protocol included T1-weighted spin echo and proton-density fat-saturated sequences in 2 planes each with simultaneous acquisition of PET over 20 min. PET/CT included a native isotropic (0.6 mm) diagnostic CT scan (80 kV, 165 mAs) and a subsequent PET scan (2 min per bed position). By consensus, 2 masked interpreters randomly assessed both PET datasets for image quality (3-point scale) and for the presence of focal lesions with increased (18)F-fluoride uptake (maximum of 4 lesions). For each dataset (PET/CT vs. PET/MR), the diagnoses were defined using both PET and a...

Research paper thumbnail of Bone marrow oedema on MR imaging indicates ARCO stage 3 disease in patients with AVN of the femoral head

European Radiology, 2014

Objectives To test the hypothesis that bone marrow oedema (BME) observed on MRI in patients with ... more Objectives To test the hypothesis that bone marrow oedema (BME) observed on MRI in patients with avascular necrosis (AVN) of the femoral head represents an indicator of subchondral fracture. Methods Thirty-seven symptomatic hips of 27 consecutive patients (53 % women, mean age 49.2) with AVN of the femoral head and associated BME on magnetic resonance (MR) imaging were included. MR findings were correlated with computed tomography (CT) of the hip and confirmed by histopathological examination of the resected femoral head. Imaging studies were analysed by two radiologists with use of the ARCO classification. Results On MR imaging a fracture line could be identified in 19/37 (51 %) cases, which were classified as ARCO stage 3 (n=15) and stage 4 (n=4). The remaining 18/37 (49 %) cases were classified as ARCO stage 2. However, in all 37/37 (100 %) cases a subchondral fracture was identified on CT, indicating ARCO stage 3/4 disease. The extent of subchondral fractures and the femoral head collapse was graded higher on CT as compared to MRI (P<0.05). Histopathological analysis confirmed bone necrosis and subchondral fractures. Conclusions In patients with AVN, BME of the femoral head represents a secondary sign of subchondral fracture and thus indicates ARCO stage 3 disease.

Research paper thumbnail of Lesions of the Biceps Pulley: Diagnostic Accuracy of MR Arthrography of the Shoulder and Evaluation of Previously Described and New Diagnostic Signs

Radiology, 2012

To retrospectively determine the diagnostic accuracy of magnetic resonance (MR) arthrography of t... more To retrospectively determine the diagnostic accuracy of magnetic resonance (MR) arthrography of the shoulder in the evaluation of lesions of the biceps pulley and to evaluate previously described and new diagnostic signs. Institutional review board approval was obtained; the requirement for informed consent was waived. MR arthrograms of 80 consecutive patients (mean age, 34.2 years; 53 male, 27 female) with arthroscopically proved intact or torn pulley systems were assessed for the presence of a pulley lesion by three radiologists who were blinded to arthroscopic results. Criteria evaluated were displacement of the long head of the biceps tendon (LHBT) relative to the subscapularis tendon on oblique sagittal images (displacement sign), medial subluxation of the LHBT on transverse images, nonvisibility or discontinuity of the superior glenohumeral ligament (SGHL), presence of biceps tendinopathy, and rotator cuff tears adjacent to the rotator interval. There were 28 pulley lesions noted at arthroscopy. For observers 1, 2, and 3, respectively: MR arthrography showed a sensitivity of 89%, 86%, and 82% and a specificity of 96%, 98%, and 87% in the detection of pulley lesions. Nonvisibility or discontinuity of the SGHL was sensitive (79%, 89%, and 79%) and specific (83%, 79%, and 75%). With the displacement sign, sensitivity was 86%, 82%, and 75% and specificity was 96%, 98%, 90%. Tendinopathy of the LHBT on oblique sagittal images showed a sensitivity of 93%, 82%, 64%; specificity was 81%, 96%, and 85%. Subluxation of the LHBT was insensitive (36%, 50%, and 64%) but specific (100%, 98%, and 96%). MR arthrography is accurate in the detection of pulley lesions; the displacement sign, nonvisibility or discontinuity of the SGHL, and tendinopathy of the LHBT on oblique sagittal images are the most accurate criteria for the detection of pulley lesions.

