Diffusion-weighted Imaging MRI Research Articles

Prostate Cancer Detection using Deep Convolutional Neural Networks

Prostate cancer is one of the most common forms of cancer and the third leading cause of cancer death in North America. As an integrated part of computer-aided detection (CAD) tools, diffusion-weighted magnetic resonance imaging (DWI) has been intensively studied for accurate detection of prostate cancer. With deep convolutional neural networks (CNNs) significant success in computer vision tasks such as object detection and segmentation, different CNN architectures are increasingly investigated in medical imaging research community as promising solutions for designing more accurate CAD tools for cancer detection. In this work, we developed and implemented an automated CNN-based pipeline for detection of clinically significant prostate cancer (PCa) for a given axial DWI image and for each patient. DWI images of 427 patients were used as the dataset, which contained 175 patients with PCa and 252 patients without PCa. To measure the performance of the proposed pipeline, a test set of 108 (out of 427) patients were set aside and not used in the training phase. The proposed pipeline achieved area under the receiver operating characteristic curve (AUC) of 0.87 (95{boldsymbol{ % }} Confidence Interval (CI): 0.84–0.90) and 0.84 (95{boldsymbol{ % }} CI: 0.76–0.91) at slice level and patient level, respectively.

The Added Value of Quantitative DWI MRI in Differentiation between Benign and Malignant Osseous Musculoskeletal Tumours

Abstract Background: MRI has a key role in identification of MSK masses, especially in depiction of their nature, borders, regional involvement and their relation to the surrounding organs and neurovascular bundle. MRI aids clinicians in assessment of osseous tumors to depict the extra-osseous component, and the regional location as well, since both parameters are crucial for the pre-operative assessment. Aim of Study: To evaluate the role of Diffusion Weighted Imaging (DWI) in differentiation of benign and malignant osseus musculoskeletal (MSK) tumors and its added value clinically on patient's management. Patients and Methods: The study included 100 patients; 65 males (65%), and 35 females (35%). Their ages ranged from 3 to 69 years with mean age about 31 years. Patients were selected based on clinical and X-ray image suspicion of MSK tumors. Signal intensity of the lesion on DWI was determined and Attenuation Diffusion Coefficient (ADC) map was measured. The Region of Interest (ROI) for each lesion was placed at least 3 times, and then the mean ADC value for the lesion was calculated. Histopathological findings and clinical follow-up were used as standard of reference. Results: Twenty one 21 (21%) patients had benign tumors, 73 (73%) patients had malignant tumors and 6 (13.6%) patients had tumor like lesion. The cut-off value for mean ADC was <1 X 10–3mm2/sec. The gold standard of this study was the histopathological correlation and the imaging-clinical correl-ative features for the benign lesions. Conclusion: DWI MRI technique that is easily included in a routine MR study with short scanning time offering valuable data about the cellularity of a MSK lesion and properly differentiating benign and malignant lesions.

Value of dynamic and DWI MRI in evaluation of HCC viability after TACE via LI-RADS v2018 diagnostic algorithm

BackgroundDetection of the value of DCE (dynamic contrast enhanced) MRI and DWI (diffusion-weighted imaging) in follow-up of treatment response for HCC (hepatocellular carcinoma) lesions post TACE (trans-arterial chemo-embolization) through LI-RADS v2018 algorithmic approach.ResultsA prospective study was performed on 30 patients with 41 treated hepatic focal lesions. The patients underwent DCE MRI with DWI in less than 1-month duration following TACE procedure and were radiologically assessed to observe tumoral post treatment response; then, another follow-up after another 3 months later was done for non-viable, equivocal, and non-evaluable post treatment response categories. Statistical analysis showed that DCE MRI had 100% level of sensitivity, specificity of 95.24%, PPV of 95.00%, and NPV of 100% with an overall agreement of 97.50%. While on the other hand, statistics showed that DWI has 52.63% level of sensitivity, specificity of 90.48%, PPV of 83.33%, PPV of 67.86%, and NPV of 72.50%.The difference between non-viable and viable groups’ ADC variables was found statistically significant at P value < 0.001, and best cut off value that augments sensitivity and specificity is 1.35. At this ADC value, sensitivity reaches 78.9% and specificity is 85.7%.ConclusionsOur study showed that DCE MRI has 100% level of sensitivity via application of LI-RADS v2018 diagnostic algorithmic approach while DWI alone has 52.63% level of sensitivity, yet it can enhance the diagnostic confidence of DCE MRI for post treatment response viability detection.

