Deep learning-based 3D quantitative total tumor burden predicts early recurrence of BCLC A and B HCC after resection.

OBJECTIVES: This study aimed to evaluate the potential of deep learning (DL)-assisted automated three-dimensional quantitative tumor burden at MRI to predict postoperative early recurrence (ER) of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This was a single-center retrospective study enrolling patients who underwent resection for BCLC A and B HCC and preoperative contrast-enhanced MRI. Quantitative total tumor volume (cm3) and total tumor burden (TTB, %) were obtained using a DL automated segmentation tool. Radiologists' visual assessment was used to ensure the quality control of automated segmentation. The prognostic value of clinicopathological variables and tumor burden-related parameters for ER was determined by Cox regression analyses. RESULTS: A total of 592 patients were included, with 525 and 67 patients assigned to BCLC A and B, respectively (2-year ER rate: 30.0% vs. 45.3%; hazard ratio (HR) = 1.8; p = 0.007). TTB was the most important predictor of ER (HR = 2.2; p < 0.001). Using 6.84% as the threshold of TTB, two ER risk strata were obtained in overall (p < 0.001), BCLC A (p < 0.001), and BCLC B (p = 0.027) patients, respectively. The BCLC B low-TTB patients had a similar risk for ER to BCLC A patients and thus were reassigned to a BCLC An stage; whilst the BCLC B high-TTB patients remained in a BCLC Bn stage. The 2-year ER rate was 30.5% for BCLC An patients vs. 58.1% for BCLC Bn patients (HR = 2.8; p < 0.001). CONCLUSIONS: TTB determined by DL-based automated segmentation at MRI was a predictive biomarker for postoperative ER and facilitated refined subcategorization of patients within BCLC stages A and B. CLINICAL RELEVANCE STATEMENT: Total tumor burden derived by deep learning-based automated segmentation at MRI may serve as an imaging biomarker for predicting early recurrence, thereby improving subclassification of Barcelona Clinic Liver Cancer A and B hepatocellular carcinoma patients after hepatectomy. KEY POINTS: Total tumor burden (TTB) is important for Barcelona Clinic Liver Cancer (BCLC) staging, but is heterogenous. TTB derived by deep learning-based automated segmentation was predictive of postoperative early recurrence. Incorporating TTB into the BCLC algorithm resulted in successful subcategorization of BCLC A and B patients.

[The Value of MRI Texture Analysis in Identifying Intraductal Carcinoma of the Prostate Gland].

OBJECTIVE: To explore the value of a radiomics approach based on MRI texture analysis (TA) in identifying intraductal carcinoma of the prostate gland (IDCP). METHODS: MRI images of 56 patients with pathological proven prostate cancer were analyzed retrospectively, including 31 patients with pure prostate adenocarcinoma and 25 patients with IDCP component in the prostate adenocarcinoma lesions. After imaging features of lesions were analyzed, then enhanced arterial and venous phase images were imported into Omni-Kinetics software for the extraction the TA features of region of interests' lesion according to the T2-weighted imaging. In order to set up a regression prediction model which based on texture parameters and morphological features. Furthermore, the comparison of diagnostic accuracy of each TA regression models were assessed by operating characteristic curves (ROC). RESULTS: Among the imaging features of peripheral lesions, the incidence of surgical capsule invasion, prostatic capsule involvement, and seminal vesicle invasion in patients with IDCP was higher than that in patients with adenocarcinoma alone ( P<0.05). Among the imaging features of transitional zone lesions, patients with adenocarcinoma containing IDCP had a higher incience of imaging features as benign prostatic hyperplasia, extracapsular invasion of the prostate, seminal vesicles invasion, and vascular nerve bundles than that in pure adenocarcinoma group ( P<0.05). In order to differential diagnosis of simple adenocarcinoma and adenocarcinoma containing IDCP, 4 arterial phase texture features were used to build the regression model in the peripheral zone group, and the area under the curve ( AUC) of the TA model and combined model with or without seminal vesicles invasion were 0.890 and 0.938, respectively. In the transitional zone group, 2 arterial phase texture features and 2 venous phase features were used in TA regression model, and the AUC of texture model and the combined model with or without vascular nerve bundles were 0.844 and 0.901, respectively. CONCLUSION: The incidence of adenocarcinoma with IDCP is higher in high-grade invasive prostate cancer. It is wonderful that when compared with T2WI, enhanced sequential texture analysis is more valuable when using the radiomics approach based on MRI texture analysis in identifying IDCP in prostate cancer.

