[Chronic sports injuries of the knee joint]. / Chronische Sportverletzungen des Kniegelenks.

Chronic sports injuries of the knee joint are common and mainly caused by repetitive (micro) trauma and exertion. Chronic insertion tendinopathies and avulsion fractures and symptoms related to entrapment, friction and impingement can be pathophysiologically distinguished in athletes. In this review, we depict the characteristic magnetic resonance imaging (MRI) findings of the most commonly occurring pathologies.

Value of tomosynthesis for lesion evaluation of small joints in osteoarthritic hands using the OARSI score.

OBJECTIVE: To determine the diagnostic performance of tomosynthesis in depicting osteoarthritic lesions in comparison to conventional radiographs, with use of computed tomography (CT) as standard-of-reference. METHODS: Imaging of 12 cadaveric hands was performed with tomosynthesis in dorso-palmar (dp) projection, conventional radiographs (dp) and multi-detector CT. Distal interphalangeal joint (DIP)II, DIPIII, proximal interphalangeal joint (PIP)II, PIPIII, first carpometacarpal (CMC) and scaphotrapezotrapezoidal joint (STT) were graded by two independent readers using the Osteoarthritis Research Society International (OARSI) score. The mean score for each feature was calculated for all modalities. Additional wrists were evaluated for presence of calcium pyrophosphate disease (CPPD). CT served as reference-standard. Inter-reader agreement (ICC) was calculated. RESULTS: Comparing tomosynthesis and conventional radiographs to CT, the sensitivity for the presence of osteophytes was 95,7% vs 65,2%; for joint space narrowing 95,8% vs 52,1%; for subchondral sclerosis 61,5% vs 51,3%; for lateral deformity 83.3% vs 83,3%; and for subchondral cysts 45,8% vs 29,2%. Erosions were not present. While tomosynthesis showed no significant difference in OARSI score grading to CT (mean OARSI-score CT: 16.8, SD = 10.6; mean OARSI-score Tomosynthesis: 16.3, SD = 9.6; P = 0.84), conventional radiographs had significant lower mean OARSI scores (mean OARSI-score X-ray: 11.1, SD = 8.3; P = 0.04). Inter-reader agreement for OARSI scoring was excellent (ICC = 0.99). CPPD calcifications present in CT, were also visible with tomosynthesis, but not with conventional radiography. CONCLUSION: In conclusion, tomosynthesis depicts more osteoarthritic changes in the small joints of the hand than conventional radiography using the OARSI scoring system and CT as the standard of reference.

Semiautomatic superimposition improves radiological assessment of curve flexibility in scoliosis.

OBJECTIVE: Assessment of scoliotic curve flexibility and stiffness is essential for planning surgical treatment in adolescent idiopathic scoliosis (AIS). Measurement of curve flexibility is currently insufficiently precise. The purpose of this study was to introduce and validate a novel method of superimposing radiographs for more reliable measurement of curve flexibility. MATERIAL AND METHODS: Two independent radiologists measured Cobb angles separately on standard anterior-posterior (AP) (n = 48) and supine bending radiographs (n = 48), in patients with AIS, who were randomly included from a surgical database. The same readers repeated the measurements after the bending radiographs were semi-automatically superimposed on the AP radiographs by fusing the caudad end vertebra. Curve flexibility was calculated. Inter-reader agreement between the two independent readers was calculated using interclass correlation coefficient (ICC). RESULTS: A moderate inter-reader agreement was achieved in the upper curve (ICC = 0.57) and a good agreement in the lower curve (ICC = 0.72) with the standard method of assessing curve flexibility. With the use of the semiautomatic superimposition, however, almost perfect agreement was achieved for both the upper and the lower curves flexibilities (ICC = 0.93 and 0.97, respectively). CONCLUSION: The introduced semi-automatic superimposition technique for measurement of scoliotic curve flexibility in AIS is more precise and reliable than the current standard method.

[Comparison of functional results with MRI findings after surgical treatment of transscaphoid perilunate fracture dislocations of the wrist: the role of scapholunate ligament lesions]. / Vergleich der funktionellen Resultate mit MRT-Befunden nach operativer Versorgung von transskaphoidalen perilunären Luxationsfrakturen: Die Rolle von skapholunären Bandläsionen.

