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Abstract Background Rectal cancer is the most prevalent gastrointestinal tumor. Early diagnosis, accurate staging as well as early treatment are the keys for improving the five-year survival rate. The objective of this research is to assess the effectiveness of diffusion-weighted MRI (DWI) in identifying lymph nodes and distinguishing between benign and metastatic nodes throughout the first stage of primary rectal cancer. Results The study showed that mean ADC value was significantly higher in mucinous carcinoma (1.72 ± 0.36 × 10–3 mm2/sec) than that in non-mucinous carcinoma (0.981 ± 0.276 × 10–3 mm2/sec) with a cutoff value of (1.3 × 10–3) mm2/s which was the precise value to produce high sensitivity, specificity and accuracy of 93%, 94%, and 94%, respectively. ADC analysis showed either intermediate or low signal in 49 (70%) and high signal in 21 (30%) L.Ns. Mean ADC value showed a significant reduction in malignant L.Ns (1.01 ± 0.54 × 10–3 mm2/sec) compared to benign L.Ns (1.51 ± 0.51 × 10–3 mm2/sec), AUC of 0.674 (P = 0.008) and a cutoff value of 0.987 × 10–3 mm2/s with sensitivity, specificity and accuracy of 44.4%, 91.2% and 67.5%, respectively. The mean L.N /tumor ratio was 1.65 ± 0.73 in benign L.Ns and 1.06 ± 0.37 in malignant L.Ns. Conclusions In rectal cancer, there was a significant difference between benign and malignant L.Ns regarding diffusion result, L.Ns size, shape, and margin. The study demonstrated the effectiveness of DWI in diagnosing lymph node metastasis in colorectal cancer; true diffusion restriction was significantly noted in malignant L.Ns compared to benign L.Ns. Mean ADC value showed a significant reduction in malignant L.Ns compared to benign L.Ns. L.N/tumor ratio showed a significant reduction in malignant L.Ns compared to benign L.Ns.

Background: Rectal cancer is the most prevalent gastrointestinal tumor. Early diagnosis, accurate staging as well as early treatment are the keys for improving the five-year survival rate. The objective of this research is to assess the effectiveness of diffusion-weighted MRI (DWI) in identifying lymph nodes and distinguishing between benign and metastatic nodes throughout the first stage of primary rectal cancer. Results: The study showed that mean ADC value was significantly higher in mucinous carcinoma (1.72 ± 0.36 × 10–3 mm2/sec) than that in non-mucinous carcinoma (0.981 ± 0.276 × 10–3 mm2/sec) with a cutoff value of (1.3 × 10–3) mm2/s which was the precise value to produce high sensitivity, specificity and accuracy of 93%, 94%, and 94%, respectively. ADC analysis showed either intermediate or low signal in 49 (70%) and high signal in 21 (30%) L.Ns. Mean ADC value showed a significant reduction in malignant L.Ns (1.01 ± 0.54 × 10–3 mm2/sec) compared to benign L.Ns (1.51 ± 0.51 × 10–3 mm2/sec), AUC of 0.674 (P = 0.008) and a cutoff value of 0.987 × 10–3 mm2/s with sensitivity, specificity and accuracy of 44.4%, 91.2% and 67.5%, respectively. The mean L.N /tumor ratio was 1.65 ± 0.73 in benign L.Ns and 1.06 ± 0.37 in malignant L.Ns. Conclusions: In rectal cancer, there was a significant difference between benign and malignant L.Ns regarding diffusion result, L.Ns size, shape, and margin. The study demonstrated the effectiveness of DWI in diagnosing lymph node metastasis in colorectal cancer; true diffusion restriction was significantly noted in malignant L.Ns compared to benign L.Ns. Mean ADC value showed a significant reduction in malignant L.Ns compared to benign L.Ns. L.N/tumor ratio showed a significant reduction in malignant L.Ns compared to benign L.Ns. [ABSTRACT FROM AUTHOR]

Background: Prostate cancer is considered the most common malignant neoplasm in males worldwide and the 2nd important reason for cancer-related male deaths after bronchogenic carcinoma. Objective: The purpose of this research is to assess how diffusion weighted image (DWI) and apparent diffusion coefficient (ADC) value characterise prostatic cysts, senile prostatic hyperplasia, prostate cancer, and the normal prostatic gland. Patients and methods: We enrolled 60 cases with suspicious prostatic lesions,20 cases with benign prostatic hypertrophy, 20 cases prostate cancer and 20 with prostatic cyst along with 20 controls. All underwent magnetic resonance imaging (MRI) for prostatic assessment and Trans-rectal ultrasonography (TRUS) guided biopsy. Results: Prostate cancer had a considerably lower mean ADC value (p-value < 0.001) than normal central gland (CG), peripheral zone (PZ), and benign prostatic hyperplasia (BPH) nodules. The ADC value of the PZ tissue had been substantially higher than that of the normal central zone (CZ) (p<0.001). While the prostatic cyst's ADC value was much greater than CZ's (p < 0.001), the BPH lesion's ADC value had been significantly lower than CZ's (p < 0.001). Conclusions: DWI has been a useful tool for gathering information on the tissue properties of the prostate's various anatomical zones. In contrast to normal tissue, BPH, and prostate cysts, prostate carcinoma cause restricted diffusion of water, which may be used in the differential diagnosis of benign and malignant lesions. [ABSTRACT FROM AUTHOR]

Modern magnetic resonance imaging (MRI) experiments require simultaneous spin and spatial dynamics treatment. This paper aims to demonstrate the possibility of simulating a large spin system for diffusion-weighted MRI experiments. The numerical simulation of diffusion MRI depends on Bloch-Torrey equations. The latter describe the behavior of spin systems under the influence of magnetic fields and diffusion processes. They are particularly relevant in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) studies. The equations deal with uncoupled (−1/2) spins associated with three-dimensional spatial dynamics represented by diffusion and flow. The proposed method recommends using an unopened Kronecker product for evolution generators to minimize the simulation time and reduce the occupied computer memory. Two and three-dimensional diffusion-weighted magnetic resonance imaging associated with four pairs of coupled spin systems were utilized to achieve the study's goals. Utilizing four pairs of coupled spin systems in MRI simulation enhances accuracy and realism in modeling interactions between spins, leading to improved tissue characterization and diagnostic capabilities. The obtained results were impossible using previous simulation packages. The results of the study demonstrate that the Spinach library can simulate complex spin systems with significant spatial dynamics.

Current research in the field of neuroimaging is focused on the possibilities of using data from various diffusion MR models: diffusion tensor visualization (DTI), diffusion-curtosis visualization (DKI), diffusion-spectral visualization (DSI), generalized q-sample visualization (GQI), Q-ball visualization (QBI) in the assessment reorganization of the brain. The purpose of this study is to compare the results of dynamic observation of post–stroke brain reorganization by diffusion MR models (DTI, DKI). Material and methods. Dynamic MR examination of the brain of 129 patients was performed on a Ingenia 3.0 T (Philips, Netherlands) on 1–3 days, 7–10 days, 3–4 months after the manifestation of stroke according to a routine protocol (DWI-EPI, FLAIR-SPIR, T2-WI, T1W-TFE) with DTI method. The stroke was verified and DTI, GQI, and DKI maps were built. Results and discussion It was showed that the fractional anisotropy (FA) of DTI significantly changed from 1–3 days to 7–10 days in the stroke area; the mean, axial and radial diffusions increased in the affected area over the three studies. For DKI model – the curtosis FA significantly changed in the lesion area by 3–4 months; the mean curtosis decreased by the second observation in the stroke area, axial curtosis decreased in the same area throughout all studies; radial kurtosis significantly increased in the affected area throughout the study. The results confirm the world data and also indicate that diffusion metrics can interpret the neuroplasticity of the brain in various diseases, however, this requires further study. The applied diffusion models indicated the reorganization of the ischemic area and the intact contralateral area. The use of diffusion models for the dynamic assessment is a promising direction in the study of the neuroplasticity mechanisms.

