Objective To explore the application of texture analysis basing on computed tomography (CT) images in predicting lymph-node metastasis in patients with clinical stage IA lung adenocarcinoma. Methods In total, 256 patients with clinical stage IA lung adenocarcinoma who had underwentgone preoperative CT examinations were enrolled. A total of 25 texture features using MaZda (version 4.6) software and conventional radiological features were extracted from raw CT data sets. Based on surgical results, patients were stratified into lymph node metastasis–positive and –negative groups. Independent-sample t-tests and Mann–Whitney U tests were used to compare continuous variables between the groups. Continuity-correction and χ2 tests were used for categorical variable comparison. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of lymph-node metastasis. Results In total, 256 clinical stage IA lung adenocarcinoma cases were proved by pathology: 39 (15.23%) cases with lymph-node metastasis (14 N1a, seven N1b, six N2a1, ten N2a2, and two N2b) and 217 (84.77%) cases without lymph-node metastasis. Univariate and multivariate logistic regression analyses demonstrated that total volume (OR 3.777, p=0.015), average CT value of whole tumor (OR 16.271, p<0.001), three texture parameters (mean OR 8.473, p<0.001; skewness OR 6.393, p=0.001; and entropy OR 0.343, p=0.049) were independent factors associated with lymph-node status. As such, early-stage lung adenocarcinoma with higher total volume (>4.05 cm3), average CT value of whole tumor (>–70 HU), mean (>133.79), entropy (>1.98), and lower skewness (≤0.02) pointed to positive lymph-node metastasis. Conclusion Texture parameters were independent factors associated with lymph-node status in clinical stage IA lung adenocarcinoma.

*These authors contributed equally to this work Objective: To explore the application of texture analysis basing on computed tomography (CT) images in predicting lymph-node metastasis in patients with clinical stage IA lung adenocarcinoma. Methods: In total, 256 patients with clinical stage IA lung adenocarcinoma who had underwentgone preoperative CT examinations were enrolled. A total of 25 texture features using MaZda (version 4.6) software and conventional radiological features were extracted from raw CT data sets. Based on surgical results, patients were stratified into lymph node metastasis–positive and –negative groups. Independent-sample t-tests and Mann–Whitney U tests were used to compare continuous variables between the groups. Continuity-correction and χ tests were used for categorical variable comparison. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of lymphnode metastasis. Results: In total, 256 clinical stage IA lung adenocarcinoma cases were proved by pathology: 39 (15.23%) cases with lymph-node metastasis (14 N1a, seven N1b, six N2a1, ten N2a2, and two N2b) and 217 (84.77%) cases without lymph-node metastasis. Univariate and multivariate logistic regression analyses demonstrated that total volume (OR 3.777, p=0.015), average CT value of whole tumor (OR 16.271, p<0.001), three texture parameters (mean OR 8.473, p<0.001; skewness OR 6.393, p=0.001; and entropy OR 0.343, p=0.049) were independent factors associated with lymph-node status. As such, early-stage lung adenocarcinoma with higher total volume (>4.05 cm), average CT value of whole tumor (>–70 HU), mean (>133.79), entropy (>1.98), and lower skewness (≤0.02) pointed to positive lymph-node metastasis. Conclusion: Texture parameters were independent factors associated with lymph-node status in clinical stage IA lung adenocarcinoma.

Abstract Background To investigate whether MRI findings, including texture analysis, can differentiate KRAS mutation status in rectal cancer. Methods Totally, 158 patients with pathologically proved rectal cancers and preoperative pelvic MRI examinations were enrolled. Patients were stratified into two groups: KRAS wild-type group (KRASwt group) and KRAS mutation group (KRASmt group) according to genomic DNA extraction analysis. MRI findings of rectal cancers (including texture features) and relevant clinical characteristics were statistically evaluated to identify the differences between the two groups. The independent samples t test or Mann-Whitney U test were used for continuous variables. The differences of the remaining categorical polytomous variables were analyzed using the Chi-square test or Fisher exact test. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminatory power of MRI features. The area under the ROC curve (AUC) and the optimal cut-off values were calculated using histopathology diagnosis as a reference; meanwhile, sensitivity and specificity were determined. Results Mean values of six texture parameters (Mean, Variance, Skewness, Entropy, gray-level nonuniformity, run-length nonuniformity) were significantly higher in KRASmt group compared to KRASwt group (p < 0.0001, respectively). The AUC values of texture features ranged from 0.703~0.813. In addition, higher T stage and lower ADC values were observed in the KRASmt group compared to KRASwt group (t = 7.086, p = 0.029; t = − 2.708, p = 0.008). Conclusion The MRI findings of rectal cancer, especially texture features, showed an encouraging value for identifying KRAS status.

