Ultrasound-based "CEUS-Bosniak"classification for cystic renal lesions: an 8-year clinical experience.

PURPOSE: Renal cysts comprise benign and malignant entities. Risk assessment profits from CT/MRI imaging using the Bosniak classification. While Bosniak-IIF, -III, and -IV cover complex cyst variants, Bosniak-IIF and -III stand out due to notorious overestimation. Contrast-enhanced ultrasound (CEUS) is promising to overcome this deficit but warrants standardization. This study addresses the benefits of a combined CEUS and CT/MRI evaluation of renal cysts. The study provides a realistic account of kidney tumor boards' intricacies in trying to validate renal cysts. METHODS: 247 patients were examined over 8 years. CEUS lesions were graded according to CEUS-Bosniak (IIF, III, IV). 55 lesions were resected, CEUS-Bosniak- and CT/MRI-Bosniak-classification were correlated with histopathological diagnosis. Interobserver agreement between the classifications was evaluated statistically. 105 lesions were followed by ultrasound, and change in CEUS-Bosniak-types and lesion size were documented. RESULTS: 146 patients (156 lesions) were included. CEUS classified 67 lesions as CEUS-Bosniak-IIF, 44 as CEUS-Bosniak-III, and 45 as CEUS-Bosniak-IV. Histopathology of 55 resected lesions revealed benign cysts in all CEUS-Bosniak-IIF lesions (2/2), 40% of CEUS-Bosniak-III and 8% of CEUS-Bosniak-IV, whereas malignancy was uncovered in 60% of CEUS-Bosniak-III and 92% of CEUS-Bosniak-IV. Overall, CEUS-Bosniak-types matched CT/MRI-Bosniak types in 58% (fair agreement, κ = 0.28). CEUS-Bosniak resulted in higher stages than CT/MRI-Bosniak (40%). Ultrasound follow-up of 105 lesions detected no relevant differences between CEUS-Bosniak-types concerning cysts size. 99% of lesions showed the same CEUS-Bosniak-type. CONCLUSION: The CEUS-Bosniak classification is an essential tool in clinical practice to differentiate and monitor renal cystic lesions and empowers diagnostic work-up and patient care.

The Role of Magnetic Resonance Imaging in the Diagnosis of Penile Fracture in Real-Life Emergency Settings: Comparative Analysis with Intraoperative Findings.

PURPOSE: We evaluated the role of magnetic resonance imaging of the penis in the diagnosis of penile fracture and/or concomitant urethral lesions in real-life emergency settings compared with intraoperative findings. MATERIALS AND METHODS: A total of 43 patients presented with suspicion of penile fracture between January 2006 and December 2016. Magnetic resonance imaging was performed in 28 patients prior to surgical treatment in the emergency setting. Surgery was done in all patients via a subcoronal, circumferential degloving approach. We calculated sensitivity, specificity, and positive and negative predictive values as well as likelihood ratios of the positive and negative results of the agreement between magnetic resonance imaging and intraoperative findings. RESULTS: Intraoperatively penile fracture was confirmed in 19 of 28 patients (67.9%) and a concomitant urethral lesion was observed in 5 of 28 (17.9%). Magnetic resonance imaging findings were highly associated with intraoperative findings of tunical rupture, including 100% sensitivity (95% CI 98.5-100), 77.8% specificity (95% CI 50.6-100), 90.5% positive predictive value (95% CI 78-100), 100% negative predictive value (95% CI 97.6-100) and a positive result likelihood ratio of 4.5. Magnetic resonance imaging had lower accuracy for urethral lesions with 60% sensitivity (95% CI 17.1-100), 78.3% specificity (95% CI 61.5-95.1), 37.5% positive predictive value (95% CI 4-71), 90% negative predictive value (95% CI 76.9-100) and a positive result likelihood ratio of 2.76. CONCLUSIONS: Magnetic resonance imaging may be applicable in the emergency setting if the goal is to treat all men who warrant intervention. It has high sensitivity and negative predictive value for tunical rupture and concomitant urethral lesions. Therefore, it could help avoid unnecessary surgery by excluding the diagnosis. However, solitary magnetic resonance imaging is not sufficient for diagnosis and it should not replace clinical assessment or delay surgical exploration.

