Zhiguo Zhuang

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

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).

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

BackgroundThe 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).MethodsDKI 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.ResultsCompared 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.ConclusionsThe 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.

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

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.

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/mm2) 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.

Multidetector Computed Tomography Angiography in the Evaluation of Potential Living Donors for Liver Transplantation: Single-Center Experience in China

OBJECTIVE To evaluate relevant arterial, hepatic, and portal venous anatomy using multidetector computed tomography (CT) angiography in potential living liver donors at a single liver transplantation center in China. METHODS One hundred two consecutive potential liver donors underwent CT angiography in the arterial, portal, and hepatic venous phases with a 16-row CT scanner. All source and reconstructed images were evaluated for hepatic vasculature anatomy by an experienced radiologist and a surgeon in consensus. The anatomic variants of arterial system, portal venous system, and hepatic veins were characterized according to the classification system of Michels, Akgul, and Nakamura respectively. In 42 donors of right hepatic lobectomy, CT findings were compared with the results of surgery. RESULTS Of 102 candidates, 63 had type I, 8 type II, 12 type III, 3 type IV, 11 type V, 2 type VI, 2 type VIII, and 1 type IX hepatic arterial anatomy. According to the classification of the portal venous system created by Akgul, type A was seen in 81 subjects. Type B, type C, and type E were revealed in 15, 4, and 2 subjects, respectively. According to the classification of the right hepatic drainage pattern by Nakamura, type 1 drainage was seen in 71 subjects (69.6%), type 2 in 22 candidates (21.6%), and type 3 in 9 subjects (8.8%). Forty five right inferior hepatic veins were identified in 41 potential donors, and 68.9% of these veins were larger than 5 mm in diameter. CT angiography findings were confirmed in all donors who underwent operations. CONCLUSIONS Multidetector CT angiography can successfully show the relevant hepatic vascular anatomy in potential liver donors.

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.

Utility of apparent diffusion coefficient as an imaging biomarker for assessing the proliferative potential of invasive ductal breast cancer

AIM To determine the clinical utility of apparent diffusion coefficient (ADC) metrics for the non-invasive assessment of tumour proliferation indicated by Ki-67 labelling index (LI) in invasive ductal breast cancer. MATERIALS AND METHODS Eighty patients with 80 histopathologically proven invasive ductal breast cancers underwent diffusion-weighted imaging with b-values of 0 and 800 s/mm2 at a 3-T system. ADC metrics including ADCmean, ADCmedian, ADCmin, ADCmax, and ΔADC (ADCmax-ADCmin) were recorded from the entire tumour volume on ADC maps, and correlated with the Ki-67 LI. Ki-67 staining of ≥14% was considered to indicate high proliferation and <14% was considered to indicate low proliferation. RESULTS ADCmin, ADCmax, and ΔADC showed significant correlations with the Ki-67 LI (for all tumours, r=-0.311, 0.436, and 0.551, respectively; for luminal/human epidermal growth factor receptor 2 (HER2)-negative group, r=-0.437, 0.512, and 0.639, respectively; all p<0.01), whereas ADCmean and ADCmedian showed no significant correlation (both p>0.05). Receiver operating characteristic (ROC) curve analysis for the differentiation of high- from low-proliferation groups showed that ΔADC yielded the highest area under the ROC curve for the whole tumour population (0.825; 95% confidence interval [CI]: 0.724, 0.901), as well as for the luminal/HER2-negative group (0.844; 95% CI: 0.692, 0.940). CONCLUSION ΔADC may serve as a promising imaging biomarker for the prediction of Ki-67 proliferation status in invasive ductal breast cancer.

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.

Apparent diffusion coefficient measurement in luminal breast cancer: will tumour shrinkage patterns affect its efficacy of evaluating the pathological response?

AIM To determine which region of interest (ROI) placement method of apparent diffusion coefficient (ADC) measurement has the best performance for predicting pathological complete response (PCR) at two cycles of neoadjuvant chemotherapy (NAC) according to different tumour shrinkage patterns of luminal breast cancer and to assess the evaluative accuracy of ADC value combined with other clinicopathological indicators. MATERIALS AND METHODS Sixty-one patients who underwent NAC for histopathologically confirmed breast cancer were enrolled in this retrospective study. The ADC values of different shrinkage patterns (concentric shrinkage, nest or dendritic shrinkage, and mixed shrinkage) for tumours shown by diffusion-weighted imaging (DWI) were measured independently using three ROI placement methods (single-round, three-round, and freehand). Intraclass correlation coefficients (ICCs) were used to assess the interobserver variability in the ADC values. Multivariate logistic regression analysis was performed to identify the independent predictors of PCR. RESULTS The best placement method found was single-round ROI in all the patients (AUC=0.863). When analysed separately, the effectiveness results differed: the single-round method was optimal for concentrically shrinking tumours (AUC=0.970); the freehand method was optimal for nest or dendritically shrinking tumours (AUC=0.714); and the three-round method was optimal for mixed shrinking tumours (AUC=0.975). Multivariate logistic analysis showed that oestrogen receptor (ER), ΔADC% and tumour diameter reduction (ΔD%) were independent factors in evaluating the PCR. CONCLUSION The methods for measuring ADC values vary across different shrinkage patterns of luminal tumours. ΔADC%, ER and ΔD% were independent factors for evaluating the PCR.