Rationale and Objectives: This study aimed to determine the correlation between intravoxel incoherent motion (IVIM) and multiphase dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters in patients with rectal cancer. Materials and Methods: Ninety-seven patients with rectal cancer were included in this study. All pelvic MRI examinations were performed in a 3.0 T MR unit, including diffusion-weighted imaging with 16 b values, DCE-MRI with two different flip angles (5 degrees and 10 degrees, respectively), and T1-fast field echo sequences as the reference. The IVIM perfusion-related parameters (f, perfusion fraction; D*, pseudo-diffusion coefficient; f.D*, the multiplication of the two parameters) were calculated by biexponential analysis. Quantitative DCE-MRI parameters were transfer constant (K-trans) between blood plasma and extravascular extracellular space), K-ep (rate between extravascular extracellular space and blood plasma), V-e (extravascular volume fraction), V-p (plasma volume fraction), and area under the gadolinium concentration curve. Interobserver agreements were evaluated using the intraclass correlation coefficient and Bland-Altman analysis. A p value <0.05 indicated a statistically significant difference. Results: The study included 75 males and 22 females with a median age of 58.8 years (range, 26-85years). Interobserver reproducibility for IVIM perfusion-related parameters and DCE-MRI quantitative parameters was good to excellent (intraclass correlation coefficient = 0.8618-0.9181, intraclass correlation coefficient = 0.7826-0.9088, respectively). Moderate correlations were found between f.D* and K-trans (r = 0.533; p < 0.001), and relatively weak correlations between D* and K-trans (r = 0.389; p < 0.001), D* and V-p (r = 0.442; p < 0.001), f.D* and Vp (r = 0.466; p < 0.001), and f and V-p (r = -0.234; p = 0.021). Conclusion: IVIM perfusion-related parameters, especially f.D*, demonstrated moderate correlations with DCE-MRI quantitative parameters in rectal cancer.

PURPOSE:To evaluate the diagnostic potential of DW-MRI relative parameters for differentiation of rectal cancers with different Kirsten rat sarcoma viral oncogene homologue (KRAS) mutation status.METHODS:Fifty-one patients with rectal cancer underwent diffusion-weighted MR imaging with eight b values. ADCs (including Max-ADC, Min-ADC and Mean-ADC) and IVIM parameters (D, pure diffusion; f, perfusion fraction; D*, pseudodiffusion coefficient) were respectively calculated by mono- and bi-exponential analysis. Patients were stratified into two groups: KRAS wild type and mutant. The DW-MRI-derived parameters between the KRAS wild-type group and KRAS mutant group were compared using the Mann-Whitney U test. Receiver-operating characteristic (ROC) analysis of discrimination between KRAS wild-type and KRAS mutant rectal cancer was performed for the DW-MRI-derived parameters.RESULTS:Max-ADC, Mean-ADC and D values were significantly lower in the KRAS mutant group than in the KRAS wild-type group, whereas a higher D* value was demonstrated in the KRAS mutant group. According to the ROC curve, Mean-ADC and D* values showed moderate diagnostic significance with the AUC values of 0.756 and 0.710, respectively. The cut-off values for Mean-ADC and D* were 1.43 × 10-3mm2/s and 26.58 × 10-3mm2/s, respectively.CONCLUSION:Rectal cancers had distinctive diffusion/perfusion characteristics in different KRAS mutation statuses. The DW-MRI-derived parameters, specifically Mean-ADC and D*, show a moderate diagnostic significance for KRAS status.KEY POINTS:• Rectal cancers with different KRAS mutation statuses demonstrated distinctive diffusion/perfusion characteristics. • Max-ADC, Mean-ADC and D values were lower in the KRAS mutant group. • A higher D* value was demonstrated in the KRAS mutant group. • IVIM-DW MRI may potentially help preoperative KRAS mutant status prediction.

