Real-time jellyfish classification and detection algorithm based on improved YOLOv4-tiny and improved underwater image enhancement algorithm.

The outbreak of jellyfish blooms poses a serious threat to human life and marine ecology. Therefore, jellyfish detection techniques have earned great interest. This paper investigates the jellyfish detection and classification algorithm based on optical images and deep learning theory. Firstly, we create a dataset comprising 11,926 images. A MSRCR underwater image enhancement algorithm with fusion is proposed. Finally, an improved YOLOv4-tiny algorithm is proposed by incorporating a CBMA module and optimizing the training method. The results demonstrate that the detection accuracy of the improved algorithm can reach 95.01%, the detection speed is 223FPS, both of which are better than the compared algorithms such as YOLOV4. In summary, our method can accurately and quickly detect jellyfish. The research in this paper lays the foundation for the development of an underwater jellyfish real-time monitoring system.

Flow imaging using differential Golay encoded ultrasound.

In our research we present a new method of differential compression of the Golay encoded ultrasound (DCGEU) in the standard beamforming mode to visualize the slow (<1cm/s) blood mimicking fluid flow in small diameter tubes. The proposed DCGEU method is based on synthesis of several subsequent B-mode frames acquired with certain time intervals (30 ms in this study) followed by the visualization of differential beamformed radio frequency (RF) echoes, which yielded the images of the scatterers moving slowly in the vessel and suppressing the static echoes outside the vessel. In order to extract small backscattered echoes from the vessel area we took an advantage of improved sensitivity of the complementary Golay coded sequences (CGCS). The validation of the proposed DCGEU method was carried out in two stages. In the first one, we compared the flow images in small tubes with a diameter of 1 mm and 2.5 mm, reconstructed from numerically simulated acoustic data for the standard transmission of short pulses and 16-bits long CGCS signals. In the second stage of the research, the experimental data were acquired in a flow phantom with silicone tubes with an internal diameter of 1.5 mm and 4.5 mm and a fluid flow velocity of 0.9 cm/s. The experiments were carried out using preprogrammed Verasonics Vantage™ research ultrasound system equipped with ALT L12-5/50 mm MHz linear array transducer with 7.8 MHz center frequency. It was evidenced both in simulations and experiments that the DCGEU provided a good flow image along the entire length of tubing with virtually angle independent detection in comparison with the conventional short pulse interrogation.

[Clinical application of LASEREO endoscopic system in early gastric cancer].

Objective: To evaluate the clinical application of LASEREO endoscopic system in early gastric cancer (EGC). Methods: A total of 68 patients diagnosed with EGC were retrospectively analyzed between August 2017 to December 2020 in Fuding Hospital Affiliated to Fujian University of Traditional Chinese Medicine. There were 50 males and 18 females finally enrolled with a median age of 64 years. EGCs were analyzed from subjective and objective aspect, as well as from magnification and non-magnification status. Six endoscopists evaluated the visibility of the EGC (RSC) and calculated the color difference (ΔEC) between EGC and the surrounding mucosa in white light imaging (WLI), blue light imaging-bright (BLI-Bri) and linked color imaging (LCI) modes. In the case of magnification (×80), the visibility of the microstructures and microvessels (RSV) was analyzed and the color difference (ΔEV) between microvessels and non-vessels areas were calculated in WLI, BLI and LCI modes. The visibility was evaluated using visibility ranking scale(RS) and the color difference (ΔE) was calculated using L*a*b* color space. Results: In WLI, BLI-Bri, and LCI modes, the mean (±SD) RSC were 2.56±0.68, 2.63±0.59 and 3.17±0.50, and the mean(±SD) ΔEC were 15.71±5.58, 12.04±3.73, and 22.84±8.46, respectively, which in LCI were higher than those in WLI and BLI-Bri modes (P<0.001).Regarding the data evaluated by senior endoscopists, the RSC was higher in BLI-Bri than that in WLI mode (2.98±0.58 vs. 2.79±0.73, P<0.001), but as to those evaluated by junior endoscopists, there were no significant differences between the WLI and BLI-Bri modes(2.29±0.72 vs. 2.23±0.72,P =0.218).In magnifying endoscopy with WLI, BLI, and LCI modes, the mean(±SD) RSV were 2.95±0.28, 3.46±0.40, and 3.38±0.33, and the mean (±SD) ΔEV were 21.68±7.52, 44.29±10.94, and 45.38±14.29, respectively.The RSV and ΔEV in LCI and BLI were higher than that in WLI mode (P<0.001). Conclusions: LCI improves the visibility of EGC by increasing ΔEC, especially in junior endoscopists. Both BLI and LCI improve the visibility of microstructures and microvessels under magnification.

