To analyze the correlation of the CT imaging features and CT texture analysis (CTTA) parameters with risk stratifications of the gastric stromal tumors (GSTs).
 Methods: CT (plain scans with portal phase contrast enhanced scans) images from 98 GSTs patients before surgery were collected. CT features of the tumors were retrospectively analyzed and pathological risk stratifications were determined. Feature parameters of CTTA at plain and portal phase were obtained by using a MaZda software. The correlations of CT imaging features and CTTA parameters with the risk stratifications were analyzed.
 Results: CT imaging features including tumor size, growth pattern, shape, margin, the relationship between mass and adjacent organs, enhancement pattern, necrosis or cystic change, and the abnormal tumor vessels were associated with the risk stratifications (P<0.05). For CTTA, entropy was associated with the risk stratifications (P<0.05).
 Conclusion: Certain CT imaging features and CTTA parameters are associated with risk classifications in GSTs.
Gastrointestinal Stromal Tumors ; diagnostic imaging ; Humans ; Retrospective Studies ; Stomach Neoplasms ; diagnostic imaging ; Tomography, X-Ray Computed

Objective To investigate the value of dynamic three-dimensional contrast-enhanced ultrasound (3D-CEUS) in evaluating therapeutic response of hepatoma treated with radiofrequency ablation (RFA).Methods Totally 48 cases of patients with hepatic carcinoma (48 lesions) admitted in Xiangya Hospital of Central South University from September 2012 to January 2014 were selected.All patients underwent radiofrequency ablation,of which 30 patients were diagnosed by pathology after surgery,18 patients by clinical diagnosis.All patients underwent two-dimensional contrast-enhanced ultrasound (2D-CEUS) and 3D-CEUS 1 month and 3 months after RFA treatment to evaluate the therapeutic response,and the results of contrast-enhanced ultrasound and enhanced computed tomography (CT) [or magnetic resonance imaging (MRI)] were compared.The final diagnostic results of pathologic biopsy or more than two imaging examinations [ultrasonography,CT,MRI,positron emission tomography (PET)],tumor markers,and more than 3 months follow-up of patients were used as the gold standard.The sensitivity,specificity and accuracy of dynamic 3D-CEUS,2D-CEUS,enhanced CT (or MRI) in the diagnosis of tumor inactivation were calculated respectively.Results After radiofrequency ablation,dynamic 3D-CEUS could provide more valuable information in 75.0％ (36/48) lesions,which contribute to assess the efficacy of radiofrequency ablation.While compared with 2D-CEUS,3D-CEUS did not change the diagnosis or clinical management in 12 (25.0％) lesions.40 of 48 lesions were found no-enhancement in entire CEUS procedure suggesting that the tumor completely inactivated,while 8 lesions showed local enhancement on the edge of lesion suggesting that part of the tumors were active.39 of 48 lesions showed no-enhancement and other 9 with irregular enhancement on enhanced CT (or MRI).The sensitivity,specificity and accuracy of CEUS and enhanced CT (or MRI) in detection of residual tumor after radiofrequency ablation were 80.0％,100％,95.8％ and 80.0％,97.4％,93.8％,respectively.Conclusions There was no statistical significance among 3D-CEUS,2D-CEUS and enhanced CT or MRI in evaluating therapeutic response of hepatoma treated with radiofrequency ablation.But 3D-CEUS can provide more valuable information,3D-CEUS has potential usefulness in the evaluation of percutaneous radiofrequency ablation of hepatic tumors.

OBJECTIVE: To determine whether an optimal blood suppression inversion time (BSP TI) can boost arterial visibility and whether the optimal BSP TI is related to breathing rate (BR) and heart rate (HR) for hypertension subjects in spatial labeling with multiple inversion pulses (SLEEK). MATERIALS AND METHODS: This prospective study included 10 volunteers and 93 consecutive hypertension patients who had undergone SLEEK at 1.5T MRI system. Firstly, suitable BSP TIs for displaying clearly renal artery were determined in 10 volunteers. Secondly, non-contrast enhanced magnetic resonance angiography with the suitable BSP TIs were performed on those hypertension patients. Then, renal artery was evaluated and an optimal BSP TI to increase arterial visibility was determined for each patient. Patients' BRs and HRs were recorded and their relationships with the optimal BSP TI were analyzed. RESULTS: The optimal BSP TI was negatively correlated with BR (r1 = -0.536, P1 < 0.001; and r2 = -0.535, P2 < 0.001) and HR (r1 = -0.432, P1 = 0.001; and r2 = -0.419, P2 = 0.001) for 2 readers (kappa = 0.93). For improving renal arterial visibility, BSP TI = 800 ms could be applied as the optimal BSP TI when the 95% confidence interval were 17-19/min (BR1) and 74-82 bpm (HR1) for reader#1 and 17-19/min (BR2) and 74-83 bpm (HR2) for reader#2; BSP TI = 1100 ms while 14-15/min (BR1, 2) and 71-76 bpm (HR1, 2) for both readers; and BSP TI = 1400 ms when 13-16/min (BR1) and 63-68 bpm (HR1) for reader#1 and 14-15/min (BR2) and 64-70 bpm (HR2) for reader#2. CONCLUSION: In SLEEK, BSP TI is affected by patients' BRs and HRs. Adopting the optimal BSP TI based on BR and HR can improve the renal arterial visibility and consequently the working efficiency.
Adult ; Female ; *Heart Rate ; Humans ; Hypertension/pathology ; Kidney/*blood supply ; Magnetic Resonance Angiography/*methods ; Male ; Middle Aged ; Prospective Studies ; Renal Artery/*physiology ; *Respiratory Rate

