Gallbladder carcinoma: an initial clinical experience of reduced field-of-view diffusion-weighted MRI

Delineation of Spatially-Varied High-Risk GTV in Pancreatic Adenocarcinoma Using MRI-ADC Maps

Magnetic resonance imaging (MRI) has now become the best modality for the preoperative staging of cervical cancer. This study was to compare the value of high-resolution reduced field-of-view diffusion-weighted MR imaging (r-FOV DWI) with conventional field-of-view (c-FOV DWI) in the diagnosis of cervical cancer. Forty-five patients (25 patients with cervical cancer and 20 patients with normal cervix) received magnetic resonance (MR) scans (3.0T), including both r-FOV DWI and c-FOV DWI sequences. The image quality (IQ) of both sequences was subjectively assessed by two attending radiologists using a double-blind method and quantitatively by the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Moreover, apparent diffusion coefficient (ADC) values for cervical cancer were blindly measured by one technician on the ADC map. The subjective scores of r-FOV DWI images were higher than those of c-FOV DWI (P<0.0001), and the interrater reliability was in good agreement [Cohen's kappa coefficient (κ) =0.547-0.914]. There was a significant difference in CNR between the two DWI image groups (r-FOV DWI 12.73±5.56 vs. c-FOV DWI 11.21±5.92, P=0.019). The difference in mean ADC values between the two DWI sequences was statistically significant [r-FOV DWI (0.690±0.195)×10-3 mm2/s vs. c-FOV DWI (0.794±0.167)×10-3 mm2/s, P<0.001]. The ADC value of cervical cancer lesions [(0.690±0.195)×10-3 mm2/s] was significantly lower than that of normal cervix ADC value [(1.506±0.188)×10-3 mm2/s]. r-FOV DWI can effectively improve the spatial resolution of the image while reducing distortion and artifacts. Furthermore, it can help to diagnose cervical cancer more accurately for the more realistic ADC values.

Aim: We compared head computed tomography (HCT) and diffusion-weighted magnetic resonance imaging (DW-MRI) findings before target temperature management (TTM) to predict neurological outcomes in out-of-hospital cardiac arrest survivors. Methods: Using prospectively collected data from a TTM registry, we included patients who underwent HCT and DW-MRI within 6 h of return of spontaneous circulation (ROSC). We examined the gray-to-white matter ratio (GWR) on HCT and apparent diffusion coefficient (ADC) values obtained through voxel-based analysis of DW-MRI. We analyzed the mean ADC value and the % voxels of ADC thresholds (percentage of voxels below ADC thresholds per total voxel) at 50-step intervals ranging from 200 to 1200 х 10 -6 mm/s, identifying thresholds that differentiate between good and poor neurological outcomes. Additionally, we analyzed the combination of pupillary light reflex (PLR) and neuron-specific enolase (NSE) values acquired at the same time points to predict the neurological outcomes. The primary outcome measure was the dichotomized cerebral performance category (CPC) at six months, defined as good (CPC 1-2) or poor (CPC 3-5). Results: Of 131 patients (26% female), 74 (57%) had poor outcomes. The time from ROSC to HCT and DW-MRI scans was 1.7h and 3.2h, respectively. The group with a good outcome had higher GWR (1.26 vs. 1.20) and mean ADC (787.10 vs. 697.49) values, but lower values in all ranges (250-1150) of ADC values (all P&lt;0.001). Mean ADC and ADC values in the range of 350-650 demonstrated better predictive performance for poor outcomes than the GWR (P &lt; 0.05). The mean ADC value had the highest sensitivity of 51.3% (95% CI 39.4-63.1; cutoff value ≤ 739.2 х 10 –6 mm 2 /s) when the false positive rate (FPR) was 0%. Furthermore, when combined with PLR and NSE values, the prognostic performance was significantly improved compared to using Mean ADC alone (0.83 vs 0.92; P&lt;0.01). Conclusions: In this cohort study, early voxel-based quantitative ADC analysis after ROSC (i.e., before TTM) was associated with poor neurological outcomes 6 months after cardiac arrest. We found that the Mean ADC value showed the highest sensitivity when the FPR was 0% and that combining the NSE and PLR values resulted in an even better prognostic performance.

Study of the Reduced Field-of-View Diffusion-Weighted Imaging of the Breast

BackgroundDWI has been proposed for SpA diagnosis and disease monitoring1,2. The clinical correlation and effectiveness of this imaging when compared to the traditional STIR sequence is still under evaluation.ObjectivesTo compare...

