Diffusion-weighted MRI for predicting pathologic response to neoadjuvant chemotherapy in breast cancer: evaluation with mono-, bi-, and stretched-exponential models.

BACKGROUND: To investigate the performance of diffusion-weighted (DW) MRI with mono-, bi- and stretched-exponential models in predicting pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) for breast cancer, and further outline a predictive model of pCR combining DW MRI parameters, contrast-enhanced (CE) MRI findings, and/or clinical-pathologic variables. METHODS: In this retrospective study, 144 women who underwent NACT and subsequently received surgery for invasive breast cancer were included. Breast MRI including multi-b-value DW imaging was performed before (pre-treatment), after two cycles (mid-treatment), and after all four cycles (post-treatment) of NACT. Quantitative DW imaging parameters were computed according to the mono-exponential (apparent diffusion coefficient [ADC]), bi-exponential (pseudodiffusion coefficient and perfusion fraction), and stretched-exponential (distributed diffusion coefficient and intravoxel heterogeneity index) models. Tumor size and relative enhancement ratio of the tumor were measured on contrast-enhanced MRI at each time point. Pre-treatment parameters and changes in parameters at mid- and post-treatment relative to baseline were compared between pCR and non-pCR groups. Receiver operating characteristic analysis and multivariate regression analysis were performed. RESULTS: Of the 144 patients, 54 (37.5%) achieved pCR after NACT. Overall, among all DW and CE MRI measures, flow-insensitive ADC change (ΔADC200,1000) at mid-treatment showed the highest diagnostic performance for predicting pCR, with an area under the receiver operating characteristic curve (AUC) of 0.831 (95% confidence interval [CI]: 0.747, 0.915; P < 0.001). The model combining pre-treatment estrogen receptor and human epidermal growth factor receptor 2 statuses and mid-treatment ΔADC200,1000 improved the AUC to 0.905 (95% CI: 0.843, 0.966; P < 0.001). CONCLUSION: Mono-exponential flow-insensitive ADC change at mid-treatment was a predictor of pCR after NACT in breast cancer.

Stroke assessment with intravoxel incoherent motion diffusion-weighted MRI.

Intravoxel incoherent motion (IVIM) diffusion-weighted MRI can simultaneously measure diffusion and perfusion characteristics in a non-invasive way. This study aimed to determine the potential utility of IVIM in characterizing brain diffusion and perfusion properties for clinical stroke. The multi-b-value diffusion-weighted images of 101 patients diagnosed with acute/subacute ischemic stroke were retrospectively evaluated. The diffusion coefficient D, representing the water apparent diffusivity, was obtained by fitting the diffusion data with increasing high b-values to a simple mono-exponential model. The IVIM-derived perfusion parameters, pseudodiffusion coefficient D*, vascular volume fraction f and blood flow-related parameter fD*, were calculated with the bi-exponential model. Additionally, the apparent diffusion coefficient (ADC) was fitted according to the mono-exponential model using all b-values. The diffusion parameters for the ischemic lesion and normal contralateral region were measured in each patient. Statistical analysis was performed using the paired Student t-test and Pearson correlation test. Diffusion data in both the ischemic lesion and normal contralateral region followed the IVIM bi-exponential behavior, and the IVIM model showed better goodness of fit than the mono-exponential model with lower Akaike information criterion values. The paired Student t-test revealed significant differences for all diffusion parameters (all P < 0.001) except D* (P = 0.218) between ischemic and normal areas. For all patients in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001) and f (r = 0.541, P < 0.001; r = 0.262, P = 0.008); significant correlation was also found between ADC and fD* in the ischemic region (r = 0.254, P = 0.010). For all pixels within the region of interest from a representative subject in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001), f (r = 0.823, P < 0.001; r = 0.652, P < 0.001) and fD* (r = 0.294, P < 0.001; r = 0.340, P < 0.001). These findings may have clinical implications for the use of IVIM imaging in the assessment and management of acute/subacute stroke patients. Copyright © 2016 John Wiley & Sons, Ltd.