The aim of this study was to evaluate the short-term test-retest reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) parameters of rectal cancer with 3.0T MRI.Twenty-six patients with rectal cancer underwent MRI, including diffusion-weighted imaging with 8 b values. Apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) parameters (D, pure diffusion; f, perfusion fraction; D*, pseudodiffusion coefficient) were, respectively, calculated. The short-term test-retest reproducibility, the intra and interobserver variation of the IVIM parameters were assessed based on the repeatability coefficient and Bland-Altman limits of agreement.There was no significant intra or interobserver difference observed in the parameters on the same DW-MRI scan. The corresponding repeatability coefficient of intra- and interobserver analysis for ADC, D, f, and D* was 5.4%, 11.1%, 55.4%, and 40.3%; 10.9%, 41.6%, 134.0%, and 177.6%, respectively. The test-retest repeatability coefficient for ADC, D, f, and D* was 19.1%, 24.5%, 126.3%, and 197.4%, respectively, greater than the intraobserver values.ADC and D have better short-term test-retest reproducibility than f and D*. Considering the poor test-retest reproducibility for f and D,* variance in these 2 parameters should be interpreted with caution in longitudinal studies on rectal cancer in which treatment response and recurrence are monitored.

BackgroundMany locally advanced rectal cancer (LARC) patients can benefit from neoadjuvant chemotherapy (NACT), with some achieving a pathological complete response (pCR). However, there is limited research reporting on the value of intravoxel incoherent motion (IVIM) in monitoring pCR in patients with LARC.PurposeTo identify whether IVIM parameters derived from whole‐tumor volume (WTV) before and after NACT could accurately assess pCR in patients with LARC.Study TypeProspective patient control study.PopulationFifty‐one patients with LARC before and after NACT, prior to surgery.Field Strength/SequenceIVIM‐diffusion imaging at 3T.AssessmentApparent diffusion coefficient (ADC), slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion‐related diffusion fraction (f) values were obtained on diffusion‐weighted magnetic resonance images (DW‐MRI) using WTV methods and calculated using a biexponential model before and after NACT.Statistical TestsDWI‐derived ADC and IVIM‐derived parameters and their percentage changes (ΔADC%, ΔD%, ΔD*%, and Δf%) were compared using independent‐samples t‐test and Mann–Whitney U‐test between the pCR and non‐pCR groups. The diagnostic performance of IVIM parameters and their percentage changes were evaluated using receiver operating characteristic curves.ResultsCompared with the non‐pCR group, the pCR group exhibited significantly lower pre‐ADCmean (P = 0.003) and pre‐D values (P = 0.024), and significantly higher post‐f (P = 0.002), ΔADCmean% (P = 0.002), ΔD% (P = 0.001), and Δf% values (P = 0.017). Receiver operating characteristic curves showed that the pre‐D value had the best specificity (95.12%) and accuracy (86.27%) in predicting the pCR status, and ΔD% had the highest area under the curve (0.832) in assessing the pCR response to NACT.Data ConclusionsThe IVIM‐derived D value is a promising tool in predicting the pCR status before therapy. The percentage changes in D values after therapy may help assess the pCR status prior to surgery.Level of Evidence: 2Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2017.

Abstract The aim of this study was to evaluate the short-term test-retest reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) parameters of rectal cancer with 3.0T MRI. Twenty-six patients with rectal cancer underwent MRI, including diffusion-weighted imaging with 8 b values. Apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) parameters (D, pure diffusion; f, perfusion fraction; D*, pseudodiffusion coefficient) were, respectively, calculated. The short-term test-retest reproducibility, the intra and interobserver variation of the IVIM parameters were assessed based on the repeatability coefficient and Bland-Altman limits of agreement. There was no significant intra or interobserver difference observed in the parameters on the same DW-MRI scan. The corresponding repeatability coefficient of intra- and interobserver analysis for ADC, D, f, and D* was 5.4%, 11.1%, 55.4%, and 40.3%; 10.9%, 41.6%, 134.0%, and 177.6%, respectively. The test-retest repeatability coefficient for ADC, D, f, and D* was 19.1%, 24.5%, 126.3%, and 197.4%, respectively, greater than the intraobserver values. ADC and D have better short-term test-retest reproducibility than f and D*. Considering the poor test-retest reproducibility for f and D,* variance in these 2 parameters should be interpreted with caution in longitudinal studies on rectal cancer in which treatment response and recurrence are monitored.

Objective: To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis.Date Sources: We retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis.Study Selection: We reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application.Results: VWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy.Conclusions: This review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management.