Detection and identification of tea leaf diseases based on AX-RetinaNet.

The accurate detection and identification of tea leaf diseases are conducive to its precise prevention and control. Convolutional neural network (CNN) can automatically extract the features of diseased tea leaves in the images. However, tea leaf images taken in natural environments have problems, such as complex backgrounds, dense leaves, and large-scale changes. The existing CNNs have low accuracy in detecting and identifying tea leaf diseases. This study proposes an improved RetinaNet target detection and identification network, AX-RetinaNet, which is used for the automatic detection and identification of tea leaf diseases in natural scene images. AX-RetinaNet uses an improved multiscale feature fusion module of the X-module and adds a channel attention module, Attention. The feature fusion module of the X-module obtains feature maps with rich information through multiple fusions of multi-scale features. The attention module assigns a network adaptively optimized weight to each feature map channel so that the network can select more effective features and reduce the interference of redundant features. This study also uses data augmentation methods to solve the problem of insufficient samples. Experimental results show the detection and identification accuracy of AX-RetinaNet for tea leaf diseases in natural scene images is better than the existing target detection and identification networks, such as SSD, RetinaNet, YOLO-v3, YOLO-v4, Centernet, M2det, and EfficientNet. The AX-RetinaNet detection and identification results indicated the mAP value of 93.83% and the F1-score value of 0.954. Compared with the original network, the mAP value, recall value, and identification accuracy increased by nearly 4%, by 4%, and by nearly 1.5%, respectively.

Right ventricular endomyocardial biopsy in patients with cardiac magnetic resonance showing left ventricular myocarditis.

AIMS: The aim of this study was to evaluate the sensitivity of right ventricular endomyocardial biopsy (EMB) in myocarditis patients with cardiac magnetic resonance (CMR) and electroanatomical mapping (EAM) showing left ventricular abnormalities. METHODS: We performed right ventricular EMB in 144 consecutive patients (66% men, age 43 ±â€Š15 years) with acute symptoms and CMR-proved diagnosis of left ventricular myocarditis. Right ventricular EMB sensitivity has been evaluated in patients with different localization and extension of abnormal substrate at both CMR and -- when performed -- EAM. Abnormal substrate was defined, respectively, by late gadolinium enhancement (LGE) and low-voltage areas (LVAs). RESULTS: Globally, right ventricular EMB sensitivity was 87.5%. EMB-negative cases had significantly smaller fragment sizes (cumulative area 2.8 ±â€Š1.7 vs. 3.8 ±â€Š1.8 mm2, P = 0.023), and lower LGE surface extension (24.7 ±â€Š14.2 vs. 38.5 ±â€Š20.2%, P = 0.006) and transmurality (32.0 ±â€Š26.1 vs. 49.3 ±â€Š22.6, P = 0.003). Right ventricular EMB sensitivity in patients with LGE involving both right ventricular and interventricular septum (IVS), isolated right ventricular or IVS, and remote left ventricular areas (n = 10, 49 and 67 cases) was 83.3, 84.4 and 90.5%, respectively (P = 0.522). Overall, 34 patients (23.6%) underwent EAM. On the basis of EAM, right ventricular EMB sensitivity was 85.3%: in detail, it was 50.0, 88.2 and 86.7% in patients with both right ventricular and IVS, isolated right ventricular/IVS and distant left ventricular involvement (n = 2, 17 and 15, respectively, P > 0.05). Sample size area was the only factor associated with right ventricular EMB sensitivity (hazard ratio = 1.6/mm2, 95% confidence interval 1.1-2.4, P = 0.013). CONCLUSION: Right ventricular EMB is still an accurate technique to confirm diagnosis in patients with CMR-proved left ventricular myocarditis. In particular, provided there is an adequate sample size, its sensitivity is comparable among patients with heterogeneous LGE or LVA localization.

