Diffusion-weighted Imaging Signal Intensity Research Articles

Quantitative evaluation of diffusion-weighted MRI for differentiating benign and malignant thyroid nodules larger than 4 cm

PurposeOur study aimed to diagnose benign or malignant thyroid nodules larger than 4 cm using quantitative diffusion-weighted imaging (DWI) analysis.MethodsEighty-two thyroid nodules were investigated retrospectively and divided them into benign (n = 62) and malignant groups (n = 20). We calculated quantitative features DWI and apparent diffusion coefficient (ADC) signal intensity standard deviation (DWISD and ADCSD), DWI and ADC signal intensity ratio (DWISIR and ADCSIR), mean ADC and minimum ADC value (ADCmean and ADCmin) and ADC value standard deviation (ADCVSD). Univariate and multivariate logistic regression were conducted to identify independent predictors, and develop a prediction model. We performed receiver operating characteristic (ROC) analysis to determine the optimal threshold of risk factors, and constructed combined threshold models. Our study calculated diagnostic performance including area under the ROC curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and unnecessary biopsy rate of all models were calculated and compared them with the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) result.ResultsTwo independent predictors of malignant nodules were identified by multivariate analysis: DWISIR (P = 0.007) and ADCmin (P < 0.001). The AUCs for multivariate prediction model, combined DWISIR and ADCmin thresholds model, combined DWISIR and ADCSIR thresholds model and ACR-TIRADS were 0.946 (0.896–0.996), 0.875 (0.759–0.991), 0.777 (0.648–0.907) and 0.722 (0.588–0.857). The combined DWISIR and ADCmin threshold model had the lowest unnecessary biopsy rate of 0%, compared with 56.3% for ACR-TIRADS.ConclusionQuantitative DWI demonstrated favorable malignant thyroid nodule diagnostic efficacy. The combined DWISIR and ADCmin thresholds model significantly reduced the unnecessary biopsy rate.

Diffusion-weighted Breast MRI at 3 Tesla: Improved Lesion Visibility and Image Quality with a Combination of Water-excitation and Spectral Fat Saturation

In breast MRI with diffusion-weighted imaging (DWI), fat suppression is essential for eliminating the dominant lipid signal. This investigation evaluates a combined water-excitation-spectral-fatsat method (WEXfs) versus standard spectral attenuated inversion recovery (SPAIR) in high-resolution 3-Tesla breast MRI. Multiparametric breast MRI with 2 echo-planar DWI sequences was performed in 83 patients (50.1 ± 12.6 years) employing either WEXfs or SPAIR for fat signal suppression. Three radiologists assessed overall DWI quality and delineability of 88 focal lesions (28 malignant, 60 benign) on images with b values of 800 and 1600 s/mm2, as well as apparent diffusion coefficient (ADC) maps. For each fat suppression method and b value, the longest lesion diameter was determined in addition to measuring the signal intensity in DWI and ADC value in standardized regions of interest. Regardless of b values, image quality (all p < 0.001) and lesion delineability (all p ≤ 0.003) with WEXfs-DWI were deemed superior compared to SPAIR-DWI in benign and malignant lesions. Irrespective of lesion characterization, WEXfs-DWI provided superior signal-to-noise, contrast-to-noise and signal-intensity ratios with 1600 s/mm2 (all p ≤ 0.05). The lesion size difference between contrast-enhanced T1 subtraction images and DWI was smaller for WEXfs compared to SPAIR fat suppression (all p ≤ 0.007). The mean ADC value in malignant lesions was lower for WEXfs-DWI (p < 0.001), while no significant ADC difference was ascertained between both techniques in benign lesions (p=0.947). WEXfs-DWI provides better subjective and objective image quality than standard SPAIR-DWI, resulting in a more accurate estimation of benign and malignant lesion size.

Breaking with a dogma: persisting diffusion restrictions (pDWI) in follow-up after endovascular treatment for stroke

BackgroundPost-stroke diffusion weighted imaging (DWI) signal transformation of the infarct core, which results in high apparent diffusion coefficient (ADC) values and variable DWI signal intensity, is completed no later than...