Perfusion of the penumbra tissue below the flow threshold for functional disturbance but above that for the maintenance of morphological integrity is the target for therapy in acute ischaemic stroke. The measurement of the oxygen extraction fraction (OEF) may provide a direct assessment of tissue viability, so that irreversible tissue damage and penumbra can be reliably identified. By using an asymmetric spin echo single-shot echo planar imaging (ASE-SSEPI) sequence, the quantitative OEF was obtained in the ischaemic brain tissues of canine models with internal carotid artery occlusion. TTC staining, which delineated the regions of infarct and penumbra, was used for defining the corresponding regions on OEF maps. The threshold of the OEF to discriminate the infarct cores and penumbral tissues was then determined according to the OEF values at different times. With repeated-measures ANOVA, the OEF of the infarcted regions was found to be time dependent. An OEF greater than 0.48 best predicted cortical infarction at 1.5 hr, with an area under the receiving operating characteristic curve of 0.968, a sensitivity of 97.5% and a specificity of 92.5%. Our results may be helpful in the evaluation of tissue viability during stroke events.

Rationale and Objectives: The study aimed to assess the relationship between tumor marker index (TMI) and high-resolution computed tomography features in early-stage lung adenocarcinoma.Materials and Methods: Seventy-four stage IA lung adenocarcinomas confirmed pathologically were retrospectively evaluated. Lung nodules were divided into two types: solid nodule (SN) and subsolid nodule (SSN). The maximum diameters on mediastinal window in axial imaging (D-m) and tumor shadow disappearance rate (TDR) were measured. Meanwhile, other computed tomography features of lung nodules were also recorded: TMI represents the geometric mean of normalized CEA and CYFRA 21-1 values, and the discriminatory value of TMI in this study was set at 1.0. The evaluation of discriminatory values for D-m and the TMI between SNs and SSNs was done with Mann-Whitney U-test. The relationship between TDR and TMI in SSNs was evaluated by Pearson correlation analysis.Results: Of 74 cases, 40 cases (54.05%) showed SNs and 34 cases (45.95%) showed SSNs. D-m and TMI were higher in SNs than in SSNs (z = -4.782, P < 0.001; z = -2.647, P = 0.008). TDR demonstrated negative relationship with TMI in SSNs (r = -0.448, P = 0.008). Spiculation (odds ratio [OR] = 14.685; 95% confidence interval [CI]: 2.739-78.729; P = 0.002), nodule type (OR = 6.215; 95% CI: 1.531-25.228; P = 0.011), and gender (OR = 0.227; 95% CI: 0.062-0.833; P = 0.025) were independent factors associated with TMI.Conclusions: Early-stage lung adenocarcinoma with lower TDR coexisting with spiculation was associated with higher TMI, especially in patients with solid nodule, which tended to have poor prognosis.

Background: The difference between renal oncocytomas (RO) and renal clear cell carcinomas (RCCs) presents the greatest diagnostic challenge. The aim of this study was to retrospectively determine if RO and RCCs could be differentiated on computed tomography (CT) images on the basis of their enhancement patterns with a new enhancement correcting method. Methods: Forty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study. Fourteen of those were RO and 32 were RCCs. All patients were examined with contrast-enhanced CT. The pattern and degree of enhancement were evaluated. We selected the area that demonstrated the greatest degree of enhancement of the renal lesion in the corticomedullary nephrographic and excretory phase images. Regions of interest (ROI) were also placed in adjacent normal renal cortex for normalization. We used the values of the normal renal cortex that were measured at the same time as divisors. The ratios of lesion-to-renal cortex enhancement were calculated for all three phases. The Student's t-test and Pearson's Chi-square test were used for statistical analyses. Results: All RCCs masses showed contrast that appeared to be better enhanced than RO on all contrast-enhanced phases of CT imaging, but there was no significant difference in absolute attenuation values between these two diseases (P > 0.05). The ratio of lesion-to-cortex attenuation in the corticomedullary phase showed significantly different values between RO and RCCs. The degree of contrast enhancement in RCCs was equal to or greater than that of the normal renal cortex, but it was less than that of the normal cortex in RO in the corticomedullary phase. The ratio of lesion-to-cortex attenuation in the corticomedullary phase was higher than the cut off value of 1.0 in most RCCs (84%, 27/32) and lower than 1.0 in most RO (93%, 13/14) (P < 0.05). In the nephrographic phase, the ratio of lesion-to-cortex attenuation was higher than that in the corticomedullary phase in most RO (71%, 10/14), showing a prolonged enhancement pattern; and was lower than that in most RCCs (97%, 31/32), showing an early washout pattern (P < 0.05). In the differentiation of RO from RCCs, the sensitivity was 93%, specificity 84%, positive predictive value 72%, negative predictive value 84%, and accuracy for RO was 87, if the ratio of lesion-to-cortex attenuation in a cortex phase was lower than the cutoff value of 1.0. The sensitivity was 71%, specificity was 97%, positive predictive value was 91%, negative predictive value was 91%, and accuracy for RO was 89%, if the ratio of lesion-to-cortex attenuation in nephrographic phase was higher than that in the corticomedullary phase. Conclusions: The ratios of renal lesion-to-cortex attenuation ratios may be helpful in differentiating RO from RCCs.