Reporting Templates for MRI and Water-Soluble Contrast Enema in Patients With Ileal Pouch-Anal Anastomosis: Experience From a Large Referral Center.

Ileal pouch-anal anastomosis (IPAA) surgery is the reference standard surgical procedure for treatment of ulcerative colitis and most patients with familial adenomatous polyposis. This procedure allows preservation of fecal continence and gastrointestinal continuity. However, it is associated with a wide variety of complications, which often have nonspecific and overlapping clinical presentations, making imaging an important part of workup for pouch dysfunction. The purpose of this article is to propose structured reporting templates for MRI and water-soluble contrast enema (WSCE), based on our referral pouch center's experience, in patients who have undergone IPAA surgery. We review salient surgical technique, pouch anatomy, and imaging protocols, with an emphasis on a systematic search pattern for evaluation of ileal pouch complications using proposed structured reporting templates for MRI and WSCE.

Lipiodol hysterosalpingogram: A modified HSG technique to minimize risks associated with lipiodol use.

Assessment of tubal patency and therapeutic tubal flushing using Lipiodol, an oil-soluble contrast media (OSCM), has been shown to enhance fertility, resulting in increased interest in the use of Lipiodol. A modified hysterosalpingogram (HSG) technique, including a supplementary ultrasound with the contrast in situ, is recommended when using Lipiodol, taking into account both safety issues and technical challenges specific to Lipiodol.

Faster, sharper, more precise: Automated Cluster-FLIM in preclinical testing directly identifies the intracellular fate of theranostics in live cells and tissue.

Fluorescence microscopy is widely used for high content screening in 2D cell cultures and 3D models. In particular, 3D tissue models are gaining major relevance in modern drug development. Enabling direct multiparametric evaluation of complex samples, fluorescence lifetime imaging (FLIM) adds a further level to intensity imaging by the sensitivity of the fluorescence lifetime to the microenvironment. However, the use of FLIM is limited amongst others by the acquisition of sufficient photon numbers without phototoxic effects in live cells. Herein, we developed a new cluster-based analysis method to enhance insight, and significantly speed up analysis and measurement time for the accurate translation of fluorescence lifetime information into pharmacological pathways. Methods: We applied a fluorescently-labeled dendritic core-multishell nanocarrier and its cargo Bodipy as molecules of interest (MOI) to human cells and reconstructed human tissue. Following the sensitivity and specificity assessment of the fitting-free Cluster-FLIM analysis of data in silico and in vitro, we evaluated the dynamics of cellular molecule uptake and intracellular interactions. For 3D live tissue investigations, we applied multiphoton (mp) FLIM. Owing to Cluster-FLIM's statistics-based fitting-free analysis, we utilized this approach for automatization. Results: To discriminate the fluorescence lifetime signatures of 5 different fluorescence species in a single color channel, the Cluster-FLIM method requires only 170, respectively, 90 counts per pixel to obtain 95% sensitivity (hit rate) and 95% specificity (correct rejection rate). Cluster-FLIM revealed cellular interactions of MOIs, representing their spatiotemporal intracellular fate. In a setting of an automated workflow, the assessment of lysosomal trapping of the MOI revealed relevant differences between normal and tumor cells, as well as between 2D and 3D models. Conclusion: The automated Cluster-FLIM tool is fitting-free, providing images with enhanced information, contrast, and spatial resolution at short exposure times and low fluorophore concentrations. Thereby, Cluster-FLIM increases the applicability of FLIM in high content analysis of target molecules in drug development and beyond.