Directional and inter-acquisition variability in diffusion-weighted imaging and editing for restricted diffusion.

PurposeTo evaluate and quantify inter‐directional and inter‐acquisition variation in diffusion‐weighted imaging (DWI) and emphasize signals that report restricted diffusion to enhance cancer conspicuity, while reducing the effects of local microscopic motion and magnetic field fluctuations.MethodsTen patients with biopsy‐proven prostate cancer were studied under an Institutional Review Board‐approved protocol. Individual acquisitions of DWI signal intensities were reconstructed to calculate inter‐acquisition distributions and their statistics, which were compared for healthy versus cancer tissue. A method was proposed to detect and filter the acquisitions affected by motion‐induced signal loss. First, signals that reflect restricted diffusion were separated from the acquisitions that suffer from signal loss, likely due to microscopic motion, by imposing a cutoff value. Furthermore, corrected apparent diffusion coefficient maps were calculated by employing a weighted sum of the multiple acquisitions, instead of conventional averaging. These weights were calculated by applying a soft‐max function to the set of acquisitions per‐voxel, making the analysis immune to acquisitions with significant signal loss, even if the number of such acquisitions is high.ResultsInter‐acquisition variation is much larger than the Rician noise variance, local spatial variations, and the estimates of diffusion anisotropy based on the current data, as well as the published values of anisotropy. The proposed method increases the contrast for cancers and yields a sensitivity of 98.8% with a false positive rate of 3.9%.ConclusionMotion‐induced signal loss makes conventional signal‐averaging suboptimal and can obscure signals from areas with restricted diffusion. Filtering or weighting individual acquisitions prior to image analysis can overcome this problem.

Multiparametric evaluation of bone tumors utilising diffusion weighted imaging and dynamic contrast enhanced magnetic resonance imaging

AimThis study aimed to use multiparametric magnetic resonance imaging (MRI) techniques, namely, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate bone tumors. MethodsThirty-three patients with primary untreated bone tumors were assessed utilizing DWI and DCE-MRI. Various parameters like ADC values from DWI and percentage peak signal intensity (%PSI), the maximum slope of increase (MSI), and time to peak signal intensity (TTP) values were assessed in different cases, and the final correlation was drawn with histopathological findings. ResultParameters of semi-quantitative DCE-MRI, i.e., %PSI, MSI and, TTP, correlated significantly with the histopathological characteristics of the tumor (p values < 0.001). Minimum ADC value in the tumor also showed a strong correlation with the tumor characteristic (p values < 0.001). Also, the correlation between parameters of DWI and DCI-MRI is well correlated with each other. ConclusionThe results of this study provide grounds for the integration of multiparametric pre-treatment evaluation of bone tumors. In our study, we not only tried to utilize different parameters of functional MRI in bone tumors as well as re-explored the semi-quantitative analysis of DCE-MRI.

Anti-NMDAR encephalitis with bilateral basal ganglia MRI lesions at a distance of time: a case report

BackgroundApproximately half (55%) of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is known to show abnormal brain images, including high signal intensity in T2 or fluid attenuated inversion recovery (FLAIR) images. In a minority of anti-NMDAR encephalitis cases, high signal intensity on diffusion-weighted imaging (DWI) has been reported, a finding that is highly suggestive of a stroke.Case presentationWe present the case of a 66-year-old man who experienced two separate focal seizure events, which involved first the right and then the left upper extremity in a short period of time. The patient showed focal clonic seizures involving right arm and hand, which sometimes evolved to bilateral tonic-clonic seizures on his first admission. Brain magnetic resonance imaging (MRI) showed high signal intensity on DWI and low signal intensity on the apparent diffusion coefficient (ADC) map of the left caudate nucleus and putamen. The patient was discharged symptom-free with anti-epileptic drugs for 2 weeks. The second admission occurred 4 days after the discharge. He exhibited a new symptom of focal clonic seizures involving left arm and hand while showing a brain lesion on the opposite side which is hyperintense on DWI image and hypointense on ADC map. The patient was eventually diagnosed with anti-NMDAR encephalitis according to the cerebrospinal fluid (CSF) antibody test.ConclusionsThis is the case of anti-NMDAR encephalitis patient whose DWI/ADC images revealed sequential involvement on the left and right basal ganglia with a short time interval. When stroke-like brain lesions on DWI are found in a patient with a focal seizure, a CSF study could help rule out autoimmune encephalitis. We also suggest that DWI/ADC map images may be useful for the early detection of anti-NMDAR encephalitis.