BACKGROUND:There are few studies for evaluating plaque characteristics of nonstenotic basilar arteries (BA). Our aim was to determine entire BA plaques with a three-dimensional volumetric isotropic turbo spin-echo acquisition (VISTA) and investigate the differences between the patients with and without isolated pontine infarction (IPI).METHODS:Twenty-four consecutive symptomatic patients with nonstenotic BA on time of flight magnetic resonance angiography (TOF MRA) were enrolled from China-Japan Friendship Hospital between January 2014 and December 2014. BA was classified as "normal" or "irregular" based on TOF MRA, and "normal wall", "slight wall-thickening", and "plaque" based on three-dimensional VISTA images. Outcomes from MRA and VISTA were compared. Patients were categorized as IPI and non-IPI groups based on the diffusion-weighted imaging. Clinical and plaque characteristics were compared between the two groups.RESULTS:A total of 1024 image slices including 311 (30.37%) plaque slices, 427 (41.70%) slight wall-thickening slices, and 286 (27.93%) normal wall slices for the entire BA from 23 patients were finally included for analysis. VISTA images detected plaques in all the 9 (100%) irregular MRA patients and 7 of 14 (50%) normal MRA patients. IPI was found in 11 (47.83%) patients. Compared to non-IPI group, the IPI group had a higher percentage of plaque slices (P = 0.001) and lower percentage of normal wall slices (P = 0.014) than non-IPI group.CONCLUSIONS:Three-dimensional VISTA images enable detection of BA plaques not visualized by MRA. BA plaques could be found in both the IPI and non-IPI group. However, IPI group showed plaques more extensively in BA than the non-IPI group.

Rationale and Objectives: The preoperative assessment of tumor grade has important clinical implications for the treatment and prognosis of patients with colorectal adenocarcinomas. The purpose of this study is to investigate the predictive significance of colorectal adenocarcinoma grade using 256-slice whole-tumor computed tomography (CT) perfusion.Materials and Methods: Fifty-three patients with proven colorectal adenocarcinomas were enrolled. All of them underwent 256-slice whole-tumor CT perfusion. They were divided into two different subgroups according to postoperative pathological results: low grade and high grade. The Kruskal-Wallis test or one-way analysis of variance was used for comparison of CT perfusion parameters between different tumor grades. Multivariant correlation between pathologic tumor stage, histologic tumor differentiation, and whole-tumor CT perfusion parameters was evaluated by Spearman rank correlation coefficient. According to receiver operating characteristic (ROC) curves, perfusion parameters including blood flow (BF), peak enhancement index (PEI), blood volume (BV), and time to peak (UP) of 53 patients were analyzed, and the sensitivity, specificity, and accuracy of these parameters in predicting tumor grade were calculated.Results: There were significant differences in BF and UP between low-grade and high-grade tumors. According to the ROC curve, BF and TTP were of diagnostic significance, with the area under the curve values of 0.828 and 0.736, respectively. The diagnostic threshold of BF was 32.12 mL/min/100 g and that of TTP was 18.10 seconds.Conclusions: The CT perfusion parameters (BF, TTP) of first-pass 256-slice whole-tumor CT perfusion imaging can reflect tumor grade in colorectal adenocarcinoma.