Quantitative computed tomography in comparison with transpulmonary thermodilution for the estimation of pulmonary fluid status: a clinical study in critically ill patients.

Extravascular lung water (index) (EVLW(I)) can be estimated using transpulmonary thermodilution (TPTD). Computed tomography (CT) with quantitative analysis of lung tissue density has been proposed to quantify pulmonary edema. We compared variables of pulmonary fluid status assessed using quantitative CT and TPTD in critically ill patients. In 21 intensive care unit patients, we performed TPTD measurements directly before and after chest CT. Based on the density data of segmented CT images we calculated the tissue volume (TV), tissue volume index (TVI), and the mean weighted index of voxel aqueous density (VMWaq). CT-derived TV, TVI, and VMWaq did not predict TPTD-derived EVLWI values ≥ 14 mL/kg. There was a significant moderate positive correlation between VMWaq and mean EVLWI (EVLWI before and after CT) (r = 0.45, p = 0.042) and EVLWI after CT (r = 0.49, p = 0.025) but not EVLWI before CT (r = 0.38, p = 0.086). There was no significant correlation between TV and EVLW before CT, EVLW after CT, or mean EVLW. There was no significant correlation between TVI and EVLWI before CT, EVLWI after CT, or mean EVLWI. CT-derived variables did not predict elevated TPTD-derived EVLWI values. In unselected critically ill patients, variables of pulmonary fluid status assessed using quantitative CT cannot be used to predict EVLWI.

Prospective head-to-head comparison of 11C-choline-PET/MR and 11C-choline-PET/CT for restaging of biochemical recurrent prostate cancer.

PURPOSE: Whole-body integrated 11C-choline PET/MR might provide advantages compared to 11C-choline PET/CT for restaging of prostate cancer (PC) due to the high soft-tissue contrast and the use of multiparametric MRI, especially for detection of local recurrence and bone metastases. MATERIALS AND METHODS: Ninety-four patients with recurrent PC underwent a single-injection/dual-imaging protocol with contrast-enhanced PET/CT followed by fully diagnostic PET/MR. Imaging datasets were read separately by two reader teams (team 1 and 2) assessing the presence of local recurrence, lymph node and bone metastases in predefined regions using a five-point scale. Detection rates were calculated. The diagnostic performance of PET/CT vs. PET/MR was compared using ROC analysis. Inter-observer and inter-modality variability, radiation exposure, and mean imaging time were evaluated. Clinical follow-up, imaging, and/or histopathology served as standard of reference (SOR). RESULTS: Seventy-five patients qualified for the final image analysis. A total of 188 regions were regarded as positive: local recurrence in 37 patients, 87 regions with lymph node metastases, and 64 regions with bone metastases. Mean detection rate between both readers teams for PET/MR was 84.7% compared to 77.3% for PET/CT (p > 0.05). Local recurrence was identified significantly more often in PET/MR compared to PET/CT by team 1. Lymph node and bone metastases were identified significantly more often in PET/CT compared to PET/MR by both teams. However, this difference was not present in the subgroup of patients with PSA values ≤2 ng/ml. Inter-modality and inter-observer agreement (K > 0.6) was moderate to substantial for nearly all categories. Mean reduction of radiation exposure for PET/MR compared to PET/CT was 79.7% (range, 72.6-86.2%). Mean imaging time for PET/CT was substantially lower (18.4 ± 0.7 min) compared to PET/MR (50.4 ± 7.9 min). CONCLUSIONS: 11C-choline PET/MR is a robust imaging modality for restaging biochemical recurrent PC and interpretations between different readers are consistent. It provides a higher diagnostic value for detecting local recurrence compared to PET/CT with the advantage of substantial dose reduction. Drawbacks of PET/MR are a substantially longer imaging time and a slight inferiority in detecting bone and lymph node metastases in patients with PSA values >2 ng/ml. Thus, we suggest the use of 11C-choline PET/MR especially for patients with low (≤2 ng/ml) PSA values, whereas PET/CT is preferable in the subgroup with higher PSA values.