Intracavitary contrast-enhanced ultrasonography in children: review with procedural recommendations and clinical applications from the European Society of Paediatric Radiology abdominal imaging task force.

Contrast-enhanced ultrasonography (US) has become an important supplementary tool in many clinical applications in children. Contrast-enhanced voiding urosonography and intravenous US contrast agents have proved useful in routine clinical practice. Other applications of intracavitary contrast-enhanced US, particularly in children, have not been widely investigated but could serve as a practical and radiation-free problem-solver in several clinical settings. Intracavitary contrast-enhanced US is a real-time imaging modality similar to fluoroscopy with iodinated contrast agent. The US contrast agent solution is administered into physiological or non-physiological body cavities. There is no definitive list of established indications for intracavitary US contrast agent application. However, intracavitary contrast-enhanced US can be used for many clinical applications. It offers excellent real-time spatial resolution and allows for a more accurate delineation of the cavity anatomy, including the internal architecture of complex collections and possible communications within the cavity or with the surrounding structures through fistulous tracts. It can provide valuable information related to the insertion of catheters and tubes, and identify related complications such as confirming the position and patency of a catheter and identifying causes for drainage dysfunction or leakage. Patency of the ureter and biliary ducts can be evaluated, too. US contrast agent solution can be administered orally or a via nasogastric tube, or as an enema to evaluate the gastrointestinal tract. In this review we present potential clinical applications and procedural and dose recommendations regarding intracavitary contrast-enhanced ultrasonography.

Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance.

Superparamagnetic iron oxide nanoparticles (SPION) are extensively used for magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), as well as for magnetic fluid hyperthermia (MFH). We here describe a sequential centrifugation protocol to obtain SPION with well-defined sizes from a polydisperse SPION starting formulation, synthesized using the routinely employed co-precipitation technique. Transmission electron microscopy, dynamic light scattering and nanoparticle tracking analyses show that the SPION fractions obtained upon size-isolation are well-defined and almost monodisperse. MRI, MPI and MFH analyses demonstrate improved imaging and hyperthermia performance for size-isolated SPION as compared to the polydisperse starting mixture, as well as to commercial and clinically used iron oxide nanoparticle formulations, such as Resovist® and Sinerem®. The size-isolation protocol presented here may help to identify SPION with optimal properties for diagnostic, therapeutic and theranostic applications.

Prognosticating brain tumor patient survival after laser thermotherapy: Comparison between neuroradiological reading and semi-quantitative analysis of MRI data.

BACKGROUND AND PURPOSE: Given increasing interest in laser interstitial thermotherapy (LITT) to treat brain tumor patients, we explored if examining multiple MRI contrasts per brain tumor patient undergoing surgery can impact predictive accuracy of survival post-LITT. MATERIALS AND METHODS: MRI contrasts included fluid-attenuated inversion recovery (FLAIR), T1 pre-gadolinium (T1pre), T1 post-gadolinium (T1Gd), T2, diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), susceptibility weighted images (SWI), and magnetization-prepared rapid gradient-echo (MPRAGE). The latter was used for MRI data registration across preoperative to postoperative scans. Two ROIs were identified by thresholding preoperative FLAIR (large ROI) and T1Gd (small ROI) images. For each MRI contrast, a numerical score was assigned based on changing image intensity of both ROIs (vs. a normal ROI) from preoperative to postoperative stages. The fully-quantitative method was based on changing image intensity across scans at different stages without any human intervention, whereas the semi-quantitative method was based on subjective criteria of cumulative trends across scans at different stages. A fully-quantitative/semi-quantitative score per patient was obtained by averaging scores for each MRI contrast. A standard neuroradiological reading score per patient was obtained from radiological interpretation of MRI data. Scores from all 3 methods per patient were compared against patient survival, and re-examined for comorbidity and pathology effects. RESULTS: Patient survival correlated best with semi-quantitative scores obtained from T1Gd, ADC, and T2 data, and these correlations improved when biopsy and comorbidity were included. CONCLUSION: These results suggest interfacing neuroradiological readings with semi-quantitative image analysis can improve predictive accuracy of patient survival.