Background/Aim: Endometrial abnormalities represent a diagnostic challenge due to overlapping imaging features with normal endometrium. Aim of this study was to assess accuracy of dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging (MRI) in evaluation of endometrial lesions in comparison with T2 and to assess local staging validity and degree of myometrial invasion in malignancy. Methods: Forty patients with abnormal vaginal bleeding or sonographic thickened endometrial were recruited. MRI examination of pelvis was per-formed using 1.5 T scanner with a pelvic array coil. Conventional T1-and T2, dynamic contrast-enhanced (DCE) sequences and diffusion-weighted image (DWI) were performed. Results: Mean age of patients was 53.2 years and 60 % of patients COM-plained of post-menopausal bleeding. Irregular margin, type III enhancement curve, a high signal in T2WI and DWI and low signal of apparent diffusion coefficient (ADC) were significantly associated with malignancy. The optimum ADC threshold value for distinguishing benign from malignant endometrial lesions was 0.905 × 10 -3 mm 2 /S, with 95.5 % sensitivity and 92.9 % specificity. DWI was most sensitive to malignant endometrial lesions, followed by DCE (89.6 %, 98.4 %) and T2 (86.7 %, 91.4 %). DWI and DCE staging correlated with FIGO staging (p = 0.0001 and p = 0.019, respectively). DWI had the best sensitivity for myometrial invasion (95.6 %), followed by DCE (91.9 %) and T2WI (90.1 %). All three sequences had 89.7 % specificity. Conclusion: DWI and DCE MRI were superior to conventional MRI at distinguishing malignant from benign endometrial lesions and can improve myometrial invasion depth evaluation and therapy planning when COM-bined with morphological T2WI. ADC cutoff at a high b value improved MRI diagnostic sensitivity and specificity.

This article discusses the use of dynamic contrast-enhanced MRI (DCE MRI) and diffusion-weighted imaging (DWI) in the evaluation of endometrial lesions. The study found that DWI and DCE MRI were more accurate than conventional MRI in distinguishing between benign and malignant lesions and in assessing the depth of myometrial invasion. Combining these techniques with morphological T2 imaging can improve the diagnosis and planning of therapy for endometrial lesions. The study also found that certain MRI characteristics, such as enhancement curves and signal intensity, were associated with the nature of the endometrial lesion. Overall, MRI can be a useful tool in distinguishing between benign and malignant endometrial lesions and in staging endometrial cancer. [Extracted from the article]

Although the existing cardiac diffusion tensor imaging (DTI) denoising methods have achieved promising results, most of them are dependent on the number of diffusion gradient directions, noise distributions, and noise levels. To address these issues, we propose a novel self-supervised cardiac DTI denoising network, Node2Node, which firstly expresses the diffusion-weighted (DW) image volumes along different directions as a graph, then the graph framelet transform (GFT) is implemented to map the DW signals into the GFT coefficients at different spectral bands, allowing us to accurately match the DW image pairs. After that, using the matched image pairs as input and target, a ResNet-like network is used to denoise in a self-supervised manner. In addition, a novel edge-aware loss based on pooling operation is proposed to retain the edge. Through comparison with several state-of-the-art methods on synthetic, ex vivo porcine, and in vivo human cardiac DTI datasets, we showed that the root mean square error (RMSE) of DW images and the average angular error (AAE) of fiber orientations obtained using Node2Node are the smallest, improved by 47.5% and 23.7%, respectively, on the synthetic dataset, demonstrating that Node2Node is not sensitive to the properties of the dataset. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop and evaluate the technique for volumetric tumor segmentation based on diffusion-weighted magnetic resonance imaging (DW-MRI) in predicting and assessing the response to chemotherapy in patients with bladder cancer (BC). Material and Methods. We examined 26 patients with morphologically verified transitional cell carcinoma of the bladder. The group was characterized by the presence of one or several tumors with a size of 17 to 46 mm. Before planning chemotherapy according to the M-VAC scheme, a study and post-processing of DW-MRI with volumetric segmentation of lesions, assessment of the volume and apparent diffusion coefficient (ADC) in the entire tumor mass were performed. According to the ADC data, shape of the tumor and its relation to the bladder wall, the coefficient (C) for predicting the response to chemotherapy was calculated. Results. In the cases with a coefficient value below 0.51, a high risk of treatment failure was predicted, at C≥0.74, a positive effect of treatment was predicted. With a value of 0.51≤C

Purpose: To design an unsupervised deep neural model for correcting susceptibility artifacts in single‐shot Echo Planar Imaging (EPI) and evaluate the model for preclinical and clinical applications. Methods: This work proposes an unsupervised cycle‐consistent model based on the restricted subspace field map to take advantage of both the deep learning (DL) and the reverse polarity‐gradient (RPG) method for single‐shot EPI. The proposed model consists of three main components: (1) DLRPG neural network (DLRPG‐net) to obtain field maps based on a pair of images acquired with reversed phase encoding; (2) spin physical model–based modules to obtain the corrected undistorted images based on the learned field map; and (3) cycle‐consistency loss between the input images and back‐calculated images from each cycle is explored for network training. In addition, the field maps generated by DLRPG‐net belong to a restricted subspace, which is a span of predefined cubic splines to ensure the smoothness of the field maps and avoid blurring in the corrected images. This new method is trained and validated on both preclinical and clinical datasets for diffusion MRI. Results: The proposed network could effectively generate smooth field maps and correct susceptibility artifacts in single‐shot EPI. Simulated and in vivo preclinical/clinical experiments demonstrated that our method outperforms the state‐of‐the‐art susceptibility artifact correction methods. Furthermore, the ablation experiments of the cycle‐consistent network and the restricted subspace in generating field maps did show the advantages of DLRPG‐net. Conclusion: The proposed method (DLRPG‐net) can effectively correct susceptibility artifacts for preclinical and clinical single‐shot EPI sequences. [ABSTRACT FROM AUTHOR]

Objective: to evaluate the current possibilities of diffusion-weighted imaging (DWI) in liver magnetic resonance imaging (MRI) for the diagnosis of alcoholic liver disease (ALD).Material and methods. The examined patients were at the inpatient and outpatient stages of observation in the gastroenterology department on the basis of the Clinical Hospital No. 1 (Smolensk) and received treatment for diffuse liver diseases of alcoholic etiology. The study included 128 patients: 76 (59%) males and 52 (41%) females, mean age 42.3 ± 4.7 years. Patients were monitored from 2019 to 2022. All of them underwent abdominal organs ultrasound with liver clinical elastography and liver MRI with DWI; in 34 cases liver multi-slice computed tomography was performed.Results. When comparing the results of a qualitative assessment of liver DWI MRI with the CAGE (Cut, Annoyed, Guilty, Eye-opener) test data and the results of patients and relatives survey about the use of alcoholic beverages, a high correlation was established between the diffusion restriction in the liver during MRI and impaired withdrawal regimen (r = 0.901). The diagnostic and prognostic significance of the developed criteria for liver DWI MRI in patients with ALD at admission was assessed: for qualitative assessment AUROC 0.827 (95% CI 0.792–0.873), for quantitative assessment AUROC 0.949 (95% CI 0.912–0.981); in dynamic observation: for qualitative assessment AUROC 0.958 (95% CI 0.925–0.984), for quantitative assessment AUROC 0.947 (95% CI 0.947–0.981).Conclusion. The obtained quantitative indicators of liver DWI MRI make it possible to predict the clinical form of ALD: apparent diffusion coefficient for steatosis is 2.66 ± 0.9 × 10–3 mm2/s, for steatohepatitis – 2.14 ± 0.5 × 10–3 mm2/s, for hepatitis – 1.75 ± 0.6 × 10–3 mm2/s, for cirrhosis – 1.15 ± 0.6 × 10–3 mm2/s (AUROC 0.948; 95% CI 0.922–0.983). Qualitative parameters of liver DWI MRI (there is/is not a diffusion restriction) predict violations of the withdrawal regimen in patients with ALD in all its clinical forms (AUROC 0.931; 95% CI 0.822–0.979).