Does the Diffusion Weighted Images and Subtration MRI of Hepatocellular Carcinoma has a Role in Predicting Outcome of Transarterial Chemoembolization?

AbstractBackground: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has a poor prognosis unless treated. Ablative therapies are promising treatment options for patients who are not eligible for surgery.Aim of Study: Is to evaluate the predictive values of diffusion-weighted imaging (DWI) and Subtration MRI in evaluating the efficacy of transcatheter arterial chemoembol-ization (TACE) in treatment of patients with hepatocellular carcinoma (HCC).Patients and Methods: This study included 30 patients with pathologically proven HCC (38 HCC lesions) who were referred to the Radiology Department of Ain Shams University Hospitals and National Liver Institute, Menofiya University for post therapeutic assessment after transarterial hepatic chemoembolization. The study was carried on over a period of 12 month (from August 2017 to August 2018). Patients' ages ranged from 59 to 73 with a mean of age 59.6 years. Of the 30 patients only 6 were females and 24 were males.Results: We found that dynamic study is the gold standard in detection of recurrent lesions. Well defined nodular en-hancement, thick irregular marginal enhancement or gross enlargement of the lesion with arterial phase enhancement and contrast wash out were considered positive for malignancy. Ill-defined persistent enhancement or well defined rim marginal enhancement were considered benign post ablation changes. We found that subtraction technique was essential in differ-entiation between the normal hyperintense T1 signal of the ablation zone and arterial enhancement of the lesion. The high signal intensity seen in T1 images post TACE was explained by haemorrhagic coagulative necrosis. Subtraction imaging is ideally suited for such a role where the unenhanced T1-weighted sequence is subtracted from the identical contrast enhanced sequence.Conclusion: We conclude that in evaluation of HCC after TACE, ADC calculated at DWI had weaker correlation to tumor necrosis degree than did findings with subtraction contrast-enhanced MRI. However, there was no difference between both methods in diagnosis of complete tumor necrosis.We suggest that whenever possible, gadolinium contrast enhancement and subtraction imaging be used for assessment of tumor necrosis after TACE.

Surgical mapping of middle ear cholesteatoma with fusion of computed tomography and diffusion-weighted magnetic resonance images: Diagnostic performance and interobserver agreement

ObjectiveTo assess the diagnostic performance in detecting primary cholesteatoma at various anatomical subsites using Computed Tomography (CT), Diffusion-weighted Magnetic Resonance Imaging (DWMRI) and Fusion of CT and DWMRI (Fusion CT-MRI) images. Study designA retrospective study of 22 children identified from a prospective database of surgically treated cholesteatoma cases over a five year period. All cases underwent pre-operative CT, non-echo planar DWMRI and Fusion CT-DWMRI, and with clearly documented surgical findings. For each imaging modality, two radiologists scored for the presence or absence of cholesteatoma with confidence levels at different anatomical subsites. The radiologists were blinded to the surgical findings to which their findings were compared. SettingLarge Teaching Hospital in London. Patients22 children with cholesteatoma confirmed surgically. InterventionCT, DWMRI imaging and fusion CT-MRI. Main outcome measureDiagnostic performance of subsite localisation of cholesteatoma by CT, DWMRI and fusion CT-MRI imaging with intra-operative findings. ResultsTwenty-two patients were included (12 women and 10 men). The median age of patients was 11 years. When considering all subsites combined, the result for all imaging methods suggested ‘good’ agreement between both observers. When all subsites were examined together, all methods had relatively high sensitivity values (87% for CT vs 84% for DWMRI vs 85% for fusion CT-DWMRI). Specificity was highest with fusion CT-DWMRI (46% for CT vs 76% for DWMRI vs 97% for fusion CT-DWMRI), as was accuracy (66% for CT vs 80% for DWMRI vs 91% for fusion). ConclusionsOur study has demonstrated that fusion CT-DWMRI is superior to DWMRI or CT separately in localizing cholesteatoma at various middle ear cleft subsites and bony relations, making it a valuable tool for surgical planning.

Invasive ductal breast cancer: preoperative predict Ki-67 index based on radiomics of ADC maps.