Prognostic value of computed tomography before radical cystectomy in patients with invasive bladder cancer: imaging predicts survival.

PURPOSE: Computed tomography (CT) is current standard-of-care for preoperative staging in patients with invasive bladder cancer before radical cystectomy (RC). There are only sparse data on the association between preoperative CT findings and postoperative survival of patients. METHODS: We retrospectively evaluated preoperative CTs of 206 patients with invasive bladder cancer undergoing RC in an academic tertiary referral center. CTs were analyzed retrospectively for relative bladder wall thickness (BWT) and size of lymph nodes (LN). Associations between CT findings and risk of death from any cause (AC) as well as risk of death from bladder cancer (BC) were assessed by Kaplan-Meier estimates, cumulative incidence curves and multivariable Cox regression analysis. RESULTS: The median follow-up was 40 months. Increased BWT was significantly correlated with higher risk of death (AC: HR 1.68; p = 0.043; BC: HR 2.00; p = 0.027), as well as LN with a size of 6-10 mm (AC: HR 2.13; p = 0.002; BC: HR 2.77; p = 0.002) and >10 mm (AC: HR 2.47; p = 0.018; BC: HR 3.66; p = 0.007) when compared to LN ≤ 5 mm. CONCLUSION: Our data showed a significant correlation of bladder wall thickness and LN size with the risk of death. Also lymph nodes >5 mm but ≤ 10 mm (resp. ≤ 8 mm)-usually considered non-pathologic-were associated with a significantly worse prognosis. This information can be used to counsel patients preoperatively. It might also be useful for a risk-adapted approach in regard to neoadjuvant chemotherapy.

Evaluation of a new imaging tool for use with major trauma cases in the emergency department.

BACKGROUND: The aim of this study was to evaluate potential benefits of a new diagnostic software prototype (Trauma Viewer, TV) automatically reformatting computed tomography (CT) data on diagnostic speed and quality, compared to CT-image data evaluation using a conventional CT console. METHODS: Multiple trauma CT data sets were analysed by one expert radiology and one expert traumatology fellow independently twice, once using the TV and once using the secondary conventional CT console placed in the CT control room. Actual analysis time and precision of diagnoses assessment were evaluated. The TV and CT-console results were compared respectively, but also a comparison to the initial multiple trauma CT reports assessed by emergency radiology fellows considered as the gold standard was performed. Finally, design and function of the Trauma Viewer were evaluated in a descriptive manner. RESULTS: CT data sets of 30 multiple trauma patients were enrolled. Mean time needed for analysis of one CT dataset was 2.43 min using the CT console and 3.58 min using the TV respectively. Thus, secondary conventional CT console analysis was on average 1.15 min shorter compared to the TV analysis. Both readers missed a total of 11 diagnoses using the secondary conventional CT console compared to 12 missed diagnoses using the TV. However, none of these overlooked diagnoses resulted in an Abbreviated Injury Scale (AIS) > 2 corresponding to life threatening injuries. CONCLUSIONS: Even though it took the two expert fellows a little longer to analyse the CT scans on the prototype TV compared to the CT console, which can be explained by the new user interface of the TV, our preliminary results demonstrate that, after further development, the TV might serve as a new diagnostic feature in the trauma room management. Its high potential to improve time and quality of CT-based diagnoses might help in fast decision making regarding treatment of severely injured patients.

Evaluation of Computed Tomography for Lymph Node Staging in Bladder Cancer Prior to Radical Cystectomy.