Diagnostic Performance of Monoexponential DWI Versus Diffusion Kurtosis Imaging in Prostate Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVE: We aimed to compare the diagnostic performance of monoexponential DWI and diffusion kurtosis imaging (DKI) for the detection of prostate cancer (PCa). MATERIALS AND METHODS: A systematic literature search was conducted for studies evaluating the diagnostic value of monoexponential DWI and DKI for PCa in the same patient cohorts with sufficient data to construct 2 × 2 contingency tables. Qualities of the included studies were assessed by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Data were extracted to calculate pooled sensitivities and specificities. We constructed summary ROC curves and calculated AUCs to determine the performances of DKI parameters (diffusion coefficient and kurtosis characterizing the deviation from the monoexponential decay) and apparent diffusion coefficient (ADC) values in diagnosing PCa. RESULTS: Five studies (463 patients) were included, with eight, nine, and 10 subsets of data available for analysis of ADC, diffusion, and kurtosis, respectively. Pooled sensitivities were 89% (95% CI, 80-94%) for ADC, 91% (95% CI, 84-95%) for diffusion, and 87% (95% CI, 83-91%) for kurtosis. Pooled specificities were 86% (95% CI, 80-90%) for ADC, 78% (95% CI, 71-84%) for diffusion, and 85% (95% CI, 81-89%) for kurtosis. According to the summary ROC analyses, the AUC was 0.93 (95% CI, 0.90-0.95) for ADC, 0.89 (95% CI, 0.86-0.92) for diffusion, and 0.93 (95% CI, 0.90-0.95) for kurtosis. There was no notable publication bias, but significant heterogeneity was observed. CONCLUSION: Monoexponential DWI and DKI showed comparable diagnostic accuracies for PCa. DKI is a potentially helpful method for the diagnosis of PCa. Therefore, on the basis of current evidence, we do not recommend including DKI in routine clinical assessment of PCa for the moment.

Diagnostic value of renal perfusion in patients with chronic kidney disease using 3D arterial spin labeling.

PURPOSE: To evaluate the diagnostic value of 3D arterial spin labeling (ASL) for noninvasive quantification of renal blood flow (RBF) in patients with chronic kidney disease (CKD). MATERIALS AND METHODS: CKD patients (n = 27) and healthy volunteers (n = 36) underwent renal 3T ASL magnetic resonance imaging, with inversion times from 1200 to 2000 msec for volunteers in the preliminary test, and 1800 to 2000 msec for volunteers and CKD patients in the formal experiments. The cortical RBFs were compared, and a correlation between RBF and estimated glomerular filtration rate (eGFR) was evaluated. RESULTS: For healthy volunteers, RBF values increased with TIs from 1200 to 1600 msec, but were almost constant at TIs from 1600 to 2000 msec. The cortical RBF values of CKD patients were lower than that of healthy volunteers at TIs from 1800 to 2000 msec. In addition, the CKD patients had lower cortical RBF values than the healthy volunteers (P < 0.01 for both), and their RBF values positively correlated with eGFR. CONCLUSION: 3D ASL is a potential noninvasive method for measuring renal perfusion that can provide valuable information for clinical CKD diagnosis. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:589-594.

Diffusion-weighted imaging of the kidneys and its relationship with residual renal function in continuous ambulatory peritoneal dialysis patients.

