Morphological chest CT changes in cystic fibrosis and massive hemoptysis.

BACKGROUND: Massive hemoptysis (MH) is a rare but potentially life-threatening condition of patients with mainly advanced cystic fibrosis (CF). Morphological lung changes are aggravated with disease progression. The aim of this study was to determine whether morphological lung changes differ between patients with CF (pwCF) who have MH and pwCF without MH. METHODS: Chest computed tomography (CT) scans of pwCF and MH acquired at a maximum of 4 months prior to MH (1/2008 to 2/2015) were evaluated for morphological changes and bronchial artery (BA) diameters. Lung lobes with MH were compared with lobes without MH and with matched control patients with end-stage CF and no hemoptysis using the Helbich scoring system. RESULTS: The study included 26 patients with MH (PMH; 15 female, median age 29 years, interquartile range [IQR]: 25-33.75) and 17 matched control patients (11 male, median age 24 years, IQR: 19.5-30). No difference in Helbich score was detected between lobes with MH and matched control patients (p = 0.051). Higher scores were detected in lobes with MH compared to lobes without MH in PMH (p = 0.021), but no difference was detected in the subscores. The BA diameters were larger in PMH (p = 0.02); 85% of PMH had unilateral MH, with 65% of MH involving only one or two lobes. CONCLUSION: Morphological changes are more severe in lobes with MH in the same patient, but there is no difference when compared with matched control patients. Besides abscess/sacculation, no specific changes for MH were identified. Other factors such as BA hypertrophy might play a pivotal role in the pathogenesis of MH in pwCF. Commonly used scores to evaluate chest CT in pwCF cannot be used to assess MH, and other factors, e.g., hypertrophied BA, not represented and not measured in these scores, might be more suitable for assessing the risk for MH.

Bronchial artery diameter in massive hemoptysis in cystic fibrosis.

BACKGROUND: Massive hemoptysis is a rare but potentially life-threatening condition of patients with cystic fibrosis (CF) and advanced pulmonary disease. Hypertrophied bronchial arteries are understood to cause massive hemoptysis when rupturing. Risk factors to predict massive hemoptysis are scarce and bronchial artery diameters are not part of any scoring system in follow-up of patients with CF. Aim of this study was to correlate bronchial artery diameter with massive hemoptysis in CF. METHODS: Bronchial artery and non-bronchial systemic artery diameters were measured in contrast enhanced computed tomography (CT) scans in patients with massive hemoptysis and compared to patients with end-stage CF and no history of hemoptysis. Demographic and clinical data and side of bronchial artery/non-bronchial systemic artery hypertrophy and coil embolization were documented. RESULTS: In this retrospective multicenter study 33 patients with massive hemoptysis were included for bronchial artery/non-bronchial systemic artery diameter measurements, (13 female, 20 male, median age 30 years (18-55)). Bronchial artery diameters were significantly larger in the case group than in the control group with median 4 mm (2.2-8.2 mm), and median 3 mm (1-7 mm), respectively (p = 0.002). Sensitivity of bronchial arteries ≥ 3.5 mm to be associated with hemoptysis was 0.76 and specificity 0.71 with ROC creating an area under the curve of 0.719. If non-bronchial systemic arteries were present, they were considered culprit and embolized in 92% of cases. CONCLUSION: Bronchial arteries ≥ 3.5 mm and presence of hypertrophied non-bronchial systemic arteries correlate with massive hemoptysis in patients with CF and might serve as risk predictor for massive hemoptysis. Therefore, in patients with advanced CF we propose CT scans to be carried out as CT angiography to search for bronchial arteries ≥ 3.5 mm and for hypertrophied non-bronchial systemic arteries as possible risk factors for massive hemoptysis.

Ovarian torsion: diagnosis, surgery, and fertility preservation in the pediatric population.