The purpose of this study is to develop a radiomics model for predicting the Ki-67 proliferation index in patients with invasive ductal breast cancer through magnetic resonance imaging (MRI) preoperatively. A total of 128 patients who were clinicopathologically diagnosed with invasive ductal breast cancer were recruited. This cohort included 32 negative Ki67 expression (Ki67 proliferation index < 14%) and 96 cases with positive Ki67 expression (Ki67 proliferation index ≥ 14%). All patients had undergone diffusion-weighted imaging (DWI) MRI before surgery on a 3.0T MRI scanner. Radiomics features were extracted from apparent diffusion coefficient (ADC) maps which were obtained by DWI-MRI from patients with invasive ductal breast cancer. 80% of the patients were divided into training set to build radiomics model, and the rest into test set to evaluate its performance. The least absolute shrinkage and selection operator (LASSO) was used to select radiomics features, and then, the logistic regression (LR) model was established using fivefold cross-validation to predict the Ki-67 index. The performance was evaluated by receiver-operating characteristic (ROC) analysis, accuracy, sensitivity and specificity. Quantitative imaging features (n = 1029) were extracted from ADC maps, and 11 features were selected to construct the LR model. Good identification ability was exhibited by the ADC-based radiomics model, with areas under the ROC (AUC) values of 0.75 ± 0.08, accuracy of 0.71 in training set and 0.72, 0.70 in test set. The ADC-based radiomics model is a feasible predictor for the Ki-67 index in patients with invasive ductal breast cancer. Therefore, we proposed that three-dimensional imaging features from ADC maps could be used as candidate biomarker for preoperative prediction the Ki-67 index noninvasively.

Accuracy of multiparametric magnetic resonance imaging for detecting extracapsular extension in prostate cancer: a systematic review and meta-analysis.

To evaluate the diagnostic accuracy of multiparametric MRI (mpMRI) for detecting extracapsular extension (ECE) in patients with prostate cancer (PCa). We searched MEDLINE, PubMed, Embase and the Cochrane library up to December 2018. We included studies that used mpMRI to differentiate ECE from organ-confined PCa with a combination of T2 weighted imaging (T2WI), diffusion-weighted imaging, and dynamic contrast-enhanced MRI. All studies included had pathological diagnosis with radical prostatectomy. Two reviewers independently assessed the methodological quality of included studies by using Quality Assessment of Diagnostic Accuracy Studies 2 tool. We calculated pooled sensitivity, specificity, positive and negative predictive values, diagnostic odds ratios and receiver operating characteristic curve for mpMRI from 2 × 2 tables. A total of 17 studies that comprised 3374 participants were included. The pooled data showed a sensitivity of 0.55 (95% confidence interval 0.43, 0.66]) and specificity of 0.87 (95% confidence interval 0.82, 0.91) for extracapsular extension detection in PCa. First, our meta-analysis shows moderate sensitivity and high specificity for mpMRI to differentiate ECE from organ-confined prostate cancer before surgery. Second, our meta-analysis shows that mpMRI had no significant differences in performance compared with the former meta-analysis with use of T2WI alone or with additional functional MRI. It is the first meta-analysis to evaluate the accuracy of mpMRI in combination of TWI, diffusion-weightedimaging and dynamiccontrast-enhanced-MRI for extracapsular extension detection.

Neonatal hypoxic encephalopathy: Correlation between post-cooling brain MRI findings and 2 years neurodevelopmental outcome.

Objective:This study aims to evaluate the magnetic resonance imaging (MRI) brain patterns among hypoxic-ischemic encephalopathy (HIE) babies who underwent post-cooling MRI brain as well as to correlate the post-cooling brain scoring with patient's neurodevelopmental outcome at 2 years.Subjects and Methods:It was a retrospective cross sectional study carried out at a tertiary university hospital. Record of patients diagnosed with neonatal HIE from 2007 until 2016 who completed 72 h of cooling therapy and had MRI brain within 2 weeks of life were included in this study. A new scoring system by Trivedi et al. that emphasizes on subcortical deep gray matter and posterior limb internal capsule injury were utilized upon MRI assessment, using TW, T2W, and diffusion-weighted imaging (DWI) sequences. Cumulative MRI brain score was obtained and graded as none, mild, moderate, and severe brain injury. The MRI brain scoring was then correlated with patient's 2 years neurodevelopmental outcome using Fisher's Exact Test.Results:A total of 23 patients were eligible of which 19 term neonates were included. 13% of these neonates (n = 3) had mild MRI brain injury grading with 52.2% (n = 12) moderate and 34.8% (n = 8) severe. There was no significant correlation seen between MRI brain grading and developmental outcome at 2 years old (P > 0.05).Conclusion:There was no significant correlation between neonatal MRI brain injury grading and 2 years neurodevelopmental outcome. Nevertheless, the new MRI brain scoring by Trivedi et al. is reproducible and comprehensive as it involves various important brain structures, assessed from different MRI sequences.