OBJECTIVE: The objective of our study was to prospectively evaluate renal diffusion as shown by diffusion-weighted imaging (DWI) and its relationship with the residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD) patients. SUBJECTS AND METHODS: Forty CAPD patients and 40 healthy volunteers were recruited, and all underwent conventional and fat-saturated echo-planar DWI with three b values (0, 300, 600 s/mm(2)). The renal parenchymal thickness and apparent diffusion coefficients (ADCs) were measured, and both were compared between the two groups. The relationships between ADC values and clinical indexes--which included RRF, serum creatinine value, cystatin C value, and urine output--were analyzed. RESULTS: Compared with the renal parenchymal thickness and ADC values in control subjects, these values in CAPD patients were significantly decreased (p < 0.0001). In CAPD patients, the ADC values were positively correlated with RRF (r = 0.447, p = 0.004). A mild linear correlation was also found between the ADC values and cystatin C value (r = -0.352, p = 0.026). CONCLUSION: The renal diffusion function as shown by DWI is impaired in CAPD patients and correlates with RRF.

Childhood cystic teratoma of the pancreas: clinical presentation, evaluation and management.

Pancreatic cystic teratoma in children is extremely rare. Here we present a female infant with a mature cystic teratoma of the pancreatic body. The patient was admitted for a palpable abdominal mass and anorexia. Computed tomography (CT) indicated a huge cystic mass in the abdominal cavity. Exploratory laparotomy was performed, and the tumor was excised completely. Pathology confirmed the tumor was a mature cystic teratoma of pancreatic origin. Two months after the initial surgery, a pseudocyst was detected and then cystojejunostomy was performed. Fourteen months after the second surgery, tumor relapse occurred and distal pancreatectomy was performed. The patient remained well without tumor recurrence during the next 24 months of follow-up. Our experience suggests that clinical manifestations of children with pancreatic cystic teratomas might be nonspecific and preoperative diagnosis is difficult. Radical tumor resection and maximized preservation of healthy pancreatic tissue should always be balanced in surgical treatment.

[Early abnormalities of kidneys in patients with primary hypertension by 3.0 T functional magnetic resonance imaging].

This study aims to detect early changes of kidney in patients with primary hypertension by 3.0 T functional magnetic resonance imaging (fMRI). 26 patients with primary hypertension (hypertension group) and 33 healthy volunteers (control group) underwent conventional and functional magnetic resonance scans, which included blood oxygen level-dependent (BOLD) MRI, diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI). We measured renal cortical thickness (CT), parenchymal thickness (PT), and functional values of renal cortex and medulla including R2* value, apparent diffusion coefficient (ADC) value and fractional anisotropy (FA) value in each group, and then calculated the cortical/parenchymal thickness ratio (CPR). Compared with those in the control group, CT and CPR in hypertension group were larger (P < 0.01), cortical and medullar R2* values increased (P < 0.01) whereas medullar FA values decreased (P < 0.05). It could be well concluded that noninvasive 3.0 T functional MRI would have important clinical significance in identifying early abnormalities of kidney in hypertension patients.

The effect of post-labeling delay on cerebral blood flow is influenced by age and sex: a study based on arterial spin-labeling magnetic resonance imaging.