Background: There are few studies for evaluating wall characteristics of intracranial vertebral artery hypoplasia (VAH). The aim of this study was to determine wall characteristics of VAH with three-dimensional volumetric isotropic turbo spin echo acquisition (3D VISTA) images and differentiate between acquired atherosclerotic stenosis and VAH.Methods: Thirty patients with suspicious VAH by luminograms were retrospectively enrolled between January 2014 and February 2015. The patients were classified as "acquired atherosclerotic stenosis" or "VAH" based on 3D VISTA images. The wall characteristics of VAH were assessed to determine the presence of atherosclerotic lesions, and the patients were classified into two subgroups (VAH with atherosclerosis and VAH with normal wall). Wall characteristics of basilar arteries and vertebral arteries were also assessed. The clinical and wall characteristics were compared between the two groups.Results: Five of 30 patients with suspicious VAH were finally diagnosed as acquired atherosclerotic stenosis by 3D VISTA images. 25 patients were finally diagnosed as VAH including 16 (64.00%) patients with atherosclerosis and 9 (36.00%) patients with normal wall. In the 16 patients with atherosclerosis, plaque was found in 9 patients, slight wall thickening in 6 patients, and thrombus and wall thickening in 1 patient. Compared with VAH patients with normal wall, VAH patients with atherosclerosis showed atherosclerotic basilar arteries and dominant vertebral arteries more frequently (P = 0.000).Conclusions: Three-dimensional VISTA images enable differentiation between the acquired atherosclerotic stenosis and VAH. VAH was also prone to atherosclerotic processes.

Objective To determine the consistency between quantitative CT perfusion measurements of colorectal cancer obtained from single section with maximal tumor dimension and from average of whole tumor,and compare intra-and inter-observer consistency of the two analysis methods.Methods Twenty-two patients with histologically proven colorectal cancer were examined prospectively with 256-slice CT and the whole tumor perfusion images were obtained.Perfusion parameters were obtained from region of interest (ROI) inserted in single section showing maximal tumor dimension,then from ROI inserted in all tumor-containing sections by two radiologists.Consistency between values of blood flow (BF),blood volume (BV) and time to peak (TTP) calculated by two methods was assessed.Intra-observer consistency was evaluated by comparing repeated measurements done by the same radiologist using both methods after 3 months.Perfusion measurements were done by another radiologist independently to assess inter-observer consistency of both methods.The results from different methods were compared using paired t test and Bland-Altmnan plot.Results Twenty-two patients were examined successfully.The perfusion parameters BF,BV and TTP obtained by whole tumor perfusion and single-section analysis were (35.59 ± 14.59) ml · min-1 · 100 g-1,(17.55 ±4.21) ml · 100 g-1,(21.30 ±7.57) s and (34.64 ± 13.29)ml· min-1 · 100 g-1,(17.61 ±6.39)ml± · 100 g-1,(19.82 ±9.01)s,respectively.No significant differences were observed between the means of the perfusion parameters (BF,BV,TTP)calculated by the two methods (t =0.218,-0.033,-0.668,P ＞ 0.05,respectively).The intra-observer 95％ limits of consistency of perfusion parameters were BF-5.3％ to 10.0％,BV-13.8％ to 10.8％,TTP-15.0％ to 12.6％ with whole tumor analysis,respectively; BF-14.3％ to 16.5％,BV-24.2％ to 22.2％,TTP-19.0％ to 16.1％ with single section analysis,respectively.The inter-observer 95％ limits of consistency of perfusion parameters were BF-8.0％ to 8.3％,BV-10.9％ to 11.5％,TTP -14.5％ to 11.1％ with whole volume analysis,respectively; BF-10.2％ to 14.1％,BV-19.0％ to 17.6％,TTP-22.0％ to 24.0％ with single section analysis,respectively.Conclusion There was no statistically different between the single section and whole volume analysis of tumor perfusion CT.The whole volume perfusion analysis apparently improves intra-and inter-observer consistency and can reflect the whole tumor angiogenesis more accurately and repeatedly.

We describe the computed tomography (CT) imaging findings in six cases (five males and one female; age range 61-78 years; mean age 67.3 years) with histologically proven hepatoid adenocarcinoma of the stomach (HAS).Five of the six patients had elevated serum alpha-fetoprotein levels.The most common type of gross appearance HAS on CT is a polypoid mass (83%, 5/6).The most common contrast enhancement pattern was heterogeneous.All six patients had a regional lymphadenopathy larger than 6 mm in its short axis.Liver metastases (n = 3) were noted.Venous tumor thrombosis was identified in the portal vein (n = 2) of the regions near primary gastric tumors or metastatic masses.Our findings suggest in an elderly, male patients with a large heterogeneous enhancement tumor, the presence of distant metastases, regional lymphadenopathy and characteristically increased serum alphafetoprotein levels indicates a high likelihood of HAS.

