[Injuries of ligaments and tendons of foot and ankle : What every radiologist should know]. / Band- und Sehnenverletzungen an Fuß und Sprunggelenk : Was jeder Radiologe wissen sollte.

Injuries of the ligaments and tendons of the ankle and foot are among the most common musculoskeletal injuries. A correct and precise description of the pathology and possible accompanying injuries is essential for treatment planning by trauma and orthopedic surgeons. While X­ray is used to exclude fractures, ultrasound is a very useful tool to assess the ligaments and tendons. For the radiologist, magnetic resonance imaging (MRI) is invaluable regarding the correct assessment of (partial) ruptures, as well as for evaluating accompanying injuries. The aim of the present overview is to provide the most relevant facts for radiologists regarding injuries of ligaments and tendons of the ankle and foot. A description of expected MRI findings and possible pitfalls are presented. For each ligament complex or tendon, we review the anatomy, followed by relevant facts on biomechanics and typical findings in case of injury. The lateral and medial ligament complex, syndesmosis, spring ligament complex, and the Lisfranc ligament are shown in detail. The Achilles tendon and the peroneal tendons are also discussed.

Diagnostic accuracy of contemporary multidetector computed tomography (MDCT) for the detection of lumbar disc herniation.

OBJECTIVES: To evaluate the diagnostic accuracy of multidetector CT (MDCT) for detection of lumbar disc herniation with MRI as standard of reference. METHODS: Patients with low back pain underwent indicated MDCT (128-row MDCT, helical pitch), 60 patients with iterative reconstruction (IR) and 67 patients with filtered back projection (FBP). Lumbar spine MRI (1.5 T) was performed within 1 month. Signal-to-noise ratios (SNR) of cerebrospinal fluid (CSF), annulus fibrosus (AF) and the spinal cord (SC) were determined for all modalities. Two readers independently rated image quality (IQ), diagnostic confidence and accuracy in the diagnosis of lumbar disc herniation using MRI as standard of reference. Inter-reader correlation was assessed with weighted κ. RESULTS: Sensitivity, specificity, precision and accuracy of MDCT for disc protrusion were 98.8%, 96.5%, 97.1%, 97.8% (disc level), 97.7%, 92.9%, 98.6%, 96.9% (patient level). SNR of IR was significantly higher than FBP. IQ was significantly better in IR owing to visually reduced noise and improved delineation of the discs. κ (>0.90) was excellent for both algorithms. CONCLUSION: MDCT of the lumbar spine yields high diagnostic accuracy for detection of lumbar disc herniation. IR improves image quality so that the provided diagnostic accuracy is principally equivalent to MRI. KEY POINTS: • MDCT is an accurate alternative to MRI in disc herniation diagnosis. • By IR enhanced image quality improves MDCT diagnostic confidence similar to MRI. • Advances in CT technology contribute to improved diagnostic performance in lumbar spine imaging.

Prediction of Stent-Retriever Thrombectomy Outcomes by Dynamic Multidetector CT Angiography in Patients with Acute Carotid T or MCA Occlusions.

BACKGROUND AND PURPOSE: The selection of patients for endovascular therapy is an important issue in stroke imaging. The aim of this study was to determine the predictive value of 3 different dynamic CT angiography parameters, occlusion length, collateralization extent, and time delay to maximum enhancement, for latest generation of stent retriever thrombectomy recanalization outcomes in patients with acute ischemic stroke. MATERIALS AND METHODS: In this study, subjects were selected from an initial cohort of 2059 consecutive patients who had undergone multiparametric CT, including whole-brain CT perfusion. We included all patients with a complete occlusion of the M1 segment of the MCA or the carotid T and subsequent intra-arterial stent retriever thrombectomy. Dynamic CT angiography was reconstructed from whole-brain CT perfusion raw datasets. Angiographic outcome was scored by using the modified TICI scale; and clinical outcome, by using the modified Rankin Scale. Logistic regression analyses were performed to determine independent predictors of a favorable angiographic (mTICI = 3) and clinical outcome (mRS ≤2). RESULTS: Sixty-nine patients (mean age, 68 ± 14 years; 46% men) were included for statistical analysis. In the regression analysis, a short occlusion length was an independent predictor of favorable angiographic outcome (OR, 0.41; P < .05). Both collateralization grade (OR, 1.00; P > .05) and time delay to peak enhancement (OR, 0.90; P > .05) failed to predict a favorable angiographic outcome. None of the dynamic CT angiography predictors were significantly associated with clinical outcome on discharge (OR, 0.664-1.011; P = .330-.953) or at 90 days (OR, 0.779-1.016; P = .130-.845). CONCLUSIONS: A short occlusion length as determined by dynamic CT angiography is an independent predictor of a favorable angiographic outcome of stent retriever thrombectomy in patients with ischemic stroke.

