Role Of Diffusion-weighted Imaging Research Articles

The role of Diffusion-Weighted Imaging in better delineating the extent of Diffuse Axonal Injury in a pediatric patient: A case report and brief review of the literature

Introduction: Diffuse axonal injury (DAI) is a major cause of disability in the pediatric patient. Herein we describe the MRI/DWI findings in a case with DAI. We also discuss the current role of CT and MRI with DWI in the evaluation of DAI.

Role of diffusion-weighted imaging in differentiation between posterior fossa brain tumors

BackgroundDiffusion-weighted imaging (DWI) is an imaging modality using multi-section single-shot spin echo planar imaging (EPI) sequence which is extremely sensitive for detection of water motion within intra, extra, and transcellular regions. This character is important to differentiate between brain tumors either low (benign) or highly (malignant) cellular tumors.ObjectiveTo evaluate the role of DWI and apparent diffusion coefficient (ADC) in evaluation and differentiation between different brain posterior fossa tumors in children and adults.Patients and methodsThe study included 34 patients with different brain posterior fossa tumors for evaluation by conventional MRI (using 1.5 T MRI PHILIPS Achieva 2.1 Best Netherland) and DWI.ResultsOur study showed that mean ADC values were significantly different between the four groups of posterior fossa tumors in children: juvenile pilocytic astrocytoma (JPA), medulloblastoma, ependymoma, and brain stem glioma while mean ADC values were not significantly different between posterior fossa tumors in the adult group. Regions of interest were manually positioned, and all values were automatically calculated and expressed in 10−3 mm2/s.ConclusionDWI is an ideal additional imaging technique, which is a rapid, easy, non-invasive imaging modality, with no contrast injection needed. It has been widely applied in the differentiation between posterior fossa brain tumors and in the diagnosis of various intracranial diseases.

Primary and post-chemoradiotherapy MRI detection of extramural venous invasion in rectal cancer: the role of diffusion-weighted imaging.

To assess the added value of diffusion-weighted imaging (DWI) to high-resolution T2-weighted sequences (HRT2w) in MRI detection of extramural venous infiltration (EMVI), according to the previous experience of radiologists. A cross-sectional study of a retrospective database including 1.5T MRI records from 100 patients with biopsy-proven rectal cancer (2011-2016; 75 male/25 female, average 63 y/o), which included primary staging (54) and post-chemoradiotherapy follow-up MRIs (46). The reference standard was histology of surgical specimens. All cases were individually blindly reviewed by ten radiologists: three specialists in abdominal radiology, three specialized in different areas and four residents. In each case, the presence of EMVI was assessed twice: first, using just HRT2w; second, with DWI added to HRT2w. The results were pooled by experience, analyzing sensitivity, specificity, accuracy (area under ROC curve), likelihood ratios, predictive values and overstaging/understaging. Addition of DWI improved diagnostic performance by specialists radiologists, particularly post-chemoradiotherapy (accuracy 0.74-0.84; positive likelihood ratio 3.9-9.1; overstaging 16-8%), less so at primary staging (specificity 76-87.2%; overstaging 21-11%). Non-specialist radiologists also improved, but only at primary staging (accuracy 0.59-0.63). Residents showed small changes, except for notably increased sensitivity in both primary staging (35.7-43%) and post-chemoradiotherapy (41.7-58.3%) staging, at the expense of increased overstaging. The addition of DWI improved the diagnostic performance of EMVI by experienced radiologists, downgrading overstaging, especially in post-chemoradiotherapy follow-up. It resulted in fewer changes for inexperienced radiologists (enhanced primary staging) and residents (increased sensitivity).