OBJECTIVES: To retrospectively evaluate the value of CT for lymph node (LN) staging in bladder cancer. METHODS: Two uroradiologists reviewed CT scans of 231 patients who underwent radical cystectomy and pelvic lymphadenectomy according to a predefined 12-field template. A 5-step model was used to grade the radiological likelihood of a LN to represent malignant spread based on size, configuration and structure as well as regional clustering. Statistical analyses were performed both on patient- and field-based levels. RESULTS: LN metastases were found in 59 of 231 patients (25.5%). On a patient-based level, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 52.6, 93.6, 73.2, 85.6 and 83.4%, respectively. Using the field-based approach, a total of 1,649 anatomical fields were evaluable, of which 114 fields showed malignancy (6.9%). On a field basis, sensitivity, specificity, PPV, NPV and accuracy were 30.2, 98, 51.5, 94.5 and 93.3%, respectively. Concerning local staging (pT category), the overall accuracy was 78%; overstaging occurred in 6% and understaging in 16%. CONCLUSIONS: In line with prior studies, the sensitivity of CT imaging for the detection of LN metastases was low, while high values for specificity were achieved. This was further underlined by analyzing standardized anatomical fields. Concerning local staging, postoperative changes after TURB-T rarely led to overstaging.

Local Staging of Soft-Tissue Sarcoma: Emphasis on Assessment of Neurovascular Encasement-Value of MR Imaging in 174 Confirmed Cases.

PURPOSE: To evaluate utility of magnetic resonance (MR) imaging in local staging of soft-tissue sarcoma, with an emphasis on assessment of neurovascular encasement. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent requirement was waived. Preoperative MR images in 174 patients with soft-tissue sarcoma were analyzed by two readers. Tumor staging according to the American Joint Committee on Cancer/Union International Contre le Cancer and Enneking staging systems and analysis of osseous and articular invasion were performed. To assess neurovascular encasement, contact between tumor and arteries, between tumor and veins, and between tumor and nerves was classified (no contact, contact ≤90°, 91°-180°, 181°-270°, >271°). Interobserver agreement was determined; imaging findings were correlated with intraoperative findings and/or histopathologic findings (Pearson correlation coefficient [r] and Cohen κ coefficient). RESULTS: Intraoperative evaluation and/or histopathologic evaluation confirmed osseous, articular, and neurovascular invasion in 8.6%, 2.9%, and 25.3% of patients. Interobserver agreement was excellent for tumor staging (American Joint Committee on Cancer/Union International Contre le Cancer staging, κ = 0.811; Enneking staging, κ = 0.943) and osseous invasion (κ = 1.000). It was substantial for articular invasion (κ = 0.794). Sensitivity and specificity for osseous invasion were 100% and 98.7%, respectively (both readers). For articular invasion, sensitivity was 80% (both readers); specificities were 100% and 98.8% for readers 1 and 2, respectively. Interobserver agreement in quantifying contact between tumor and vessels and between tumor and nerves was excellent for arteries, veins, and nerves (κ = 0.845, 0.892, 0.893, respectively). Receiver operating characteristic analysis revealed optimal threshold of greater than 180° for prediction of arterial and venous encasement (both readers). For neural encasement, optimal threshold was greater than 180° (reader 1) and greater than 270° (reader 2). Sensitivities in diagnosing encasement for arteries, veins, and nerves were 84.6%, 84.6%, and 77.8% (reader 1) and 84.6%, 84.6%, and 72.2% (reader 2). Specificities for encasement of arteries, veins, and nerves, respectively, were 97.5%, 97.5%, and 93.2% (reader 1) and 93.8%, 94.7%, 97.3% (reader 2). CONCLUSION: MR imaging allows reliable and accurate local staging of soft-tissue sarcoma. Encasement of arteries, veins, and nerves should be diagnosed, if the contact between tumor and vascular or neural circumference exceeds 180°.

Resectability After First-Line FOLFIRINOX in Initially Unresectable Locally Advanced Pancreatic Cancer: A Single-Center Experience.