ABSTRACTBackground. Diffusion-weighted magnetic resonance imaging (DW-MRI) and the derived apparent diffusion coefficient (ADC) value has potential for monitoring tumor response to radiotherapy (RT). Method used for segmentation of volumes with reduced diffusion will influence both volume size and observed distribution of ADC values. This study evaluates: 1) different segmentation methods; and 2) how they affect assessment of tumor ADC value during RT.Material and methods. Eleven patients with locally advanced cervical cancer underwent MRI three times during their RT: prior to start of RT (PRERT), two weeks into external beam RT (WK2RT) and one week prior to brachytherapy (PREBT). Volumes on DW-MRI were segmented using three semi-automatic segmentation methods: “cluster analysis”, “relative signal intensity (SD4)” and “region growing”. Segmented volumes were compared to the gross tumor volume (GTV) identified on T2-weighted MR images using the Jaccard similarity index (JSI). ADC values from segmented volumes were compared and changes of ADC values during therapy were evaluated.Results. Significant difference between the four volumes (GTV, DWIcluster, DWISD4 and DWIregion) was found (p < 0.01), and the volumes changed significantly during treatment (p < 0.01). There was a significant difference in JSI among segmentation methods at time of PRERT (p < 0.016) with region growing having the lowest JSIGTV (mean± sd: 0.35 ± 0.1), followed by the SD4 method (mean± sd: 0.50 ± 0.1) and clustering (mean± sd: 0.52 ± 0.3). There was no significant difference in mean ADC value compared at same treatment time. Mean tumor ADC value increased significantly (p < 0.01) for all methods across treatment time.Conclusion. Among the three semi-automatic segmentations of hyper-intense intensities on DW-MR images implemented, cluster analysis and relative signal thresholding had the greatest similarity to the clinical tumor volume. Evaluation of mean ADC value did not depend on segmentation method.

To evaluate potential of conventional MRI and diffusion-weighted imaging (DWI) for differentiating malignant from benign peripheral nerve sheath tumors (PNSTs). Eighty-seven cases of malignant or benign PNSTs in the trunk or extremities that underwent conventional MRI with contrast enhancement, DWI, and pathologic confirmation between Sep. 2014 and Dec. 2017 were identified. Of these, 55 tumors of uncertain nature on MRI were included. Tumor size, signal, and morphology were reviewed on conventional MRI, and apparent diffusion coefficient (ADC) values of solid enhancing portions were measured from DWI. Patient demographics, MRI features, and ADC values were compared between benign and malignant tumors, and robust imaging findings for malignant peripheral nerve sheath tumors (MPNSTs) were identified using multivariable models. A total of 55 uncertain tumors consisted of 18 malignant and 37 benign PNSTs. On MRI, tumor size, margin, perilesional edema, and presence of split fat, fascicular, and target signs were significantly different between groups (p < 0.05), as were mean and minimum ADC values (p = 0.002, p < 0.0001). Most inter-reader agreement was moderate to excellent (κ value, 0.45-1.0). The mean ADC value and absence of a split fat sign were identified as being associated with MPNSTs (odds ratios = 13.19 and 25.67 for reader 1; 49.05 and 117.91 for reader 2, respectively). The C-indices obtained by combining these two findings were 0.90 and 0.95, respectively. Benign and malignant PNSTs showed different features on MRI and DWI. A combination of mean ADC value and absence of split fat was excellent for discriminating malignant from benign PNSTs. • It is important to distinguish between malignant peripheral nerve sheath tumors (MPNSTs) and benign peripheral nerve sheath tumors (BPNSTs) to ensure an appropriate treatment plan. • On conventional MRI and diffusion-weighted imaging (DWI), MPNSTs and BPNSTs showed significant differences in tumor size, margin, presence of perilesional edema, and absence of split fat, fascicular, and target signs. • Absence of a split fat sign and mean apparent diffusion coefficient (ADC) values were robust imaging findings distinguishing MPNSTs from BPNSTs, with a C-index of > 0.9.