Characterization of breast masses as benign or malignant at 3.0T MRI with whole-lesion histogram analysis of the apparent diffusion coefficient.

PURPOSE: To investigate the utility of whole-lesion apparent diffusion coefficient (ADC) histogram analysis in capturing breast lesion heterogeneity and determine which ADC metric may help best differentiate benign from malignant breast mass lesions at 3.0T magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively included 101 women with breast mass lesions (benign:malignant = 36:65) who underwent 3.0T diffusion-weighted imaging (DWI) and subsequently had histopathologic confirmation. ADC histogram parameters, including the mean, minimum, maximum, 10th/25th/50th/75th/90th percentile, skewness, kurtosis, and entropy ADCs, were derived for the whole-lesion volume in each patient. Mann-Whitney U-test, univariate and multivariate logistic regression, area under the receiver-operating characteristic curve (Az ), intraclass correlation coefficient (ICC), and Bland-Altman test were used for statistical analysis. RESULTS: Mean, minimum, maximum, and 10th/25th/50th/75th/90th percentile ADCs were significantly lower (all P < 0.0001), while skewness and entropy ADCs were significantly higher (P < 0.001 and P = 0.001, respectively) in malignant lesions compared with benign ones. The Az values of minimum and 25th percentile ADCs were significantly higher than that of mean ADC (P = 0.0194 and P = 0.0154, respectively) or that of median ADC (P = 0.0300 and P = 0.0401, respectively), indicating that minimum and 25th percentile ADCs may be more accurate for lesion discrimination. Multivariate logistic regression showed that the minimum ADC was the unique independent predictor of breast malignancy. Minimum and 25th percentile ADCs had excellent interobserver agreement (ICC = 0.943 and 0.989, respectively; narrow width of 95% limits of agreement). CONCLUSION: These results suggest that whole-lesion ADC histogram analysis may facilitate the differentiation between benign and malignant breast mass lesions.

Differentiation of pyogenic hepatic abscesses from malignant mimickers using multislice-based texture acquired from contrast-enhanced computed tomography.

BACKGROUND: Pyogenic hepatic abscess may mimic primary or secondary carcinoma of the liver on contrast-enhanced computed tomography (CECT). The present study was to explore the usefulness of the analysis of multislice-based texture acquired from CECT in the differentiation between pyogenic hepatic abscesses and malignant mimickers. METHODS: This retrospective study included 25 abscesses in 20 patients and 33 tumors in 26 subjects who underwent CECT. To make comparison, we also enrolled 19 patients with hepatic single simple cyst. The images from CECT were analyzed using a Laplacian of Gaussian band-pass filter (5 filter levels with sigma weighting ranging from 1.0 to 2.5). We also quantified the uniformity, entropy, kurtosis and skewness of the multislice-based texture at different sigma weightings. Statistical significance for these parameters was tested with one-way ANOVA followed by Tukey honestly significant difference (HSD) test. Diagnostic performance was evaluated using the receiver operating characteristic (ROC) curve analysis. RESULTS: There were significant differences in entropy and uniformity at all sigma weightings (P<0.001) among hepatic abscesses, malignant mimickers and simple cysts. The significant difference in kurtosis and skewness was shown at sigma 1.8 and 2.0 weightings (P=0.002-0.006). Tukey HSD test showed that the abscesses had a significantly higher entropy and lower uniformity compared with malignant mimickers (P=0.000-0.004). Entropy (at a sigma 2.0 weighting) had the largest area under the ROC curve (0.888) in differentiating abscesses from malignant mimickers, with a sensitivity of 81.8% and a specificity of 88.0% when the cutoff value was set to 3.64. CONCLUSION: Multislice-based texture analysis may be useful for differentiating pyogenic hepatic abscesses from malignant mimickers.

Investigation of the non-Gaussian water diffusion properties in bladder cancer using diffusion kurtosis imaging: a preliminary study.