Role of diffusion-weighted imaging in evaluation of intracranial infections

Objective: The objective is to evaluate the role of diffusion weighted imaging (DWI) in evaluation of intracranial infections. Methods: The present study was conducted in the Department of Radiology, Jawaharlal Nehru Medical College, Sawangi, Maharashtra, India. Participants after understanding the study protocol and procedure were asked to give their written consent for the study. DWI was performed on 24 patients having ring-enhancing lesions on their post-contrast brain magnetic resonance imaging scans with infective etiology. Commonly found lesions were tuberculomas, cysticercosis, pyogenic abscess, and fungal infections. Correlation of all these findings was done with histopathology obtained in all these patients. DWI and mean apparent diffusion coefficient (ADC) value were calculated. Results: Tuberculomas showed heterogeneous areas of restricted diffusion on DWI were as pyogenic abscess showed homogenous restricted diffusion, the mean ADC values from of these lesions were 0.74 × 10−3 and 0.5 × 10−3 mm2/s, respectively. Fungal abscesses were also ring enhancing. They had restricted diffusion in the central nonenhancing portions. Mean ADC for all fungal lesions was 0.33 ± 0.06 × 10−3 mm2/s, with an average ADC ratio of 0.43. However, there was no significant difference between ADC values of pyogenic abscess and fungal abscess. The vesicular cysts of NCC showed ring enhancement but no significant restriction on DWI, the ADC values from the vesicular cysticercus cysts core measured (1.66 ± 0.29) ×10 − 3 mm2/s, which was highest among the infective intracranial infection. Conclusion: DWI is noninvasive method with high sensitivity and specificity which can help in differentiation of infective ring-enhancing lesions. Fungal cerebral abscesses may have central restricted diffusion similar to that of bacterial abscesses but with histologic features of acute or chronic inflammation and necrosis rather than suppuration. Altered water diffusion in these lesions likely reflects highly proteinaceous fluid and cellular infiltration. The tuberculoma and NCC lesions showed heterogeneous and no restriction on DWI respectively with significant change in the ADC values which helped in differentiating these lesions. This modality should be read in conjunction with conventional imaging.

Role of diffusion-weighted magnetic resonance imaging in the characterization of uterine neoplasms

Context Uterine malignant neoplasms are considered a frequent major cause of mortality. Aims To detect the role of diffusion-weighted images in assessing uterine neoplasms. Settings and design Department of Radiology, Assiut Faculty of Medicine, Egypt. Department of Obstetrics and Gynecology, Assiut Faculty of Medicine, Egypt. Patients and methods Our study included 20 patients with uterine neoplasms. All patients were examined by pelvic advanced MRI techniques with diffusion MRI. Statistical analysis Categorical data were reported in frequencies and percentages. Quantitative data were reported as mean (SD) and evaluated for statistically significant differences between both groups utilizing independent Student's t test. Results The apparent diffusion coefficient value in benign uterine lesions is equal to 1.088 ± 0.146 and for the malignant lesions it is equal to 0.658 ± 0.178 with a P value of 0.000 which is highly significant. A cutoff apparent diffusion coefficient value of 0.85 × 10-3 mm2/s for malignant lesions resulted in 91.7% sensitivity, 100% specificity, 100% positive predictive value, 88.7% negative predictive value, and 91.67% accuracy. Conclusions Diffusion-weighted image has a great role in differentiating malignant and benign uterine neoplasms.

The Role of Diffusion-weighted Imaging in Patients with Gastric Wall Thickening

Gastric cancer is the second leading cause of cancer death worldwide. In the benign and malign gastric pathologies, we measured the Apparent Diffusion Coefficient (ADC) value from the thickened section of the stomach wall. We assessed the diagnostic value of ADC and we wanted to see whether this value could be used to diagnose gastric pathologies. This study has a prospective study design. A total of 90 patients, 27 with malign gastric pathologies 63 with benign gastric pathologies with Gastric Wall (GW) thickening in multidector CT, were evaluated by T2 weighted axial MR imaging and Diffusion-Weighted Imaging (DWI). Measurements were made both from the thickened wall and from the normal GW. Also, a new method called GW/spine ADC ratio was performed in image analysis. The value found after ADC measurement from the GW was proportioned to the spinal cord ADC value in the same section. The ADC values measured from the pathological wall in patients with gastric malignancy (1.115 ± 0.156 x10-3 mm2/s) were significantly lower than the healthy wall measurements (1.621 ± 0.292 × 10-3 mm2/s) and benign gastric diseases (1.790± 0.359 x10-3 mm2/s). GW/spine ADC ratio was also lower in gastric malignancy group. ADC measurement in DWI can be used to distinguish between benign and malign gastric pathologies.