Diffusion-Weighted Imaging and Fluid-Attenuated Inversion Recovery Quantification to Predict Diffusion-Weighted Imaging-Fluid-Attenuated Inversion Recovery Mismatch Status in Ischemic Stroke With Unknown Onset.

Visual rating of diffusion-weighted imaging (DWI)-fluid-attenuated inversion recovery (FLAIR) mismatch can be challenging. We evaluated quantification of DWI and FLAIR to predict DWI-FLAIR mismatch status in ischemic stroke. In screened patients from the WAKE-UP trial (Efficacy and Safety of Magnetic Resonance Imaging-Based Thrombolysis in Wake-Up Stroke), we retrospectively studied relative DWI (rDWI SI) and FLAIR signal intensity (rFLAIR SI). We defined the optimal mean rFLAIR SI and interquartile range of the rDWI SI in the DWI lesion to predict DWI-FLAIR mismatch status. We investigated agreement between each quantitative parameter and the DWI-FLAIR mismatch and the association between both quantitative parameters. We evaluated the predictive value of the quantitative parameters for excellent functional outcome by logistic regression, adjusted for DWI lesion volume, treatment, age, and National Institutes of Health Stroke Scale score. In the rFLAIR and rDWI SI analysis, 213/369 and 241/421 subjects respectively had a DWI-FLAIR mismatch. A mean rFLAIR SI cutoff of 1.09 and interquartile range rDWI SI cutoff of 0.47 were optimal to predict the DWI-FLAIR mismatch with a sensitivity and specificity of 77% (95% CI, 71%-83%) and 67% (95% CI, 59%-74%), and 76% (95% CI, 70%-81%) and 72% (95% CI, 65%-79%), respectively. For both quantitative parameters, agreement with the DWI-FLAIR mismatch was fair (73%, κ=0.44 [95% CI, 0.35-0.54] for rFLAIR and 74%, κ=0.48 [95% CI, 0.39-0.56] for rDWI). Both quantitative parameters correlated moderately (Pearson R=0.54 [95% CI, 0.46-0.61]; P<0.001, n=367). The interquartile range rDWI SI (n=188), but not the mean rFLAIR SI (n=172), was an independent predictor of excellent functional outcome (odds ratio, 0.67 per 0.1 unit increase of interquartile range rDWI SI, 95% CI, 0.51-0.89, P=0.01). Agreement between the quantitative and qualitative approach may be insufficient to advocate DWI or FLAIR quantification as alternative for visual rating.

Kanser Tanısında Tüm Vucut MR ile PET-CT Karşılaştırması

Objective: Whole body diffusion-weighted imaging (DWI) has been increasingly used in oncological cases for detection and characterization of tumors and monitoring of treatment response. We compared the tumor detection capacity and diagnostic accuracy of DWI with positron emission tomography/computed tomography (PET/CT), which is regarded as the gold standard. Materials and Methods: The study included 29 adult patients (13 men and 16 women) aged between 38 and 86 years who had various types of cancer, and for whom PET/CT was indicated for staging or evaluating treatment response. A total of 240 lesions that were positive in FDG-PET/CT were identified in the DWI images, and DWI signal intensity and apparent diffusion coefficient (ADC) value were measured for each lesion. SUVmax, ADC, and DWI intensity values of PET-positive lesions and lesion areas for both methods were compared using Mann-Whitney U test and Spearman correlation test. Results: SUVmax and DWI intensities of the lesions showed significant correlation (Spearman correlation coefficient= -0.296, p&amp;lt;0.0001). When we analyzed whether lesion size was associated with SUVmax, ADC, or DWI intensity, we found a correlation between lesion diameter and DWI intensity (r=-0.30; p=0.0001). Conclusion: The DWI was generally correlated with PET/CT with very close specificity and sensitivity values between the two methods. Whole body DWI can be used as an alternative or complementary to PET/CT in investigation and follow-up of oncological cases.