Is MRI diffusion-weighted imaging a reliable tool for the diagnosis and post-therapeutic follow-up of extremity soft tissue neoplasms?

Purpose:The aim of this study was to evaluate the benefit of using quantitative diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping in the initial diagnosis and post-therapeutic follow-up of extremity soft tissue masses.Patients and Methods:This study included 90 patients with extremity soft tissue masses. The DWI was obtained with 3 b values, including 0, 400, and 800 s/mm2. Calculation of the ADC value of the lesion was done by placing the region of interest (ROI) to include the largest area of the lesion. ADC values were compared with the histopathology. Eighteen patients had posttherapeutic magnetic resonance imaging (MRI).Results:Benign masses, fibromatosis, and malignant soft tissue masses had mean ADC values of 1.18 ± 1.0191 × 10−3 mm2/s; 1.31 ± 0.245 × 10−3 mm2/sec; and 1.3 ± 0.7 × 10−3 mm2/s, respectively. Myxomatous malignant masses had an ADC value of 2.6 ± 0.55 × 10−3 mm2/s, while nonmyxomatous malignant masses had an ADC value of 1.1 ± 0.8 × 10−3 mm2/s. ADC cutoff value between benign and non-benign (including malignant and locally aggressive masses) was 0.6 × 10−3 mm2/sec with 98.3% sensitivity and 50% specificity (P = 0.5123). The statistical difference between malignant soft tissue masses (mean ADC 1.309 ± 0.723 × 10−3 mm2/s) and fibromatosis masses (mean ADC value 1.31 ± 0.245 × 10−3 mm2/s) using a comparative T-test proved to be of poor significance level (P value ~ 0.9757). Nine patients with soft tissue sarcomas (STSs) had pre and post-therapeutic MRI examinations showing a mean increase of the recorded ADC values by about 0.28 × 10−3 mm2/s in the post-therapy study as compared with the recorded initial pretreatment values. Analysis of the post-therapy follow-up studies of fibromatosis showed that lesions with favorable response to chemotherapy or radiotherapy (8/12) exhibited significantly lower ADC values than those showing progressive disease course.Conclusion:DWI with ADC mapping of extremity soft tissue tumors are so complicated that they alone may not be of much value in differentiating between benign and malignant tumors; however, it can be used as a tool for monitoring response to treatment.

Whole-body diffusion-weighted MRI for evaluation of response in multiple myeloma patients following bortezomib-based therapy: A large single-center cohort study

PurposeTo determine the feasibility of whole-body diffusion-weighted imaging (WB-DWI) MRI for evaluation of response in patients with multiple myeloma (MM) following bortezomib-based therapy and to explore the direction of apparent diffusion coefficient (ADC) changes upon treatment. MethodSeventy-two MM patients who underwent WB-DWI MRI before and after bortezomib-based chemotherapy (21 weeks) were evaluated retrospectively. The estimated tumor volume (eTV) and ADCmean values before and after chemotherapy were calculated and compared between deep and non-deep responders. Predictive value of baseline ADCmean was calculated to predict the trend of ADCmean change following treatment. ResultsFifty-five patients were classified as deep responders, and 17 cases were assigned as non-deep responders. For 327 focal lesions (FLs), the ADCmean value was significantly increased from baseline to post-treatment. However, the ADCmean value was significantly decreased following treatment in 846 representative diffuse lesions. Diffuse lesions showed a significantly decreased ADCmean value in deep responders, whereas no significant variation in ADCmean value in FLs was found between deep and non-deep responders. Baseline ADCmean at a specific value (0.808 × 10−3 mm2/s) yielded a maximum specificity (68.05%) and sensitivity (54.09%) in predicting increase of post-treatment ADCmean. ConclusionsThe ADCmean value was significantly decreased in MM patients with diffuse pattern, while it was significantly increased in those with focal pattern following bortezomib-based treatment. WB-DWI MRI could be used to discriminate deep response to induction treatment in MM patients with diffuse infiltration pattern. Baseline ADCmean value might have a potential to predict the trend of ADCmean change following treatment.