To investigate the correlations among total liver CT perfusion parameters, unpaired arteries (UAs) and microvessel area (MVA) in a rabbit liver VX2 tumor model, and to learn the tumoral angiogenesis condition and the mechanisms for perfusion imaging.
 Methods: Rabbits with or without the inoculated VX2 tumor in the liver underwent total liver CT perfusion imaging 2 weeks after the operation. Perfusion parameters included blood flow (BF), blood volume (BV), arterial liver perfusion (ALP), portal liver perfusion (PVP), hepatic perfusion index (HPI) for the tumor rim and the surrounding liver tissue. After the examination, the UAs and MVA of tumor tissues were obtained by immunohistochemical staining. The differences of perfusion parameters between the vital tumor rim and the surrounding liver tissue were compared. The correlations among perfusion parameters, UAs and MVA were analyzed.
 Results: There was significant difference between the CT perfusion parameters at the tumor rim and the surrounding liver tissue or liver tissue of the control group (P<0.05), but there was no significant difference between the perfusion parameters at the surrounding liver tissues of the experimental group and the control (P>0.05). There was positive correlation between UAs and MVA. UAs and MVA were positively correlated with BF, ALP and BV at the tumor rim. UAs and MVA were negatively correlated with PVP. HPI positively correlated with UAs, but it was not correlated with MVA.
 Conclusion: Total liver CT perfusion can provide quantitative information to evaluate the artery and portal vein perfusion of liver VX2 tumor, and to assess the degree of tumor angiogenesis.
Animals ; Arteries ; diagnostic imaging ; Blood Volume ; Carcinoma ; Immunohistochemistry ; Liver Circulation ; Liver Neoplasms ; blood supply ; diagnostic imaging ; Microvessels ; diagnostic imaging ; Neoplasm Transplantation ; Neoplasms, Squamous Cell ; Neovascularization, Pathologic ; diagnostic imaging ; Perfusion Imaging ; statistics & numerical data ; Portal System ; diagnostic imaging ; Rabbits ; Tomography, X-Ray Computed ; methods ; statistics & numerical data

Objective To evaluate the teaching effects of case introduced method based on picture archiving and communication system (PACS) system in medical imaging course.Methods Totally 148 students (2009 grade) majored in five-year clinical medicine from Xiangya Medical College were divided into 10 groups; the 10 groups were taken randomly as control group (n=75) and experimental group (n=73).Control group used traditional teaching methods (film teaching) while experimental group used case introduced method based on PACS system.Effects of teaching between were evaluated by questionnaire and test.x2 test was used to compare students' theoretical test scores,with α level =0.05.Results Based on results of questionnaires,more students in experimental group than in control group hold that case introduced method based on PACS system can achieve the purpose of teaching,improve interests in learning,and strengthen the mastery of knowledge.Test scores showed that the percentage of students scored 90-100 and 80-89 (respectively 14％,75％) in experimental group was significantly higher than that in control group (respectively 5％,66％) (x2 =17.932,P=0.000).Conclusions Application of case introduced method based on PACS system in medical imaging course not only improve students' motivation to learn and their clinical ability,but also allow teachers to find and correct shortcomings of students timely,therefore,it is worth promoting.

Experience-oriented teaching approach was introduced into the bilingual course of medical imaging in order to improve the teaching effect.This approach was performed through English literature translation activities and scene-teaching.Meanwhile it points out that this approach has particular advantages in stimulating students' interest and initiative in study.