BACKGROUND: FOLFIRINOX is an active but relatively toxic chemotherapeutic regimen for patients with metastatic pancreatic ductal adenocarcinoma (PDAC). The increased frequency of responding tumors shift interest to neoadjuvant approaches. We report our institutional experience with FOLFIRINOX for therapy-naïve patients with locally advanced and initially unresectable PDAC. METHODS: All patients with unresectable locally advanced PDAC who underwent treatment with FOLFIRINOX at a single center between 2011 and 2014 were identified and evaluated retrospectively regarding chemotherapy response, toxicity, conversion to resectability, and survival. Resectability, response to chemotherapy, and postoperative complications were reported according to NCCN-guidelines, RECIST-criteria, and Clavien-Dindo-classification, respectively. RESULTS: Overall, 14 patients received FOLFIRINOX as first-line therapy for locally advanced and unresectable PDAC. Fifty-seven percent of the patients had severe tumor-related comorbidities at the time of diagnosis, and in 86 %, dose reduction due to toxicity was necessary during a median of seven cycles. Nevertheless, only one patient had progressive disease during FOLFIRINOX, whereas the others experienced stable disease (n = 6) or partial remission (n = 6; no restaging in one patient). Oncological tumor resection was possible in 4 patients (29 % of all patients) with no postoperative mortality and only one grade 2 surgical complication. After a median follow-up of 10 months, 4 of the 14 patients were still in remission, 5 were alive with stable disease under ongoing systemic chemotherapy, and 5 died tumor-related. CONCLUSIONS: FOLFIRINOX is a powerful first-line regimen that leads to resectability in a substantial portion of patients with initially unresectable pancreatic cancer.

Detection of liver metastases in patients with adenocarcinomas of the gastrointestinal tract: comparison of (18)F-FDG PET/CT and MR imaging.

PURPOSE: Aim of our study was to compare the diagnostic performance of (18)F-FDG PET/CT and MR imaging (MRI) in the detection of liver metastases in patients with adenocarcinomas of the gastrointestinal tract. METHODS: A total of 49 patients with adenocarcinomas of the gastrointestinal tract who had undergone (18)F-FDG PET/CT and MRI of the liver were included in this study. The MRI protocol included diffusion-weighted imaging and dynamic contrast-enhanced MR imaging after intravenous injection of Gd-DTPA. PET and MR images were analyzed by two experienced radiologists. Imaging results were correlated with histopathological findings or imaging follow-up as available. Sensitivities of both modalities were compared using McNemar Test. Receiver operating characteristic (ROC) curves were calculated to determine the diagnostic performance in correctly identifying liver metastases. RESULTS: A total of 151 metastases were confirmed. For lesion detection, MRI was significantly superior to (18)F-FDG PET/CT. Sensitivity of MRI in detecting metastases was 86.8% for Reader 1 (R1) and 87.4% for Reader 2 (R2), of PET/CT 66.2% for R1 and 68.2% for R2. Regarding only metastases with diameters of 10 mm or less, sensitivities of MRI were 66.7% for R1 and 75.0% for R2, and were significantly higher than those of PET/CT (17.9% for R1 and 20.5% for R2). ROC analysis showed superiority for lesion classification of MRI as compared to (18)F-FDG PET/CT. CONCLUSION: MRI is significantly superior to (18)F-FDG PET/CT in the detection and classification of liver metastases in patients with adenocarcinomas of the gastrointestinal tract, especially in the detection of small metastases.

Preoperative lymph node staging in patients with primary prostate cancer: comparison and correlation of quantitative imaging parameters in diffusion-weighted imaging and 11C-choline PET/CT.

PURPOSE: To compare the diagnostic performance of DWI and 11C-choline PET/CT in the assessment of preoperative lymph node status in patients with primary prostate cancer. MATERIAL AND METHODS: Thirty-three patients underwent DWI and 11C-choline PET/CT prior to prostatectomy and extended pelvic lymph node dissection. Mean standardised uptake value (SUV(mean)) and mean apparent diffusion coefficient (ADC) of 76 identified lymph nodes (LN) were measured and correlated with histopathology. ADC values and SUVs were compared using linear regression analysis. RESULTS: A significant difference between benign and malignant LN was observed for ADC values (1.17 vs. 0.96 × 10(-3) mm(2)/s; P < 0.001) and SUV(mean) (1.61 vs. 3.20; P < 0.001). ROC analysis revealed an optimal ADC threshold of 1.01 × 10(-3) mm(2)/s for differentiating benign from malignant LN with corresponding sensitivity/specificity of 69.70%/78.57% and an area under the curve (AUC) of 0.785. The optimal threshold for SUV(mean) was 2.5 with corresponding sensitivity/specificity of 69.72%/90.48% and with an AUC of 0.832. ADC values and SUV(mean) showed a moderate significant inverse correlation (r = -0.63). CONCLUSION: Both modalities reveal similar moderate diagnostic performance for preoperative lymph node staging of prostate cancer, not justifying their application in routine clinical practice at this time. The only moderate inverse correlation between ADC values and SUV(mean) suggests that both imaging parameters might provide complementary information on tumour biology. KEY POINTS: • Conventional imaging shows low performance for lymph node staging in prostate cancer. • DWI and 11C-choline PET/CT both provide additional functional information • Both functional modalities reveal only moderate diagnostic performance.