Background: Vessels encapsulating tumor clusters (VETC) have been considered an important cause of hepatocellular carcinoma (HCC) metastasis. Purpose: To compare the potential of various diffusion parameters derived from the monoexponential model and four non-Gaussian models (DKI, SEM, FROC, and CTRW) in preoperatively predicting the VETC of HCC. Methods: 86 HCC patients (40 VETC-positive and 46 VETC-negative) were prospectively enrolled. Diffusion-weighted images were acquired using six bvalues (range from 0 to 3000 s/mm2). Various diffusion parameters derived from diffusion kurtosis (DK), stretched-exponential (SE), fractional-order calculus (FROC), and continuous-time random walk (CTRW) models, together with the conventional apparent diffusion coefficient (ADC) derived from the monoexponential model were calculated. All parameters were compared between VETC-positive and VETC-negative groups using an independent sample t-test or Mann-Whitney U test, and then the parameters with significant differences between the two groups were combined to establish a predictive model by binary logistic regression. Receiver operating characteristic (ROC) analyses were used to assess diagnostic performance. Results: Among all studied diffusion parameters, only DKI_K and CTRW_a significantly differed between groups (P=0.002 and 0.004, respectively). For predicting the presence of VETC in HCC patients, the combination of DKI_K and CTRW_a had the larger area under the ROC curve (AUC) than the two parameters individually (AUC=0.747 vs. 0.678 and 0.672, respectively). Conclusion: DKI_K and CTRW_a outperformed traditional ADC for predicting the VETC of HCC. rt [ABSTRACT FROM AUTHOR]

Central nervous system involvement related to decompression sickness (DCS) is a very rare complication of breath-hold diving. So far, it has been postulated that repeated dives with short surface intervals represent a key factor in the development of breath-holding-related DCS. We report the case of a breath-hold diver who, after repeated immersion, developed DCS with brain involvement. After treatment in a hyperbaric chamber, there was a clinical improvement in the symptoms. Magnetic resonance imaging of the brain showed hyperintense lesions in long-time repetition sequences (FLAIR, T2WI) in the left frontal and right temporal lobes. Diffusion-weighted imaging (DWI) sequences and the apparent diffusion coefficient (ADC) map were characteristic of vasogenic edema, allowing us to exclude the ischemic nature of the process. These findings, together with the acute clinical presentation, the resolution of lesions in evolutionary radiological controls and the possible involvement of blood–brain barrier/endothelial dysfunction in DCS, could suggest a new form of posterior reversible encephalopathy syndrome (PRES)-like presentation of DCS. This would represent a novel mechanism to explain the pathophysiology of this entity. We conducted a literature review, analyzing the pathophysiological and neuroimaging characteristics of DCS in breath-hold diving based on a case of this rare disease.

Although the existing cardiac diffusion tensor imaging (DTI) denoising methods have achieved promising results, most of them are dependent on the number of diffusion gradient directions, noise distributions, and noise levels. To address these issues, we propose a novel self-supervised cardiac DTI denoising network, Node2Node, which firstly expresses the diffusion-weighted (DW) image volumes along different directions as a graph, then the graph framelet transform (GFT) is implemented to map the DW signals into the GFT coefficients at different spectral bands, allowing us to accurately match the DW image pairs. After that, using the matched image pairs as input and target, a ResNet-like network is used to denoise in a self-supervised manner. In addition, a novel edge-aware loss based on pooling operation is proposed to retain the edge. Through comparison with several state-of-the-art methods on synthetic, ex vivo porcine, and in vivo human cardiac DTI datasets, we showed that the root mean square error (RMSE) of DW images and the average angular error (AAE) of fiber orientations obtained using Node2Node are the smallest, improved by 47.5% and 23.7%, respectively, on the synthetic dataset, demonstrating that Node2Node is not sensitive to the properties of the dataset.

Background and aims: Transient global amnesia (TGA) is a clinical syndrome characterized by sudden anterograde amnesia not accompanied by other neurological symptoms. There is no consensus on the underlying pathophysiological mechanism. However, diffusion-weighted imaging (DWI) of the magnetic resonance imaging (MRI) has demonstrated hippocampal lesions in as many as 50% of cases. This paper describes a series of patients with TGA and hippocampal lesions. Methods: This study assessed vascular risk factors in patients older than age 18 admitted to the Hospital Universitario San Ignacio, Bogota, Colombia, from May 2017 to June 2020 with a diagnosis of TGA and evidence of hippocampal ischemic lesion on 3 Tesla brain MRI. Results: The authors identified 36 patients, 72.2% female, with mean age 62 years. Cardiovascular risk factors, most frequently high blood pressure, carotid disease, and dyslipidemia, were present in 75% of these patients. Hippocampal lesions were unilateral in 80% of cases, with median size 2.5 mm, most frequently located at the hippocampal body. Approximately 14% of patients also presented acute ischemic lesions in locations other than the hippocampus. Conclusions: TGA is a clinical entity previously considered to have undetermined etiology. The present study used brain MRI to identify a group of patients with hippocampal ischemic lesions, finding associated vascular risk factors in a high proportion of them. [ABSTRACT FROM AUTHOR]

Central nervous system involvement related to decompression sickness (DCS) is a very rare complication of breath-hold diving. So far, it has been postulated that repeated dives with short surface intervals represent a key factor in the development of breath-holding-related DCS. We report the case of a breath-hold diver who, after repeated immersion, developed DCS with brain involvement. After treatment in a hyperbaric chamber, there was a clinical improvement in the symptoms. Magnetic resonance imaging of the brain showed hyperintense lesions in long-time repetition sequences (FLAIR, T2WI) in the left frontal and right temporal lobes. Diffusion-weighted imaging (DWI) sequences and the apparent diffusion coefficient (ADC) map were characteristic of vasogenic edema, allowing us to exclude the ischemic nature of the process. These findings, together with the acute clinical presentation, the resolution of lesions in evolutionary radiological controls and the possible involvement of blood–brain barrier/endothelial dysfunction in DCS, could suggest a new form of posterior reversible encephalopathy syndrome (PRES)-like presentation of DCS. This would represent a novel mechanism to explain the pathophysiology of this entity. We conducted a literature review, analyzing the pathophysiological and neuroimaging characteristics of DCS in breath-hold diving based on a case of this rare disease. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to (1) clarify the size and apparent diffusion coefficient (ADC) value of lymph nodes (LN) in each state in their quantitative evaluation diffusion-weighted imaging, and (2) to determine the diagnostic utility of size and ADC values in the quantitative evaluation of LNs using diffusion-weighted imaging. Methods: This was a retrospective cohort study at our hospital conducted between April 2017 and March 2019. A total of 50 patients (20 men, 30 women) with 118 LNs, aged 34–90 years (mean age 61.18 years), undergoing magnetic resonance imaging examination were included in the study. The predictor variable was disease status. The primary outcome variable was the mean size and ADC values of the LNs. The other variables were age and sex. Data were analyzed using a Kruskal–Wallis test, and hoc Mann–Whitney tests with Bonferroni adjustment and a receiver operating characteristic (ROC) curve. P < 0.05 was considered to indicate statistical significance. Results: We analyzed the records of 50 patients (118 LNs) with and without osteomyelitis. Of these, 21 had acute osteomyelitis, and 16 had chronic osteomyelitis. The size and ADC values of LNs in the osteomyelitis group were significantly greater and higher, respectively, than those in the non-myelitis group (P < 0.01). ROC analysis revealed a cutoff short-axis size of 4.42 and 4.04 mm for lymphadenopathy caused by osteomyelitis, corresponding to levels IB and level II, respectively. Moreover, the ADC cutoff values for the same were 0.85 and 0.86, respectively. Conclusion: The results suggest that size and ADC values are useful parameters for the quantitative evaluation of lymphadenopathy caused by osteomyelitis. [ABSTRACT FROM AUTHOR]