Background: Whether the effect of post-labeling delay (PLD) on cerebral blood flow (CBF) is influenced by age and sex in adults is unknown. In this study, we mainly aimed to explore the potential influence of age and sex on the effect of PLD on CBF. Methods: This prospective study enrolled 90 healthy adult volunteers (49.47±15.63 years of age; age range, 20-77 years; 47 female; 43 male). All participants underwent 3-dimensional (3D) pseudo-continuous arterial spin labeling (ASL) imaging with 3 different PLDs (1,525, 2,025, and 2,525 ms). The CBF values for each PLD, the arterial transit time (ATT), and the spatial coefficient of variation (spatial CoV) were computed for 21 regions of interest (ROIs) in every participant. Multivariate regression analysis was conducted to assess the potential influence of age and sex on the effect of PLD on CBF and the relationships among CBF, ATT, PLD, age, sex, and spatial CoV. Results: The CBF increased for 7.32 to 9.87 mL/100 g/min as the PLD increased per 1 second in the global gray matter, bilateral frontal, temporal lobes, the vascular territories of bilateral anterior and middle carotid artery. When the age increased per 1 year, the speed of the changes for CBF decreased for 0.26 to 0.3 mL/100 g/min/s in these regions. However, the CBF decreased for 12 to 17 mL/100 g/min as the PLD increased per 1 second in the bilateral limbic lobes, insula, and deep gray matter. In these regions, the speed of the changes for CBF increased for 0.2 to 0.28 mL/100 g/min/s as the age increased per 1 year. Furthermore, compared to the female, the speed of the changes for CBF decreased for 3.58 to 4.6 mL/100 g/min/s for the male in global gray matter, bilateral frontal, limbic lobes, and the vascular territories of bilateral anterior carotid artery, and the speed increased 4.49 to 5.09 mL/100 g/min/s for the male in the limbic lobes. In addition, the CBF decreased with aging and the CBF tended to be higher in females compared to males. At the same time, we found that the ATT of all ROIs increased with age and manifested higher in males than females. Moreover, we found that CBF decreased with the increase of ATT, and the effect of ATT on CBF was less influenced by PLD. Finally, we found that the spatial CoV of ASL in certain regions increased with the increase of ATT and age, and was greater in males. Conclusions: The effect of PLD on CBF can be influenced by age and sex. The relationships among CBF, ATT, PLD, age, sex, and spatial CoV found in this study may have certain significance for the study of ASL imaging in the future.

[The diagnostic value of conventional MRI in the differentiation of malignant tumor from benign lesion in prostatic peripheral zone].

OBJECTIVE: To evaluate the diagnostic capabilities of conventional MRI (T1WI, T2WI and Gd-enhancement T1WI) for differentiating prostate cancer from benign prostatic disorders in prostatic peripheral zone (PZ). METHODS: Respectively analyze the characteristics of conventional MRI in 46 cases of prostate cancer and 25 cases of benign prostatic disorders (with 28 lesions). Six indexes were initially screened by Chi2-test, and receiver operating characteristic curves (ROC) of these indexes were depicted, then Bayes discriminator was applied to discriminate all the lesions according to the indexes with statistic meaning. The discriminant function was evaluated with new sample validation. RESULTS: The indexes showing statistics meaning between prostate cancer and benign prostatic disorders were uniform low SI on T2WI, shape, pseudocapsule extension, prostate-capsule extension, size change of PZ with lesion and enhancement style. Furthermore, uniform low SI on T2WI, enhancement style and size change of PZ with lesion were consist of the function after discrimination, AUC of these 3 indexes were all above 0. 7, which were wider than that of the other 3 indexes. The discriminating accuracy rates of the new sample for benign prostatic disorders and prostate cancer were 83% and 77%. CONCLUSION: The importance of uniform low SI on T2WI, enhancement style and size change of PZ with lesion should be highlighted in the differentiation of prostate cancer and benign prostatic disorders in PZ.

Records of trace metals since the Holocene in sediments of Laizhou Bay, Bohai Sea, China.

Trace metal (Cu, Pb, Zn, Cr, Cd, As, Hg, Ni, Li, and Co) concentration profiles along a sediment core were investigated to obtain background values, assess depositional trends and contamination levels in the Laizhou Bay, China. The enrichment factors of the metals indicated no anthropogenic enrichment, except for Pb, Cd, and Hg, which have been influenced by human activities since 7 ka. The mean concentrations of trace metals in the 10-7 ka phase can be considered as the background values in the study area. Principal component analysis indicated that the metals were mainly naturally sourced throughout the observed depositional period. Their geoaccumulation indices indicated that the sediments were not contaminated by Cu, Zn, Cr, Ni, and Co, but were contaminated by Pb, Cd, and Hg during the 7-0 ka period.

[Distinguishing benign from malignant incidental adrenal lesions in enhanced CT imaging].