BackgroundThe most effective treatment for osteosarcoma is neoadjuvant chemotherapy along with surgical resection of the tumor. The prognosis significantly correlates with the degree of tumor necrosis following preoperative chemotherapy. The tumor necrosis will result in loss of the cell membrane integrity and expansion of the extracellular diffusion space which can be detected as an increase in the mean ADC value. The aim of our work is to evaluate the use of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) value measurement for monitoring the therapeutic response after chemotherapy in osteosarcoma.ResultsThis study included 25 cases of osteosarcoma: 15 males and 10 females. The age of the patients ranged from 7 to 46 years with mean age 22 years. All were assessed by magnetic resonance imaging (MRI) including DWI and the mean and minimum ADC values were calculated before and after chemotherapy. Follow-up DWI post-therapy revealed a rise in mean ADC value in 17 patients who considered having good response. The ADC value had been raised from 1.05 ± 0.4 × 10−3 mm2/s to 1.82 ± 0.45 × 10−3 mm2/s (P < 0.027) that is statistically moderately significant. In 8 patients, the post-therapy ADC value was similar to that of pre- or with a little change and they were considered having poor response. It showed changes from 1.29 ± 0.35 × 10−3 mm2/s to 1.32 ± 0.36 × 10−3 mm2/s (P > 0.05) that means no significant difference.ConclusionDWI and ADC value measurement play an important role in monitoring the therapeutic response after chemotherapy in osteosarcoma patients by comparing the mean ADC values before and after treatment.

BackgroundThe colorectal cancer (CRC) is one of the deadliest cancers in the world. Local tumor stage, vascular or lymphatic invasion, and tumor grade are essential for accurate management. The main imaging modality for initial assessment and therapeutic response evaluation of CRC is magnetic resonance imaging (MRI). The purpose of this prospective study was to illustrate the role of diffusion-weighted MRI (DWI) and apparent diffusion coefficient (ADC) value in initial assessment and grading of colorectal carcinoma as well as evaluation of its response to chemotherapy or combined chemoradiation.ResultsRestricted diffusion in DWI was found in 37 out of 40 patients with sensitivity of about 92.5%. In the studied group, the median ADC value was 1.21 (min 0.80, max 1.31) and the average ADC value was 1.14 ± 0.161. The mean ADC value in poorly differentiated tumors was 0.979 × 10−3mm2/s. The mean ADC value in moderately differentiated tumors was 1.112 × 10−3mm2/s. The mean ADC value in well-differentiated tumors was 1.273 × 10−3mm2/s. The sensitivity, specificity, PPV, NPV, and accuracy were higher with addition of DWI and ADC value to conventional MRI reaching 100%, 80%, 83.3%, 100%, and 90%, respectively.ConclusionAdding DW imaging with ADC value to conventional MRI yields better diagnostic accuracy than using conventional MR imaging alone in detection, correlation with tumor histologic grade, initial staging, and response evaluation to neoadjuvant chemoradiotherapy in patients with locally advanced colorectal cancer.

Objectives: This study aimed to study the minimum and mean ADC values in the differentiation of high and low grade gliomas. Background: Diffusion-weighted imaging (DWI) has greatly enhanced the ability of MRI to differentiate high and low grade gliomas where the ADC values inversely correlated with the tumor grade. Methods: This retrospective study included 50 patients (M/F 23/27) with pathologically proven gliomas (30 patients with high grade and 20 with low grade gliomas) who underwent MRI with diffusion weighted sequence ((b-value 1000 s/mm2) acquired on a 1.5T scanner at menoufia university hospital. Results: Diffusion restriction was found in 93.3% of cases of high grade gliomas (n=28/30) with mean calculated ADC value of calculated mean and minimum ADC values were 0.87±0.3 x 10-3 mm2/sec and 0.82±0.2 x 10-3 mm2/sec respectively. In low grade gliomas diffusion restriction was identified in 7 cases (n=7/20, 35%) with a mean calculated ADC values of 1.3±0.3 x 10-3 mm2/sec and 1.15±0.2 x 10-3 mm2/sec for the mean and minimum ADC respectively. Statistical significance was found between the calculated ADC values of the high and low grade gliomas when using the minimum and mean ADC values between the high and low grade gliomas (p value <0.001) Conclusion: We have demonstrated that both mean and minimum ADC values measurements can be used when trying to differentiate high and low grade gliomas with both showing statistical significance.

Role of Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Grading of Hepatic Steatosis in Patients With Non-alcoholic Fatty Liver Disease: Comparison With Ultrasonography and Magnetic Resonance Spectroscopy