Purpose: The goal of the study was an assessment of the diagnostic performance of diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) of magnetic resonance imaging (MRI) in distinguishing local recurrence (LR) of renal cell carcinoma (RCC) from benign conditions after partial nephrectomy. Material and methods: Thirty-nine patients after partial nephrectomy for solid RCC were enrolled in the study. Patients were followed up using MRI, which included DWI sequence (b = 800 s/mm²). All patients with MRI features of LR were included in the main group (n = 14) and patients without such features – into the group of comparison (n = 25). Apparent diffusion coefficient (ADC) values of suspicious lesions were recorded. In all patients with signs of locally recurrent RCC, surgical treatment was performed followed by pathologic analysis. Results: The mean ADC values of recurrent RCC demonstrated significantly higher numbers compared to benign fibrous tissues and were 1.64 ± 0.15 × 10-3 mm²/s vs. 1.02 ± 0.26 × 10-3 mm²/s (p < 0.001). The mean ADC values of RCCs’ LR and benign post-op changes in renal scar substantially differed from mean ADC values of healthy kidneys’ parenchyma; the latter was 2.58 ± 0.05 × 10-3 mm²/s (p < 0.001). In ROC analysis, the use of ADC with a threshold value of 1.28 × 10-3 mm²/s allowed us to differentiate local recurrence of RCC from benign postoperative changes with 100% sensitivity, 80% specificity, and accuracy: AUC = 0.980 (p < 0.001). Conclusions: The apparent diffusion coefficient of DWI of MRI can be used as a potential imaging marker for the diagnosis of local recurrence of RCC. [ABSTRACT FROM AUTHOR]

Purpose of the study. To study the diagnostic informativeness of magnetic resonance imaging (MRI) with the assessment of diffusion- weighted images and the measured diffusion coefficient in the diagnosis of endometrial tumor lesions in polyineoplasias.Materials and methods. The article presents the results of a study of patients with synchronous and metachronous polyneoplasias who were in the AU "Republican clinical oncological dispensary" of the Ministry of health of the Chuvash Republic from 2014 to 2018. All were performed magnetic resonance imaging on Excelart Vantage Atlas (Toshiba, Japan, 1.5 T), ultrasound (Aplio, Xario and Nemio, Toshiba, Japan; Sono Scape, China), x-ray computed tomography on Light Speed VEX Plus and Light Speed RT 16 (GE, USA). All MRI results were compared with morphological data obtained afterhistomorphological examination of the postoperative material. The differences were considered significant at values p≤0.05.Results. 80 cases of endometrial tumor lesions in polyineoplasias (N1a) were detected, which was 44.7% of all cases of the main group (N1; n=179), of which metachronous polyineoplasias were found in 56 (70.0%), synchronous — in 11 (13.7%), combined — in 13 (16.3%) patients. The informative value of MRI in the diagnosis of malignant neoplasms with lesions of the endometrium when multiple neoplasias were: sensitivity of 91.3%, specificity — 82,4%, accuracy was 89.7% (p

This scientific review assesses the current diagnostic capabilities of diffusion-weighted images used in the magnetic resonance imaging protocol for bladder cancer. It actualizes this impulse sequence employed within the framework of a multiparametric MRI study as one of the functional techniques. The review deals with the possibilities of diffusion-weighted images used in an independent version and in combination with T2-weighted images to visualize a tumor, postoperative changes, and associated pathology. It gives differential diagnostic criteria in identifying the extent of tumor invasion, including that with accuracy assessment according to the measured diffusion coefficient.The sources of the review are publications included in the peer-reviewed databases PubMed, Scopus, eLIBRARY and the open sources Google Scholar, Researchgate.

Acquired ear canal stenosis can be caused by trauma, inflammation, postoperative scar formation, or tumors. There is a risk of cholesteatoma formation because of keratinized deposits in the closed space, with a reduction in quality of life because of conductive hearing loss. A cholesteatoma that has grown in a closed external auditory canal is difficult to find because of its location and the original hearing loss because of ear canal stenosis. Regarding imaging for cholesteatoma, CT absorption values are nonspecific, but MRIs are said to be effective. In an MRI, diffusion-weighted images are useful for distinguishing cholesteatoma. In surgery for ear canal stenosis, it is important to adopt strategies that will prevent post-operative restenosis and re-closure. If a cholesteatoma is also present, besides excising it, the ear canal should be enlarged. It is also important to follow-up patients with traumatic ear canal stenosis. We present a case of cholesteatoma associated with traumatic ear canal stenosis discovered 50 years after injury. Here, the cholesteatoma was diagnosed by MRI, and the external ear canal was enlarged during surgery. No postoperative recurrence was observed during follow-up.

Objective. To evaluate the efficiency of magnetic resonance spectroscopy in the diagnosis and prognosis of breast cancer (BC).Material and methods. Twenty-eight patients aged 37 to 80 years with established primary invasive BC were examined. Its grade was determined according to pathomorphological verification with immunohistochemical analysis. Breast MRI was performed using the standard protocol, by determining the measured diffusion coefficient (MDC), dynamic contrast enhancement (DCE). Proton magnetic resonance spectroscopy was carried out using the Breeze software package. The clinical and morphological findings and the results of radiation studies were compared to determine Nottingham prognostic index (NPI) scores. To identify the Spearman rank correlation coefficient between MRI findings (the type of pharmacokinetic curves, the total choline-containing (tCho) peak integral) and the values characterizing tumor size and grade.Results. NPI calculation showed that the scoring range was 2.4 to 6.76; the expected 5-year survival rates reached 93%. The mean MDC was 0.856×10-3 mm2/sec; type II pharmacokinetic curve prevailed (n=16; 57.1%). There was a statistically significant negative correlation between the values of MDC, the type of a contrast agent accumulation curve, the levels of HER2/neu and the proliferation marker Ki-67; there was a statistically significant strong positive correlation between the presence of 1H-MPC tCho peak and the indicators determining tumor malignancy (the levels of HER2/neu and Ki-67). Statistically significant differences between the type of a pharmacokinetic curve in DCE and the level of tCho in the prognostic groups defined when calculating NPI were determined in patients with moderate (n=4; 14.2%) and poor (n=10; 35.7%) prognosis.Conclusion. The capabilities of MR spectroscopy are superior in information content to the data obtained by determining the MDC, the nature of contrast medium accumulation in breast tumor, and are comparable with the data determining the type of a tumor (the presence of the HER2/neu gene, Ki-67 proliferation marker) in predicting BC cancer grade and 5-year survival rates.