Magnetic Resonance Enema in Rectosigmoid Endometriosis.

Intestinal endometriosis occurs in 4% to 37% of women with deep endometriosis (DE). Noninvasive diagnosis of presence and characteristics of rectosigmoid endometriosis permits the best counseling of patients and ensures best therapeutic planning. Magnetic resonance enema (MR-e) is accurate in diagnosing DE. After colon cleansing, rectal distention and opacification improves the performance of MR-e in diagnosing rectosigmoid endometriosis. MR imaging cannot optimally assess the depth of penetration of endometriosis in the intestinal wall. There is a need for multicentric studies with a larger sample size to evaluate reproducibility of MR-e in diagnosis of rectosigmoid endometriosis for less experienced radiologists.

Optimizing Image Quality When Evaluating Blood Flow at Doppler US: A Tutorial.

Doppler US is an essential component of nearly all diagnostic US procedures. In this era of increased awareness of the effects of ionizing radiation and the side effects of iodine- and gadolinium-based contrast agents, Doppler US is poised to play an even bigger role in medical imaging. It is safe, cost-effective, portable, and highly accurate when performed by an experienced operator. The sensitivities and specificities of Doppler US for detecting blood flow and determining the direction and velocity of blood flow in various organs and vascular systems have increased dramatically in the past decade. With use of advanced flow techniques that are available for use with most modern equipment, US can provide vascular information that is comparable to or even more accurate than that obtained with other cross-sectional and interventional modalities. However, there remains concern that US (including newer more advanced flow-evaluating techniques) will not be used to its full potential owing to dependence on operator skill and expertise. Thorough understanding of image optimization techniques and expanded knowledge of the physical principles, instrumentation, application, advantages, and limitations of this modality are of utmost importance. The authors provide a simple practical guide for optimizing images for vascular flow detection by reviewing various cases and focusing on the parameters that should be optimized. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by Pellerito.

Clinical experience with two-point mDixon turbo spin echo as an alternative to conventional turbo spin echo for magnetic resonance imaging of the pediatric knee.

BACKGROUND: Two-point modified Dixon (mDixon) turbo spin-echo (TSE) sequence provides an efficient, robust method of fat suppression. In one mDixon acquisition, four image types can be generated: water-only, fat-only, in-phase and opposed-phase images. OBJECTIVE: To determine whether PD mDixon TSE water-only and, by proxy, PD in-phase images generated by one acquisition can replace two conventional PD TSE sequences with and without fat suppression in routine clinical MR examination of the knee. MATERIALS AND METHODS: This is a retrospective study of 50 consecutive pediatric knee MR examinations. PD mDixon TSE water-only and PD fat-saturated TSE sequences (acquired in the sagittal plane with identical spatial resolution) were reviewed independently by two pediatric radiologists for homogeneity of fat suppression and detection of intra-articular pathology. Thirteen of the 50 patients underwent arthroscopy, and we used the arthroscopic results as a reference standard for the proton-density fat-saturated and proton-density mDixon results. We used the Kruskal-Wallis rank test to assess difference in fat suppression between the proton-density mDixon and proton-density fat-saturated techniques. We used kappa statistics to compare the agreement of detection of intra-articular pathology between readers and techniques. We also calculated sensitivity, specificity and accuracy between arthroscopy and MR interpretations. RESULTS: Proton-density mDixon water-only imaging showed significant improvement with the fat suppression compared with proton-density fat-saturated sequence (P=0.02). Each observer demonstrated near-perfect agreement between both techniques for detecting meniscal and ligamentous pathology and fair to substantial agreement for bone contusions, and chondral and osteochondral lesions. CONCLUSION: Two-point mDixon water-only imaging can replace conventional proton-density fat-saturated sequence. When same-plane proton-density fat-saturated and non-fat-saturated sequences are required, proton-density water-only and proton-density in-phase image types acquired in the same acquisition shorten the overall examination time while maintaining excellent intra-articular lesion conspicuity.