Research paper thumbnail of Magnetic resonance perfusion and diffusion imaging characteristics of transient bone marrow edema, avascular necrosis and subchondral insufficiency fractures of the proximal femur

European Journal of Radiology, 2014

To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients w... more To evaluate magnetic resonance (MR) perfusion and diffusion imaging characteristics in patients with transient bone marrow edema (TBME), avascular necrosis (AVN), or subchondral insufficiency fractures (SIF) of the proximal femur. 29 patients with painful hip and bone marrow edema pattern of the proximal femur on non-contrast MR imaging were examined using diffusion-weighted and dynamic gadolinium-enhanced sequences. Apparent diffusion coefficients (ADCs) and perfusion parameters were calculated for different regions of the proximal femur. Regional distribution and differences in ADC values and perfusion parameters were evaluated. Seven patients presented with TBME, 15 with AVN and seven with SIF of the proximal femur. Perfusion imaging showed significant differences for maximum enhancement values (Emax), slope (Eslope) and time to peak (TTP) between the three patient groups (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). In contrast, no significant differences for ADC values were calculated when comparing TBME, AVN, and SIF patients. Diffusion weighted imaging of bone marrow of the proximal femur did not show significant differences between patients with TBME, AVN or SIF. In contrast, MR perfusion imaging demonstrated significant differences for the different patient groups and may as a complementary imaging technique add information to the understanding of the pathophysiology of diseases associated with bone marrow edema.

Research paper thumbnail of Rupturen am Footprint der Rotatorenmanschette: Prävalenz und Morphologie in 305 MR-Arthrographien der Schulter mit klinischer Korrelation

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2010

Research paper thumbnail of MR-Arthrographie der Schulter bei Pulley-Läsionen: Diagnostische Leistung etablierter und neuer Befundkriterien

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2012

Research paper thumbnail of Ultraschallgesteuerte intraartikuläre Kontrastmittelapplikation für die MR-Arthrografie der Schulter

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2010

To evaluate ultrasound guidance for intraarticular contrast injection via an anterolateral approa... more To evaluate ultrasound guidance for intraarticular contrast injection via an anterolateral approach in comparison with fluoroscopic guidance. Contrast agent injection was performed in 40 consecutive patients, 20 under sonographic guidance and 20 under fluoroscopic guidance. None of the patients had previous shoulder surgery. The procedure time was measured and the efficiency of joint distension, incidence of extravasation and intraarticular air on the consecutive MR arthrograms were assessed by three blinded radiologists with musculoskeletal radiology experience. Statistical analysis was performed using the Kruskal-Wallis test. Intraarticular contrast injection was successfully accomplished in all 40 patients. Subsequent MR arthrograms did not show any significant difference between sonographic and fluoroscopic guidance with respect to diagnostic quality, joint distension (p=0.6665), intraarticular air bubbles (p=0.1567) and occurrence of contrast extravasation (p=0.8565). The mean duration of ultrasound-guided injection was 7:30 min compared to a shorter procedure time of 4:15 min for fluoroscopic guidance. In both groups, no procedural complications were observed. Ultrasound-guided injection for MR arthrography of the shoulder via an anterolateral approach represents a simple, safe, and effective technique which yields comparable results to those of injection under fluoroscopic guidance, but is slightly more time-consuming.

Research paper thumbnail of View-Angle Tilting (VAT) und Slice-encoding Metal Artifact Correction (SEMAC) zur MR Bildgebung orthopädischer Tumor-Prothesen

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013

Research paper thumbnail of MR Bildgebung des Gelenkknorpels am OSG: Bessere Beurteilbarkeit durch axiale Traktion?