Uterine myxoid leiomyosarcomas (MLMSs) are extremely rare. Here, we report a rare case of uterine MLMS with unique and bizarre magnetic resonance imaging (MRI) findings on diffusion-weighted images (DWIs) and dynamic contrast-enhanced (DCE) MRI scans. A 67-year-old woman presented with a uterine MLMS that had a multilocular cystic mass with a septum and solid components. The tumour demonstrated marked hyperintensity on T2-weighted images in a myxoid stroma with gradual partial contrast enhancement and diffusion restriction, which could be a characteristic feature suggestive of a myxoid malignant smooth muscle tumour of the uterus rather than a uterine leiomyoma with myxoid degeneration.

Background: Grade of brain tumor is thought to be the most significant and crucial component in treatment management. Recent development in medical imaging techniques have led to the introduce non-invasive methods for brain tumor grading such as different magnetic resonance imaging (MRI) protocols. Combination of different MRI protocols with fusion algorithms for tumor grading is used to increase diagnostic improvement. This paper investigated the efficiency of the Laplacian Re-decomposition (LRD) fusion algorithms for glioma grading. Procedures: In this study, 69 patients were examined with MRI. The T1 post enhancement (T1Gd) and diffusion-weighted images (DWI) were obtained. To evaluated LRD performance for glioma grading, we compared the parameters of the receiver operating characteristic (ROC) curves. Findings: We found that the average Relative Signal Contrast (RSC) for high-grade gliomas is greater than RSCs for low-grade gliomas in T1Gd images and all fused images. No significant difference in RSCs of DWI images was observed between low-grade and high-grade gliomas. However, a significant RSCs difference was detected between grade III and IV in the T1Gd, b50, and all fussed images. Conclusions: This research suggests that T1Gd images are an appropriate imaging protocol for separating low-grade and high-grade gliomas. According to the findings of this study, we may use the LRD fusion algorithm to increase the diagnostic value of T1Gd and DWI picture for grades III and IV glioma distinction. In conclusion, this article has emphasized the significance of the LRD fusion algorithm as a tool for differentiating grade III and IV gliomas.

The aim is to evaluate the diagnostic potential of the diffusion-weighted MRI sequences (DW-MRI) as compared with multi-spiral computed tomography (MSCT) for staging of ovarian malignancies (OVM).Materials and Methods. The study was conducted (from February to December 2016) on 73 patients with suspected ovarian malignancies who underwent preoperative examination, including abdominal / pelvic MSCT and DW-MRI, using a 1.5T scanner with b-factors of 0.1000 s/mm2 and the calculation of apparent diffusion coefficient (ADC). Using the obtained data, the peritoneal cancer index (PCI) was calculated and ROC curves for DW-MRI vs MSCT were created. The imaging-based diagnoses were then compared with surgical staging and histopathological examination.Results. The following stages of OVM were determined: 5 (6.8%) IV; 35 (47.9%) IIIC; 23 (31.5%) IIIB; 10 (13.6%) IIIA. The overall sensitivity was 55% for MSCT and 77% for DW-MRI. For example, DW-MRI was markedly superior to MSCT in detecting a tumor implantation into the large intestine mesentery (83.8% and 37.8%, respectively), into the small intestine serosa (77.8% and 28.9%), and the para-aortic lymph nodes (71.4 and 35.7%). The specificity of the compared imaging modalities was similar (79.6% – DW-MRI and 81% – MSCT). The peritoneal cancer index (PCI) calculated from the DW-MRI results correlated with the surgical staging data better than the PCI based on MSCT (r=0.706 for DW-MRI, r=0.544 for MSCT). Based on the obtained data, the ROC curves were plotted to show the areas under the curves of 0.913 and 0.655 for DW-MRI and MSCT, respectively. A decrease in the ADC values was found in secondary tumor foci (1.120±0.25 for the ovaries, 0.820±0.23 for the omentum, 0.790±0.19Ч10-3 mm2/s for peritoneal implants).Conclusion. For the assessment of ovar-ian cancer spread, DW-MRI is significantly more sensitive than MSCT.

Currently, malignant tumors of ovaries take the third place in the structure of oncogynecological diseases, being a leading cause of death among pathology of female reproductive system. Due to the lack of effective screening programs and asymptomatic course of the disease in its early stages, in the majority of cases ovarian cancer (OC) is detected in form of disseminated process, what greatly reduces the effectiveness of primary treatment and has a negative impact on the further prognosis. In connection with the above, timely diagnosis and organization of OC screening, as well as monitoring of its recurrence is a major problem for oncologists around the world.In the present literature review the opportunities of magnetic — resonance imaging (MRI) in detection of primary ovarian cancer and its recurrence are considered, the analysis of the method diagnostic efficiency based on the use of various techniques is done. The opportunities of MRI show a lot of information necessary for the characterization of detected ovarian formations, estimates of the prevalence of primary ovarian cancer and its recurrence. However, the analysis of performed literature revealed a significant lack of materials devoted to the definition of the diagnostic capabilities of various MRI techniques, including diffusion — weighted imaging (DWI), what indicates the necessity for further studies in this direction.

Background: White matter hyperintensities (WMH) are a common finding in aged individuals affected by carotid artery disease and are a risk factor for first-ever and recurrent stroke. We investigated if white matter damage increases the risk of brain microembolism during carotid artery stenting (CAS), as evaluated by the appearance of new areas of restricted diffusion on diffusion-weighted images (DWI). Methods: We evaluated 47 patients with severe internal carotid artery (ICA) stenosis undergoing CAS, comparing preprocedural clinical, ultrasound and radiological characteristics. WMH volume was computed on FLAIR images before CAS. After CAS, the DWI scan was looked over for areas of restricted diffusion (DWI lesions). A first univariate analysis was adopted to compare groups according to the occurrence of DWI lesions. Then, the variable DWI lesion was modelled by means of a logistic regression model. Results: Seventeen patients developed at least 1 DWI lesion after CAS. Compared with non-DWI, DWI patients were more commonly treated in the left ICA (p = 0.007) and had a more severe WMH damage (p = 0.027). Indeed, the risk of a DWI lesion was higher in left versus right stenosis (OR = 9.0, 95% CI 1.9-42.7, p = 0.005) and increased for each log-unit of WMH lesion load (OR = 7.05, 95% CI 1.07-46.49, p = 0.042). A WMH lesion load of at least 5.25 cm3 had a 50% probability of occurrence of a new DWI lesion. Conclusions: Treated side and preexisting white matter damage are risk conditions for brain microembolism during CAS. This should be taken into account to optimize severe carotid artery disease management.