OBJECTIVE: The objective of this study was to investigate the non-Gaussian water diffusion properties in bladder cancer and assess the efficacy of diffusion kurtosis imaging for estimating the histological grade of bladder cancer. METHODS: Twenty-one patients with bladder cancer (high-grade, 12; low-grade, 9) and 17 negative controls who underwent preoperative 3.0-T magnetic resonance imaging including multi-b value diffusion-weighted imaging (b values, 0, 500, 800, 1200, 1500, and 2000 s/mm) were included. Besides apparent diffusion coefficient (ADC) maps, diffusion kurtosis imaging maps for diffusion coefficient (Dapp) and kurtosis (Kapp) were also obtained. Data were analyzed using the Mann-Whitney U test, Spearman correlation test, and receiver operating characteristic curves. RESULTS: Bladder cancer showed significantly lower ADC values, lower Dapp values, and higher Kapp values compared with normal bladder wall (all P < 0.001). The Kapp values were significantly higher in high-grade than in low-grade tumors (P = 0.007). Significant correlations were found between Dapp and ADC (r = 0.901, P < 0001) as well as between Kapp and ADC (r = -0.910, P <0.001). The areas under the receiver operating characteristic curve were 0.843 and 0.796 for estimation of high-grade bladder cancer by using the Kapp values and ADC values, respectively. CONCLUSIONS: Diffusion in bladder cancer follows a non-Gaussian behavior. The new metric Kapp may potentially serve as a biomarker of grade of bladder cancer.

Assessment of in vivo microstructure alterations in gray matter using DKI in Internet gaming addiction.

BACKGROUND: The aim of the current study was to investigate the utility of diffusional kurtosis imaging (DKI) in the detection of gray matter (GM) alterations in people suffering from Internet Gaming Addiction (IGA). METHODS: DKI was applied to 18 subjects with IGA and to 21 healthy controls (HC). Whole-brain voxel-based analyses were performed with the following derived parameters: mean kurtosis metrics (MK), radial kurtosis (K⊥), and axial kurtosis (K//). A significance threshold was set at P <0.05, AlphaSim corrected. Pearson's correlation was performed to investigate the correlations between the Chen Internet Addiction Scale (CIAS) and the DKI-derived metrics of regions that differed between groups. Additionally, we used voxel-based morphometry (VBM) to detect GM-volume differences between the two groups. RESULTS: Compared with the HC group, the IGA group demonstrated diffusional kurtosis parameters that were significantly less in GM of the right anterolateral cerebellum, right inferior and superior temporal gyri, right supplementary motor area, middle occipital gyrus, right precuneus, postcentral gyrus, right inferior frontal gyrus, left lateral lingual gyrus, left paracentral lobule, left anterior cingulate cortex, and median cingulate cortex. The bilateral fusiform gyrus, insula, posterior cingulate cortex (PCC), and thalamus also exhibited less diffusional kurtosis in the IGA group. MK in the left PCC and K⊥ in the right PCC were positively correlated with CIAS scores. VBM showed that IGA subjects had higher GM volume in the right inferior and middle temporal gyri, and right parahippocampal gyrus, and lower GM volume in the left precentral gyrus. CONCLUSIONS: The lower diffusional kurtosis parameters in IGA suggest multiple differences in brain microstructure, which may contribute to the underlying pathophysiology of IGA. DKI may provide sensitive imaging biomarkers for assessing IGA severity.

Trait impulsivity and impaired prefrontal impulse inhibition function in adolescents with internet gaming addiction revealed by a Go/No-Go fMRI study.