Role of diffusion-weighted imaging in the discrimination of purulent intrasinusal content: A retrospective study.

The objective of this study was to analyse MRI with morphological (T1, T2) and diffusion sequences (DWI, b1000) in patients presenting non-aggressive patterns of sinus opacity and operated on by functional endoscopic sinus surgery (FESS). A retrospective study. Diffusion imaging in paranasal sinus pathology remains little known. To date, no imaging system is capable of determining the purulent content of a non-enhanced sinus filling. We included consecutive patients having undergone FESS in whom MRI of the paranasal sinuses was performed. Subjects were allocated to Case (pus) or Control (no pus) groups depending on sinus content found intraoperatively. FESS was performed for bacterial acute rhinosinusitis, acute exacerbations of chronic rhinosinusitis, non-purulent sinusitis, naso-sinusal polyposis, antrochoanal polyp, isolated polyp, angiomatous polyp and eosinophilic fungal sinusitis. Tumours, mucoceles and fungus balls were excluded. We analysed T1, T2, b1000 and MRI sequences and ADC map. On univariate analysis, intermediate signal in T2 and high signal in b1000 were associated with Cases (P<0.001) as were low ADC values (P<0.001). The difference in mean ADC values between Cases and Controls was statistically significant (respectively, 0.518 vs 2.041×10-3 mm2 /sec, P<0.01). On multivariate analysis, MRI with ADC<0.725×10-3 mm2 /sec and b1000_SI>brain was significantly associated with the case group. MRI with b1000_SI<brain and ADC>1.450×10-3 mm2 /sec was significantly associated with the control group. Diffusion MRI offers extremely promising results regarding content characterisation of infectious sinus diseases.

Role of Diffusion-weighted Imaging in Detecting Early Ischemic Brain Injury Following Aneurysmal Subarachnoid Hemorrhage.

Background:Aneurysmal SAH is the significant cause of morbidity and mortality in stroke patients. Early brain injury and delayed cerebral ischemia are the two main responsible pathophysiologic processes. Cerebral ischemia needs to be detected early so that early aggressive therapy could be started. Although Diffusion weighted imaging (DWI) has often been utilized for the measurement of acute ischemic strokes, its role in the detection of early cerebral ischemia due to aneurysmal subarachnoid hemorrhage has not been extensively investigated. This study is being carried out to describe the role of DWI in detecting early ischemic brain injury and outcome after aneurysmal SAH.Aim:Efficacy of DWI in detecting ischemic injury and predicting outcome after aneurysmal SAH.Material and Methods:In this prospective study 44 consecutive patients who had aneurysmal SAH; admitted within 7 days of their ictus were included. Hunt and Hess grade on admission and modified Fisher grade of SAH were noted. Plain CT brain and MR DWI was done on day before surgery. Diffusion restriction on DWI was correlated with postoperative neurological deficit, postoperative CT finding and outcome of the patient at 1 month follow-up.Results:DWI revealed restricted diffusion in 12 patients, out of which 1 patient was having infarction in preoperative CT scan, 6 patients were having postoperative deficit in the form of disorientation, hemiparesis and aphasia, and all patients were having infarction in postoperative CT scan. When DWI findings were compared on the basis of postoperative neurological deficit, postoperative CT finding and modified Rankin outcome score at 1month follow-up, results were statistically significant.Conclusion:DWI shows cerebral ischemia much earlier than CT scan in cases of aneurysmal SAH. It has significant correlation with postoperative neurological status and outcome of the patient.