OBJECTIVE: To characterize the differences in radiologic features between benign and malignant adrenal lesions. METHODS: Enhanced multiple-slice spiral CT images of 99 patients with adrenal tumors were reviewed retrospectively, investigating into morphological features of different kinds of adrenal lesions with Wash-in Amplitude (WA, venous phase attenuation-unenhanced attenuation) and relative wash-in ratio (RWR, WA/artery phase attenuation). RESULTS: A combination of threshold in diameter = 3.2 cm, unenhanced attenuation = 24 HU, and RWR value = 0.879 produced 94.28% sensitivity and 98.43% specificity in diagnosing adenomas. CONCLUSION: Enhanced CT imaging improves diagnostic accuracy of incidental adrenal lesions.

Assessment of heavy metal contamination in surface sediments off the Dongying coast, Bohai Sea.

In this study, 214 surface sediment samples were collected from the offshore area of the Dongying coast and were analysed for heavy metals; particularly, their concentrations and pollution status were evaluated. The copper (Cu) and chromium (Cr) distributions were similar, their concentrations were the highest in the northeast areas and the Xiaoqing River estuary, where dominated by fine-grained sediments. Higher concentrations of lead (Pb), zinc (Zn), cadmium (Cd), and arsenic (As) were generally found in the offshore area of the study location, and the highest Cd concentration was observed in the Xiaoqing River estuary. The sediments were not polluted by Cu, Pb, Zn, and Cr; they were not polluted or moderately polluted by Cd and As. Results of the principal component analysis indicated that Cu, Pb, Zn, and Cr were derived from natural sources and Cd and As were derived from anthropogenic sources.

Practice-Based Learning Using Smart Class: A Competency-Based Model in Undergraduate Radiology Education.

RATIONALE AND OBJECTIVES: A need for adequate and early exposure to radiology practice is rising in undergraduate students, taking competency development as the orientation. We aimed to develop a competency-based model of practice-based learning for undergraduate radiology education. MATERIALS AND METHODS: The model of practice-based learning was constructed upon an e-learning smart class environment, with case-based learning and simulators for competency development. To assess the model effectiveness, a randomized controlled experiment was performed, where 57 third-year medical students received the model (Smart-Class group) and another 57 received traditional teaching (Traditional group). Seven quizzes, a final exam, and a survey were performed in both groups. RESULTS: Smart-Class group achieved higher mean score in the quizzes (r = -0.4, p < 0.001) and application subscore in the final exam (r = -0.3, p = 0.005) compared to Traditional group. Smart-Class group also gave higher ratings in students' perceptions concerning promotion of learning interests, radiology skills, and diagnostic reasoning (r = -0.2 to -0.3, p = 0.001-0.034). CONCLUSION: Practice-based learning using smart class improved students' application ability and satisfactions in undergraduate radiology education, suggesting it a practical model for early exposure to radiology practice and competency development for undergraduate medical students.

[Non-invasive assessment of renal oxygenation with BOLD MRI in patients with type 2 diabetes].

OBJECTIVE: To evaluate renal oxygenation in patients with type 2 diabetes using blood oxygenation level-dependent magnetic resonance imaging (BOLD MRI). METHODS: The R2* values of cortex and medulla as well as cortical thickness were measured in 25 patients with type 2 diabetes and 30 normal controls. The associations between R2* values and clinical parameters were analyzed. RESULTS: The medulla R2* value of the patients with diabetes was significantly higher than that of the normal controls. No significant difference in cortical thickness was found between the patients with diabetes and the normal controls. The medulla R2* value increased with eGFR in the patients with diabetes. CONCLUSION: BOLD MRI is a non-invasive and efficient method to assess the oxygenation in different regions of kidney. Abnormality of kidney in diabetic patients can be detected earlier by BOLD MRI than traditional imaging.

Arterial Spin Labeling Magnetic Resonance Imaging in Healthy Adults: Mathematical Model Fitting to Assess Age-Related Perfusion Pattern.

OBJECTIVE: To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. MATERIALS AND METHODS: In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey's regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. RESULTS: Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. CONCLUSION: In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.

