Appendicolith appendicitis: should we be operating sooner? A retrospective cohort study.

INTRODUCTION: Evidence suggests that delaying an appendicectomy for up to 24 hours does not increase the risk of complicated appendicitis. Appendicoliths are a risk factor for perforation. No study has explored the temporal relationship between appendicolith presence and time to perforation. In this retrospective cohort study, we hypothesise that the presence of an appendicolith confirmed on preoperative computerised tomography scan (pCT) leads to a shorter time to complicated appendicitis. METHODS: We undertook a retrospective single-centre study of patients admitted between 2018 and 2020. Inclusion criteria included: age ≥18 years, appendicitis confirmed on histopathology following an operation and a pCT scan. Complicated appendicitis was defined intraoperatively as an appendicular abscess, gangrenous or perforated appendix. RESULTS: Some 310 patients were included in the study. Forty-five per cent presented with complicated appendicitis (n = 138). Appendicoliths were present in 79 (25.5%) patients. Multivariate logistic regression identified an appendicolith as a significant risk factor for perforation (odds ratio 3.50, 95% confidence interval [CI] 1.16-10.59; p = 0.027). Within the first 12 hours of admission, patients with an appendicolith accounted for a significantly greater proportion of those with complicated appendicitis intraoperatively compared with those without (56.7% vs 43.3%, respectively; p = 0.003). Within 12 hours of admission, those with an appendicolith were 2.05 times more likely to suffer from complicated appendicitis than those without (95% CI 1.28-3.29). CONCLUSIONS: Patients with an appendicolith appendicitis should be considered for an early appendicectomy. Future large-scale multicentre prospective studies are required to explore this further, perhaps informing future guidelines.

Application value of deep learning reconstruction algorithm in CT imaging of abdominal phantoms / 中华放射医学与防护杂志

Objective:To explore the value of the deep learning image reconstruction (DLIR) algorithm in improving the CT image quality of abdominal phantoms under different radiation doses by comparing the DLIR algorithm with the conventional Adaptive Statistical Iterative Reconstruction-V (ASIR-V) technique.Methods:Two groups with tube voltages of 100 kV and 120 kV (also referred to as the 100 kV and 120 kV groups, respectively) were involved. Each group was further divided into six subgroups based on different volumetric CT dose indices (CTDI vol: 2, 4, 6, 8, 10 and 15 mGy). Subsequently, CT images based on the filtered back projection (FBP) algorithm were obtained and were then reconstructed using the ASIR-V algorithm with different weights (ASIR-V 50%, 80%, and 100%) and the DLIR algorithm with different levels (DLIR-L, M, and -H). As a result, 84 groups of images were obtained in total. Afterward, this study compared and analyzed the variations in CT values, noise, signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), and subjective scores of various parts in various CTDI vol subgroups under different reconstruction conditions. In addition, the subjective scores of the image quality were compared using the Kruskal-Wallis H test, while objective indices and radiation doses were compared through the univariate analysis of variance (ANOVA) and the paired t test. Results:Under the same tube voltage, there were statistically significant differences in the noise, SNRs, and CNRs of various parts in various CTDI vol subgroups under different reconstruction conditions ( F = 415.39, 315.30, P < 0.001), while there was no statistically significant difference in the noise, SNRs, and CNRs of images constructed using ASIR-V 50% and DLIR-L ( P > 0.05). Under different tube voltages, the subjective scores of both groups show statistically significant differences (100 kV group: H = 13.47, P = 0.036; 120 kV group: H = 12.99, P = 0.043). Moreover, two physicians offered consistent subjective scores, with Kappa values > 0.70. Among these images, DLIR-H images showed the highest subjective scores, followed by DLIR-M and ASIR-V 50% images, which had roughly consistent subjective scores. Moreover, the subjective scores of the 100 kV group were slightly higher than those of the 120 kV group. With the ASIR-V 50% images of the subgroup with a CTDI vol of 15 mGy as references, the DLIR-L, -M, and -H reduced radiation doses by more than 30%, 70% and 85%, respectively on the premise that diagnostic requirements were met. Conclusions:The DLIR algorithm can not only significantly reduce the image noise and improve the image quality, but also effectively decrease the radiation doses on the premise of meeting the diagnostic requirements. It is recommended that 100 kV tube voltage combined with a medium- or high-level DLIR algorithm should be applied to low-dose abdominal CT scans in clinical applications.