Low relative diffusion weighted image signal intensity can predict good prognosis after endovascular thrombectomy in patients with acute ischemic stroke

BackgroundIt is vital to identify a surrogate last-known-well time to perform proper endovascular thrombectomy in acute ischemic stroke; however, no established imaging biomarker can easily and quickly identify eligibility for...

Lymphoepithelial cyst mimicking pancreatic cancer: a case report and literature review

BackgroundPancreatic lymphoepithelial cyst (LEC) is a rare nonmalignant cyst consisting of a benign collection of keratinizing squamous epithelial cells with lymphoid tissue. Diagnosing LEC preoperatively is considered difficult because of its non-specific clinical features; therefore, LEC is generally treated the same as a malignant tumor.Case presentationOur case was a 65-year-old man who underwent pancreatoduodenectomy 3 years previously for carcinoma arising from the ampulla of Vater. A pancreatic mass in the remnant pancreatic tail was detected through follow-up abdominal contrast-enhanced computed tomography (CT). This revealed two adjacent ring-enhanced masses that had been in tight contact with the left diaphragm and were enlarged. The tumors had high signal intensity in diffusion-weighted images of magnetic resonance imaging, and fluorodeoxyglucose-positron emission tomography (FDG-PET) showed abnormal uptake (standardized uptake value maximum: 17.4). Therefore, we conducted a partial resection of the remnant pancreas with concomitant resection of the left diaphragm. Microscopically, one of the tumors revealed rare fragments of apparently benign squamous epithelium on a background of keratinous debris, cyst contents, and scattered lymphocytes, and the adjacent mass revealed infiltrated neutrophils. The histopathological diagnosis was an LEC with chronic abscess. The patient recovered uneventfully and was discharged on postoperative day 10.ConclusionsWe reported a rare case of LEC with chronic abscess that was positively visualized on FDG-PET. When a pancreatic malignancy cannot be excluded, surgical resection is considered inevitable.

The value of MRI plain scan and DWI in the diagnosis of brain metastases

Objective: To investigate the clinical value of magnetic resonance imaging (MRI) plain scan and diffusion weighted imaging (DWI) in the diagnosis of brain metastases. Methods: The MRI plain imaging findings of 105 cases with brain metastases and 103 cases without brain metastases confirmed by enhanced MRI examination and clinical diagnosis were retrospectively analyzed. The comparisons of plain MRI findings including T1 weighted image (T1WI), T2WI, T2/fluid attenuated inversion recovery (T2/FLAIR), DWI and apparent diffusion coefficient (ADC) values were made between brain metastases and non-brain metastases. Results: The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T1WI in the brain metastatic group were 54, 23, 9 and 19, respectively, while the numbers of hypo-intensity and iso-intensity in the non-brain metastatic group were 52 and 51, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI in the brain metastatic group were 1, 9, 72 and 23, respectively, while the numbers of iso-intensity and hyper-intensity in the non-brain metastatic group were 11 and 92, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, hyper-intensity and heterogeneous signal intensity of DWI in the brain metastatic group were 4, 31 and 65, respectively, while the number of hyper-intensity in the non-brain metastatic group was 4 and others were iso-intensity, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI/FLAIR in the brain metastatic group were 4, 5, 60 and 36, respectively, while all cases in the non-brain metastatic group were hyper-intensity, with statistically significant difference (P<0.001). The number of lesion accompanied with peripheral edema in the brain metastatic group were 69 cases, significantly higher than 0 cases in the non-brain metastatic group (P<0.001). The mean ADC value in the brain metastatic group were (0.919±0.019)×10(-3) mm(2)/s, significantly lower than (1.098±0.012)×10(-3) mm(2)/s of non-brain metastatic group (P<0.05). Conclusions: For patients with a history of primary malignancy, the MRI plain scan signals of T1WI, T2WI, T2WI/FLAIR and DWI are significantly different between brain metastatic tumor and non-metastatic tumor. The mixed signal, peripheral edema and the restriction of DWI diffusion indicate brain metastases. The combined application of the above parameters can improve the diagnostic efficacy of predicting brain metastases, and contrast enhancement MRI examination should be performed for the confirmation of diagnosis.