Colorectal cancer: Parametric evaluation of morphological, functional and molecular tomographic imaging.

Colorectal cancer (CRC) represents one of the leading causes of tumor-related deaths worldwide. Among the various tools at physicians’ disposal for the diagnostic management of the disease, tomographic imaging (e.g., CT, MRI, and hybrid PET imaging) is considered essential. The qualitative and subjective evaluation of tomographic images is the main approach used to obtain valuable clinical information, although this strategy suffers from both intrinsic and operator-dependent limitations. More recently, advanced imaging techniques have been developed with the aim of overcoming these issues. Such techniques, such as diffusion-weighted MRI and perfusion imaging, were designed for the “in vivo” evaluation of specific biological tissue features in order to describe them in terms of quantitative parameters, which could answer questions difficult to address with conventional imaging alone (e.g., questions related to tissue characterization and prognosis). Furthermore, it has been observed that a large amount of numerical and statistical information is buried inside tomographic images, resulting in their invisibility during conventional assessment. This information can be extracted and represented in terms of quantitative parameters through different processes (e.g., texture analysis). Numerous researchers have focused their work on the significance of these quantitative imaging parameters for the management of CRC patients. In this review, we aimed to focus on evidence reported in the academic literature regarding the application of parametric imaging to the diagnosis, staging and prognosis of CRC while discussing future perspectives and present limitations. While the transition from purely anatomical to quantitative tomographic imaging appears achievable for CRC diagnostics, some essential milestones, such as scanning and analysis standardization and the definition of robust cut-off values, must be achieved before quantitative tomographic imaging can be incorporated into daily clinical practice.

Diffusion-weighted and perfusion-weighted magnetic resonance imaging of the prostate gland of healthy adult dogs.

To describe diffusion and perfusion characteristics of the prostate gland of healthy sexually intact adult dogs as determined by use of diffusion-weighted and perfusion-weighted MRI. 12 healthy sexually intact adult Beagles. Ultrasonography of the prostate gland was performed. Subsequently, each dog was anesthetized, and morphological, diffusion-weighted, and perfusion-weighted MRI of the caudal aspect of the abdomen was performed. The apparent diffusion coefficient was calculated for the prostate gland parenchyma in diffusion-weighted MRI images in the central ventral and peripheral dorsal areas. Perfusion variables were examined in multiple regions of interest (ROIs) in the ventral and dorsal areas of the prostate gland and in the gluteal musculature. Signal intensity was determined, and a time-intensity curve was generated for each ROI. Results of ultrasonographic examination of the prostate gland revealed no abnormalities for any dog. Median apparent diffusion coefficient of the prostate gland was 1.51 × 10-3 mm2/s (range, 1.04 × 10-3 mm2/s to 1.86 × 10-3 mm2/s). Perfusion-weighted MRI variables for the ROIs differed between the prostate gland parenchyma and gluteal musculature. Results provided baseline information about diffusion and perfusion characteristics of the prostate gland in healthy sexually intact adult dogs. Additional studies with dogs of various ages and breeds, with and without abnormalities of the prostate gland, will be necessary to validate these findings and investigate clinical applications.

Final Trial Results of Repeated Diffusion-Weighted MRI and FDG-PET Imaging for the Prediction of Response to Chemoradiation Therapy in Esophageal Cancer