Purpose: The aim of this study was to compare the diagnostic accuracy of magnetic resonance imaging (MRI) and dual-energy computed tomography (DECT) to identify residual–recurrent cholesteatoma using the second-look surgery as the reference standard. Methods: This prospective, institutional review board-approved study included 19 consecutive patients (11 males and 8 females; mean age of 62.2, range 34–80 years). Since five patients were studied bilaterally, a total of 24 ears were evaluated with DECT and MRI between February 2017 and June 2018. Any abnormal middle ear attenuation on high-resolution CT images (HRCT) or DECT color-coded maps, and any abnormal signal on MRI images was evaluated by four experienced radiologists. Diagnostic accuracy values of HRCT, DECT maps and CT numbers (by using receiver operator curves) and MRI were compared. Interobserver and intraobserver agreement were calculated. Results: Residual–recurrent cholesteatoma was diagnosed at surgery in 16/24 ears (66.6%). MRI and DECT revealed a total of 15/16 and 14/16 cholesteatomas, respectively. The sensitivity, specificity, PPV and NPV and accuracy of MRI and DECT were 93.7, 87.5, 93.7, 87.5, and 91.6% and 87.5, 87.5, 93.3, 87.5 and 87.5%, respectively. CT numbers were significantly different between positive (mean 57.6 HU, range − 65, 112 HU) and negative cases (mean 5.4 HU, range − 100, 66 HU) with p < 0.001. The interobserver and intraobserver agreement were k = 0.87 and k = 0.83, respectively. Conclusion: DECT may provide an accurate demonstration of residual–recurrent middle ear cholesteatoma. [ABSTRACT FROM AUTHOR]

• Unexpected error is an important remaining issue in deep learning-based noise reduction. • The devised model has a restricted degree of freedom to reduce the chance of error. • Multiple pathways divided the function to balance the capability and the constraints. • The model can perform adequate denoising even under the restricted freedom. • The model utilized the characteristics of MRI to incorporate the unique loss function. In deep learning-based noise reduction, larger networks offer advanced and complex functionality by utilizing its greater degree of freedom, but come with increased unpredictability, raising the potential risk of unforeseen errors. Here, we introduce a novel denoising model for diffusion-weighted images that intentionally limits the network output freedom by incorporating multiple pathways with varying degrees of freedom, with the aim of minimizing the chance of unintended alterations to the input. The purpose of this pilot study is to assess the model's ability to perform effective denoising under the constraints. Images from 10 healthy volunteers were used. Key innovations in our model development include: (1) neural network architecture that separated the function for calculating the specific output values from the function for adjusting the calculation for each pixel and (2) training that optimised the network based on both image and secondary obtained diffusion tensor. The generated images were compared with the original ones by measuring the deviation from ground truth images (averaged across eight acquisitions). The generated images demonstrated closer alignment with the ground truth images, both visually and statistically (Q < 0.05), compared to the original images. Furthermore, the advantage of the generated images over the original images was also found in the secondary obtained quantitative parameter maps with significance (Q < 0.05). The usefulness of the proposed method was suggested because it was successful in improving both the quality of the generated images and accuracy of the major diffusion parameter maps under the given restrictions. [ABSTRACT FROM AUTHOR]

Objective: to determine whether the measurable diffusion coefficient (MIC) may be used to differentiate normal and lymphomatosisaltered lymph nodes (LNs) in patients with Hodgkin lymphoma (HL).Material and methods. Whole-body magnetic resonance (MR) imaging was used to compare the MICs of LNs in 27 apparently healthy individuals and 41 patients with a verified diagnosis of HL.Results. Construction of 95% confidence intervals showed that the MICs of normal LNs were in the range of 1.00 to 1.73× ×10-3 mm2/sec and significantly higher (p

Dengue is a common viral infection worldwide with presentation varying from clinically silent infection to dengue fever, dengue hemorrhagic fever, and severe fulminant dengue shock syndrome. Neurological manifestation usually results from multisystem dysfunction secondary to vascular leak. Presentation as hemorrhagic encephalitis is very rare. Here we present the case of a 13-year-old female admitted with generalized tonic clonic seizures. Plain computed tomography (CT) scan of head revealed hypodensities in bilateral deep gray matter nuclei and right posterior parietal lobe without any hemorrhage. Cerebrospinal fluid (CSF) and serology were positive for IgM and IgG antibodies to dengue viral antigen. Contrast-enhanced magnetic resonance imaging (MRI) revealed multifocal T2 and fluid attenuated inversion recovery (FLAIR) hyperintensities in bilateral cerebral parenchyma including basal ganglia. No hemorrhage was seen. She was managed with steroids. As her clinical condition deteriorated, after being stable for 2 days, repeat MRI was done which revealed development of hemorrhage within the lesions, and diagnosis of acute hemorrhagic encephalitis of dengue viral etiology was made.

Previous studies in singleton pregnancies reported conflicting trends in apparent diffusion coefficient (ADC) values with gestational age (GA) and stable relative ADC (rADC; ADC placenta divided by ADC globe) throughout pregnancy. The purpose of our study was to compare the ADC and rADC of placentas of twin and singleton pregnancies.Materials and Methods: Fetal MRI of 11 twin and 23 singleton pregnancies were retrospectively analyzed. Each group was further divided by GA (≤24 and >24 weeks). On ADC, 3 regions of interest were selected in the placenta and 1 in the globe. ADC and rADC measurements were compared between different GA and between singleton and twin placentas.Results: No significant difference was shown between ADC and rADC values of singleton and twin placentas as well as between ADC and rADC values of singleton and twin placentas at different GA. No significant difference was shown when accounting for both GA and number of fetuses.Conclusion: The diffusion characteristics of twin placentas are similar to those of singleton placentas. ADC and rADC remain stable throughout pregnancy in twin and singleton placentas, reflecting stable extracellular water diffusion, despite changes associated with placental maturation. [ABSTRACT FROM AUTHOR]

High-intensity focused ultrasound (HIFU) is an emerging technique for noninvasive ablative treatment. However, HIFU has rarely been performed for the treatment of soft-tissue tumors. Thus, we aimed to assess the feasibility and safety of performing extracorporeal HIFU for the treatment of soft-tissue tumor. The treatment response was assessed using functional magnetic resonance imaging (MRI) techniques. Materials and methods: In the rabbit VX2 intramuscular tumor model, HIFU was performed using an extracorporeal HIFU device (YDME FEP-BY02) by varying the electric power from 50 to 400 W, with the other parameters being fixed. The HIFU beam was insonated to one layer of focal spots having a depth of 8 mm. The degree of ablation was evaluated by histological examination and functional MRI techniques including dynamic contrast-enhanced MRI (DCE-MRI) and apparent diffusion coefficient (ADC) map. The presence of skin burn was also evaluated. Results: Applying HIFU with an electric power of 200 W discretely produced the ablation zone without skin burn as planned before treatment (maximal depth: 8–9 mm), which shows the suitability of using HIFU (with 200 W electric power) for the treatment of soft-tissue tumors. By contrast, HIFU with an electric power of 100 W produced an ill-marginated ablation zone with internal residual tumor foci, and HIFU with 300–400 W produced ablation zones with a maximum depth of 13–24 mm, which far exceeded the planned depth and caused skin burn. Perfusion maps of DCE-MRI demonstrated the devascularized ablation zone more conspicuously than conventional contrast-enhanced T1-weighted images, and ADC map demonstrated the surrounding edema or granulation tissue better than conventional T2-weighted images. Conclusion: Extracorporeal HIFU treatment for soft-tissue tumor may be a feasible approach with adjustment of input energy level. For post-treatment assessment, functional MRI techniques including DCE-MRI and ADC map may be useful and complementary to conventional MRI.

Heroin has physical effects on many parts of the body, for example, respiratory and digestive system, muscles, and nervous system. Neurologic complications include brain abscess, neuropathy, transverse myelitis, and leukoencephalopathy.Magnetic resonance image is more sensitive in detecting lesions with low signal on T1W and high signal on T2W, and FLAIR images in the white matter and other areas of brain. Imaging findings are similar to other leukoencephalopathies (hereditary diseases, abnormal metabolic diseases, and intoxications).In the course of finding ways to differentiate heroin-induced spongiform leukoencephalopathy from other leukoencephalopathies, attention has been changed to diffusion magnetic resonance imaging in recent years.Nevertheless, studies do not verify that diffusion-weighted image is a valuable tool in establishing the diagnosis.