Prediction of sorafenib treatment-related gene expression for hepatocellular carcinoma: preoperative MRI and histopathological correlation.

PURPOSE: To investigate the feasibility of prediction for targeted therapy-related gene expression in hepatocellular carcinoma (HCC) using preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ninety-one patients (81 men, mean age 53.9 ± 12 years) with solitary HCC who underwent preoperative enhanced MRI were retrospectively analyzed. Features including tumor size, signal homogeneity, tumor capsule, tumor margin, intratumoral vessels, peritumor enhancement, peritumor hypointensity, signal intensity ratio on DWI, T1 relaxation times, and the reduction rate between pre- and post-contrast enhancement images were assessed. The operation and histopathological evaluation were performed within 2 weeks after MRI examination (mean time 7 days). The expression levels of BRAF, RAF1, VEGFR2, and VEGFR3 were evaluated. The associations between these imaging features and gene expression levels were investigated. RESULTS: Tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.002) were significantly associated with BRAF expression, and tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.013) with RAF1 expression. There was no significant association between the expression of VEGFR2, VEGFR3, and all examined MRI features. Multivariate logistic regression showed that incomplete tumor capsule (p = 0.002) and non-capsule (p = 0.004) were independent risk factors of HCC with high BRAF expression; incomplete tumor capsule (p < 0.001) and non-capsule (p = 0.040) were independent risk factors of HCC with high RAF1 expression. CONCLUSION: The presence of incomplete capsule or intratumoral vessels and the absence of capsule are potential indicators of high BRAF and RAF1 expression. Gadoxetic acid-enhanced MRI may facilitate the choice of gene therapy for patients with HCC. KEY POINTS: • Incomplete tumor capsule and non-capsule were independent risk factors of HCC with high BRAF and RAF1 expression. • The presence of intratumoral vessels was a potential indicator of high BRAF and RAF1 expression. • Gadoxetic acid-enhanced MRI may be a predictor of efficacy of treatment with sorafenib.

Benefits and pitfalls of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging in clinical application of the cervical spine MR.

AIM: To evaluate efficacy of T2-weighted (T2W) iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)-fast spin echo (FSE) imaging of the cervical spine. MATERIALS AND METHODS: The cervical spine of 100 symptomatic patients was imaged using routine magnetic resonance imaging (MRI) versus IDEAL-FSE imaging. The signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), and image quality were analysed. To compare the diagnostic efficiency of degenerative spondylopathy, evaluations of spondylolisthesis, retrolisthesis, disc herniation, myelopathy, disc degeneration, and bone marrow oedema were also performed. RESULTS: IDEAL-FSE showed significantly higher SNRs and CNRs (all p<0.001) than fat-suppressed (FS) T2W-FSE. Sixteen of 100 patients had cervical spine instrumentation; in those patients, IDEAL-FSE provided significantly better uniformity of fat suppression (p<0.001) and fewer metallic artefacts (p<0.001). For patients without instrumentation, FS T2W-FSE showed significantly better overall image quality (p<0.001) and homogeneity of the cerebrospinal fluid (CSF; p<0.001) with fewer motion artefacts (p<0.001). IDEAL-FSE, however, provided significantly better uniformity of fat suppression (p<0.001). There were no significant differences in the diagnoses of spondylolisthesis, retrolisthesis, disc herniation, or myelopathy between IDEAL and FS T2W images. The only significant differences between the IDEAL and FS T2W images were noted when diagnosing degenerative disc disease at the C2-3 and C5-6 disc levels (p=0.019, p=0.002, respectively) and bone marrow oedema at C3 vertebral body (p=0.029). CONCLUSION: T2W IDEAL-FSE imaging should only be considered as an additional sequence to conventional FS T2W images in patients with poor fat suppression or severe metallic artefacts.