[Renal and non-renal tumors within the perirenal space in infants and children: multi-detector row CT characteristics].

OBJECTIVE: To determine the characteristics of Multi-detector Row CT (MDCT) image in distinguishing renal tumors from non-renal tumors within the perirenal space in infants and children. METHODS: Data from 40 patients with surgically and pathologically proved retroperitoneal neoplasms within the perirenal space were collected. Based on the pathological findings, the patients were divided into renal tumor group (n=14) and non-renal tumor group (n=26). The major clinical characteristics and CT characteristics of the two groups were compared. RESULTS: Incomplete renal contour with "crescent sign", "beak sign", "embedded kidney sign" and "prominent feeding artery sign" appeared in renal tumors more often than in non-renal tumors (P < 0.05). The sign of "renal displacement and renal axis rotation" and "extra-renal central plane of tumor" appeared more often in non-renal tumors than in renal tumors (P < 0.05). Large solid tumors with "pseudocapsule", "necrosis and cystic change", "vascularity", inferior vena cava tumor thrombus, and distant metastasis were more likely to be renal tumors than non-renal tumors (P < 0.05). Irregular mass with calcifications appeared more often in non-renal tumors than in renal tumors (P < 0.05). CONCLUSION: MDCT can detect the location, origin and histological feature of retroperitoneal neoplasms in infants and children. The MDCT characteristics can help differentiate renal and non-renal tumors within the perirenal space.

Effect of post-labeling delay on regional cerebral blood flow in arterial spin-labeling MR imaging.

BACKGROUND: Investigating the effect of post-labeling delay (PLD) on regional cerebral blood flow (CBF) in adults and optimizing the PLD for arterial spin-labeling (ASL) magnetic resonance (MR) imaging are important. METHODS: Pseudo-continuous ASL imaging with a three PLDs protocol was performed in 90 healthy adult volunteers from January 2018 to February 2019. Healthy subjects were divided into youth group (mean age, 30.63 years; age range, 20-44 years), middle-aged group (mean age, 52.16 years; age range 45-59 years) and elderly group (mean age, 66.07 years; age range, 60-77 years). After preprocessing, analyses of variance (ANOVA) and volume-of-interest (VOI) were conducted to compare the CBF in each brain region. According to the trends of CBF changing with PLD and the results of ANOVA, we optimized the PLD for ASL imaging in different brain regions and age groups. RESULTS: The CBF values of 87 VOIs [global gray matter (global GM) and other 86 VOIs] for each subject were obtained. Young people had less statistically significant VOIs than middle-aged and elderly people [Numbers of VOIs which had statistical significance (P < .05) in the analysis of ANOVA: 42 (youth group), 79 (middle-aged group), and 71 (elderly group)]. In youth group, the deep GM, occipital lobe and temporal lobe were more affected by PLDs than limbic system, frontal lobe and parietal lobe [VOIs with statistical significance (P < .05)/total VOIs: 8/8 (deep GM) > 8/12 (occipital lobe) > (8/14) (temporal lobe) > 5/12 (limbic system) > 11/28 (frontal lobe) > (2/12) parietal lobe]. In middle-aged group, the limbic system, deep GM and temporal lobe were more affected by PLDs than parietal lobe, frontal lobe and occipital lobe [VOIs with statistical significance (P < 0.05)/total VOIs: 12/12 (limbic system) = 8/8 (deep GM) > (13/14) (temporal lobe) > (11/12) parietal lobe > 25/28 (frontal lobe) > 9/12 (occipital lobe)]. In elderly group, the temporal lobe, parietal lobe, and frontal lobe were more affected by PLDs than occipital lobe, limbic system, and deep GM [VOIs with statistical significance (P < .05)/total VOIs: 14/14 (temporal lobe) > 12/12 (parietal lobe) > 22/28 (frontal lobe) > 9/12 (occipital lobe) > 8/12 (limbic system) > 5/8 (deep GM)]. The optimal PLD for most VOIs in youth group was 1525 ms. However, for middle-aged and elderly group, the optimal PLD for most VOIs was 2525 ms. CONCLUSION: Young people are less affected by PLDs than middle-aged and elderly people. The middle-aged people are most affected by PLDs. In addition, the spatial distributions of PLD effect were different among the three age groups. Optimizing the PLD for ASL imaging according to age and brain regions can obtain more accurate and reliable CBF values.