Objectives: To assess major imaging features of Liver Imaging Reporting and Data System (LI-RADS) on contrast-enhanced CT and gadoxetic acid-enhanced MRI and to estimate whether the combination of signal intensity favouring HCC on hepatobiliary phase (HBP) and diffusion-weighted images (DWI) can act as a major feature in LI-RADS.Methods: Four hundred twenty one patients with 445 observations were included. Major features of LI-RADS on CT and MRI as well as HBP and DWI features were assessed. Diagnostic performances of LR-5 according to LI-RADS v2014 and modified LI-RADS which incorporate combination of HBP and DWI were assessed. Pairwise comparisons of the receiver operating characteristic (ROC) curves were performed.Results: For HCCs, capsule appearance had the highest rate of discordance between CT and MRI (32.7%), followed by washout appearance (22.2%). Specificity (75%) of LR-5 of LI-RADS v2014 was lower than that (77.1-79.2%) of modified LI-RADS. Area under the ROC curve of modified LI-RADS (0.755-0.775) was not significantly different from that of LI-RADS v 2014 (0.709) (p > 0.05).Conclusions: There were substantial discordances between CT and MRI for capsule and washout appearances in hepatic observations, and combination of gadoxetic acid-enhanced MRI and DWI might be able to be incorporated as a major feature of LI-RADS.Key Points: • Major imaging features of LI-RADS showed substantial discordances on CT and MRI. • An observation may be categorized differently depending on used imaging exam. • CT and MRI should both be performed for LR-3 and LR-4 observations. • Combination of gadoxetic acid-enhanced MRI and DWI may be a major feature. [ABSTRACT FROM AUTHOR]

Background: Small punctuate lesions in the hippocampus on diffusion-weighted images are a typical finding in transient global amnesia. Consequently, it has been suggested that diffusion-weighted images findings might corroborate the diagnosis of transient global amnesia. However, isolated punctuate hippocampal infarction might be a differential diagnosis of transient global amnesia. Aim: Evaluation of isolated punctuate hippocampal infarction frequency and comparison of its clinical presentation and MRI findings to transient global amnesia. Methods: From an MRI database, we identified 10 patients with isolated punctuate hippocampal infarction and compared these to 12 patients with transient global amnesia with diffusion-weighted images lesion with regard to clinical symptoms and MRI findings. Results: Disorientation and memory deficits were more common in transient global amnesia patients, whereas dysphasia/ aphasia and vertigo were more common in hippocampal infarction patients. MRI findings in isolated punctuate hippocampal infarction and transient global amnesia did not differ significantly, neither regarding the affected hemisphere, lesion distribution, size, nor relative ADC values. Conclusions: Differentiation of isolated punctuate hippocampal infarction and transient global amnesia based on neuroimaging findings is not possible. Thus, in the case of isolated punctuate hippocampal diffusion-weighted images lesions the final diagnosis of hippocampal infarction or transient global amnesia should be based on the clinical presentation. [ABSTRACT FROM AUTHOR]

A 67‐year‐old man was admitted to our hospital for gait disturbance due to muscle weakness of the right lower limb lasting for 2 months. Brain MRI demonstrated multiple small cerebral white matter lesions showing a subacute infarct pattern (approximately 10–21 days after ischemic stroke onset), characterized by both hyperintensities on diffusion‐weighted images and intermediate apparent diffusion coefficient (ADC) values. The ADC values of the lesions remained almost unchanged 4 months after onset and decreased in some lesions 8 months after onset. Random skin biopsy established a diagnosis of intravascular lymphoma (IVL). Brain lesions showing a persistent subacute infarct pattern on MRI may be an early feature of brain IVL. [ABSTRACT FROM AUTHOR]

Introduction: Corticobasal syndrome (CBS) has a heterogeneous clinical presentation with no specific pathologic substratum. Its accurate diagnosis is a challenge for neurologists; in order to establish CBS definitively, postmortem confirmation is required. Some clinical and radiological features can help to distinguish it from other neurodegenerative conditions, such as Creutzfeldt-Jakob disease (CJD). Clinical Case: A 74-year-old woman presented with language impairment, difficulty in walking and poor attentiveness that had begun 10 days before. Other symptoms, such as asymmetrical extra-pyramidal dysfunction, limb dystonia and ‘alien limb’ phenomena, were established over the next 2 months, with rapid progression. Death occurred 3 months after symptom onset. Laboratory results were normal. Initially, imaging only showed restricted diffusion with bilateral parieto-occipital gyri involvement on DWI-MRI, with unspecific EEG changes. An autopsy was performed. Brain neuropathology confirmed sporadic CJD (sCJD). Conclusions: CBS is a heterogeneous clinical syndrome whose differential diagnosis is extensive. CJD can occasionally present with clinical characteristics resembling CBS. MRI detection of abnormalities in some sequences (FLAIR, DWI), as previously reported, has high diagnostic utility for sCJD diagnosis – especially in early stages – when other tests can still appear normal. Abnormalities on DWI sequencing may not correlate with neuropathological findings, suggesting a functional basis to explain the changes found.

Background: Vessels encapsulating tumor clusters (VETC) have been considered an important cause of hepatocellular carcinoma (HCC) metastasis., Purpose: To compare the potential of various diffusion parameters derived from the monoexponential model and four non-Gaussian models (DKI, SEM, FROC, and CTRW) in preoperatively predicting the VETC of HCC., Methods: 86 HCC patients (40 VETC-positive and 46 VETC-negative) were prospectively enrolled. Diffusion-weighted images were acquired using six b-values (range from 0 to 3000 s/mm2). Various diffusion parameters derived from diffusion kurtosis (DK), stretched-exponential (SE), fractional-order calculus (FROC), and continuous-time random walk (CTRW) models, together with the conventional apparent diffusion coefficient (ADC) derived from the monoexponential model were calculated. All parameters were compared between VETC-positive and VETC-negative groups using an independent sample t-test or Mann-Whitney U test, and then the parameters with significant differences between the two groups were combined to establish a predictive model by binary logistic regression. Receiver operating characteristic (ROC) analyses were used to assess diagnostic performance., Results: Among all studied diffusion parameters, only DKI&#95;K and CTRW&#95;α significantly differed between groups (P=0.002 and 0.004, respectively). For predicting the presence of VETC in HCC patients, the combination of DKI&#95;K and CTRW&#95;α had the larger area under the ROC curve (AUC) than the two parameters individually (AUC=0.747 vs. 0.678 and 0.672, respectively)., Conclusion: DKI&#95;K and CTRW&#95;α outperformed traditional ADC for predicting the VETC of HCC., Competing Interests: Authors HZ and HG were employed by Siemens Healthcare Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Wen, Xie, Chen, Dang, Zhang, Guo and Long.)