PURPOSE: The aim of this study was to review the outcome of transscaphoid perilunate fracture dislocations by MRI to use the advantages of MRI to show the post-traumatic degenerative changes, the examination of cartilage, the integrity of the ligaments and the vascularisation of the carpal bones. A second aim of this study is to interpret the findings in correlation to the functional results and the individual perception of hand functionality (PRWE). PATIENTS AND METHODS: In this retrospective study, 20 patients (1 woman and 19 men), who were treated with open reduction and internal fixation at our institution, were reviewed at a mean of 67 (25-145) months postoperative. The mean age was 30 (12-73) years. The functional results were measured by range of motion (ROM), grip and pinch strength. The Mayo and Krimmer wrist scores were calculated and the SF-36 and the patient-rated wrist evaluation (PRWE) questionnaires were performed. Radiological findings included consolidation of the fracture and the radiological measures (revised carpal height, SL gap, SL and RL angle). An MRI, performed without a contrasting agent, was used to assess the degenerative changes of the joints, the vascularisation of the carpalia and the integrity of the SL ligament. Statistical data was calculated with SPSS. RESULTS: Range of motion and strength were reduced by 10-20% compared to the uninjured opposite side. Although the majority of the patients (85%) achieved good to very good results in the Mayo and Krimmer wrist scores, the MRI showed osteoarthritis in 95% of the cases in at least in 1 out of 5 patients evaluated intracarpal joints. MRI showed signs of complete SL ligament tears in 5 patients and a partial tear in 2 patients. The same group also showed the strongest degenerative changes. However, there was no correlation between patient satisfaction and imaging results. CONCLUSION: MRI findings, as well as X-ray findings, do not correlate with the subjective and objective functional outcomes after surgical treatment of transscaphoid perilunate fracture dislocations. It can be assumed that SL ligament lesions seen in MRI play a major role over the long term course.

[Delayed splenic rupture 13 days post-trauma after initially inconspicuous computed tomography examination]. / Zweizeitige Milzruptur am 13. postraumatischen Tag nach initial unauffällig befundener CT-Untersuchung.

Delayed splenic injuries are rare but nevertheless well known and very dangerous complications after blunt abdominal trauma. The highest incidence is reported between four and eight days after trauma; however some cases with a latent period of weeks have been published. We present a case of delayed splenic rupture 13 days after trauma where most computed tomography (CT) examinations were interpreted as normal and present a review of the pathophysiology of delayed rupture, diagnosis and therapy.

Anatomic MR imaging and functional diffusion tensor imaging of peripheral nerve tumors and tumorlike conditions.

BACKGROUND AND PURPOSE: A number of benign and malignant peripheral nerve tumor and tumorlike conditions produce similar imaging features on conventional anatomic MR imaging. Functional MR imaging using DTI can increment the diagnostic performance in differentiation of these lesions. Our aim was to evaluate the role of 3T anatomic MR imaging and DTI in the characterization of peripheral nerve tumor and tumorlike conditions. MATERIALS AND METHODS: Twenty-nine patients (13 men, 16 women; mean age, 41±18 years; range, 11-83 years) with a nerve tumor or tumorlike condition (25 benign, 5 malignant) underwent 3T MR imaging by using anatomic (n=29), functional diffusion, DWI (n=21), and DTI (n=24) techniques. Images were evaluated for image quality (3-point scale), ADC of the lesion, tractography, and fractional anisotropy of nerves with interobserver reliability in ADC and FA measurements. RESULTS: No significant differences were observed in age (benign, 40±18 versus malignant, 45±19 years) and sex (benign, male/female=12:12 versus malignant, male/female=3:2) (P>.05). All anatomic (29/29, 100%) MR imaging studies received "good" quality; 20/21 (95%) DWI and 21/24 (79%) DTI studies received "good" quality. ADC of benign lesions (1.848±0.40×10(-3) mm2/s) differed from that of malignant lesions (0.900±0.25×10(-3) mm2/s, P<.001) with excellent interobserver reliability (ICC=0.988 [95% CI, 0.976-0.994]). There were no FA or ADC differences between men and women (P>.05). FA of involved nerves was lower than that in contralateral healthy nerves (P<.001) with excellent interobserver reliability (ICC=0.970 [95% CI, 0.946-0.991]). ADC on DTI and DWI was not statistically different (P>.05), with excellent intermethod reliability (ICC=0.943 [95% CI, 0.836-0.980]). Tractography differences were observed in benign and malignant lesions. CONCLUSIONS: 3T MR imaging and DTI are valuable methods for anatomic and functional evaluation of peripheral nerve lesions with excellent interobserver reliability. While tractography and low FA provide insight into neural integrity, low diffusivity values indicate malignancy in neural masses.