Value of assessment of multivoxel proton chemical shift imaging to predict long term outcome in patients after out-of-hospital cardiac arrest: A preliminary prospective observational study.

BACKGROUND: Existing methods to predict recovery after out-of-hospital cardiac arrest (OHCA) lack of accuracy. The aim of this study was to determine whether quantitative proton chemical shift imaging (1H-CSI) during the subacute stage of OHCA can predict neurological outcome of such patients. METHODS: This monocentric prospective observational study was conducted in a Intensive Care Unit of a teaching hospital. Forty consecutive patients with OHCA were enrolled between January 1st 2011-December 31st 2013. Multivoxel 1H-CSI values were compared to structural magnetic resonance imaging (MRI) sequences (fluid-attenuated inversion recovery and diffusion-weighted imaging). Ratios of N-acetyl-aspartate (NAA) to creatine (Cr) and choline compounds were analyzed using region of interest in bilateral lenticular cores and thalami. The outcome evaluated was the Cerebral Performance Category (CPC) at 6 months, dichotomized as favorable (CPC 1-2) and unfavorable outcome (CPC 3-5). The performance was compared by area under the receiver operating characteristic (ROCAUC) curves analysis. RESULTS: Twenty nine OHCA had an interpretable MRI. Eight patients (28%) had favorable outcome at 6 months. The worst NAA/Cr in lenticular cores was the best 1H-CSI marker, with 80% sensitivity (95% confidence interval (CI), 57-94) and a 100% specificity (95% CI, 63-100) with a positive predictive value of 100%. Prognostic accuracy, as quantified by the ROCAUC, was higher with the worst NAA/Cr in lenticular cores (ROCAUC 0.88; 95% CI, 0.70-0.97) than with the structural MRI sequences. CONCLUSION: In this preliminary study we found that multivoxel 1H-CSI in lenticular cores was highly predictive of unfavorable outcome at 6 months.

Prediction of post-TACE necrosis of hepatocellular carcinoma usingvolumetric enhancement on MRI and volumetric oil deposition on CT, with pathological correlation.

OBJECTIVE: To investigate whether volumetric enhancement on baseline MRI and volumetric oil deposition on unenhanced CT would predict HCC necrosis and response post-TACE. METHOD: Of 115 retrospective HCC patients (173 lesions) who underwent cTACE, a subset of 53 HCC patients underwent liver transplant (LT). Semiautomatic volumetric segmentation of target lesions was performed on dual imaging to assess the accuracy of predicting tumour necrosis after TACE in the whole cohort and at pathology in the LT group. Predicted percentage tumour necrosis is defined as 100 % - (%baseline MRI enhancement - %CT oil deposition). RESULTS: Mean predicted tumour necrosis by dual imaging modalities was 61.5 % ± 31.6%; mean percentage tumour necrosis on follow-up MRI was 63.8 % ± 31.5 %. In the LT group, mean predicted tumour necrosis by dual imaging modalities was 77.6 % ± 27.2 %; mean percentage necrosis at pathology was 78.7 % ± 31.5 %. There was a strong significant correlation between predicted tumour necrosis and volumetric necrosis on MRI follow-up (r = 0.889, p<0.001) and between predicted tumour necrosis and pathological necrosis (r = 0.871, p<0.001). CONCLUSION: Volumetric pre-TACE enhancement on MRI and post-TACE oil deposition in CT may accurately predict necrosis in treated HCC lesions. KEY POINTS: • Imaging-based tumour response can assist in therapeutic decisions. • Lipiodol retention as carrier agent in cTACE is a tumour necrosis biomarker. • Predicting tumour necrosis with dual imaging potentially obviates immediate post-treatment MRI. • Predicting tumour necrosis would facilitate further therapeutic decisions in HCC post-cTACE. • Pre-TACE MRI and post-TACE CT predict necrosis in treated HCC.