Value of Diffusion Weighted Magnetic Resonance Imaging in Diagnosis of Cervical Carcinoma

Abstract Background: Carcinoma of the uterine cervix is the third most frequently diagnosed malignancy in women worldwide. It remains a leading cause of cancer-related death for women in developing countries. Conventional MRI has an established role in gynecologic imaging. However, increasing clinical demand for improved lesion characterization and disease mapping to optimize patient management has resulted in the incorporation of newer sequences, such as diffusion-weighted imaging (DWI). Aim of Study: The aim of this study is to evaluate the role of DW-MRI in the diagnosis of cervical carcinoma. Patients and Methods: This is a descriptive exploratory (case-series) study that included 20 female patients diagnosed with cervical cancer, Pelvic MR, DWI and DCE- MR were done for all patient. The study was conducted in El-Demerdash Hospital from March 2019 – Feb. 2020. Results: This study group consisted of 20 female patients diagnosed with cancer cervix, Pelvic MR with DWI and DCE-MR were done for all patients. Lesions in all cases were seen restricted on DWI (high signal intensity in DWI with low ADC map) with hetrogenous patterns was seen in (17/20, 85%) cases, homogenous patterns was seen in (2/20, 10%) and mural pattern in (1/20,5%) case. All lesions showed low ADC maps from 0.6 to 1.2 (x10-3mm2/sec), <0.8 x10-3mm2/ sec was seen in 5 cases (25%) and ³0.8 x10-3mm2/sec was seen in 15 cases (75%). A total 20 cervical cancer lesions, 5 lesions were stage IIA (25%), 10 lesions were stage IIB(10%), 4 lesions were stage IVA (20%) and 1 lesion was stage IVB (5%) of figo classification. Conclusion: DWI is a potentially useful adjunct to con-ventional MRI in the evaluation of gynecologic tumors, thus improving the overall diagnostic accuracy, tumor staging.

The impact of position-orientation adaptive smoothing in diffusion weighted imaging-From diffusion metrics to fiber tractography.

In contrast to commonly used approaches to improve data quality in diffusion weighted imaging, position-orientation adaptive smoothing (POAS) provides an edge-preserving post-processing approach. This study aims to investigate its potential and effects on image quality, diffusion metrics, and fiber tractography of the corticospinal tract in relation to non-post-processed and averaged data. 22 healthy volunteers were included in this study. For each volunteer five clinically applicable diffusion weighted imaging data sets were acquired and post-processed by standard averaging and POAS. POAS post-processing led to significantly higher signal-to-noise-ratios (p < 0.001), lower fractional anisotropy across the whole brain (p < 0.05) and reduced intra-subject variability of diffusion weighted imaging signal intensity and fractional anisotropy (p < 0.001, p = 0.006). Fiber tractography of the corticospinal tract resulted in significantly (p = 0.027, p = 0.014) larger tract volumes while fiber density was the lowest. Similarity across tractography results was highest for POAS post-processed data (p < 0.001). POAS post-processing enhances image quality, decreases the intra-subject variability of signal intensity and fractional anisotropy, increases fiber tract volume of the corticospinal tract, and leads to higher reproducibility of tractography results. Thus, POAS post-processing supports a reliable and more accurate fiber tractography of the corticospinal tract, being mandatory for the clinical use.