PET/MR in prostate cancer: technical aspects and potential diagnostic value.

PET/MR is a new multimodal imaging technique that is expected to improve diagnostic performance of imaging in conditions in which assessment of changes in soft tissue is important such as prostate cancer. Despite substantial changes in PET technology compared to PET/CT, initial studies have demonstrated that integrated PET/MR provides comparable image quality to that of PET/CT, retaining PET quantification efficacy. In this review we briefly describe technological changes compared to PET/CT that made integrated PET/MR possible, propose acquisition protocols for evaluation of prostate cancer with this new multimodal approach, present initial results concerning the application of PET/MR in prostate cancer, and outline the potential for further clinical applications, focusing on potential incremental value compared to present diagnostic performance.

Lesions of the biceps pulley: diagnostic accuracy of MR arthrography of the shoulder and evaluation of previously described and new diagnostic signs.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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%). CONCLUSION: 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.

Targeted dual-energy single-source CT for characterisation of urinary calculi: experimental and clinical experience.

OBJECTIVE: To assess the accuracy of targeted dual-energy single-source multi-detector CT (MDCT) for characterisation of urinary calculi. METHODS: For proof of principle, 71 ex-vivo calculi underwent single-source 256-slice MDCT. Low-dose CT was performed in 154 patients with suspected urinary calculi. In 104 patients with urinary calculi targeted dual-energy imaging within one breath-hold was added. 46 patients with sufficient material for infrared-spectroscopy were analysed. Potential anatomical misregistrations between 80- and 140-kV(p)-images and HU-values were measured. DEIs (dual-energy-indices) were compared with the standard of reference. Effective doses were calculated. RESULTS: In 26 of 46 patients no misregistration was present. Mean deviations were 2.7 mm in the z-axis (16 patients) and 4.3 mm in the axial plane (10 patients). The DEIs were 0.018 ± 0.016 for uric acid (UA), 0.035 ± 0.015 for mixed UA and 0.102 ± 0.015 for calcified stones in-vitro and 0.017 ± 0.002 for UA, 0.050 ± 0.019 for mixed UA and 0.122 ± 0.024 for calcified calculi in-vivo. Significant differences were noted among calcium, mixed UA and UA stones (p < 0.05). For the low-dose examination mean effective dose was 3.11 mSv. Targed dual-energy resulted in an extra dose of 1.84 mSv (additional 59.1%). CONCLUSION: Targeted dual-energy imaging within one breath-hold is feasible for characterisation of urinary calculi using single-source MDCT allowing minimal anatomical discordance.

The epiphyseal torsion angle in MR arthrography of the hip: diagnostic utility in patients with femoroacetabular impingement syndrome.