Bisphosphonate-induced osteonecrosis of the jaw: comparison of disease extent on contrast-enhanced MR imaging, [18F] fluoride PET/CT, and conebeam CT imaging.

BACKGROUND AND PURPOSE: Imaging of bisphosphonate-induced osteonecrosis of the jaw is essential for surgical planning. We compared the extent of BONJ on contrast-enhanced MR imaging, [(18)F] fluoride PET/CT, and panoramic views derived from standard conebeam CT with clinical pre- and intraoperative examinations. MATERIALS AND METHODS: Between February 2011 and January 2012, ten subjects with written informed consent (9 women; mean, 69.6 years; range, 53-88 years) were included in this prospective ethics-board-approved study. Patients underwent CEMR imaging, [(18)F] fluoride PET/CT, and CBCT and were clinically examined pre- and intraoperatively. Surgery was performed, and BONJ was histologically confirmed in 9 patients. Location and extent of BONJ on different modalities/examinations were graphically compared (0 = no pathologic finding, 1 = smallest, 5 = largest extent of BONJ). Rank tests were used to assess overall and paired differences of ratings in 9 patients. A P value <.05 was considered statistically significant. RESULTS: Significant differences in BONJ extent among different modalities and examinations were found (P < .001). The highest median rank was seen in PET/CT (4 ± 1.12) and CEMR imaging (4 ± 1.01), followed by intraoperative examinations (3 ± 0.71), CBCT (2 ± 0.33), and preoperative examinations (1 ± 0). No significant differences were found between PET/CT and CEMR imaging (P = .23), except when comparing PET/CT to either CBCT, pre- and intraoperative examinations (all P < .05). Preoperative examinations showed significantly less extensive disease than all other modalities/examinations (all P < .05). CONCLUSIONS: [(18)F] fluoride PET/CT and CEMR imaging revealed more extensive involvement of BONJ compared with panoramic views from CBCT and clinical examinations.

Metallic artefact reduction with monoenergetic dual-energy CT: systematic ex vivo evaluation of posterior spinal fusion implants from various vendors and different spine levels.

OBJECTIVES: To evaluate optimal monoenergetic dual-energy computed tomography (DECT) settings for artefact reduction of posterior spinal fusion implants of various vendors and spine levels. METHODS: Posterior spinal fusion implants of five vendors for cervical, thoracic and lumbar spine were examined ex vivo with single-energy (SE) CT (120 kVp) and DECT (140/100 kVp). Extrapolated monoenergetic DECT images at 64, 69, 88, 105 keV and individually adjusted monoenergy for optimised image quality (OPTkeV) were generated. Two independent radiologists assessed quantitative and qualitative image parameters for each device and spine level. RESULTS: Inter-reader agreements of quantitative and qualitative parameters were high (ICC = 0.81-1.00, κ = 0.54-0.77). HU values of spinal fusion implants were significantly different among vendors (P < 0.001), spine levels (P < 0.01) and among SECT, monoenergetic DECT of 64, 69, 88, 105 keV and OPTkeV (P < 0.01). Image quality was significantly (P < 0.001) different between datasets and improved with higher monoenergies of DECT compared with SECT (V = 0.58, P < 0.001). Artefacts decreased significantly (V = 0.51, P < 0.001) at higher monoenergies. OPTkeV values ranged from 123-141 keV. OPTkeV according to vendor and spine level are presented herein. CONCLUSIONS: Monoenergetic DECT provides significantly better image quality and less metallic artefacts from implants than SECT. Use of individual keV values for vendor and spine level is recommended. KEY POINTS: • Artefacts pose problems for CT following posterior spinal fusion implants. • CT images are interpreted better with monoenergetic extrapolation using dual-energy (DE) CT. • DECT extrapolation improves image quality and reduces metallic artefacts over SECT. • There were considerable differences in monoenergy values among vendors and spine levels. • Use of individualised monoenergy values is indicated for different metallic hardware devices.

[Rare cause of acute neck pain]. / Eine seltene Ursache akuter Nackenschmerzen.

The acute calcific tendinitis of the longus colli muscle is a rare inflammatory process of the prevertebral muscles. The clinical picture includes acute neck pain, limited range of motion of the cervical spine with stiffness and odynophagia. The laboratory findings demonstrate inflammatory signs. The incidence of the disease peaks between the third and sixth decade. The knowledge of the characteristic radiologic findings and the self-limiting course prevents the patient from needless medical and surgical interventions.

Quantitative MR imaging evaluation of the cartilage thickness and subchondral bone area in patients with ACL-reconstructions 7 years after surgery.