Risk stratification of 2- to 5-cm gastric stromal tumors based on clinical and computed tomography manifestations.

OBJECTIVE: To evaluate the risk stratification of 2- to 5-cm gastric stromal tumors (GSTs) by analyzing their clinical and computed tomography (CT) manifestations with the goal of providing imaging evidence for rational selection of surgical methods. METHODS: This study involved 223 patients with pathologically diagnosed GSTs of 2 to 5 cm in diameter. According to the pathological results and malignant risk category, the patients were divided into a low-risk biological behavior group (very low and low risk) and high-risk biological behavior group (intermediate and high risk). The clinical and CT manifestations were compared between the groups. The chi-square test was used to analyze categorical variables, and the independent-samples t test was used to analyze continuous variables. Multivariate logistic regression and receiver operating characteristic curve analysis were performed for statistically significant variables. RESULTS: The tumor contour, necrosis, surface ulceration, and long diameter were significantly different between the low-risk group and the high-risk group (P < 0.05). Multivariate logistic regression analysis showed that the tumor contour and long diameter were independent risk factors. The area under the curve was 0.82, and the accuracy, sensitivity, and specificity were 0.78, 77.4 %, and 79.7 %, respectively. CONCLUSIONS: The risk associated with 2- to 5-cm GSTs can be preoperatively predicted in an indirect manner through analysis of clinical and CT manifestations, and this model has high diagnostic value.

[Clinical Application of "Three-Low" Technique Combined with Artificial Intelligence Iterative Reconstruction Algorithm in Aortic CT Angiography].

Objective: To explore the application value of the "three-low" technique (low radiation dose, low contrast agent dosage and low contrast agent flow rate) combined with artificial intelligence iterative reconstruction (AIIR) in aortic CT angiography (CTA). Methods: A total of 33 patients who underwent aortic CTA were prospectively enrolled. Based on the time of their follow-up examinations, the imaging data were divided into Group A and Group B, with Group A being the control group (100 kV, 0.8 mL/kg, 5 mL/s) and Group B being the "three-low" technique group (70 kV, 0.5 mL/kg, 3 mL/s). In group A, the images were reconstructed by Karl iterative algorithm. Group B was divided into B1 and B2 subgroups, with their images being reconstructed by Karl iterative algorithm and AIIR, respectively. The CT and SD values of the ascending aorta, descending aorta, abdominal aorta, left common iliac artery and right common iliac artery were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The subjective scoring of image quality was performed. The radiation dose parameters were documented. Results: Differences in the CT value, SD value, SNR and CNR of the three groups were statistically significant ( P<0.001). The CT value, SNR and CNR of group B2 were significantly higher than those of group B1, while the SD value of group B2 was significantly lower than that of group B1 ( P<0.017). There was no significant difference between the CT values of group A and those of group B2 ( P>0.017). The SD values, SNR and CNR in group B2 were better than those in group A ( P>0.017). There was significant difference in the subjective evaluation of image quality among the three groups ( P<0.05), but there was no significant difference between group A and group B2 ( P>0.017). The radiation dose and contrast medium dosage in group B decreased 84.14% and 37.08%, respectively, compared with those of group A. Conclusion: With the "three-low" technique combined with AIIR algorithm, the image quality of aortic CTA obtained is comparable to that of conventional dose scanning, while the radiation dose, contrast agent dosage and contrast agent flow rate of patients are significantly reduced.

Treatment of Differentiated Thyroid Cancer and Recurrent Laryngeal Nerve Function with 131 Iodine Based on Positron Emission Tomography/Computed Tomography Image Segmentation Algorithm.

BACKGROUND: Based on the positron emission tomography (PET) computed tomography (CT) image segmentation algorithm, this article explores the application of PET/CT in the recurrence and metastasis of thyroid cancer after differentiated thyroid cancer (DTC). METHODS: In this study, 132 patients with DTC combined with 131I treatment underwent PET/CT whole-body imaging and 131I whole-body scan (131I-WBS), and the serum thyroglobulin (Tg) level was measured at the same time. RESULTS: Among 54 Tg-positive patients, 49 were positive for 131I-WBS and 32 were positive for PET/CT imaging. Of the 15 Tg-negative patients, 131I-WBS and PET/CT imaging were negative. Three patients with 131I-WBS suggesting residual thyroid tumors were all positive in PET/CT examinations; 7 patients with 131I-WBS suggesting lymph node metastasis were all positive in PET/CT examinations, and in 131I, PET/CT imaging in WBS-negative patients showed 6 lung metastases and 3 bone metastases. CONCLUSIONS: PET/CT and 131I scans are similar in the diagnosis of residual thyroid and lymph node metastasis, but PET/CT has more advantages than does the 131I scan in the diagnosis of bone metastasis and lung metastasis. PET/CT can still find other benign and malignant lesions, which is of great value in the restaging of DTC. The imaging effect of WBS lung lesions in older patients is not good. The presence of stripe, calcification, and patch shadows in the lungs is not conducive to the imaging of WBS lung metastases. Lung strips and calcification affect the WBS lung main factors for imaging of metastases.