Strategies of collateral blood flow assessment in ischemic stroke: prediction of the follow-up infarct volume in conventional and dynamic CTA.

BACKGROUND AND PURPOSE: Collateral blood flow is an important prognostic marker in the acute stroke situation but approaches for assessment vary widely. Our aim was to compare strategies of collateral blood flow assessment in dynamic and conventional CTA in their ability to predict the follow-up infarction volume. MATERIALS AND METHODS: We retrospectively included all patients with an M1 occlusion from an existing cohort of 1912 consecutive patients who underwent initial multimodal stroke CT and follow-up MR imaging or nonenhanced CT. Collateralization was assessed in both conventional CT angiography and dynamic CT angiography by using 3 different collateral grading scores and segmentation of the volume of hypoattenuation. Arterial, arteriovenous, and venous phases were reconstructed for dynamic CT angiography, and all collateral scores and the volume of hypoattenuation were individually assessed for all phases. Different grading systems were compared by using the Bayesian information criterion calculated for multivariate regression analyses (Bayesian information criterion difference = 2-6, "positive"; Bayesian information criterion difference = 6-10, "strong"; Bayesian information criterion difference = >10, "very strong"). RESULTS: One hundred thirty-six patients (mean age, 70.4 years; male sex, 41.2%) were included. In the multivariate analysis, models containing the volume of hypoattenuation showed a significantly better model fit than models containing any of the 3 collateral grading scores in conventional CT angiography (Bayesian information criterion difference = >10) and dynamic CT angiography (Bayesian information criterion difference = >10). All grading systems showed the best model fit in the arteriovenous phase. For the volume of hypoattenuation, model fit was significantly higher for models containing the volume of hypoattenuation as assessed in the arteriovenous phase of dynamic CT angiography compared with the venous phase (Bayesian information criterion difference = 6.2) and the arterial phase of dynamic CT angiography (Bayesian information criterion difference = >10) and in comparison with conventional CT angiography (Bayesian information criterion difference = >10). CONCLUSIONS: The use of dynamic CT angiography within the arteriovenous phase by using quantification of the volume of hypoattenuation is the superior technique for assessment of collateralization among the tested approaches.

Automated quantification of pulmonary perfused blood volume by dual-energy CTPA in chronic thromboembolic pulmonary hypertension.

OBJECTIVES: The aim of the study was to determine whether automated quantification of pulmonary perfused blood volume (PBV) in dual-energy computed tomography pulmonary angiography (DE-CTPA) can be used to assess the severity of chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Automated quantification of PBV was performed in 25 consecutive CTEPH patients undergoing DE-CTPA. PBV values were correlated with cardiac index and pulmonary vascular resistance quantified by right heart catheterization and walking distance in the 6-minute walk test using Pearson's correlation coefficient and multivariate linear regression analysis to control for age and gender. RESULTS: DE-CTPA derived PBV values inversely correlated with systolic (r = -0.64, p = 0.001) and mean (r = -0.57, p = 0.004) pulmonary arterial pressure. There was a trend for PBV values to inversely correlate with pulmonary vascular resistance (r = -0.20, p = 0.35). No significant correlation was found between PBV values and cardiac index or 6-minute walking distance. These correlations were confirmed to be independent of age and gender on multivariate linear regression analysis. CONCLUSION: DE-CTPA can be used for an automated quantification of pulmonary PBV in chronic thromboembolic pulmonary hypertension. PBV values correlate inversely with systolic and mean pulmonary arterial pressure and can thus be used to estimate the severity of pulmonary hypertension in these patients. Citation Format: • Meinel FG, Graef A, Thierfelder KM et al. Automated Quantification of Pulmonary Perfused Blood Volume by Dual-Energy CTPA in Chronic Thromboembolic Pulmonary Hypertension. Fortschr Röntgenstr 2014; 186: 151 - 156.