Abnormal Whole Brain Functional Connectivity Pattern Homogeneity and Couplings in Migraine Without Aura.

Previous studies have reported abnormal amplitude of low-frequency fluctuation and regional homogeneity in patients with migraine without aura using resting-state functional magnetic resonance imaging. However, how whole brain functional connectivity pattern homogeneity and its corresponding functional connectivity changes in patients with migraine without aura is unknown. In the current study, we employed a recently developed whole brain functional connectivity homogeneity (FcHo) method to identify the voxel-wise changes of functional connectivity patterns in 21 patients with migraine without aura and 21 gender and age matched healthy controls. Moreover, resting-state functional connectivity analysis was used to reveal the changes of corresponding functional connectivities. FcHo analyses identified significantly decreased FcHo values in the posterior cingulate cortex (PCC), thalamus (THA), and left anterior insula (AI) in patients with migraine without aura compared to healthy controls. Functional connectivity analyses further found decreased functional connectivities between PCC and medial prefrontal cortex (MPFC), between AI and anterior cingulate cortex, and between THA and left precentral gyrus (PCG). The functional connectivities between THA and PCG were negatively correlated with pain intensity. Our findings indicated that whole brain FcHo and connectivity abnormalities of these regions may be associated with functional impairments in pain processing in patients with migraine without aura.

Extranodal NK/T-cell lymphoma in adolescents: imaging findings of a consecutive 7-year case series.

OBJECTIVES: Extranodal NK/T-cell lymphoma is reportedly a rare but emerging type of lymphoma in adolescents. The present study was performed to specify its imaging characteristics. METHODS: Our hospital's picture archiving and communication systems were searched from January 2009 to December 2016. We identified 13 patients aged <18 years with pathologically confirmed extranodal NK/T-cell lymphoma in the head and neck region. The computed tomography and magnetic resonance images were reviewed to summarize the imaging characteristics of extranodal NK/T-cell lymphoma in adolescents. RESULTS: The mean age at onset was 15.2 ± 1.46 years (range, 12-17 years) with a male:female ratio of 1.17:1.00. Most of the patients (n = 10) displayed nasal cavity and/or paranasal involvement. The tumor was homogeneous in both computed tomography and magnetic resonance images and showed slight enhancement. No calcification or liquefactive necrosis was observed. Adjacent structures were usually involved. CONCLUSION: Suggestive imaging characteristics could acquaint specialists with extranodal NK/T-cell lymphoma in adolescents, facilitating improved early recognition of the diagnosis and helping to improve the patient's outcome.

[Relationship between renal apparent diffusion coefficient and renal interstitial fibrosis: preliminary study].

OBJECTIVE: To explore the relationship between renal ADCs (apparent diffusion coefficient values) and renal interstitial fibrosis (RIF) grades. METHODS: Twenty four patients with chronic renal diseases and 48 healthy volunteers (control group) were examined with SS-EPI DWI at 3. OT MR. In chronic renal disease group, RIF of 14 patients who received renal biopsy was determined as grade I and II based on the tubuleinterstitial damage degree, while RIF of 10 patients with uremia, who did not receive biopsy but had nephrogenic renal atrophy, was categorized as grade III. RESULTS: With comparison of the study group and control group, ADCs of renal cortex were significantly different. In either grade II or III RIF, and ADCs of renal medulla showed difference in grade III RIF (P<0.05). Also, ADCs of both cortex and medulla displayed a decreasing trend as RIF grade increased (P<0.05). CONCLUSION: ADCs of renal cortex and medulla may reflect the grades of RIF. ADC of renal cortex might be more sensitive than that of renal medulla.