OBJECTIVE: (1)To obtain the perfusion parameters of hepatocellular carcinomas(HCCs), peritumour livers and normal livers by multi-slice CT(MSCT)and to investigate their characteristics and clinical significances;(2)To investigate the correlation among perfusion parameters, survivin expression, microvessel density(MVD)and pathologic grade of HCCs. METHODS: A total of 31 patients with HCC (5 well-differentiated HCCs, 17 moderately differentiated HCCs, and 9 poorly differentiated HCCs) and 10 normal liver were studied. All underwent CT plain scan, perfusion scan, and conventional enhancement scan of the whole liver using 16-slice spiral CT (Philips Brilliance 16). Perfusion parameters were obtained by time-density curves (TDC) of region of interest (ROI) through the perfusion scans. Tissue sections of HCCs and their corresponding peritumour liver tissues of the 31 patients were detected by immunohistochemistry (SABC methods) for protein expression of survivin and MVD, and 10 normal liver tissue sections were as used as negative controls. The correlation among the perfusion parameters, survivin expression, MVD and pathology grade were analysed. RESULTS: (1)The mean values of HAP, HPP, TLP, and HAI of HCCs were 27.50 mL/(min.100 mL), 19.37 mL/(min.100 mL), 46.87 mL/(min.100 mL), and 60.38%, respectively. The mean values of those of the peritumour livers were 14.93 mL/(min.100 mL), 55.70 mL/(min.100 mL), 69.63 mL/(min.100 mL), and 21.51%, respectively. The mean value of those of the normal livers were 12.22 mL/(min.100mL), 74.56 mL/(min.100 mL), 86.78 mL/(min.100 mL), and 14.00%, respectively. The values of HAP and HAI of HCCs were significantly higher than those of the peritumor livers and the normal livers(P<0.01), and the HPP and TLP of HCCs were significant lower than those of the normal livers(P<0.01).The increase of HAP and decrease of HPP of peritumor livers were both significant compared with that of the normal livers(P<0.05). The HAP, HPP, and HAI of HCCs were significantly different from those of peritumor livers (P<0.01)except TLP. (2) Survivin expression in HCCs was detected in 23/31(74.1%), which was significantly higher than that in corresponding non-cancerous adjacent liver tissues and normal liver tissues (P<0.01). Survivin expression was positively correlated with MVD in HCCs. (3) HAP values were significantly and positively correlated with survivin expression (r=0.932,P<0.01)in HCCs.(4)The values of HAP and HAI were correlated with the pathologic grade in HCCs, and those values were increased gradually(P<0.05) among well differentiated HCCs, moderately differentiated, and poorly differentiated HCCs. CONCLUSION CTPI can quantitatively reflect abnormal blood supply of HCCs, which will be helpful for the detection and differentiation of lesions. CT perfusion parameters well correlate with survivin expression, MVD, and the pathologic grade in HCCs, which illustrate that CTPI could hopefully be used to evaluate the angiogenesis and biological behaviors of HCCs prospectively, noninvasively, and dynamically.
Adult ; Aged ; Carcinoma, Hepatocellular ; blood supply ; diagnostic imaging ; metabolism ; pathology ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; biosynthesis ; genetics ; Liver Neoplasms ; blood supply ; diagnostic imaging ; metabolism ; pathology ; Male ; Microvessels ; diagnostic imaging ; Middle Aged ; Perfusion Imaging ; methods ; Survivin ; Tomography, Spiral Computed

OBJECTIVE: To compare the value of CT using different equipment and scanning methods in preoperative localization of insulinoma and to investigate the possible causes that might influence the detection ratio on CT. METHODS: A total of 47 patients with insulinomas confirmed by operation and pathologic examination from 1990 were collected, and the related clinical information and imaging data of CT were retrospectively analyzed. RESULTS: The diagnostic accuracy for conventional CT with conventional enhancement scanning, spiral CT with pancreatic phase scanning, and multislice spiral CT with dual phasic enhancement scanning were 35.3%, 57.1%, and 81.3%, respectively, and the overall diagnostic accuracy of CT was 57.4%. The diagnostic accuracy of multislice spiral CT was greater than that of conventional CT (P<0.01). For the 2 phases of dual phasic imaging, arterial phase and portal phase had a detective rate of 75.0%and 62.5%, respectively. None of the main clinical information was related to the detection ratio on CT. The detection rate of lesions with diameter of > or =1.5 cm was significantly higher than that of <1.5 cm (76.2%vs. 42.3%). Typical appearance of the lesions on CT was isoattenuation on plain scanning, and enhanced considerably after contrast enhancement. CONCLUSION The size of lesion is the major factor that influences the detection of insulinoma on CT. Multislice spiral CT with dual phasic enhancement scanning has a relatively high detection rate and is recommended for preoperative localization of insulinoma.
Adolescent ; Adult ; Aged ; Child ; Female ; Humans ; Insulinoma ; diagnostic imaging ; Male ; Middle Aged ; Pancreatic Neoplasms ; diagnostic imaging ; Preoperative Period ; Retrospective Studies ; Tomography, Spiral Computed ; Tomography, X-Ray Computed ; methods ; Young Adult