Objective To assess the sensitivity and specificity of detecting subarticular bone erosion of sacroiliac (SI) joint in patients with spondyloarthritis (SpA) using MRI three-dimensional water selective balanced steady-state free precession sequence (3D-WS-bSSFP) and T1-weighted (T1W) sequence. Materials and methods Radiography, CT and MRI of SI joint from 43 SpA patients were retrospectively analyzed. MRI examination sequences include T1W, short tau inversion recovery (STIR) and 3D-WS-bSSFP. Two radiologists, blinded to clinical data, independently determined bone erosion at bilateral sacral and iliac sides of the SI joint on radiography, CT, T1W and 3D-WS-bSSFP respectively. X2 test was used to compare the sensitivity of detecting bone erosion among different diagnostic methods. Results Of the 86 sacral and 86 iliac articular surfaces from the 43 cases, radiography, CT, MRI T1W and 3D-WS-bSSFP showed the presence of bone erosion in 40, 74, 50 and 71 articular surfaces respectively. CT and MRI 3D-WS-bSSFP demonstrated similar sensitivity (x2 = 0.11, P = 0.74), and both were superior to radiography (x2 = 15.17, P < 0.01 and x2 = 12.78, P < 0.01, respectively) and T1W (x2 = 7.26, P < 0.01 and x2 = 5.62, P < 0.05). Using CT diagnosis as the gold standard, the sensitivity and specificity of detecting bone erosion for MRI 3D-WS-bSSFP and T1W sequences were 91.8%, 96.9%, and 60.8%, 94.9% respectively. Conclusion MRI 3D-WS-bSSFP sequence is associated with short scanning time, zero ionizing radiation, high sensitivity and specificity of displaying the subarticular bone erosion of SI joints in patients with SpA. Therefore, it can be considered an alternative to CT.

Objective To evaluate the prevalence,anatomic features of right superior septal artery (RSSA) with 256-slice MSCT.Methods A retrospective analysis of coronary artery computed tomography angiography with 256-slice CT was performed in 1 646 consecutive patients.Multi-planar reconstruction (MPR),maximum intensity projection (MIP) images on coronal and sagittal planes,and three-dimensional volume rendering (VR) reconstruction images were obtained and used for the evaluation of the anatomic features of the RSSA.The images were transferred to EBW4.52 workstation to trace the vessel and to analyze the origin,diameter,and length of the RSSA.Student's t test was performed to compare the differences in the length and diameter of the RSSA between patients with different coronary artery distribution dominant types,different genders.Analysis of variance (ANOVA) was used to compare the differences in the length and diameter of the RSSA among patients with and without coronary artery stenosis.Results The RSSA was present in 130 (7.9％) of 1 646 patients.The origin of RSSA was from the proximal portion of the right coronary artery in 104 patients,from the right sinus of valsalva in 26 patients.The artery co-existed with the conus artery in 22(16.9％) of 130 patients.The mean length of RSSA was (31.7±15.6) mm (range from 8.9 to 70.7 mm),and the mean diameter was (1.0±0.4) mm (range from 0.2 to 2.5 mm).The average length and diameter of RSSA in men were (33.5±15.7) and (1.0±0.4) mm,respectively; The average length and diameter of RSSA in women were (24.5 ± 13.0) and (0.9 ±0.4) mm,respectively.There was a significant difference in RSSA length between men and women (t=2.718,P=0.007),but there was no significant difference in the RSSA diameter between men and women (t=1.134,P=0.259).There was no significant differencein RSSA length and diameter between different coronary artery distribution dominant types (t=-0.219 and-0.080 respectively,P＞ 0.05).In the patients with left anterior descending artery (LAD) and right coronary artery (RCA) stenosis,the mean length and diameter of RSSA were (38.9±17.9),(1.1 ±0.4) mm,respectively.In the patients without LAD and RCA stenosis,the mean length and diameter of RSSA were (28.9±14.4),(0.9± 0.4) mm,respectively.Patients with coronary artery stenosis tended to have longer RSSAs in comparison to those without coronary artery stenosis (P＜0.05).Conclusions RSSA variantions can evaluated with a cardiac 256-slice MSCT scan.The recognition of this vessel is useful for physians dealing with diagnosis and treatment of coronary artery disease.