Ovarian torsion is rare in the pediatric population. Delayed diagnosis can significantly impact fertility. The aim of this review is to highlight current knowledge regarding clinical presentation, diagnosis, surgical management, and follow-up in the pediatric population. Whilst the presentation is often very unspecific, most children will present with sudden severe unilateral pelvic pain associated with vomiting. A key diagnostic test is pelvic ultrasonography, which may help demonstrate an asymmetric enlarged ovary with peripherally displaced follicles. In the pediatric population, ovarian torsion may occur in a normal ovary. However, underlying lesions can be found in half of cases. Benign neoplasms (teratomas or cystic lesions) represent the commonest etiology, with the risk of malignancy being less than 2%. Surgical management should be focused on fertility preservation. This is achievable through ovarian detorsion ± ovarian cystectomy ± oophoropexy to avoid recurrence. Follow-up studies demonstrate excellent recovery rates of detorsed ovaries including those with ischemic appearances. What is Known: • Ovarian torsion is a rare diagnosis in the pediatric population. • Aspecific symptoms and differential diagnoses lead to missed or delayed diagnosis increasing the risk of oophoprectomy and further infertility. What is New: • Reviewing the latest knowledge about clinical presentation, diagnostic, surgical management, and follow-up of ovarian torsion in the pediatric population. • Adiponectin was negatively associated with diastolic blood pressure and HOMA-IR, and chemerin was negatively associated with glucose.

Fully automated detection of primary sclerosing cholangitis (PSC)-compatible bile duct changes based on 3D magnetic resonance cholangiopancreatography using machine learning.

OBJECTIVES: To develop and evaluate a deep learning algorithm for fully automated detection of primary sclerosing cholangitis (PSC)-compatible cholangiographic changes on three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) images. METHODS: The datasets of 428 patients (n = 205 with confirmed diagnosis of PSC; n = 223 non-PSC patients) referred for MRI including MRCP were included in this retrospective IRB-approved study. Datasets were randomly assigned to a training (n = 386) and a validation group (n = 42). For each case, 20 uniformly distributed axial MRCP rotations and a subsequent maximum intensity projection (MIP) were calculated, resulting in a training database of 7720 images and a validation database of 840 images. Then, a pre-trained Inception ResNet was implemented which was conclusively fine-tuned (learning rate 10-3). RESULTS: Applying an ensemble strategy (by binning of the 20 axial projections), the mean absolute error (MAE) of the developed deep learning algorithm for detection of PSC-compatible cholangiographic changes was lowered from 21 to 7.1%. Sensitivity, specificity, positive predictive (PPV), and negative predictive value (NPV) for detection of these changes were 95.0%, 90.9%, 90.5%, and 95.2% respectively. CONCLUSIONS: The results of this study demonstrate the feasibility of transfer learning in combination with extensive image augmentation to detect PSC-compatible cholangiographic changes on 3D-MRCP images with a high sensitivity and a low MAE. Further validation with more and multicentric data is now desirable, as it is known that neural networks tend to overfit the characteristics of the dataset. KEY POINTS: • The described machine learning algorithm is able to detect PSC-compatible cholangiographic changes on 3D-MRCP images with high accuracy. • The generation of 2D projections from 3D datasets enabled the implementation of an ensemble strategy to boost inference performance.

Ablation zone geometry after CT-guided hepatic microwave ablation: evaluation of a semi-automatic software and comparison of two different ablation systems.

Purpose: The aims of this study were to evaluate a semi-automatic segmentation software for assessment of ablation zone geometry in computed tomography (CT)-guided microwave ablation (MWA) of liver tumors and to compare two different MWA systems.Material and Methods: 27 patients with 40 hepatic tumors (primary liver tumor n = 20, metastases n = 20) referred for CT-guided MWA were included in this retrospective IRB-approved study. MWA was performed using two systems (system 1: 915 MHz; n = 20; system 2: 2.45 GHz; n = 20). Ablation zone segmentation and ellipticity index calculations were performed using SAFIR (Software Assistant for Interventional Radiology). To validate semi-automatic software calculations, results (2 perpendicular diameters, ellipticity index, volume) were compared with those of manual analysis (intraclass correlation, Pearson's correlation, Mann-Whitney U test; p < 0.05 deemed significant.Results: Manual measurements of mean maximum ablation zone diameters were 43 mm (system 1) and 34 mm (system 2), respectively. Correlations between manual and semi-automatic measurements were r = 0.72 and r = 0.66 (both p < 0.0001) for perpendicular diameters, and r = 0.98 (p < 0.001) for volume. Manual analysis demonstrated that ablation zones created with system 2 had a significantly lower ellipticity index compared to system 1 (mean 1.17 vs. 1.86, p < 0.0001). Results correlated significantly with semi-automatic software measurements (r = 0.71, p < 0.0001).Conclusion: Semi-automatic assessment of ablation zone geometry using SAFIR is feasible. Software-assisted evaluation of ablation zones may prove beneficial with complex ablation procedures, especially for less experienced operators. The 2.45 GHz MWA system generated a significantly more spherical ablation zone compared to the 915 MHz system. The choice of a specific MWA system significantly influences ablation zone geometry.