Preoperative diagnosis of atypical pelvic leiomyoma and sarcoma: the potential role of diffusion-weighted imaging

The objective of our study was to determine the utility of diffusion-weighted magnetic resonance (DWMR) to differentiate the atypical uterine leiomyomas and sarcomas, establishing a cut-off value of the apparent diffusion coefficient (ADC) to rule out the malignancy. We performed a diagnostic accuracy retrospective study including 10 patients with pelvic sarcomas and 17 patients with leiomyomas. Atypical morphological features in magnetic resonance (MR) studies occurred in 58.8% of the patients, leading to a significant number of indeterminate diagnoses. In contrast, ADC values were consistent for leiomyomas, sarcomas, primary tumours, recurrences, intrauterine and in the extrauterine pelvic locations. The ADC cut-off value was set in 1 (×10−3 mm2/s). Thus, the ADC values equal or superior to 1 × 10−3 mm2/s were always associated with a leiomyoma. The structural MR accuracy was 66.7%, reaching 100% when using DWMR with dichotomised ADC values. Diffusion-weighted imaging with the quantitative measurement of ADC may be considered a useful preoperative test for the differentiation of atypical leiomyomas from sarcomas.Impact statementWhat is already known on this subject? Papers reporting the utility of a diffusion-weighted MR for the diagnosis of uterine sarcomas are scarce and consist of a small series. However, the published results are consistent with our study, with the decreased ADCs in the case of malignancy.What do the results of this study add? The main differential characteristic of our study is that we selected only the atypical leiomyomas: they share sonographic and MR features with sarcomas, which often leads to an inaccurate diagnosis. This is also the first paper reporting on the role of DWMR with ADC for these types of tumours in extrauterine pelvic locations. We demonstrated a consistent relationship between dichotomised ADC values in leiomyomas/sarcomas for these particular cases and in recurrent tumours, with no overlap between both the groups, as a difference with the previous reports.What are the implications of these findings for clinical practice and/or further research? Our study can be considered as a proof of concept supporting DWMR with ADC measurement as a useful tool to enhance the diagnostic accuracy of MR, highlighting its value to rule out malignancy. Hence, DWMR seems to be a potential useful test to include in the preoperative evaluation of clinically atypical uterine tumours.

The Role of Diffusion-weighted Imaging in Patients with Brain Tumors

The Role of Diffusion-weighted Imaging in Patients with Brain Tumors

Role of diffusion-weighted imaging in the discrimination of benign and metastatic parotid area lymph nodes in patients with nasopharyngeal carcinoma

To assess the utility of apparent diffusion coefficient (ADC) determined on diffusion-weighted MR imaging (DWI) to differentiate between benign and malignant parotid area lymph nodes (PLN) in nasopharyngeal carcinoma (NPC) patients. Thirty-nine consecutive NPC patients with a total of 40 enlarged, biopsied PLNs underwent DWI examination. ADC values for benign and malignant PLNs were measured and compared. Receiver operating characteristic (ROC) curve analysis was to evaluate the optimal threshold level of ADC values for metastatic PLNs. The kappa was to assess the degree of agreement between histopathological diagnoses and ADC values, or imaging features of PLNs on MRI. We found the mean ADC value for benign PLNs was markedly higher than malignant PLNs. A threshold ADC of 1.01 × 10−3 mm2/s was associated with a sensitivity of 85.7% and a specificity of 72.7% (area under the curve: 0.84). A moderate agreement was observed between the histopathological diagnosis and the threshold of ADC value (k value: 0.483). However, short axis diameter, necrosis, extranodal extension, and regional grouping of PLNs on MRI showed only a fair agreement with the histopathological diagnosis (k value: 0.257, 0.305, 0.276, and 0.205, respectively). Therefore, DWI may be a promising technique to differentiate metastatic from benign PLNs.

Routine addition of diffusion-weighted imaging to pediatric brain imaging with acute presentation: An initial experience