To present the final results of a prospective study to evaluate imaging predictors for pathologic complete response (pathCR) to chemoradiation therapy (CRT) in esophageal cancer using repeated diffusion-weighted magnetic resonance imaging (DW-MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging before, during, and after CRT. Between January 2014 and July 2017, 60 patients with stage II-III esophageal cancer were prospectively enrolled. DW-MRI and FDG-PET imaging were acquired before treatment (baseline), 12-14 days after initiation of CRT (interim, IM), and at first follow-up 4-6 weeks after completing CRT. The primary outcome was pathCR as assessed after subsequent surgery, with secondary outcomes evaluating locoregional and distant progression-free survival (LPFS and DPFS), and overall survival (OS) according to the imaging parameters. Logistic regression analysis was used to evaluate the association of primary tumor apparent diffusion coefficient (ADC) values, maximum and mean standardized uptake value (SUV), metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG) at baseline and their relative changes (Δ) at interim and follow-up scans with pathCR. Survival analyses applied to evaluate the association of the imaging parameters with LPFS, DPFS, and OS. Surgery after CRT was performed in 29 (48%) of 60 included patients. Imaging data was eligible for analysis in 28 patients in whom pathCR was observed in 7 (25%). The change in tumor mean ADC from the baseline to the interim DW-MRI scan, at a threshold of +27.7%, was best predictive for pathCR (c-statistic=0.98). The change in TLG from the baseline to interim FDG-PET scan, at a threshold of 58% decrease, was the best FDG-PET-based predictor of pathCR (c-statistic=0.77). Multivariable logistic regression suggested no significant added value of ΔTLGIM to ΔADCIM for the prediction of pathCR. Median follow-up was 29 months (range: 5-59) overall and 36 months (range: 24-59) for survivors. In surgical patients no locoregional progression was seen, and studied DW-MRI and FDG-PET parameters were not significantly associated with DPFS or OS. For non-surgical patients with ΔADCIM above vs below +27.7%, observed locoregional recurrence rates were 1/5 (20%) vs 7/25 (28%) (NS), and distant recurrence rates were 1/5 (20%) vs 15/25 (60%) (NS). For non-surgical patients with ΔTLGIM below vs above -58%, observed locoregional recurrence rates were 2/11 (18%) vs 5/17 (29%) (NS), and distant recurrence rates were 3/11 (27%) vs 12/17 (71%) (log-rank test, p=0.04). No association between imaging parameters and OS was observed. ΔADC on DW-MRI after 2 weeks of CRT strongly predicts pathologic complete response in esophageal cancer, with superior performance to repeated FDG-PET imaging. Early response assessment using DW-MRI is potentially useful for stratification of esophageal cancer patients to treatment intensification or organ-preserving strategies.

Automated Detection of Brain Stroke in MRI with Hybrid Fuzzy C-Means Clustering and Random Forest Classifier

Neuroimaging investigation is an essential parameter to detect infarct lesion in stroke patients. Precise detection of brain lesions is an important task related to impaired behavior. In this paper, we aimed to develop an automatic method to segment and classify infarct lesion in diffusion-weighted imaging (DWI) of brain MRI. The method includes hybrid fuzzy [Formula: see text]-means (HFCM) clustering in which the structure of [Formula: see text]-means clustering is modified with rough sets and fuzzy sets to improve the segmentation performance with self-adjusted intensity thresholds. Quantitative evaluation was carried out on 128 MRI slices of brain image collected from ischemic stroke patients at the Department of Radiology, IMS and SUM Hospital, Bhubaneswar. The informative statistical features have been extracted using gray-level co-occurrence matrix (GLCM) and used to classify the types of stroke infarct according to the Oxfordshire Community Stroke Project (OCSP) classification. The parameters such as accuracy, Dice similarity index (DSI) and Jaccard index (JI) were utilized to evaluate the effectiveness of the proposed method in detecting the stroke lesions. The segmentation method achieved the average accuracy, DSI and JI of 96.8%, 95.8% and 92.2%, respectively, in support vector machine (SVM) classifier. The obtained results are higher in terms of random forest (RF) classification. With a high Dice coefficient of 0.958 and other evaluated parameters, the proposed method outperforms earlier published results.

Value of Serial Multi-Parametric Functional MRI and FDG-PET during Radiation Therapy in Predicting Clinical Outcomes in Patients with Head and Neck Squamous Cell Carcinoma