BACKGROUND: Recent studies suggest that Internet gaming addiction (IGA) is an impulse disorder, or is at least related to impulse control disorders. In the present study, we hypothesized that different facets of trait impulsivity may be specifically linked to the brain regions with impaired impulse inhibition function in IGA adolescents. METHODS: Seventeen adolescents with IGA and seventeen healthy controls were scanned during performance of a response-inhibition Go/No-Go task using a 3.0 T MRI scanner. The Barratt Impulsiveness Scale (BIS)-11 was used to assess impulsivity. RESULTS: There were no differences in the behavioral performance on the Go/No-Go task between the groups. However, the IGA group was significantly hyperactive during No-Go trials in the left superior medial frontal gyrus, right anterior cingulate cortex, right superior/middle frontal gyrus, left inferior parietal lobule, left precentral gyrus, and left precuneus and cuneus. Further, the bilateral middle temporal gyrus, bilateral inferior temporal gyrus, and right superior parietal lobule were significantly hypoactive during No-Go trials. Activation of the left superior medial frontal gyrus was positively associated with BIS-11 and Chen Internet Addiction Scale (CIAS) total score across IGA participants. CONCLUSIONS: Our data suggest that the prefrontal cortex may be involved in the circuit modulating impulsivity, while its impaired function may relate to high impulsivity in adolescents with IGA, which may contribute directly to the Internet addiction process.

Hepatic blood volume imaging with the use of flat-detector CT perfusion in the angiography suite: comparison with results of conventional multislice CT perfusion.

PURPOSE: To prospectively determine the feasibility of flat-detector (FD) computed tomography (CT) perfusion to measure hepatic blood volume (BV) in the angiography suite in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty patients with HCC were investigated with conventional multislice and FD CT perfusion. CT perfusion was carried out on a multislice CT scanner, and FD CT perfusion was performed on a C-arm angiographic system, before transarterial chemoembolization procedures. BV values of conventional and FD CT perfusion were measured within tumors and liver parenchyma. The arterial perfusion portion of CT perfusion BV was extracted from CT perfusion BV by multiplying it by a hepatic perfusion index. Relative values (RVs) for CT perfusion arterial BV and FD CT perfusion BV (FD BV) were defined by dividing BV of tumor by BV of parenchyma. Relationships between BV and RV values of these two techniques were analyzed. RESULTS: In all patients, both perfusion procedures were technically successful, and all 33 HCCs larger than 10 mm were identified with both imaging methods. There were strong correlations between the absolute values of FD BV and CT perfusion arterial BV (tumor, r = 0.903; parenchyma, r = 0.920; both P < .001). Bland-Altman analysis showed a mean difference of -0.15 ± 0.24 between RVs for CT perfusion arterial BV and FD BV. CONCLUSIONS: The feasibility of FD CT perfusion to assess BV values of liver tumor and surrounding parenchyma in the angiographic suite was demonstrated.

Fumarate hydratase mutation associated uterine leiomyomas: A case report and literature review.

The patient was found to have multiple uterine myomas at the age of 19, underwent laparoscopic myomectomy at the age of 20, and underwent laparotomic myomectomy again at the age of 23 due to the recurrence of uterine myoma. At the age of 25, the patient reappeared with symptoms and recurrence, and was diagnosed with uterine leiomyomas (ULMs) of FH mutation and high-grade squamous intraepithelial lesion (HSIL/CIN III) with gland involvement, after complete examination. Fumarate hydratase (FH) mutation screening is important when gynecologists encounter patients with early onset and multiple ULMs, it can give early diagnosis and treatment and fertility guidance. The patient had their uterus removed at the age of 26. FH mutation screening is important when gynecologists encounter patients with early onset and multiple ULMs, it can give early diagnosis and treatment and fertility guidance. It is also helpful for early diagnosis of renal cell carcinoma.

Voxel-level comparison of arterial spin-labeled perfusion magnetic resonance imaging in adolescents with internet gaming addiction.