The ability and utility of diffusion-weighted magnetic resonance imaging with different 'b' values in the differentiation of benign from malignant lung lesions.

PurposeTo evaluate the ability and the utility of diffusion-weighted magnetic resonance imaging (MRI) with different ‘b’ values to visualise benign and malignant lung lesions, and to determine which ‘b’ value (b = 300, 500, or 1000 s/mm2) was most useful in differentiating benign from malignant lung lesions.Material and methodsA total of 100 patients (28 women, 72 men; mean age = 57.19 ± 13.44 years; age range = 20-83 years). Diffusion-weighted imaging (DWI) was obtained with ‘b’ values of 300, 500, and 1000 s/mm2. The signal intensity of lesions on DWI images was analysed, and the apparent diffusion coefficient (ADC) values of the lesions were calculated. MRI was performed in all patients after having presented at our department for thoracic computed tomography for various reasons.ResultsA statistically significant difference in DWI signal scores was detected between benign and malignant lesions for all ‘b’ factors (p < 0.0001 for each). The sensitivity and specificity were 95% and 64%, respectively, when a score of 3 for β = 300 s/mm2; 90% and 69%, respectively, when a score of 3 for β = 500 s/mm2; and 84% and 74%, respectively, when a score of 3 for β = 1000 s/mm2. ADC values showed significant differences between benign and malignant lesions for all ‘b’ factors (p < 0.0001 for each).ConclusionsUsing ‘b’ values of 300, 500, and 1000 s/mm2, DWI signal intensity scores and ADC values are effective methods for the differential diagnosis of malignant and benign pulmonary lesions.

Neuroimaging findings of cerebral syphilitic gumma.

Cerebral syphilitic gumma is a rarely reported disease of the central nervous system. Magnetic resonance imaging (MRI) is an important diagnostic method for syphilitic gumma. The present study aimed to describe and characterize neuroimaging results from 6 patients with pathologically diagnosed cerebral syphilitic gumma. The 6 patients (age, 32–61 years) underwent brain CT and MRI, with 1 patient also undergoing whole-body 2-deoxy-2-(fluorine-18)fluoro-D-glucose-positron emission tomography/CT (18F-FDG PET/CT). Non-enhanced CT, conventional T1 weighted imaging (T1WI) and T2WI, diffusion weighted imaging (DWI) and gadolinium-enhanced T1WI images were acquired for all patients. The CT and MRI scans were retrospectively reviewed by two experienced radiologists for consensus on the location, number, size, T1WI, T2WI and DWI signal intensity characteristics, extent of vasogenic oedema, and enhancement patterns. In total, the 6 patients exhibited 10 lesions, nine of which were located in the cerebral hemisphere, primarily in the grey matter. The remaining lesion was located in the fourth ventricle, leading to mild-to-moderate hydrocephalus. The diameters of the identified 10 lesions ranged from 0.9–6.5 cm, with a mean diameter of 3.9 cm. The main feature observed in CT was low density and in MRI the features were T1WI and DWI hypointensity and T2WI hyperintensity. A single case exhibited syphilis gumma with massive haemorrhage. Ring-like or strip-like signs (n=5), accompanied by the dural tail sign (n=2) and homogeneous enhancement (n=1), were noted on T1WI with gadolinium. The 18F-FDG PET/CT performed in one patient of a cerebral syphilis gumma revealed low uptake and metabolism. The present study indicated that gadolinium-enhanced MRI combined with 18F-FDG PET/CT and laboratory examinations are helpful in distinguishing cerebral syphilitic gumma from brain tumors and infectious diseases, therefore avoiding unnecessary surgery.

Correlation between ADC values and Gleason score in evaluation of prostate cancer: multicentre experience and review of the literature.