To assess the utility of mid-treatment FDG-PET, DWI and R2*-MR functional imaging in predicting clinical response in patients receiving definitive radiotherapy (RT) for mucosal head and neck squamous cell carcinoma (HNSCC). Patients undergoing definitive radiotherapy with/without systemic therapy were recruited in a prospective imaging biomarker study. FDG-PET/CT was performed at baseline, during (week 3) and post RT (3 months). Diffusion-weighted imaging (DWI) and susceptibility-weighted MRI were performed using 3T scanner at baseline and during RT (week 2, 3, 5 and 6). The mean apparent diffusion coefficient (ADCmean) from DWI, mean R2* values derived from T2*-MRI and PET metabolic parameters including maximum standardized uptake (SUVmax), mean standardized uptake (SUVmean), metabolic tumor volume (MTV) and total lesional glycolysis (TLG) were measured for the primary tumor. Absolute and relative percentage change (%Δ) in serial PET and MR parameters were correlated to local and distant recurrence and survival using the Mann-Whitney U test. Poor imaging response was dichotomized in relation to; 1) mean values of ADCmean and; 2) 50% reduction in PET parameters for Kaplan-Meier survival analysis. Pre-treatment scans were performed in 33 patients and analyzable mid-treatment scans were available for 21 patients. Median follow-up was 43 months and 2-year local recurrence-free survival (LRFS), distant metastatic relapse-free survival (DMFS) and overall survival (OS) rates were 81%, 90% and 62%, respectively. Patients with local recurrence (LR) had a significantly lower %Δ in SUVmax (p=0.05), SUVmean (p=0.04) and TLG (p=0.05) at week 3 compared to baseline. There was trend towards higher pre-treatment ADCmean in patients with LR (1.09 vs 1.27 x 10-3mm2s-1) without reaching statistical significance potentially due to sample size. A significant rise in ADCmean was found during the first half (p < 0.001) of RT but not in the second half of the treatment. Patients with poor week 2 %Δ ADCmean rise during RT had worse LRFS (100% vs 63%, p<0.04). %Δ ADCmean at subsequent weeks were not associated with LRFS, DMFS, or OS. No absolute or %Δ R2* values were associated with clinical outcomes. Using combination of poor week 2 %Δ ADCmean and SUVmax response at week 3 was associated with improved LRFS (100% vs 43%, p=0.005). Early changes in FDG-PET and ADC can potentially predict clinical response to radiotherapy in HNSCC and aid in future risk-adaptation studies. Combination of functional imaging parameters show a promising avenue to enhance prediction of response. Based on our results week 2 appears to be a promising time period for mid-treatment DWI assessment of tumor response.

Baseline Diffusion Weighted Magnetic Resonance Imaging to Predict Recurrence of Anal Squamous Cell Carcinoma (ASCC) Following Chemoradiotherapy

The aim of this study was to investigate the added value of baseline diffusion weighted MRI (DWI) heterogeneity analysis to predict response to chemoradiotherapy (CRT) in patients with primary squamous cell carcinoma of anal canal. We have previously demonstrated that MRI heterogeneity features may have an added value in response prediction in ASCC, here, we present the effect of DWI texture features on disease free survival in an expanded patient cohort. An IRB waiver was obtained for retrospective analysis of standard of care MRI including diffusion weighted sequences from consecutive patients with ASCC undergoing CRT treatment between 2010 and 2016. Whole tumor 3D volume of interest (VOI) was manually delineated on apparent diffusion coefficient (APC) parametric maps with reference to T2 & diffusion weighted imaging by two experienced readers in consensus generating 76 imaging features/VOI. Primary endpoint was disease recurrence (local or metastatic). Patients were censored either at time of event or last follow up. Kaplan Meier survival curves with log rank p-values were calculated for clinic-pathological variables. Most predictive univariate imaging features were selected based on their highest permutation based importance using Random Forest algorithm for survival. 65 patients were included in the current analysis (42 female, 23 male, median age 60 (range 37-85)). 33/65 patients had T3 or T4 disease and 48/65 were node positive. 43 patients achieved a complete response (CR) on re-staging MRI at 10-12 weeks post CRT. Median follow-up was 36 months (2-102). Recurrence occurred in 20/65 patients. Higher T stage (T3/T4), node positivity, gender and presence of CR alone were not significantly associated with improved disease free survival (p=0.52, 0.84, 0.28 and 0.3, respectively). Five baseline DWI imaging features with highest importance were found to be significantly associated with recurrence free survival: ADC maximum, ADC standard deviation, ADC CoV, ADC Log Entropy 1.5, ADC Range (HR>1, p < 0.001). Baseline ADC may have a role in predicting long term outcome in patients with ASCC undergoing CRT treatment and warrants further investigation in prospective trials.