OBJECTIVE: The purpose of the study was to evaluate whether patients with clinically suspected femoroacetabular impingement (FAI) show higher epiphyseal torsion angle values on MR arthrography than healthy volunteers. Another objective was to estimate whether patients with increased epiphyseal torsion angles show a higher incidence of hip abnormalities or a higher incidence of increased alpha angles on MR arthrography than patients with an epiphyseal torsion angle considered normal. MATERIALS AND METHODS: Sixty-eight consecutive patients with clinically suspected FAI, no history of hip surgery, and MR arthrography of the hip performed at our institution were included in the study group. The control group included 50 standard MR examinations of the hip of 25 healthy volunteers with negative findings on a clinical impingement test. Epiphyseal torsion angles and alpha angles were measured independently by three radiologists. Furthermore, MR arthrograms were retrospectively evaluated by two radiologists in consensus for hip abnormalities associated with FAI. RESULTS: The epiphyseal torsion angles were significantly higher in the study group than the control group for all three readers (reader 1, p = 0.001; reader 2, p = 0.003; reader 3, p = 0.045). There was no statistical correlation between increased epiphyseal torsion angles and pathologic alpha angles (readers 1-3: p = 0.199, p = 0.343, p = 0.058, respectively). Patients with increased epiphyseal torsion angles did not show a higher incidence of labral abnormalities than patients with epiphyseal torsion angles considered normal (readers 1-3: p = 0.335, p = 0.383, p = 0.676). CONCLUSION: Patients with clinically suspected FAI show increased epiphyseal torsion angles compared with healthy volunteers. Values greater than 20° should be considered pathologic. A pathologic retrotorsion of the femoral epiphysis may play a role in developing hip pain related to FAI and premature osteoarthritis.

Detection, classification, and characterization of focal liver lesions: Value of diffusion-weighted MR imaging, gadoxetic acid-enhanced MR imaging and the combination of both methods.

AIM: To evaluate diffusion-weighted MR imaging (DWI), gadoxetic acid-enhanced MR imaging and the combination of both methods in the detection, classification, and characterization of focal liver lesions (FLL). METHODS: A total of 119 FLL (28 HCCs, 39 metastases, 15 FNHs, 11 adenomas, 13 hemangiomas, 13 cysts) were retrospectively analyzed in 36 patients. In those patients MR imaging of the liver comprising respiratory-triggered DWI (b values of 50, 300, and 600 s/mm(2)) and gadoxetic acid-enhanced MR imaging including image acquisition in the hepatocyte-selective phase (20 min post injection) had been performed. Three image sets were assigned and compared: DWI only (set A), gadoxetic acid-enhanced MR imaging only (set B), and both modalities in combination (set C). Two readers independently interpreted the images in random order. For each reader and image set, the area under the receiver operating characteristic curve (Az) and sensitivity in the detection of FLL was determined as well as the accuracy in the classification and characterization of FLL. RESULTS: There was no significant difference between the three image sets in the detection of FLL with regards to Az. However, when only lesions with a diameter of 10 mm or less were analyzed, the Az values of set C were significantly higher than those of sets A and B for both readers. For classifying and characterizing FLL both set B and C were significantly superior to set A. CONCLUSION: Adding DWI to gadoxetic acid-enhanced MR imaging significantly increases the accuracy in the detection of small FLL.

Combined tears of the subscapularis and supraspinatus tendon: clinical outcome, rotator cuff strength and structural integrity following open repair.

BACKGROUND: Anterosuperior rotator cuff tears involving the subscapularis and supraspinatus tendons are less common than other tears of the rotator cuff. The purpose of this study was to report the clinical outcome, rotator cuff strength and structural integrity of open repair of combined anterosuperior rotator cuff tears. PATIENTS AND METHODS: Forty-eight patients at an average age of 58 years underwent open repair of a combined supraspinatus and subscapularis tendon tear. The follow-up evaluation included clinical scores, rotator cuff strength testing with a custom-made force measurement plate (FMP) and postoperative MRI to evaluate repair integrity and muscle cross-sectional area. RESULTS: After a mean follow-up of 49 months the average Constant score improved from 43 points preoperatively to 79 points postoperatively. The SST and the pain VAS were significantly improved by the procedure (each <0.05). The combined tear group with partial subscapularis tears (G1) did not achieve significantly better score results than the combined tear group with a full-thickness subscapularis tear (G2) (p > 0.05). Strength for all rotator cuff components was reduced significantly (p < 0.05) compared with the contralateral shoulder in both groups. MRI revealed a retear-rate of 4% for the subscapularis and a retear-rate of 19% for the supraspinatus. Postoperative muscle cross-sectional area of all rotator cuff muscles did not differ significantly between G1 and G2 (p > 0.05). CONCLUSION: Open repair of combined anterosuperior rotator cuff tears achieved good postoperative results despite a residual rotator cuff strength deficit. Combined supraspinatus-/full-thickness subscapularis tears achieved equal clinical and radiographic results compared with supraspinatus-/partial-thickness subscapularis tears.