BACKGROUND: Although recent studies have clearly demonstrated functional and structural abnormalities in adolescents with internet gaming addiction (IGA), less is known about how IGA affects perfusion in the human brain. We used pseudocontinuous arterial spin-labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) to measure the effects of IGA on resting brain functions by comparing resting cerebral blood flow in adolescents with IGA and normal subjects. METHODS: Fifteen adolescents with IGA and 18 matched normal adolescents underwent structural and perfusion fMRI in the resting state. Direct subtraction, voxel-wise general linear modeling was performed to compare resting cerebral blood flow (CBF) between the 2 groups. Correlations were calculated between the mean CBF value in all clusters that survived AlphaSim correction and the Chen Internet Addiction Scale (CIAS) scores, Barratt Impulsiveness Scale-11 (BIS-11) scores, or hours of Internet use per week (hours) in the 15 subjects with IGA. RESULTS: Compared with control subjects, adolescents with IGA showed significantly higher global CBF in the left inferior temporal lobe/fusiform gyrus, left parahippocampal gyrus/amygdala, right medial frontal lobe/anterior cingulate cortex, left insula, right insula, right middle temporal gyrus, right precentral gyrus, left supplementary motor area, left cingulate gyrus, and right inferior parietal lobe. Lower CBF was found in the left middle temporal gyrus, left middle occipital gyrus, and right cingulate gyrus. There were no significant correlations between mean CBF values in all clusters that survived AlphaSim correction and CIAS or BIS-11 scores or hours of Internet use per week. CONCLUSIONS: In this study, we used ASL perfusion fMRI and noninvasively quantified resting CBF to demonstrate that IGA alters the CBF distribution in the adolescent brain. The results support the hypothesis that IGA is a behavioral addiction that may share similar neurobiological abnormalities with other addictive disorders.

Objective assessment of transcatheter arterial chemoembolization angiographic endpoints: preliminary study of quantitative digital subtraction angiography.

PURPOSE: To explore the significance of quantitative digital subtraction angiography (DSA; Q-DSA) in the assessment of chemoembolization endpoints. MATERIALS AND METHODS: Twenty patients with hepatocellular carcinoma treated with chemoembolization were included in the study. All DSA series before and after chemoembolization were postprocessed with Q-DSA. The maximal enhancement and time to peak (TTP) were measured for several homologous anatomic landmarks, including the origin and embolized site of the tumor-feeding artery, parenchyma of the tumor, and ostia of the pre- and postprocedure catheter. The TTP, tumor blood supply time, and maximal enhancement of the time density curve (TDC) were analyzed. RESULTS: Of the 20 DSA series collected, 18 were successfully postprocessed. The TTPs of the landmarks before and after treatment were 3.60 seconds±1.02 and 3.57 seconds±0.78 at the ostia of the catheter, 3.91 seconds±1.01 and 4.09 seconds±1.14 at the origin site of the tumor-feeding artery, and 4.07 seconds±1.02 and 5.60 seconds±1.56 s the embolized site of the main tumor-feeding artery, respectively. Statistical differences were detected between pre- and postprocedural TTP of the embolized site of the feeding artery (P<.01), as well as between pre- and postprocedural tumor blood supply time (P<.01). The mean maximal TDC enhancements of selected tumor spots were 3.01 units±1.04 and 0.81 units±0.35 before and after the procedure (P<.01), respectively. CONCLUSIONS: Q-DSA may provide a feasible quantitative measurement in the assessment of chemoembolization endpoints.

Computed tomography perfusion study of hemodynamic changes and portal hyperperfusion in a rabbit model of small-for-size liver.

BACKGROUND: Portal hyperperfusion in the small-for-size (SFS) liver can threaten survival of rabbits. Therefore, it is important to understand the hemodynamic changes in the SFS liver. METHODS: Twenty rabbits were divided into two groups: a control group and a modulation group. The control group underwent an extended hepatectomy. The modulation group underwent the same procedure plus splenectomy to reduce portal blood flow. CT perfusion examinations were performed on all rabbits before and after operation. Perfusion parameter values, especially portal vein perfusion (PVP), were analyzed. RESULTS: PVP in the modulation group was lower than in the control group after operation (P=0.002). In the control group, postoperative PVP increased by 193.7+/-55.1% compared with preoperative PVP. A weak correlation was found between the increased percentage of PVP and resected liver-to-body weight ratio (RLBWR) (r=0.465, P=0.033). In the modulation group, postoperative PVP increased by 101.4+/-32.5%. No correlation was found between the increased percentage of PVP and RLBWR (r=0.167, P=0.644). Correlations were found between PVP and serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin after surgery (P<0.05). CONCLUSION: We successfully evaluated the characteristics of hemodynamic changes as well as the effects of splenectomy in the SFS liver in rabbits by the CT technique.