BACKGROUND: Transient imaging abnormalities, including changes on diffusion-weighted imaging (DWI), may be seen in status epilepticus. These abnormalities can be followed by hippocampal sclerosis. CASE REPORT: We report a 15-year-old lady with focal non convulsive status epilepticus (NCSE) and focal slowing on EEG. DWI exhibited abnormal hyperintense signals in bilateral temporal and insular cortices. After 3 weeks, MRI performed a localizated hippocampal atrophy. CONCLUSION: The MRI findings indicated vasogenic and cytotoxic edema during seizure activity and subsequent loss of brain parenchyma.INTRODUÇÃO: Anormalidades transitórias de imagem, incluindo imagens de ressonância magnética por difusão (DWI), podem ser vistas no status epilepticus. Essas anormalidades podem ser seguidas de esclerose hipocampal. RELATO DE CASO: Nós relatamos uma jovem de 15 anos com status focal não convulsivo e lentificação focal no EEG. DWI mostrava sinal hiperintenso em regiões temporais bilaterais e córtex insular. Após 3 semanas, RM de encéfalo mostrava atrofia localizada do hipocampo. CONCLUSÃO: Os achados de RM indicam edema vasogênico e citotóxico durante as crises epilépticas com subseqüente atrofia de parênquima cerebral.

Abstract Objective Conus medullaris teratomas are very rare tumors. Traditional preoperative diagnosis depended on the findings from magnetic resonance imaging (MRI). Tractography is a novel technique that has recently been utilized to diagnose spinal cord lesions. This case report shows that fiber tractography has great potential in preoperative diagnosis and postoperative follow-up of teratomas of the conus medullaris. Methods A 50-year-old man with a conus medullaris teratoma underwent tractography with the aim of visualizing the tumor in relation to the white matter tracts. The patient underwent a T12–L2 laminectomy, and the lesion was resected. The histopathology diagnosis was of a mature teratoma. Study Design Case report. Results Diffusion tensor imaging (DTI) and tractography provide more details about the white matter tracts in relation to space-occupying lesions that may be more sensitive than conventional MRI and have recently been utilized in spinal cord lesions. Fiber tracking has the ability to visualize the integrity of the white matter tracts at the level of the conus medullaris in relation to the lesion. The tracts appeared to be displaced by the lesion at the conus medullaris. Tractography also showed no white matter tracts within the lesion. Such findings are consistent with the characteristics of a benign lesion. Exploiting tractography in this case was helpful in predicting the nature of the lesion preoperatively and in planning the surgical intervention. Conclusions Conus medullaris teratomas mostly affect adults. Patients generally present with a long history of clinical symptoms prior to diagnosis. Surgery is required for diagnosis, and the goal should be complete tumor excision without sacrificing any neurologic functions. The use of DTI and tractography, in addition to conventional MRI, has the potential to be very valuable for the diagnosis, surgical planning, and follow-up of patients with conus medullaris teratomas.

Effective image-based artifact correction is an essential step in the analysis of diffusion MR images. Many current approaches are based on retrospective registration, which becomes challenging in the realm of high $b$ -values and low signal-to-noise ratio, rendering the corresponding correction schemes more and more ineffective. We propose a novel registration scheme based on memetic search optimization that allows for simultaneous exploitation of different signal intensity relationships between the images, leading to more robust registration results. We demonstrate the increased robustness and efficacy of our method on simulated as well as in vivo datasets. In contrast to the state-of-art methods, the median target registration error (TRE) stayed below the voxel size even for high b$ -values (3000 \mathrm {s} \cdot \mathrm {mm}^{-2} and higher) and low SNR conditions. We also demonstrate the increased precision in diffusion-derived quantities by evaluating Neurite Orientation Dispersion and Density Imaging (NODDI) derived measures on a in vivo dataset with severe motion artifacts. These promising results will potentially inspire further studies on metaheuristic optimization in diffusion MRI artifact correction and image registration in general. [ABSTRACT FROM AUTHOR]

Endophthalmitis is a sight-threatening ophthalmologic emergency. The clinical diagnosis is often challenging, and delayed diagnosis may exacerbate the poor visual prognosis. B-scan ultrasonography or spectral domain optical coherence tomography are imaging aids at the clinician’s office. Cross-sectional imaging such as CT and particularly MRI can also help in the assessment of disease extent or complications. MR imaging findings are rarely described in the literature. Here, we discuss the spectrum of imaging findings of endophthalmitis and correlate them with key anatomic and pathophysiologic details of the globe. Early disease is often subtle on MR imaging with thick uveal enhancement, while advanced disease demonstrates retinal/choroidal detachment, vitreal exudates and peribulbar inflammation. Other noninfectious inflammatory diseases of the globe can show similar findings; however, MR diffusion-weighted images help identify infectious exudates and evaluate response to therapy. Knowledge of the spectrum of imaging findings of this disease is important for radiologists and help in the management decision process. [ABSTRACT FROM AUTHOR]

Introduction: Accessory spleen has a worldwide prevalence of 10%-30% and is defined as intrapancreatic accessory spleen (IPAS) when it locates within the pancreas. This occasional finding can raise difficulties in differential diagnosis with hypervascular pancreatic lesions, such as pancreatic neuroendocrine tumor. Presentation of cases: We present five cases in which a mass of the pancreatic tail was found on radiologic investigations. The first case was a young female patient who underwent a distal pancreatectomy because of a mass of the pancreatic tail misdiagnosed as a pancreatic neuroendocrine tumor due to its radiologic features on computed tomography and magnetic resonance imaging (MRI) (small, ovoidal, and well defined). Misdiagnosis also occurred in the second case, in which an 82-year-old woman was referred to our hospital because of a pancreatic mass of uncertain diagnosis. She also underwent an operation, and pathologic examination showed splenic parenchyma. A correct diagnosis was achieved in the remaining three cases that are still under radiologic monitoring. Discussion: IPAS is a benign entity and therefore does not require surgical treatment. We discuss the best diagnostic options that have recently been experienced, focusing on diffusion-weighted and superparamagnetic iron oxide MRI, which in our experience seem to be the safest and most easily accessible diagnostic tools. Conclusion: We suggest that a multidisciplinary approach should guide the diagnosis. When a pancreatic mass with specific features (round, ovoid, and well defined) is detected by computed tomography or MRI, an IPAS should be suspected. [ABSTRACT FROM AUTHOR]

MRI grading of grade II and III gliomas may have an important impact on treatment decisions. Occasionally, both conventional MRI (cMRI) and histology fail to clearly establish the tumour grade. Three cMRI features (no necrosis; no relevant oedema; absent or faint contrast enhancement) previously validated in 196 patients with supratentorial gliomas directed our selection of 68 suspected low-grade gliomas (LGG) that were also investigated by advanced MRI (aMRI), including perfusion weighted imaging (PWI), diffusion weighted imaging (DWI) and spectroscopy. All the gliomas had histopathological diagnoses. Sensitivity and specificity of cMRI pre-operative diagnosis were 78.5 and 38.5 %, respectively, and 85.7 and 53.8 % when aMRI was included, respectively. ROC analysis showed that cut-off values of 1.29 for maximum rCBV, 1.69 for minimum rADC, 2.1 for rCho/Cr ratio could differentiate between LGG and HGG with a sensitivity of 61.5, 53.8, and 53.8 % and a specificity of 54.7, 43 and 64.3 %, respectively. A significantly longer OS was observed in patients with a maximum rCBV <1.46 and minimum rADC >1.69 (80 vs 55 months, p = 0.01; 80 vs 51 months, p = 0.002, respectively). This result was also confirmed when cases were stratified according to pathology (LGG vs HGG). The ability of aMRI to differentiate between LGG and HGG and to predict survival improved as the number of aMRI techniques considered increased. In a selected population of suspected LGG, classification by cMRI underestimated the actual fraction of HGG. aMRI slightly increased the diagnostic accuracy compared to histopathology. However, DWI and PWI were prognostic markers independent of histological grade. [ABSTRACT FROM AUTHOR]