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013

Research paper thumbnail of Reply to letter to the editor: “Is balloon osteoplasty attractive or questionable treatment for Hill-Sachs lesions?”

International Orthopaedics, 2012

Research paper thumbnail of Balloon osteoplasty—a new technique for minimally invasive reduction and stabilisation of Hill–Sachs lesions of the humeral head: a cadaver study

International Orthopaedics, 2012

Purpose Traumatic shoulder dislocation may be complicated by concomitant bony injury of the gleno... more Purpose Traumatic shoulder dislocation may be complicated by concomitant bony injury of the glenoid rim or the humeral head. In Hill-Sachs lesions, reconstruction techniques vary widely and range from open reduction to tendon transposition or humeral head derotation. These operations are extensive and have questionable outcomes. With the expertise from vertebral compression fracture reduction by kyphoplasty, we examined in a cadaver feasibility study whether reduction of the Hill-Sachs lesion via hydraulic lift might be an anatomical and minimally invasive treatment option. We postulated that the use a of a balloon-assisted kyphoplasty reduction could achieve almost anatomical correction of the defect. Methods We created Hill-Sachs lesions in six humeral specimens and performed a computed tomography (CT) scan before and after reduction with the kyphoplasty system. The entry point at the greater tuberosity and balloon positioning was visualised by fluoroscopy. The size of the Hill-Sachs lesion before and after reduction was measured using CT scans in the axial orientation. Results Using the balloon kyphoplasty system, we achieved a statistically significant reduction (80 % ) of the Hill-Sachs lesion.

Research paper thumbnail of MR arthrography including abduction and external rotation images in the assessment of atraumatic multidirectional instability of the shoulder

European Radiology, 2014

To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atrauma... more To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atraumatic multidirectional instability (MDI) of the shoulder on MR arthrography (MR-A) including abduction/external rotation (ABER) images. Twenty-one MR-A including ABER position of 20 patients with clinically diagnosed MDI and 17 patients without instability were assessed by three radiologists. On ABER images, presence of a layer of contrast between the humeral head (HH) and the anteroinferior glenohumeral ligament (AIGHL) (crescent sign) and a triangular-shaped space between the HH, AIGHL and glenoid (triangle sign) were evaluated; centring of the HH was measured. Anterosuperior herniation of the rotator interval (RI) capsule and glenoid version were determined on standard imaging planes. The crescent sign had a sensitivity of 57 %/62 %/48 % (observers 1/2/3) and specificity of 100 %/100 %/94 % in the diagnosis of MDI. The triangle sign had a sensitivity of 48 %/57 %/48 % and specificity of 94 %/94 %/100 %. The combination of both signs had a sensitivity of 86 %/90 %/81 % and specificity of 94 %/94 %/94 %. A positive triangle sign was significantly associated with decentring of the HH. Measurements of RI herniation, RI width and glenoid were not significantly different between both groups. Combined assessment of redundancy signs on ABER position MR-A allows for accurate differentiation between patients with atraumatic MDI and patients with clinically stable shoulders; measurements on standard imaging planes appear inappropriate. MR arthrography has the possibility to accurately identify patients with atraumatic MDI. Imaging of the shoulder in abduction and external rotation provides additive information. Capsular enlargement of the shoulder can be diagnosed on MR arthrography.

Research paper thumbnail of Traumatic instability of the elbow - anatomy, pathomechanisms and presentation on imaging

European Radiology, 2013

Traumatic instability of the elbow is a common problem among patients presenting to emergency dep... more Traumatic instability of the elbow is a common problem among patients presenting to emergency departments. As recurrent instability is more common than previously thought and the knowledge of the most frequent underlying causes increases, treatment of elbow instability is becoming increasingly sophisticated. Therefore, it is mandatory for the radiologist to be familiar with the important osseous and soft-tissue stabilisers of the elbow joint and to know the pathomechanisms that lead to a spectrum of joint instability. This article discusses the relevant anatomy in elbow stability with respect to imaging and function, states the mechanisms leading to elbow dislocation and displays the types of traumatic instability of the elbow on radiography, computed tomography, and magnetic resonance imaging. • Expert imaging helps the management of traumatic instability of the elbow • The lateral ulnar collateral ligament is the cornerstone for elbow stability • Soft-tissue disruption is important in posterolateral rotatory instability • Identification of small coronoid process fragments is essential for optimal surgical therapy.