Wireless video transmission into the MRI magnet room: implementation and evaluation at 1.5T, 3T and 7T.

Purpose To analyze the interference between a wireless high definition multimedia interface (WHDMI) and magnetic resonance imaging (MRI) image quality at 1.5T, 3T and 7T. Materials and methods A wireless video transmission system (WVTS) consisting of a WHDMI and a projector was used to transmit and display a video stream into the magnet room. MR image quality was analyzed at 1.5T, 3T and 7T. Signal-to-noise-ratio (SNR¯) $(\overline {{\rm{SNR}}} )$ and radio frequency (RF)-noise spectrum were measured at three transmitter positions (A: inside the cabin, B: in front of the waveguide and C: in the control room). WVTS system functionality tests included measurements of reliability, delay and image quality. Results With the WVTS mean SNR¯ $\overline {{\rm{SNR}}} $ values significantly decreased in comparison to the reference for all positions and fieldstrenghts, while the spectra's baseline is elevated at 1.5T and 3T. Peaks related to continuous wave interferences are apparent at all field strenghts. For WHDMI alone mean SNR¯ $\overline {{\rm{SNR}}} $ values were stable without significant differences to the reference. No elevation of the spectra's baseline could be observed. Functionality measurements confirmed high connection reliability with stable image quality and no delays for all field strengths. Conclusion We conclude that wireless transmission of video streams into the MRI magnet room is feasible at all field strengths without hampering image quality.

CT-Guided Microwave Ablation of Liver Tumors in Anatomically Challenging Locations.

PURPOSE: To assess the feasibility and outcome of microwave ablation (MWA) of hepatic tumors in anatomically challenging locations. MATERIALS AND METHODS: A total of 94 patients with 174 hepatic tumors referred for CT-guided MWA were included in this retrospective institutional review board-approved study. One hundred and twenty-five tumors (median size 17 mm, range 12-24 mm) with subcapsular location (n = 91) and/or in which a transpleural approach was applied (n = 53) were identified (group 1) and compared to tumors with a central intrahepatic location (group 2; n = 49, median size 19 mm, range 12-23 mm). Technical success, complications and local tumor progression (LTP) were evaluated. Risk factors were analyzed using univariate analysis, logistic regression and Kaplan-Meier curves (p < 0.05 deemed significant). RESULTS: Technical success was 100% in both groups. In group 1, complications occurred in n = 31 tumors (24.8%; pneumothorax n = 20; hematoma n = 11). Complications occurred significantly less often in group 2 (8.2%; n = 4 (hematoma); p = 0.011). There were no major complications. Transpleural approach and number of capsule punctures were identified as risk factors for complications (all p < 0.05). Median follow-up was 265 days. LTP was comparable between both groups (13.6 vs. 10.2%; p = 0.41). Use of hydrodissection was the only independent factor associated with LTP (p = 0.03, HR 3.29). CONCLUSION: CT-guided hepatic MWA of subcapsular tumors and subdiaphragmatic tumors requiring a direct or transpleural approach is feasible with increased minor but not major complications. LTP did not differ significantly between both groups.

Assessment of acute kidney injury with T1 mapping MRI following solid organ transplantation.