Context: A number of disorders affecting the pediatric brain pose a diagnostic challenge. Magnetic resonance imaging (MRI) is widely accepted as a sensitive technique for the diagnosis of ischemia, encephalitis, and leukodystrophies. Conventional MR sequences used in routine practice include T1-weighted (T1-W), T2-weighted, and fluid-attenuation inversion recovery (FLAIR) sequences. However usually, the presentation in small children is confusing and presents a diagnostic challenge even after the use of these various MR sequences requiring repeated MRI examinations. Detecting pathological changes occurring at microenvironment level is vital for early diagnosis, effective treatment, and obviating the need of repeated MRI. Aims: The purpose of our study was to assess the additional role of diffusion-weighted imaging (DWI) in better detection of these various pathologies of brain. Settings and Design: This was a prospective study. Subjects and Methods: Thirty children of ages ranging from neonate to 12 years of age with various complaints of central nervous system involvement were evaluated with MRI brain within 72 h of initial clinical presentation. T1 and T2 spin-echo sequences FLAIR and postcontrast T1-W imaging were done. DWI was performed with echoplanar imaging using depth-resolved surface coil spectroscopy sequence. The lesions were evaluated on DWI and conventional sequences. The final diagnosis was established on the basis of clinical evaluation, electroencephalographic findings, imaging, cerebrospinal fluid analysis, serologic tests, and fatty acid evaluation in plasma assay. Statistical Analysis Used: This was a descriptive study. Results: The patients were divided into three groups. Group A included patients in whom DWI detected more lesions or showed a greater extent of lesions on apparent diffusion coefficient (ADC) map than conventional MRI. This group had 11 cases including 7 cases of ischemic encephalopathy, one case of adrenoleukodystrophy (ADL) showing increased extent of lesion with restricted diffusion at the advancing edge and 3 cases of viral encephalitis. In Group B, 12 cases had similar results in both DWI and conventional MRI imaging. Of these, 7 cases with no specific diagnosis and subsequent spontaneous recovery showed no lesion on both conventional and DWI; 5 cases showed equal extent and number of lesions on DWI; 1 case was diagnosed as ADL, 2 as viral encephalitis, and 2 as ischemic encephalopathy on final workup. In Group C, T2 and FLAIR showed more lesions than DWI and had 7 cases. 5 had normal ADC maps but 1–2 small hyperintense lesions on T2 and FLAIR imaging, while the remaining two diagnosed with ischemic encephalopathy had hyperintense areas on T2 and FLAIR sequences with associated ventricular enlargement and cortical atrophy while DWI revealed them to be T2 shine through areas with increased ADC value focally. The 5 cases with hyperintensity on T2 and FLAIR, but normal ADC maps were labeled as nonspecific white matter hyperintensities. These children showed neither any progress of lesion nor any further clinical symptoms during the duration of study. Conclusions: We concluded that DWI was more sensitive than the other MR sequences in detecting early pathological changes even in cases of viral encephalitis and leukodystrophy apart from ischemia. It was also helpful in delineating the area more accurately at the microscopic level. We were also able to rule out actual pathology from nonspecific hyperintensities on T2 and FLAIR in some cases on DWI.

The diagnostic accuracy of high b-value diffusion- and T2-weighted imaging for the detection of prostate cancer: a meta-analysis

PurposeThis study aims to investigate the role of diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) in combination for the detection of prostate cancer, specifically assessing the role of high b-values (> 1000 s/mm2), with a systematic review and meta-analysis of the existing published data.MethodsThe electronic databases MEDLINE, EMBASE, and OpenSIGLE were searched between inception and September 1, 2017. Eligible studies were those that reported the sensitivity and specificity of DWI and T2WI for the diagnosis of prostate cancer by visual assessment using a histopathologic reference standard. The QUADAS-2 critical appraisal tool was used to assess the quality of included studies. A meta-analysis with pooling of sensitivity, specificity, likelihood, and diagnostic odds ratios was undertaken, and a summary receiver-operating characteristics (sROC) curve was constructed. Predetermined subgroup analysis was also performed.ResultsThirty-three studies were included in the final analysis, evaluating 2949 patients. The pooled sensitivity and specificity were 0.69 (95% CI 0.68–0.69) and 0.84 (95% CI 0.83–0.85), respectively, and the sROC AUC was 0.84 (95% CI 0.81–0.87). Subgroup analysis showed significantly better sensitivity with high b-values (> 1000 s/mm2). There was high statistical heterogeneity between studies.ConclusionThe diagnostic accuracy of combined DWI and T2WI is good with high b-values (> 1000 s/mm2) seeming to improve overall sensitivity while maintaining specificity. However, further large-scale studies specifically looking at b-value choice are required before a categorical recommendation can be made.