Prostate cancer (PCa) is one of the most common cancers in male population. Multiparametric prostate magnetic resonance imaging (mp-MRI) has assumed a primary role in the diagnosis of PCa, combining morphological and functional data. Among different sequences, functional diffusion weighted imaging (DWI) is a powerful clinical tool which provides information about tissue on a cellular level. However, there is a considerable overlap between either BPH (Benign Prostate Hypertrophy) and prostatic cancer condition, as a different DWI signal intensity could be shown in the normal architecture gland. Apparent diffusion coefficient (ADC) has shown an increasing accuracy in addition to the DWI analysis in detection and localization of PCa. Notably, ADC maps derived DWI sequences has shown an overall high correlation with Gleason score (GS), considering the importance of an accurate grading of focal lesion, as main predictor factor. Furthermore, beyond the comparative analysis with DWI, ADC values has proven to be an useful marker of tumor aggressiveness, providing quantitative information on tumor characteristics according with GS and Gleason pattern, even more strenuous data are needed in order to verify which ADC analysis is more accurate.

Clinical value of magnetic resonance imaging in identifying multiple cerebral gliomas from primary central nervous system lymphoma.

Clinical value of magnetic resonance imaging (MRI) in identifying and diagnosing multiple cerebral glioma (MCG) from primary central nervous system lymphoma (PCNSL) was evaluated. A total of 21 patients with MCG diagnosed clinically and pathologically in Zhangzhou Municipal Hospital from March 2016 to April 2017 were selected as group A, and 30 patients with PCNSL diagnosed in Zhangzhou Affiliated Hospital of Fujian Medical University during the same period as group B. Plain MRI, enhanced MRI and diffusion weighted imaging (DWI) were performed in all patients, the apparent diffusion coefficient (ADC) value of lesions was measured, and the diagnostic efficacy of ADC for MCG and PCNSL was evaluated by receiver operating characteristic (ROC) curve. The incidence of hippocampus lesions, patchy and cystic lesions, and the heterogeneous signal of plain scan in group A was significantly higher than that in group B (P<0.05), and the incidence of basal ganglia lesions was significantly lower than that in group B (P<0.05). Mass lesions in group A were significantly less than those in group B (P<0.05). The ADC value of lesions in group A was significantly higher than that in contralateral normal white matter (P<0.05), the ADC value in group B was significantly lower than that in normal contralateral white matter (P<0.05), so the ADC value in group A was significantly higher than that in group B (P<0.05). The location, lesion shape and signal characteristic of MCG and PCNSL have their own specificity; there are significant differences in DWI signal and ADC color map signal intensity of the lesions; ADC has certain diagnostic value for MCG and PCNSL; the differential diagnosis of MCG from PCNSL by MRI is of great significance.

Can MR Enterography and Diffusion-Weighted Imaging Predict Disease Activity Assessed by Simple Endoscopic Score for Crohn's Disease?

Purpose:Monitoring Crohn’s disease (CD) activity has a crucial importance, especially for evaluating treatment efficacy. Magnetic resonance enterography (MRE) and diffusion-weighted imaging (DWI) or their combination may represent potential non-invasive tools for this purpose. This study aimed to examine DWI and MRE for their potential to differentiate between different grades of ileocolonic CD activity.Materials and Methods:This retrospective study included 54 adult patients with a diagnosis of CD who underwent ileocolonoscopy and MRE including the DWI sequence. The severity of CD inflammation was categorized by Simple Endoscopic Score for Crohn’s Disease (SES-CD) as inactive, mild, moderate and severe. In addition, following conventional MRE and DWI parameters were examined: bowel wall thickness, mural T2 hyperintensity, contrast enhancement, DWI signal intensity, and apparent diffusion coefficient (ADC) values.Results:In patients with moderate to severe disease based on SES-CD, T2 hyperintensity score [1.68 ± 0.77 (1–3) vs. 2.19 ± 0.69 (1–3); p = 0.013] and mean DWI score [2.42 ± 0.58 (1–3) vs. 2.04 ± 0.69 (1–3); p = 0.037 ] were higher and mean ADC values [1.5 ± 0.4 (0.9–2.5) vs. 1.2 ± 0.3 (0.6–1.8)] were lower compared to patients with inactive to mild CD. ADC had a moderate diagnostic accuracy in predicting moderate to severe disease (AUC = 0.729, 95% CI = 0.591–0.841, p = 0.001), with a cut-off value of ≤1.47 × 10–3 mm2/sec yielded 88.5% (23/26) sensitivity, 57.1% (16/28) specificity.Conclusion:DWI, ADC and T2 signal appear to differentiate moderate to severe CD from inactive to mildly active CD, based on SES-CD evaluation and may be useful in monitoring disease activity, particularly when evaluating treatment response.