Value of a Dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions.

PURPOSE: In this study, the potential contribution of Dixon-based MR imaging with a rapid low-resolution breath-hold sequence, which is a technique used for MR-based attenuation correction (AC) for MR/positron emission tomography (PET), was evaluated for anatomical correlation of PET-positive lesions on a 3T clinical scanner compared to low-dose CT. This technique is also used in a recently installed fully integrated whole-body MR/PET system. METHODS: Thirty-five patients routinely scheduled for oncological staging underwent (18)F-fluorodeoxyglucose (FDG) PET/CT and a 2-point Dixon 3-D volumetric interpolated breath-hold examination (VIBE) T1-weighted MR sequence on the same day. Two PET data sets reconstructed using attenuation maps from low-dose CT (PET(AC_CT)) or simulated MR-based segmentation (PET(AC_MR)) were evaluated for focal PET-positive lesions. The certainty for the correlation with anatomical structures was judged in the low-dose CT and Dixon-based MRI on a 4-point scale (0-3). In addition, the standardized uptake values (SUVs) for PET(AC_CT) and PET(AC_MR) were compared. RESULTS: Statistically, no significant difference could be found concerning anatomical localization for all 81 PET-positive lesions in low-dose CT compared to Dixon-based MR (mean 2.51 ± 0.85 and 2.37 ± 0.87, respectively; p = 0.1909). CT tended to be superior for small lymph nodes, bone metastases and pulmonary nodules, while Dixon-based MR proved advantageous for soft tissue pathologies like head/neck tumours and liver metastases. For the PET(AC_CT)- and PET(AC_MR)-based SUVs (mean 6.36 ± 4.47 and 6.31 ± 4.52, respectively) a nearly complete concordance with a highly significant correlation was found (r = 0.9975, p < 0.0001). CONCLUSION: Dixon-based MR imaging for MR AC allows for anatomical allocation of PET-positive lesions similar to low-dose CT in conventional PET/CT. Thus, this approach appears to be useful for future MR/PET for body regions not fully covered by diagnostic MRI due to potential time constraints.

Whole-body MRI including diffusion-weighted imaging (DWI) for patients with recurring prostate cancer: technical feasibility and assessment of lesion conspicuity in DWI.

PURPOSE: To evaluate the principal methodological aspects of whole-body magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) with background suppression using a time-optimized protocol for restaging of prostate cancer patients in a technical feasibility study. MATERIALS AND METHODS: Seventeen patients underwent MRI at 1.5T from the base of the skull to the proximal thigh using axial T1-weighted (T1w), T2w short-tau inversion recovery (STIR), and DWI (b-values: 50 and 500 s/mm(2)) and sagittal T1w and T2w STIR of the spine. Apparent diffusion coefficient (ADC) values of liver, spleen, kidney, muscle, and bone were measured. Image quality in DWI was assessed by using a scale from 0-9. Contrast-to-noise ratios (CNRs) of lymph node and bone metastases were determined in T1w, T2w STIR, and DWI. Bone metastases were further subclassified according to their Hounsfield units (HU) in computed tomography (CT). RESULTS: Mean acquisition and mean room times were 66:20 and 75:21 minutes, respectively. ADC values of normal organs showed good concordance with reported data. Good to excellent image quality was observed for DWI (mean scores 7.41-8.00) with the exception of the neck (mean score 4.76). CNR of DWI (b-value 50 s/mm(2) ) for lymph node metastases was clearly superior compared to all other sequences. For bone metastases T1w performed significantly better for sclerotic lesions (HU > 600), DWI (b-value 50 s/mm(2) ) for nonsclerotic lesion (HU < 300). CONCLUSION: In patients with recurrent prostate cancer a whole-body MR protocol including DWI is technically robust. Due to the high CNR of DWI compared to T1w and T2w STIR, detection of malignant lesions should be facilitated by DWI, except for sclerotic bone metastases.