OBJECTIVES: To evaluate T1 mapping as a non-invasive, functional MRI biomarker in patients shortly after solid organ transplantation to detect acute postsurgical kidney damage and to correlate T1 times with renal function. METHODS: 101 patients within 2 weeks after solid organ transplantation (49 kidney transplantation, 52 lung transplantation) and 14 healthy volunteers were examined by MRI between July 2012 and April 2015 using the modified Look-Locker inversion recovery (MOLLI) sequence. T1 times in renal cortex and medulla and the corticomedullary difference were compared between groups using one-way ANOVA adjusted for multiple comparison with the Tukey test, and T1 times were correlated with renal function using Pearson's correlation. RESULTS: Compared to healthy volunteers T1 times were significantly increased after solid organ transplantation in the renal cortex (healthy volunteers 987 ± 102 ms; kidney transplantation 1299 ± 101 ms, p < 0.001; lung transplantation 1058 ± 96 ms, p < 0.05) and to a lesser extent in the renal medulla. Accordingly, the corticomedullary difference was diminished shortly after solid organ transplantation. T1 changes were more pronounced following kidney compared to lung transplantation, were associated with the stage of renal impairment and significantly correlated with renal function. CONCLUSIONS: T1 mapping may be helpful for early non-invasive assessment of acute kidney injury and renal pathology following major surgery such as solid organ transplantation. KEY POINTS: • Renal cortical T1 relaxation times are prolonged after solid organ transplantation. • Cortical T1 values increase with higher stages of renal function impairment. • Corticomedullary difference decreases with higher stages of renal function impairment. • Renal cortical T1 relaxation time and corticomedullary difference correlate with renal function. • T1 mapping may be helpful for non-invasive assessment of post-operative renal pathology.

Diffusion-Weighted imaging and diffusion tensor imaging detect delayed graft function and correlate with allograft fibrosis in patients early after kidney transplantation.

PURPOSE: To combine diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) for detection of allograft dysfunction in patients early after kidney transplantation and to correlate diffusion parameters with renal function and renal histology of allograft biopsies. MATERIALS AND METHODS: Between day 4 and 11 after kidney transplantation 33 patients with initial graft function and 31 patients with delayed graft function (DGF) were examined with a 1.5T magnetic resonance imaging (MRI) scanner. DTI and DWI sequences were acquired and fractional anisotropy (FA), apparent diffusion coefficient (ADCmono), pure diffusion (ADCdiff ), and the perfusion fraction (Fp) were calculated. Kidney biopsies in 26 patients were analyzed for allograft pathology, ie, acute tubular injury, inflammation, edema, renal fibrosis, and rejection. Histological results were correlated with MRI parameters. RESULTS: In the renal medulla FA (0.25 ± 0.06 vs. 0.29 ± 0.06, P < 0.01) and ADCmono (1.73 ± 0.13*10(-3) vs. 1.93 ± 0.16*10(-3) mm(2) /s, P < 0.001) were significantly reduced in DGF patients compared with patients with initial function. For ADCdiff and Fp similar reductions were observed. FA and ADCmono significantly correlated with renal function (r = 0.53 and r = 0.57, P < 0.001) and were inversely correlated with the amount of renal fibrosis (r = -0.63 and r = -0.65, P < 0.05). CONCLUSION: Combined DTI and DWI detected allograft dysfunction early after kidney transplantation and correlated with allograft fibrosis. J. Magn. Reson. Imaging 2016;44:112-121.

Functional MRI detects perfusion impairment in renal allografts with delayed graft function.

Delayed graft function (DGF) after kidney transplantation is not uncommon, and it is associated with long-term allograft impairment. Our aim was to compare renal perfusion changes measured with noninvasive functional MRI in patients early after kidney transplantation to renal function and allograft histology in biopsy samples. Forty-six patients underwent MRI 4-11 days after transplantation. Contrast-free MRI renal perfusion images were acquired using an arterial spin labeling technique. Renal function was assessed by estimated glomerular filtration rate (eGFR), and renal biopsies were performed when indicated within 5 days of MRI. Twenty-six of 46 patients had DGF. Of these, nine patients had acute rejection (including borderline), and eight had other changes (e.g., tubular injury or glomerulosclerosis). Renal perfusion was significantly lower in the DGF group compared with the group with good allograft function (231 ± 15 vs. 331 ± 15 ml·min(-1)·100 g(-1), P < 0.001). Living donor allografts exhibited significantly higher perfusion values compared with deceased donor allografts (P < 0.001). Renal perfusion significantly correlated with eGFR (r = 0.64, P < 0.001), resistance index (r = -0.57, P < 0.001), and cold ischemia time (r = -0.48, P < 0.01). Furthermore, renal perfusion impairment early after transplantation predicted inferior renal outcome and graft loss. In conclusion, noninvasive functional MRI detects renal perfusion impairment early after kidney transplantation in patients with DGF.