CT features of primary liver leiomyosarcoma / 中华消化外科杂志

Objective:To investigate the computed tomography (CT) features of primary liver leiomyosarcoma (PHLMS).Methods:The retrospective and descriptive study was conducted. The clinical and imaging data of 10 patients with PHLMS who were admitted to 4 medical centers including 3 cases in Wenzhou Central Hospital, 3 cases in the Second Affiliated Hospital of Wenzhou Medical University, 2 cases in Wenzhou People's Hospital and 2 cases in Yueqing People's Hospital from January 2011 to December 2020 were collected. There were 5 males and 5 females, aged from 41 to 83 years, with a median age of 55 years. All 10 patients underwent abdominal CT examination. Observation indicators: (1) CT features; (2) treatment and pathological examination; (3) follow-up and survival. Follow-up using postoperative outpatient or inpatient examination to detect patient survival was conducted. Patients underwent imaging examination to detect tumor recurrence. Follow-up was up to December 2020. Measurement data with skewed distribution were represented as M (range). Count data were described as absolute numbers. Results:(1) CT features: results of CT examination showed that each of the 10 patients had only one single tumor, including 3 cases with tumor on the left lobe of liver and 7 cases with tumor on the right lobe of liver. The tumor diameter of the 10 patients was 8.0 cm(range, 4.5-13.5 cm). Results of plain CT scan of 10 patients showed that 7 cases had tumor in expansive growth as round or oval, with clear boundaries and the tumor parenchyma showing low-density signals and patchy lower density area can be seen in the center, and 3 cases had tumor in infiltrative growth as patchy, with unclear boundaries and the tumor parenchyma showing iso-density signals. The CT scan value of 10 patients was 40 HU(range, 23-47 HU). Results of enhanced CT scan at arterial phase of the 7 cases with tumor in expansive growth showed that 3 cases undergoing tumor parenchyma with uneven mild enhancement signals, 3 cases undergoing tumor parenchyma with uneven moderate enhancement signals and 1 case undergoing tumor parenchyma with uneven significant enhancement signal. The CT scan value of 7 cases was 68 HU(range, 62-88 HU). Results of enhanced CT scan at arterial phase of the 3 cases with tumor in infiltrative growth showed that the peripheral region had high signal than the central region. The CT scan value of 3 cases was 73 HU(range, 67-90 HU). Results of enhanced CT scan at portal vein phase in the 7 cases with tumor in expansive growth showed that the tumor parenchyma showing continuous and progressive mild and moderate enhancement with uneven density, and the CT scan value was 63 HU(range, 55-78 HU). Of the 7 cases, 3 cases showed the enhancement range of tumor parenchyma with the trend of fusion and filling, and 4 cases showed small patchy or nodular enhancement and grid like enhancement in the center and periphery of the tumor. Results of enhanced CT scan at portal vein phase in the 3 cases with tumor in infiltrative growth showed that the enhancement withdrew, the density was uneven, and the CT scan value was 58 HU(range, 50-62 HU). Results of enhanced CT scan at delayed phase in 10 patients showed that the enhancement in the tumor withdrew slowly, and the CT scan value was 53 HU(range, 50-60 HU). Of the 10 patients, 4 cases showed decreased density of enhanced nodules around the tumor and 6 cases showed partially fused and filled to the center of tumor with no enhancement in the necrotic part. (2) Treatment and pathological examination: all 10 patients underwent completed tumor resection successfully, and no metastasis was found in liver or the hilar region. Results of postoperative pathological examination showed that each of the 10 patients had only one single visible tumor with tumor diameter of 8.0 cm(range, 4.5?13.5 cm). Of the 10 patients, 7 cases had tumor with complete or incomplete pseudocapsule with clear boundary and 3 cases had tumor without pseudocapsule and the boundary was unclear. All 10 patients had tumor with hard parenchyma and the section was mostly gray and fish like. Among them, patchy or punctate necrosis was seen in 7 cases, small patchy or punctate hemorrhage was seen in 3 cases, and small patchy calcification was seen in 2 cases. Microscopically, the tumor tissue was crisscross, the tumor cells were in spindle shaped, the nuclei were in round, oval, blunt at both ends or in thin rod like, with obvious heteromorphism, large and deeply staining, and obviously division. Immunohistochemical staining showed positive staining of smooth muscle actin, desmin and vimentin. (3) Follow-up and survival: all 10 patients were followed up postoperatively for 6 to 130 months, with a median follow-up time of 55 months. The overall survival time of 10 patients were 10 to 120 months, with a median overall survival time of 46 months. Of the 10 patients, 2 cases died of tumor recurrence and distant metastasis 10 and 11 months after operation, respectively and 8 cases survived >12 months.Conclusions:Results of plain CT scan of PHLMS show clear or unclear cysts and solid masses with uneven density. Results of enhancement CT scan of PHLMS show persistent uneven enhancement in tumor parenchyma and the surrounding area.

