0.05). Conclusion There is no significant correlation between MVD and perfusion. Neovascularizaton and perfusion are highly presented in early colorectal carcinoma. SCT may be more suitable for assessing tumorigenesis than histological MVD technique.

Objective To investigate the value of CT and endoscopic ultrasonography (EUS) in the diagnosis of gastrointestinal stromal tumors (GIST). Methods Eleven patients with surgically and pathologically proved GIST were collected and retrospectively analyzed.Plain CT scanning was performed in all 11 cases and enhancement in 10 cases, while additional EUS in 8 cases.Results Of the 11 lesions, 8 were located in stomach, 1 in esophagus, 1 in duodenum, and 1 in rectum, respectively.In benign GIST, the diameter of the tumor was less than 5 cm, with clear margin and homogeneous density.In malignant GIST, the characteristic appearances were as follows: (1) The diameter of the tumor was more than 7 cm; (2) The tumor was lobular in shape; (3) Lesions contained intratumoral small or large patchy necrosis; (4) The tumor had large and deep ulcers; (5) Around the tumor, small vessels arranged in clumps or in line; (6) The tumor contained scattered small calcifications; (7) Invasion of adjacent tissues and metastasis.The positive predictive value of CT for location of GIST was 54.5% (6/11), the positive predictive value of EUS was 87.5% (7/8).By pathology, benign GIST was identified in 3 cases, malignant in 7 cases, and active proliferation in 1 case.The positive predictive value of CT for differentiation of benign and malignant GIST was 72.7% (8/11), the positive predictive value of EUS was 62.5% (5/8).Conclusion CT combined with EUS are helpful in evaluating the gastrointestinal origin of GIST, and in differentiating between benign and malignant GIST, and in instructing clinical treatment and estimating prognosis.

Objective To synthesize the hydrophobic supraparamagnetic ironic oxide(SPIO) loaded and hydrophilic SPIO loaded polymeric nano-vesicles and to investigate the feasibility of using hydrophobic SPIO loaded and hydrophilic SPIO loaded polymeric nano-vesicles to display the tumor in MRI in vivo through animal experiments. Methods The polymeric nano-vesicles were prepared from poly (D, L-lactic acid) (PDLLA) and poly (ethylene glycol) (PEG) by a multiple emulsion/solvent evaporation method.The hydrophobic SPIO and hydrophilic SPIO were loaded in the polymeric nano-vesicles respectively.Eighteen nude mice models with human colorectal carcinoma xenograft were established. They were divided equally into three groups (n = 6). The three groups of nude mice models were injected with water-soluble SPIO, hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle via the mice caudal vein respectively.Dynamic MRI scan were performed in all the mice models. T2WI signal intensity and T2 relaxation time were measured in the tumor, liver and muscle by using T2 mapping software. ANOVA of repeated measurement was used to analyze if there were significant differences of signal intensity changes among the three groups, while Bonferroni method was used for pair-wise comparison. Results On T2 WI, tumors showed decrease in signal intensity after hydrophobic or hydrophilic SPIO loaded polymeric nano-vesicle injection, while no signal intensity decrease was found in the tumor after water-soluble SPIO administration. The maximum percentage of signal intensity decrease in tumor caused by hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle were 11.00%, 11.40%, respectively. There was statistical significant difference of signal intensity changes among these three groups (F = 10. 96, P ＜ 0. 01). The decrease in signal intensity in the groups with hydrophilic or hydrophobic SPIO loaded polymeric nano-vesicles injection were more pronounced as compared with that of water-soluble SPIO (P ＜ 0. 05), but there was no significant difference in signal intensity decrease between the groups of hydrophilic and hydrophobic SPIO-loaded polymeric vesicles injection (P ＞0. 05). The three agents could lead to signal intensity decrease in the liver. The maximum percentage of signal intensity decrease in liver caused by water-soluble SPIO, hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle were 32. 85%, 52. 77%, 56. 89%, respectively. There was statistical significant difference between these groups (F = 161.18, P ＜ 0. 01) . The groups of injecting hydrophilic and hydrophobic SPIO loaded polymeric nano-vesicles had the more obvious signal decrease than the one with water-soluble SPIO (P ＜ 0. 01). Hydrophilic SPIO loaded polymeric nano-vesicles exhibited more signal intensity decrease than hydrophobic SPIO loaded polymeric nano-vesicles (P ＜ 0. 01). All three agents could not lead to T2WI signal decrease in the muscle, and there was no significant difference in signal change on T2 WI among three groups (F = 0. 59, P ＞ 0. 05). Conclusion SPIO loaded polymeric nano-vesicles can cause significant T2WI signal loss in human colonic carcinoma on MR imaging in vivo. It can be used as tumor imaging contrast agents.