Diffusion-weighted MRI combined with susceptibility-weighted MRI: added diagnostic value for four common lateral ventricular tumors

Background Diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) are reliable imaging modalities for brain tumors. However, the role of DWI and SWI in the diagnosis of common lateral ventricular tumors has not been systematically evaluated. Purpose To evaluate the diagnostic performance of DWI and SWI in common lateral ventricular tumors. Material and Methods Fifty-two patients with histopathologically confirmed lateral ventricular tumors were included in this study (18 with central neurocytomas, nine with ependymomas, seven with high-grade gliomas, and 18 with meningiomas). The relative minimum apparent diffusion coefficient (rADCmin) and relative average apparent diffusion coefficient (rADCave) measured by DWI and the intratumoral susceptibility signal intensity (ITSS) of hemorrhage acquired by SWI were calculated. These quantitative parameters were evaluated using the Mann-Whitney U test, receiver operating characteristic curve, and logistic regression analyses. Results The rADCmin and rADCave ratios of central neurocytomas were significantly lower than those of the other neoplasms. The rADCmin and rADCave ratios of ependymomas and the rADCave ratio of high-grade gliomas were significantly higher than those of meningiomas. The ITSS score of meningiomas was significantly lower than those of the other tumors, while the score of central neurocytomas was obviously lower than those of ependymomas and high-grade gliomas. The combination of the rADC ratio with the ITSS showed no significant difference, except in discriminating between meningiomas and high-grade glioma-ependymomas. Conclusion The rADC ratios and ITSS may be useful for differentiating common lateral ventricular tumors. The diagnostic performance may be improved with the use of the rADC ratios and ITSS scores.

Role of diffusion-weighted imaging in head and neck lesions: Pictorial review.

Head and neck cancers are very common worldwide, causing significant morbidity and mortality. Squamous cell carcinoma originating from the epithelial lining of the upper aerodigestive tract is the most common histology. Many patients with head and neck cancers present with advanced stage disease requiring aggressive treatment consisting of extensive surgery and chemo-radiation. Appropriate treatment planning as well as prognosis of tumors depends to a large extent on accurate histological diagnosis and differentiation of malignant from benign lesions. Routine imaging modalities such as computed tomography and magnetic resonance imaging give volumetric and morphologic information. However, these modalities cannot be reliably used as a substitute for biopsy in treatment planning. However, diffusion-weighted imaging has shown promise in tissue characterization for primary tumors and nodal metastases, differentiation of recurrent tumor from post therapeutic changes, prediction and monitoring of treatment response, and many other clinical scenarios as described later in this article. In this review article, we describe the imaging findings in applications of diffusion-weighted imaging in the head and neck lesions and discuss their added value over anatomic imaging.

3-T Magnetic Resonance Diffusion-Weighted Imaging (DWI) for Characterization of Hepatic Masses

Objective: To evaluate the role of DWI and ADC in differentiating benign from malignant hepaticmasses Materials and methods: Forty-one patients with fifty-two focal hepatic masses were included in our study. MRI was done using coronal T2-weighted single-shot turbo spin-echo, breath hold axial 3-D gradient-echo, breath hold 2- D gradient-echo in and out-of-phase, respiratory-triggered axial turbo spin-echo T2 sequence with fat saturation, followed by free breathing Diffusion-weighted MR imaging using a single-shot spin-echo echo planar imaging sequence and finally triphasic -MRI. Results: Forty-one patients (Fifty-two lesions) were included in our study. Twenty-three lesions were benign; eight of them were cysts (mean ADC values of 3.15 ± 0.34 × 10-3 mm2/s) and fifteen lesions were hemangiomas (mean ADC values of 2.10 ± 0.25 × 10-3 mm2/s). Twenty-nine lesions were malignant; twelve HCC lesions (mean ADC values of 1.10 ± 0.32 × 10-3 mm2/s) and seventeen masses were metastasis (mean ADC values of 0.96 ± 0.23 × 10-3 mm2/s). Sensitivity and specificity of DWI in differentiating malignant from benign hepatic masses were 96.6% and 95.7% respectively. Conclusion: DWI is an easy technique to obtain and to be evaluated. ADC values can differentiate benign from malignant liver masses with high sensitivity and specificity.