The role of diffusion-weighted MRI on the differentiation of complex adnexal masses

Background Conventional MRI has an established role in gynecologic imaging. However, increasing clinical demand for improved lesion characterization and disease mapping to optimize patient management has resulted in the incorporation of newer sequences, such as diffusion-weighted imaging (DWI), into routine protocols for pelvic MRI. DWI provides functional information on the microenvironment of water in tissues, hence augmenting the morphologic information derived from conventional MRIs. Objective The objective of this study was to highlight the role of DWI in differentiating benign from malignant complex adnexal masses. Patients and methods Twenty-five patients with adnexal masses underwent conventional MRI and DWI and the cases were proven by postsurgery pathological examination. Analysis of the pathological specimen with lesion morphology, signal characteristics, and correlation with the appearance at DWI followed by apparent diffusion coefficient values measurement were obtained. Results Twenty-five patients with adnexal mass lesions were included. Included masses proved benign in 18 (72%) and malignant in seven (28%). Restricted diffusion was observed in proved malignant masses (24%, n = 6/25). Benign tumors with high DWI signal intensity evidence at 24% also. The mean apparent diffusion coefficient value was 1.4+0.34×10−3 and 1.02+0.06×10−3 mm2/s, for benign and malignant masses, respectively. Conclusion DWI supported by conventional MRI data can confirm or exclude malignancy in suspicious ovarian masses. A combined analysis of quantitative and qualitative criteria and a knowledge of the sequence pitfalls are required.

Magnetic resonance diffusion-weighted imaging in diagnostics of primary fallopian tube carcinoma - is it useful?

PurposePrimary fallopian tube carcinoma (PFTC) is the rarest form of female genital malignancy. The imaging applied for suspected adnexal masses includes transvaginal ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), but the vast majority of PFTC is recognised intraoperatively.Material and methodsThe study group consisted of seven women with postoperatively histopathological diagnosis of PFTC. To recognise characteristic findings for PFTC, retrospective analysis of preoperative MRI was performed. All patients underwent MRI of the pelvis and abdomen using a 1.5T MR system. Based on the results of the above imaging, suspected adnexal masses were recognised. MRI protocol contained T2-weighted images, fat-suppressed T2-weighted, T2-TIRM, DW EPI, pre- and postcontrast dynamic 3D T1 GRE in transverse orientation, with diffusion weightings of 0, 50, 100, 150, 200, 400, 800, and 1200 s/mm2. Regions of interest were outlined by a radiologist, who documented the character of adnexal masses on diffusion-weighted (DW) images and apparent diffusion coefficient (ADC) maps.ResultsIn all seven patients with PFTC unilateral tumour was found. On all DW images (with β values of 0, 50, 100, 150, 200, 400, 800, and 1200 s/mm2) the mean signal intensities of solid parts of tumour were significantly higher than the mean signal intensities of normal ovarian tissue (p = 0.0001). There were no statistically significant differences between eight β values applied for ADC calculations.ConclusionsPreoperative diagnostics of PFTC is difficult and mainly based on morphological features. Previous research did not show characteristics of PFTC in post-contrast dynamic imaging. In our material a clear increasing of signal intensity in DW imaging occurred independently of the β value.