OBJECTIVE: To evaluate the cartilage thickness (ThC) and subchondral bone area (tAB) of the operated and contra-lateral non-operated (healthy) knees in patients with anterior cruciate ligament (ACL)-reconstruction 7 years after surgery using a quantitative and regional cartilage MR imaging (qMRI) technique. METHODS: Charts of 410 patients with ACL-reconstructions were retrospectively reviewed. Fifty-two patients (male/female, 28/24; mean age, 33.3 years) were included. Patients underwent KT-1000 testing and qMRI of both knees using coronal fat-saturated 3D spoiled gradient-recalled echo (SPGR) sequences (TR/TE, 44/4 ms) at 1.5 T. Quantitative analyses of ThC and tAB in the femoro-tibial cartilage plates were performed using a subregional approach. In addition, qualitative and quantitative assessment of femoral condyle shapes was performed. t tests with Bonferroni corrections were used for statistical analysis of side-to-side differences between the operated and non-operated knees. RESULTS: KT-1000 testing was abnormal in 3/52 patients (6%). Lateral femoral tAB was significantly lower (-9.2%), and medial tibial tAB was significantly larger (+2%) in the operated vs non-operated knee (P<0.001). Regional and subregional ThC side-to-side differences were less than 0.1mm and, except for the external lateral femoral subregion, they were not statistically significant. Flattened and broader shapes of medial femoral condyles (P<0.001) were found in operated knees. No significant association of presence of cartilage or meniscus lesions at surgery with ThC 7 years post-operatively was found (P=0.06-0.98). CONCLUSION: There is evidence for changes in the tAB and femoral shape 7 years post-ACL-reconstruction, but no side-to-side differences in subregional ThC were found between the operated and contra-lateral non-operated knees.

Diagnosis Performance of Different MR Imaging Signs of Cirrhosis: the Caudate to Right Lobe Ratio, the Posterior Right Hepatic Notch, and the Expanded Gallbladder Fossa.

Background & Aims The purpose of the study is to evaluate the accuracy of the C/RL, RPN, and EGF in diagnosing cirrhosis. Methods The study population included 95 cirrhotic patients in the cirrhosis group (56 men, 39 women, age range 14-76;mean age 52.3) and 57 subjects in the control group (26 men, 31 women, age range 18-83;mean age 51). All MR examinations were performed by using the same protocol. Two radiologists independently assessed data sets in two different reading sessions. The sensitivity, specificity, and accuracy and the relative risk of the signs in diagnosing cirrhosis were calculated. The diagnosis accuracy of the C/RL sign was calculated using the ROC curve. The statistical significance of any difference of each sign between different classes of cirrhosis was also calculated. Results The interobserver agreement between the readers was excellent (κ≥ 0.81;95% CI:0.92, 1.0). There was a significant statistical difference of the diagnostic value of C/RL, RPN, and EGF between cirrhotic patients and control group (p<0.001). The sensitivity, specificity, and accuracy of C/RL were 72%, 87%, and 78%; 67%, 87%, and 75% for RPN; and 49%, 91%, and 65% for EGF. C/RL (OR=18.95) and RPN (OR=14.74) showed a higher risk for cirrhosis compared to EGF (OR=14.74). There was a statistical significance difference between C/RL and EGF (p=0.002) and between RPN and EGF for Child A class of cirrhosis (p-0.037). Conclusion The C/RL and RPN have similar performance regarding the diagnosis of cirrhosis having a higher diagnostic performance compared to EGF in cirrhosis.

[Diagnostic imaging of nerve compression syndrome]. / Bildgebende Diagnostik von Nervenkompressionssyndromen.

Compression-induced neuropathy of peripheral nerves can cause severe pain of the foot and ankle. Early diagnosis is important to institute prompt treatment and to minimize potential injury. Although clinical examination combined with electrophysiological studies remain the cornerstone of the diagnostic work-up, in certain cases, imaging may provide key information with regard to the exact anatomic location of the lesion or aid in narrowing the differential diagnosis. In other patients with peripheral neuropathies of the foot and ankle, imaging may establish the etiology of the condition and provide information crucial for management and/or surgical planning. MR imaging and ultrasound provide direct visualization of the nerve and surrounding abnormalities. Bony abnormalities contributing to nerve compression are best assessed by radiographs and CT. Knowledge of the anatomy, the etiology, typical clinical findings, and imaging features of peripheral neuropathies affecting the peripheral nerves of the foot and ankle will allow for a more confident diagnosis.