OBJECTIVE: To explore the feasibility and the value of Bayes analysis in clinical decision-making for solitary pulmonary nodules (SPNs). METHODS: We collected 352 consecutive SPN patients (malignancy, n=135; benignity, n=217) retrospectively to form the training set. Utilizing Bayes analysis, the prior odds of malignant SPNs and the likelihood ratios of clinical and CT findings were derived from the training set, which were then used to calculate the probability of malignancy in each SPN. Bayes analysis was also tested prospectively for its diagnostic validation and precision of predictive probability on the test set of 132 SPN patients (malignancy, n=61; benignity, n=71), and compared with the performance of physicians using routine judgment. The actual results of patients diagnosis were analyzed according to the scale of calculated malignant probability in SPNs. RESULTS: The sensitivity, specificity, and accuracy of Bayes analysis for the training samples were 88.9%, 93.1%, and 91.5%, respectively. In the test set, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of Bayes analysis were 88.5%, 85.9%, 87.1%, 84.4%, and 89.7%, respectively. The accuracy of Bayes analysis had no statistically significant difference with that of senior physician A (80.3%, chi2=2.37, P=0.122) and B (79.5%, chi2=3.12, P=0.076), and was higher than that of junior physician C (74.2%, chi2=7.05, P=0.012) and D (74.2%, chi2=6.56, P=0.009); The Brier score was 0.099, 0.140, 0.137,0.154, and 0.179 for Bayes analysis,senior physician A, senior physician B, junior physician C, and junior physician D, respectively. Excluding the solitary metastasis (n=11) misclassified, the false negative rate of Bayes analysis was 1.0% (5/484) for SPNs with <20% estimated probability of malignancy. CONCLUSION Bayes analysis is accurate in qualitative diagnosis, precise in forecasting the malignant probability, and has low false negative rate for SPNs. It is feasible to use Bayes analysis for the management of SPNs.
Adenocarcinoma ; diagnosis ; Adult ; Aged ; Aged, 80 and over ; Bayes Theorem ; Decision Making ; Diagnosis, Differential ; Feasibility Studies ; Female ; Humans ; Lung Neoplasms ; diagnosis ; Male ; Middle Aged ; Solitary Pulmonary Nodule ; diagnosis ; Tomography, X-Ray Computed ; Tuberculoma ; diagnosis ; Tuberculosis, Pulmonary ; diagnosis

OBJECTIVETo evaluate the value of the clinical use of CT perfusion imaging (CTPI) and CT subtraction angiography (CTSA) for diagnosing acute ischemic cerebrovascular disease (AICVD).

METHODSTwenty-four patients with AICVD onset within 24 hours were examined with regular CT, CTPI, and CTSA. Some cases received CTPI, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), digital subtraction angiography (DSA) or single photon emission computer tomography (SPECT) during follow-up examinations.

RESULTSOf the 24 cases, 11 had negative results from regular CT scans 3 - 6 hours after onset of stroke in 6 cases, 6 - 12 hours in 3 cases, and 12 - 24 hours in 2 cases. Ten of these cases were then confirmed by CTPI as having ischemic lesions, 2 with middle cerebral artery occlusion (MCAO), and 1 case with transient ischemic attack (TIA) with CTPI negative. Of the 24 cases, 13 had positive results from regular CT, 9 were diagnosed with ischemic lesions larger by using CTPI than regular CT, 1 case had MCAO and 1 had internal carotid artery occlusion (ICAO). There were 4 cases with ischemic lesions observed with regular CT having nearly the same range as that of lacunar infarctions using CTPI. Another 4 cases had more than 2 lesion areas. The peak time (PT), mean transit time (MTT) and relative flow (RF) of 24 cases were markedly different. The sides of ischemic lesions compared to each other and the core of the lesion compared to peripheral zones were also altered significantly (P < 0.01).

CONCLUSIONSCombined CTPI with CTSA can detect acute ischemic lesions at early and hyper-early stages and could distinguish between TIA, lacunar infarction and a larger area of infarction. Using semiquantitative blood perfusion analysis status, CTPI with CTSA could define position, area and range of the ischemic lesion and penumbra. These scans can also analyze the brain blood perfusion status. It is important to early diagnose the occlusion of the entire division of the internal carotid artery or middle cerebral artery and it is meaningful to assess prognosis and assignment of therapy.

Adult ; Aged ; Angiography, Digital Subtraction ; Brain Ischemia ; diagnostic imaging ; Cerebral Angiography ; Cerebrovascular Circulation ; Female ; Humans ; Male ; Middle Aged ; Tomography, X-Ray Computed