The predictive value of DKI in breast cancer: Does tumour subtype affect pathological response evaluations?

PURPOSE: To explore the differences in quantitative parameters based on diffusion weighted imaging (DWI) and diffusion kurtosis imaging (DKI) between different immunohistochemical indicator statuses and their predictive value for neoadjuvant chemotherapy (NAC) among different phenotypes of breast cancer. METHODS: Eighty-one breast cancer patients who underwent NAC were enrolled in this retrospective study. Correlations between diffusion parameters and immunohistochemical indicators were determined using Spearman's test, and receiver operating characteristic (ROC) curves were constructed to assess the apparent diffusion coefficient (ADC), mean diffusivity (MD), and mean kurtosis (MK) in predicting the pathologic complete response (PCR). RESULTS: Correlations were observed between MK values and hormone receptor (HR) expression (oestrogen receptor (ER): r = 0.315 and progesterone receptor (PR): r = 0.268). The parameters ADC(0,1000), MK, and MD all showed correlations with Ki67 expression (r = 0.276, 0.316 and - 0.224, respectively). ER and Ki67 expression and the parameters MD and MK were significantly different between the PCR and non-PCR groups (AUC = 0.783, 0.688, 0.649 and 0.684, respectively). After splitting patients into subgroups, no significant differences were observed between the PCR and non-PCR groups with human epidermal growth factor receptor 2 (HER2) + and triple-negative (TN) breast cancer. However, we were surprised to find that ADC(0, 1000), MD, and MK were significantly different between different remission groups with HR+/HER2+ subtypes, and the AUCs of each parameter reached 0.794, 0.825, and 0.712, respectively. CONCLUSION: MK was correlated with HR expression. ADC(0, 1000) and DKI were correlated with Ki67 expression. ADC(0, 1000) and the non-Gaussian diffusion model are suitable for predicting PCR in patients with HR+/HER2+ breast cancer before NAC.

Using the apparent diffusion coefficient histogram analysis to predict response to neoadjuvant chemotherapy in patients with breast cancer: comparison among three region of interest selection methods.

Background: The apparent diffusion coefficient (ADC) value using histogram analysis is helpful to predict responses to neoadjuvant chemotherapy (NAC) in breast cancer. However, the measurement method has not reached a consensus. This study was to assess the diagnostic performance of the ADC histogram analysis at predicting patient response prior to NAC in breast cancer patients using different region of interest (ROI) selection methods. Methods: A total of 75 patients who underwent diffusion weighted imaging (DWI) prior to NAC were retrospectively enrolled from February 2017 to December 2019. Images were measured using small 2-dimensional (2D) ROI, large 2D ROI, and volume ROI methods. The measurement time and ROI size were recorded. Histopathologic responses were acquired using the Miller-Payne grading system after surgery. The inter- and intra-observer repeatability was analyzed and the ADC histogram values from the three ROI methods were compared. The efficacy of each method at predicting patient response prior to NAC was assessed using the area under the receiver operating characteristic curve (AUC) for the whole study population and subgroups according to molecular subtype. Results: Among the 75 enrolled patients, 26 (34.67%) were responsive to NAC therapy. The ADC histogram values were significantly different among the three ROI methods (P≤0.038). Inter- and intra-observer repeatability of the large 2D ROI method and the volume ROI method was generally greater than that observed with the 2D ROI method. The 10% ADC value of the large 2D ROI method showed the greatest AUC (0.701) in the whole study population and in the luminal subgroup (AUC 0.804). The volume ROI method required significantly more time than the other two ROI methods (P<0.001). Conclusions: The small 2D ROI method is not appropriate for predicting response prior to NAC in breast cancer patients due to the poor repeatability. When choosing the ROI method and the histogram parameters for predicting response prior to NAC in breast cancer patients using ADC-derived histogram analysis, 10% of the large 2D ROI method is recommended, especially in luminal A subtype patients.