Objective To analyze the imaging features and to enhance the understanding of pancreatic and renal involvement in yon Hippel-Lindau disease (VHLD). Methods CT and MRI appearances and clinical data of six patients with pancreatic and renal involvement in VHLD were studied retrospectively.Six patients underwent CT scanning, and two of them also had MRI.Results Pancreatic cysts found in all six patients varied from several small cysts to cystic replacement of the entire gland.Calcifications were detected in four patients. Multiple bilateral renal lesions were detected in six patients.The renal lesions were classified as cystic, cystic with solid components and solid.Multiple combined renal lesions were found in five patients, and multiple simple cysts in one patient.Unilateral nephrectomy was performed in two patients, and the renal masses were diagnosed as clear cell carcinoma by pathology.Bile carcinoid was found in one patient, and retroperitoneal metastasis in another.Conclusion Multiple pancreatic cysts and/or multiple and bilateral combined renal lesions are highly suggestive of VHLD.

Objective To evaluate the efficacy of discriminant function analysis for pericolic infiltration in colorectal cancer on enhanced 64-slice spiral CT and to improve the diagnostic accuracy and specificity of pericolic infiltration. Methods Dynamic enhanced 64-slice spiral CT was performed in 49 colorectal cancer patients (49 masses in total) before surgery. One or two slices were selected for each mass, with a total of 96 slices. The 96 slices were classified into two groups (pericolic infiltration or nonpericolic infiltration group) according to pathological data. Discriminant analysis was performed on the CT values between the mass and the corresponding pericolic tissue 5 mm from the mass at different time points as follows; 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, and 75 s. The discriminant function was calculated, and the pericolic infiltration determined by discriminant function and CT morphology were compared with the pathological results. The CT values in pericolic and non-pericolic infiltration groups at different enhancement time points were assessed using analysis of variance. Results The mean CT values ranged from (43. 6 ±7. 8) HU to (52. 3 ±0. 8) HU in the pericolic infiltration group, and ranged from (100.4±20.3)HU to(116.2±21.4)HU in the non.perieolic infiltration group.At 20 s and 40 s,the mean CT vshle8 were(43.6±27.8)HU and(50.9±27.8)HU in the perleolic infiltration group, (102.0±16.9)HU and(116.2 ±21.4)HU in the non-perieolic infiltration group,respectively.The mean CT value in the pericolic infiltration group was significantly lower than that in the non-pericolic infiltration group at all contrast enhancement time points(F=6.278,P<0.01).A diseriminant function Was obtained as follows:D=-3.450+0.023Xl±0.017X2-0.00lX12-0.001X22+0.002X1×X2. Based on the CT morphology of colorectal cancer,69 slices were identified correctly and 27 slices were fulsely interpreted.the sensitivity.speeificity and accuracy for perieolic infiltration determination were 82.5%,64.3%and 71.9%.respectively.Based on diseriminant function,85 slices were identified correctly and 11 slices were falsely interpreted.the sensitivity,specificity and accuracy were 85.0%.91.1%and 88.5%,respectively.Conclusion The discriminant function with dynamic enhanced 64-slice spiral CT can improve the diagnostic accuracy and specificity of perieolic infiltration in eolorectal cancer patients.

Objective To explore the diagnostic value of magnetization transfer imaging (MTI) and DWI for detecting intestinal wall property of crohn's disease (CD). Methods Forty four patients with CD were prospectively enrolled in the study, and MR enterography (MRE), MTI and DWI were performed. According to MRE findings, patients were divided into three subgroups:acute inflammatory group, chronic fibrotic group and combined inflammatory with fibrotic group. Intestinal wall T2WI signal, magnetization transmisson rate (MTR) and ADC value were measured on MRE, MRI and DWI imagings, respectively. The differences of MTR and ADC among the three groups were analyzed by one-way ANOVA;the differences of T2WI scores were analysed by Kruskal Wallis;the differences of MTR and ADC values between normal and pathological intestinal wall were analyzed by paired t test;ROC curve were used to evaluate the CD fibrosis and inflammation diagnostic efficiency of MTI ana DWI based on MRE signs. Results Among the 44 cases, 11 cases were in the acute inflammatory group, 18 cases were in the chronic fibrotic group and other 15 cases were in the combination group. The T2WI score, MTR and ADC among the three groups showed significant differences (all P<0.01).The mean MTR and ADC of pathological intestinal wall of the 44 cases were (40.77±6.05)%and (1.04±0.18)× 10-3mm2/s, and the adjacent normal bowel were (21.75±4.17)%and (1.97 ± 0.23) × 10- 3mm2/s, respectively. Moreover, the difference of the above values showed significant differences (t=19.12,-21.80 respectively, all P<0.01). There was a negative correlation between MTR and T2WI score (r=-0.71,P<0.01). While ADC value was positively correlated with T2WI score (r=0.80, P<0.01). Using ROC curve analysis to differentiate the CD fibrosis from acute inflammation, the area under the curve (AUC) of MTR and ADC were 0.97 and 0.96 ,respectively. Conclusions Both MTI and DWI can be used to assess the properties of intestinal wall, which has the same diagnostic efficacy to identify the acute inflammation and fibrosis.