Acute Stroke Treatment in Patients with Basilar Artery Occlusion: A Single-Center Observational Study

Background: Acute ischemic stroke (AIS) due to basilar artery occlusion (BAO) represents 1–4% of all ischemic strokes. BAO results in strokes associated with a high risk of a poor functional outcome and, in 86–95% of the untreated cases, it results in death because of the vital cerebral structures involved. Diagnosis can be delayed because of the variability in presenting symptoms, and acute treatment is often attempted even beyond 6 h from symptoms onset because of the high risk of a fatal prognosis. Objective: In this observational study, we retrospectively analyzed patients with AIS due to BAO referred to the stroke center of the University Hospital of Messina. We aimed to assess prognostic factors and to evaluate the association between clinical outcome and posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and collateral status. Method: BAO was confirmed by cerebral computed tomography (CT) angiography or cerebral angiography. All patients underwent CT scan and magnetic resonance imaging (MRI). We assessed the pc-ASPECTS on diffusion-weighted imaging (DWI) MR images and the Posterior Circulation Collateral Score (PC-CS) for every patient. Functional outcome was assessed at 3 months using the modified Rankin Scale (mRS). Results: The study population consisted of 27 patients; 16 males and 11 females. The mean age was 66 (±14) years. We observed a favorable outcome (mRS 0–3) in 40.7% of cases, 25.9% reached mRS 0–2, and 29.6% had a poor clinical outcome (mRS 4–5). Patient survival was 70.4%, whereas 8 patients died (29.6%). In 7 patients, pc-ASPECTS was ≥7. According to the PC-CS, 33.3% had moderate collaterals and 63.0% had good collateral status prior to receiving the treatment. Favorable outcome was significantly associated with age, NIHSS score at admission, pc-ASPECTS, hypercholesterolemia, and female sex but not with the other risk factors. Conclusions: In our study, we found that younger age, low NIHSS score at admission, and high pc-ASPECTS, but not onset to treatment time, are associated with a favorable clinical outcome. Transferred patients did not have a significantly poorer outcome. These findings confirm that acute stroke treatment improves clinical outcome in BAO patients, in spite of a delayed diagnosis and an extended therapeutic window, considering lesion volume and localization in DWI MRI.

Diffusion-Weighted Magnetic Resonance Imaging for Early Detection of Chemotherapy Resistance in Non-Small Cell Lung Cancer.

BackgroundThe aim of this study was to examine the role of magnetic resonance imaging-diffusion weighted imaging (MRI-DWI) in the early detection of chemotherapy resistance in non-small cell lung cancer (NSCLC) patients.Material/MethodsMRI-DWI and computed tomography (CT) were carried out in 75 patients with newly diagnostic NSCLC before and after first, second, fourth, and sixth cycles of chemotherapy. Resistance to chemotherapy was assessed based on the change in the largest tumor diameter after chemotherapy. Diffusion of water molecule in each lesion was quantitatively measured by apparent diffusion coefficient (ADC). The diagnostic results of DWI after first and second cycle of chemotherapy were analyzed by the area under receiver operating characteristics curve (ROC).ResultsAmong the patients, 43 patients were chemo-resistance while 32 patients were chemo-sensitive. The ADC changing rate between second and first cycle of chemotherapy was significantly higher in chemo-sensitive patients compared with chemo-resistance patients (t=3.236, P=0.002). The ROC showed cutoff values of the ADC changing rate after first and second cycles of chemotherapy for resistance/sensitive discrimination were 23.6% and 5.56%, respectively. DWI after first and second cycles of therapy showed sensitivities of 55.8% and 55.8%, specificities of 65.6% and 87.5%, and area under ROC of 0.568 and 0.733, respectively.ConclusionsADC changing rate between first and second cycles of chemotherapy could sensitively distinguish chemo-sensitive and chemo-resistant tumors at earlier stages, which may direct treatment adjustment and improve the prognosis of patients.

Sudden onset of sleep caused by hypothalamic infarction: a case report

BackgroundHypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep.Case presentationA 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed.ConclusionHypothalamic stroke should be considered a cause of sudden onset of sleep.

Risk factors for new ischaemic cerebral lesions after carotid artery stenting: protocol for a systematic review and meta-analysis

IntroductionNew ischaemic cerebral lesions (NICL) detected by diffusion-weighted imaging MRI are common after carotid artery stenting (CAS), with an occurrence rate ranging from 18% to 57%. Many studies reported occurrence...