Whole brain diffusion tensor imaging histogram analysis in vascular cognitive impairment.

BACKGROUND: Studies were carried out to detect brain tissue damage in patients with vascular cognitive impairment (VCI) using diffusion tensor imaging (DTI) histogram analysis, and to determine the correlations between DTI histogram-derived measures and Mini-Mental State Examination (MMSE) scores. METHODS: Conventional MRI and DTI scans were performed on 19 patients with VCI, 19 age- and sex-matched post-stroke patients without cognitive impairment (stroke group) and 19 cognitively normal subjects (CN group). Histograms of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the whole brain were analyzed. RESULTS: Analysis showed that the patterns of the whole brain ADC and FA histograms of the VCI group differed from those of the stroke and CN groups. Compared with those of the two control groups, the mean FA value was significantly lower and the FA histogram peak height was higher in the VCI group. However, the patterns of the whole brain ADC and FA histograms in the stroke group were similar to those of the CN group, and there were no significant differences in any of the DTI histogram-derived measures between these two groups. The mean FA value, the FA histogram peak height, and the FA histogram peak location in VCI patients correlated with the MMSE scores. CONCLUSIONS: Our findings suggest that VCI leads to abnormal diffusion in brain tissue, and that DTI histogram-derived measures might be used to monitor the severity of cognitive impairment in this disease.

Vascular complications following prophylactic balloon occlusion of the internal iliac arteries resolved by successful interventional thrombolysis in a patient with morbidly adherent placenta.

The increasing incidence of morbidly adherent placenta (MAP) is placing women at a higher risk of life-threatening massive hemorrhage. The involvement of interventional radiology to manage this complex condition by performing prophylactic iliac artery balloon occlusion has been reported recently. However, the effectiveness and safety of this technique have not been fully determined. Here we report the case of a 25-year-old woman with placenta increta with preemptive bilateral internal iliac artery balloons who had external iliac artery thrombosis detected by computed tomography angiography (CTA) 72 h post cesarean section. A digital subtraction angiogram (DSA) and intra-arterial thrombolysis were instantly performed followed by supplementary conservative treatments, leading to a desirable resolution of thrombus without sequela. This is the first report of vascular complications with successful interventional thrombolysis in this setting. Our experience suggests that prophylactic iliac artery balloon occlusion should be used cautiously in cases of MAP and consideration given to minimizing vascular complications given the hypercoagulable state of pregnancy.

[The application value of the PACS in general hospitals].

In order to evaluate the diagnostic value of the PACS, the PACS has been applied to Dept.of Radiology in Renji Hospital in Shanghai for nearly two and a half years. Clinical practice shows that the doctors can work more efficiently and accurately by using the diagnostic workstation of PACS. PACS is an inevitable development trend of image diagnosis and is playing a more and more important role in clinical applications.

The influences of different spatial resolutions on the characteristics of T2 relaxation times in articular cartilage: A coarse-graining study of the microscopic magnetic resonance imaging data.

Microscopic magnetic resonance imaging (µMRI) T2 data from canine cartilage at different tibial locations were analyzed to investigate the influences of spatial resolution and pixel position on the T2 sensitivity to osteoarthritis (OA). Five experimental factors were investigated: inaccurate pixel position, different pixel resolutions, different specimen orientations in the magnetic field, topographical variations over the tibial surface, and different OA stages. A number of significant trends were identified in this analysis, which shows the subtle but substantial influences to our abilities of detecting OA due to T2 changes. In particular, any deviation in locating the cartilage pixels may result in erratic values near the cartilage surface. Significant differences were found in T2 values between nearly any two comparison-groups under all resolutions both in the meniscus-covered and -uncovered areas, which were also showed interaction between the OA degradation stages. This multiresolution project should help to improve the detection sensitivities of MRI toward cartilage degeneration. Microsc. Res. Tech. 79:754-765, 2016. © 2016 Wiley Periodicals, Inc.