The Role of Diffusion-Weighted Imaging in the Evaluation of the Whole Brain in Isolated Unilateral Polymicrogyria.

The aim is to evaluate normal-appearing brain regions in isolated unilateral polymicrogyria patients and compare them with controls by using diffusion-weighted imaging and apparent diffusion coefficient. The diffusion-weighted images (b = 0-1000 s/mm2) of 10 pediatric patients (7 boys, 3 girls; mean age = 5.8 ± 4.3 years) with isolated unilateral polymicrogyria and age-sex matched 10 control patients were assessed retrospectively. There was a significant increase in apparent diffusion coefficient values of white matter underlying polymicrogyria, uninvolved white matter, deep gray matter (thalami, lentiform nuclei, caudate nuclei) and corpus callosum in polymicrogyria patients compared to control group (P < .01). The whole brain might be affected in isolated unilateral polymicrogyria patients. The abnormal deep gray matter in polymicrogyria patients would indicate a new point of view for pediatric neurologists about the probability of additional future neurological disorders.

The role of diffusion-weighted imaging in differentiation of hepatic alveolar echinococcosis and intrahepatic cholangiocarcinoma

ObjectiveA technique is proposed for evaluating the utility of apparent diffusion coefficient (ADC) measurements in the differentiation of type 4 hepatic alveolar echinococcosis (HAE) from the mass-forming type of intrahepatic cholangiocarcinoma (IHCC), using diffusion-weighted magnetic resonance imaging (DW-MRI). MethodsThis study, conducted from November 2013 to January 2015, was approved by the ethics committee of First Affiliated Hospital of Xinjiang Medical University. All patients were given written informed consent. A total of 11 patients underwent T1WI, T2 fat-saturation, and a respiratory triggered DWI sequence by a 1.5T MR imaging system. An experienced radiologist measured the ADC in both alveolar echinococcosis and cholangiocarcinoma lesions. DWI was performed with a b-value gradient of 0 and 600. The mean ADC values of type 4 hepatic alveolar echinococcosis were compared with those of mass-forming type cholangiocarcinoma, in order to determine variations between the two. Differences in ADC between lesion types were determined by using an independent samples t-test and a statistically significant (P < 0.05) difference was observed. ResultsMean ADC values for IHCC were 1.24 ± 0.23 × 10−3 mm2/s, which was significantly lower than the 1.71 ± 0.23 × 10−3 mm2/s observed for HAE. These results supported the use of this technique as a mechanism for lesion differentiation. ConclusionsLower ADC in DW-MRI represents restricted diffusion. Due to multicellularity being higher in IHCC than HAE, the mean ADC values for IHCC were lower than for HAE.

Diffusion-weighted MRI in Crohn's disease: Current status and recommendations.

Over the past years, technological improvements and refinements in magnetic resonance imaging (MRI) hardware have made high-quality diffusion-weighted imaging (DWI) routinely possible for the bowel. DWI is promising for the detection and characterization of lesions in Crohn's disease (CD) and has been advocated as an alternative to intravenous gadolinium-based contrast agents. Furthermore, quantification using the apparent diffusion coefficient may have value as a biomarker of CD activity and has shown promise. In this article we critically review the literature pertaining to the value of DWI in CD for detection, characterization, and quantification of disease activity and complications. Although the body of supportive evidence is growing, it is clear that well-designed, multicenter studies are required before the role of DWI in clinical practice can be fully established. J. Magn. Reson. Imaging 2016;44:1381-1396.

P122. Role of diffusion-weighted imaging in MRI-enterography for the evaluation of surgical risk in patients with Crohn’s disease

P122. Role of diffusion-weighted imaging in MRI-enterography for the evaluation of surgical risk in patients with Crohn’s disease