Research paper thumbnail of Tears at the rotator cuff footprint: Prevalence and imaging characteristics in 305 MR arthrograms of the shoulder

European Radiology, 2011

To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the r... more To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the rotator cuff (RC) footprint with MR arthrography (MR-A) of the shoulder. MR arthrograms obtained in 305 patients were retrospectively reviewed. Partial articular-sided supraspinatus tendon avulsions (PASTA), concealed interstitial delaminations (CID), reverse PASTA lesions and full-thickness tears (FT) at the humeral tendon insertion were depicted. Anatomical locations were determined and depths of tears were classified. 112/305 patients showed RC tears, including 63 patients with 68 footprint tears. 34 PASTA lesions were detected with 20/34 involving the anterior supraspinatus (SSP) tendon and 17/34 PASTA lesions were grade I lesions. Most CID lesions (14/23) occurred at the posterior SSP and 20/23 were classified as grade I or II. 9 FT and 2 reverse PASTA lesions were found. Statistical analysis revealed no difference in anatomical location (p = 0.903) and no correlation with overhead sports activity (p = 0.300) or history of trauma (p = 0.928). There were significantly more PASTA lesions in patients &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 40 years of age (p = 0.029). Most RC tears detected with MR-A involve the SSP footprint and are articular-sided with predominance in younger patients, but concealed lesions are not as uncommon as previously thought.

Research paper thumbnail of A 37-year-old Man with a Painless Growing Mass of the Thorax

Clinical Orthopaedics and Related Research®, 2010

Research paper thumbnail of Detection of synovitis in the hands of patients with rheumatologic disorders: Diagnostic performance of optical imaging in comparison with magnetic resonance imaging

Arthritis & Rheumatism, 2012

Methods. Forty-five patients (30 women [67%], mean ؎ SD age 52.6 ؎ 13.4 years) in whom there was ... more Methods. Forty-five patients (30 women [67%], mean ؎ SD age 52.6 ؎ 13.4 years) in whom there was a clinical suspicion of an inflammatory arthropathy were examined with a commercially available device for ICGenhanced optical imaging as well as by contrastenhanced 3T MRI as the standard of reference. Three independent readers graded the degree of synovitis in the carpal, metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints of both hands (1,350 joints), using a 4-point ordinate scale (0 ‫؍‬ no synovitis, 1 ‫؍‬ mild, 2 ‫؍‬ moderate, 3 ‫؍‬ severe). Statistical analyses were performed using a logistic generalized estimating equation approach. Agreement of optical imaging ratings made by the different readers was estimated with a weighted kappa coefficient.

Research paper thumbnail of Primary extrahepatic alveolar echinococcosis of the lumbar spine and the psoas muscle

Annals of Clinical Microbiology and Antimicrobials, 2011

Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but i... more Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but important zoonosis especially in tempered zones of middle Europe and Northern America with endemic character in many countries. Due to the long incubation period, various clinical manifestations, critical prognosis, and outcome AE presents a serious and severe disease. The primary focus of infection is usually the liver. Although secondary affection of visceral organs is possible extrahepatic AE is highly uncommon. Moreover, the involvement of bone and muscle presents with an even lower incidence. In the literature numerous cases on hepatic AE have been reported. However, extrahepatic AE involving bones and/or muscles was described very rarely. We report a case of an 80-year-old man with primary extrahepatic alveolar Echinococcosis of the lumbar spine and the psoas muscle. The etiology, diagnosis, differential diagnoses, treatment options and outcome of this rare disease are discussed in context with the current literature.