To investigate the correlations between the minimum and mean apparent diffusion coefficient (ADC) values of hepatocellular carcinoma (HCC) and pathological grade. Preoperative magnetic resonance imaging (MRI) images of 241 patients with HCC confirmed by pathology were retrospectively analyzed. All patients underwent preoperative diffusion-weighted imaging (DWI) on a 1.5T MRI scanner. The mean and minimum ADC values of the tumors were measured. The ADC values were compared in tumors with different grades and the correlations between ADC values and pathological grade were analyzed. Receiver operating characteristic (ROC) curves of ADC values were obtained and compared to distinguish poorly and nonpoorly differentiated HCCs. Interobserver agreements were assessed by intraclass correlation coefficient (ICC). The mean and minimum ADC values of poorly differentiated HCCs were lower than those of nonpoorly differentiated HCCs (P = 0.000, 0.000, respectively). The mean and minimum ADC values were negatively correlated with pathological grade (rs = -0.180 and -0.202, respectively) (P = 0.005, 0.002, respectively). For the differentiation between poorly and nonpoorly differentiated HCCs, the mean ADC value provided a sensitivity of 69.57% and a specificity of 73.39% with a cutoff value of 0.96 × 10-3 mm2 /s while the minimum ADC value showed a sensitivity of 78.26% and a specificity of 61.47% with a cutoff value of 0.90 × 10-3 mm2 /s. No significant difference existed between both ROC curves (P = 0.64). The ICC for the measurements of the mean and minimum ADC values was 0.92 (95% confidence interval [CI] 0.90-0.93) and 0.91 (95% CI 0.89-0.93), respectively. DWI of HCC could preoperatively provide quantitative parameters for predicting tumor histological grade. J. Magn. Reson. Imaging 2016;44:1442-1447.

To determine the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted MR imaging and split renal function determined by renal scintigraphy in patients with hydronephrosis. Diffusion-weighted imaging on a 1.5 T MR unit and renal scintigraphy were performed in 36 patients with hydronephrosis (45 hydronephrotic kidneys, 21 non-hydronephrotic kidneys). ADC values of the individual kidneys were measured by diffusion-weighted MR imaging. Split renal function (glomerular filtration rate (GFR)) was determined by renal scintigraphy using 99mTc-DTPA. The relationship between ADC values and split GFR was examined in 66 kidneys. The hydronephrotic kidneys were further classified into three groups (severe renal dysfunction, GFR <10 ml/min, n=7; moderate renal dysfunction, GFR 10-25 ml/min, n= 10; normal renal function, GFR >25 ml/ min, n=28), and mean values for ADCs were calculated. In hydronephrotic kidneys, there was a moderate positive correlation between ADC values and split GFR (R2=0.56). On the other hand, in nonhydronephrotic kidneys, poor correlation between ADC values and split GFR was observed (R2=0.08). The mean values for ADCs of the dysfunctioning hydronephrotic kidneys (severe renal dysfunction, 1.32 x 10(-3) +/- 0.18 x 10(-3) mm2/s; moderate renal dysfunction, 1.38 x 10(-3) +/- 0.10 x 10(-3) mm2/s) were significantly lower than that of the normal functioning hydronephrotic kidneys (1.63 x 10(-3) +/- 0.12 +/- 10(-3) mm2/s). These results indicated that measurement of ADC values by diffusion-weighted MR imaging has a potential value in the evaluation of the functional status of hydronephrotic kidneys.

Purpose: To determine the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted MR imaging and split renal function determined by renal scintigraphy in patients with hydronephrosis. Material and Methods: Diffusion-weighted imaging on a 1.5 T MR unit and renal scintigraphy were performed in 36 patients with hydronephrosis (45 hydronephrotic kidneys, 21 non-hydronephrotic kidneys). ADC values of the individual kidneys were measured by diffusion-weighted MR imaging. Split renal function (glomerular filtration rate (GFR)) was determined by renal scintigraphy using 99mTc-DTPA. The relationship between ADC values and split GFR was examined in 66 kidneys. The hydronephrotic kidneys were further classified into three groups (severe renal dysfunction, GFR 25 ml/min, n=28), and mean values for ADCs were calculated. Results: In hydronephrotic kidneys, there was a moderate positive correlation between ADC values and split GFR (R 2=0.56). On the other hand, in non-hydronephrotic kidneys, poor correlation between ADC values and split GFR was observed (R 2=0.08). The mean values for ADCs of the dysfunctioning hydronephrotic kidneys (severe renal dysfunction, 1.32×10−3±0.18×10−3 mm2/s; moderate renal dysfunction, 1.38×10–3±0.10×10−3 mm2/s) were significantly lower than that of the normal functioning hydronephrotic kidneys (1.63×10−3±0.12±10−3 mm2/s). Conclusion: These results indicated that measurement of ADC values by diffusion-weighted MR imaging has a potential value in the evaluation of the functional status of hydronephrotic kidneys.

Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) Is Able to Distinguish Diffuse from Normal MRI Pattern of Marrow Involvement in Patients with Multiple Myeloma