[Objective]To explore the efficacy of T2* mapping for evaluating inflammatory activity in the patients with Crohn disease(CD).[Methods]A total of 98 CD patients underwent MR enterographywith T2*WI. T2* values were measured by put-ting regions of interest on the thickening bowel wall on T2*mapping. The activity of bowel segment was scored by magnetic resonance index of activity(MaRIA),to analyze the relationship between T2*values with CD activity.[Results]A total of 160 bowel segments were evaluated and includedinactive(MaRIA<7,n=26),mild(7≤MaRIA<11,n=23),and moderately-severe(MaRIA≥11, n = 111)active lesions. The differences in T2* values amongthese three groups were significant(all P < 0.05). T2* values of 160 bowel segments correlatedclosely withMaRIA(r=0.743,P<0.05). High accuracy of T2*values was shown for differentiating inac-tive from active CD(AUC=0.877)anddifferentiating inactive-mild from moderate-severe CD(AUC=0.848). The threshold T2*value of 20 ms allowed differentiation of mild from moderate-severe CD with74.5%sensitivity and 84%specificity.[Conclusions]T2*values, as thequantitative indexof T2*mapping,correlate well with CD activity and showsatisfiedefficacy for diagnosing inflammatoryactivity.

[Objective] To analyze the image findings of MR enterography (MRE) and diffusion weighted imaging (DWI) in Crohn disease (CD) and to discuss the diagnostic value of MRI for evaluating the activity of CD.[Methods] 26 patients proved by clinical,imaging and pathological data were enrolled in this study.The intra-/extra-intestinal image features of CD were retrospectively analyzed,and the intestinal lesions were evaluated by MRE+DWI scoring system.The differences in image features of active and inactive CD were compared.[Results] 26 bowel segments were evaluated and included active (n =20) and inactive CD (n =6).The intestinal performance of CD included wall thickening,T2WI hyperintensity and hyperenhancement.The pathological changes of active CD were more serious when comparing with that of inactive CD.DWI showed hyperintensity in the affected bowel wall.ADC of active C D [(0.9 ± 0.2) × 10-3 mm2/s] was significantly lower than that of inactive CD [(1.5 ± 0.4)× 10-3 mm2/s] (P ＜ 0.001).Extra-enteric performance of active CD included comb sign,lymphadenectasis of mesentery,mesenteric exudation,fistula and abdominal abscess.[Conclusion] MRE combined with DWI can accurately assess CD activity and diagnose extra-enteric complications.

Yolk sac tumor (YST) is a rare germ cell neoplasm of childhood that usually arises from the testis or ovary. The rare cases of YST in various extragonadal locations have been reported, but the primary intrarenal YST is even more uncommon. Here, we report a case of a primary intrarenal YST with tumor thrombus of the inferior vena cava and left renal vein in a 2-year-old boy, with an emphasis on the CT features. To our knowledge, this is the first reported case of an intrarenal YST with intravascular involvement.
Child, Preschool ; Humans ; Male ; Neoplasms, Germ Cell and Embryonal/*diagnosis/pathology/ultrasonography ; Renal Veins/pathology/*radiography ; Thrombosis/pathology/radiography ; *Tomography, X-Ray Computed ; Vena Cava, Inferior/pathology/*radiography

OBJECTIVETo assess the value of MDCT with vessel probe(VP) in the diagnosis and treatment of isolated superior mesenteric artery dissection (ISMAD).

METHODSClinical and imaging data of 15 patients with ISMAD admitted to the First Affiliated Hospital of Sun Yat-Sen University from June 2008 to May 2013 were retrospectively reviewed. Relationship among radiograpic features, clinical symptoms and therapeutic options of ISMAD was examined based on the imaging of 64-MDCT with VP.

RESULTSThe dissection crevasse of all the 15 patients located in anterior arterial wall, and the distance was(24.3±9.7) mm from the origin of SMA. Meanwhile dissection crevasse of 73.3%(11/15) patients located in the zone within 1 cm of proximal end and 1 cm of distal end of the proximal SMA curvature. There were significant differences between patients without abdominal pain(8 cases) and those with abdominal pain(7 cases) in dissection length, minor diameter ratio of true lumen to false lumen, major diameter ratio of true lumen to false lumen(all P<0.01). According to classification of Yun, there were 5 patients of typeI( and 3 type II(a, whose conservative treatment were successful. In other 7 patients of type II(b, 3 patients received successful conservative treatment, and 4 patients had symptom remission after turning to interventional treatment or surgery.

CONCLUSIONS64-MDCT with VP can clearly depict the image manifestation of ISMAD, which provides evidence for the diagnosis and therapeutic options of ISMAD.