Randomized comparison of long and short vascular sheaths in reduction of the operator radiation exposure during uterine artery embolization.

OBJECTIVE: To introduce a method in which a long sheath is used instead of the traditional short sheath, to reduce the radiation exposure of operators in uterine artery embolization (UAE). METHODS: 52 patients undergoing UAE were randomly divided into two groups before the procedure: an 11-cm short sheath was used in Group A (n = 25), and a 45-cm-long sheath was used in Group B (n = 27); the 45-cm-long sheath was only partly inserted such that the hub of the sheath was approximately 34 cm caudal to the groin puncture site. All the procedures were standard bilateral UAE operations through unilateral approach. The other parameters of the two groups were kept the same, including the fluoroscopy conditions and the pelvic radiation field size. The thermoluminescent personal dosemeters were attached to the left wrist and left outer side of the thyroid collar of the operator during each operation. The radiation exposure of the operator, procedure duration and fluoroscopy time of each procedure were recorded. Statistical analysis was performed using independent samples t-test. RESULTS: The radiation exposure of both the left hand and thyroid of the operator was significantly reduced with the long sheath compared with the short sheath (89.5 ± 7.2 µGy vs 186.7 ± 12.6 µGy, p < 0.001, and 54.1 ± 5.5 µGy vs 63.9 ± 7.4 µGy, p < 0.001, respectively). No significant differences were found in the procedure duration and fluoroscopy time between the two groups (p > 0.1). CONCLUSION: Using a long sheath in UAE could significantly reduce the radiation exposure to the interventionists without extending the procedure duration or fluoroscopy time. ADVANCES IN KNOWLEDGE: For the first time, we introduce a simple and convenient method to reduce the radiation exposure of the operator in the UAE procedure.

Quantitative assessment of angiographic perfusion reduction using color-coded digital subtraction angiography during transarterial chemoembolization.

PURPOSE: The aim of this study was to develop a quantitative measurement of perfusion reduction using color-coded digital subtraction angiography (ccDSA) to monitor intra-procedural arterial stasis during TACE. MATERIALS AND METHODS: A total number of 35 patients with hepatocellular carcinoma who had undergone TACE were enrolled into the study. Pre- and post-two-dimensional digital subtraction angiography scans were conducted with same protocol and post-processed with ccDSA prototype software. Time-contrast-intensity (CI[t]) curve was obtained by region-of-interest (ROI) measurement on the generated ccDSA image. Quantitative 2D perfusion parameters time to peak, area under the curve (AUC), maximum upslope, and contrast intensity peak (CI-Peak) derived from the ROI-based CI[t] curve for pre- and post-TACE were evaluated to assess the reduction of antegrade blood flow and tumor blush. Relationships between 2D perfusion parameters, subjective angiographic chemoembolization endpoint (SACE) scale, and clinical outcomes were analyzed. RESULTS: Area normalized AUC and CI-Peak revealed significant reduction after the TACE (P < 0.0001). AUCnorm decreased from pre-procedure of 0.867 ± 0.242 to 0.421 ± 0.171 (P < 0.001) after completion of TACE. CI-Peaknorm was 0.739 ± 0.221 before TACE and 0.421 ± 0.174 (P < 0.001) after TACE. Tumor blood supply time slowed down obviously after embolization. A perfusion reduction either from AUCnorm or CI-Peaknorm ranging from 30% to 40% was associated with SACE level III and a reduction ranging from 60% to 70% was equivalent to SACE level IV. For intermediate reduction (SACE level III), better tumor response was found after TACE rather than a higher reduction (SACE level IV). CONCLUSION: ccDSA application provides an objective approach to quantify the perfusion reduction and subjectively evaluate the arterial stasis of antegrade blood flow and tumor blush caused by TACE.