Value of ultrasonography, radionuclide imaging and CT in preoperative location diagnosis of primary hyperparathyroidism / 中华普通外科杂志

Objectiv:To evaluate ultrasound, radionuclide imaging and CT in preoperative localization diagnosis of primary hyperparathyroidism (PHPT).Method:A total of 170 PHPT patients admitted to the hospital between Jan 1992 and Dec 2020 were analyzed retrospectively. The preoperative localization diagnostic efficacy of ultrasonography, radionuclide and CT alone and in combination was compared in groups.Results:The overall sensitivity of ultrasound, radionuclide and CT were 82.13%,80.43% and 75.74%. For normal positioned parathyroid adenoma: as for sensitivity of location diagnosis, ultrasound (86.67%) was higher than radionuclide (81.82%, P<0.05) and CT (80.59%, P<0.05), ultrasound/CT parallel test (94.70%, P<0.05) was higher than ultrasound alone. For specificity of location diagnosis, radionuclide (97.78%) was higher than ultrasound (91.62%) and CT (93.39%), both ultrasound/radionuclide series tests (99.00%, P<0.001)and ultrasound/CT series tests (96.94%, P<0.001) were higher than ultrasound alone. In case of ectopic parathyroid adenoma and parathyroid hyperplasia: the sensitivity and specificity of radionuclide seemed higher than ultrasound and CT. Conclusions:Ultrasound is the first choice for preoperative location diagnosis of PHPT. Ultrasound combined with radionuclide or CT can significantly improve the diagnostic efficiency of parathyroid lesions.

Imaging Characteristics of Renal Cell Carcinoma Associated with Xp11.2 Translocation/TFE3 Gene Fusions in Children / 肿瘤防治研究

Objective To investigate the imaging characteristics of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion. Methods We retrospectively analyzed the clinical and imaging data of five children with Xp11.2 tRCC confirmed by surgery and pathology in our hospital from January 2015 to December 2020. Four cases underwent CT plain scan and contrast-enhanced examination, and one case underwent MRI plain scan, contrast-enhanced examination and DWI examination. We observed and analyzed the location, size, shape, boundary, composition, enhancement pattern and degree, the relation with the renal hilum and adjacent large vessels, and the metastasis of the tumor. Results All cases were cortical-medullary type. Four cases were solid/cystic-solid lesions, iso- or slightly hyper-density on CT scans with calcification and necrosis, in which a few with bleeding or cystic lesions. Enhanced scanning primarily showed mild to moderate enhancement, and enhancement of pseudocapsule was seen during the delayed phase. One case was cystic lesion, the cystic fluid presented as hypo-density on CT, and T1 hypo-intensity and T2 hyper-intensity, as well as restricted diffusion on DWI. No enhancement was found in the cystic part after enhancement. There were irregular and thickened cystic wall and septum, and mural nodules on enhanced MRI. Conclusion Several characteristics of Xp11.2 tRCC in children could be drawn. Punctate and patchy calcifications in or around the solid/cystic-solid lesions and delayed "pseudocapsule sign" are typical. The possibility of Xp11.2 tRCC should be considered when there are irregular and thickened cystic wall and septum and the enhancement of mural nodules.

Observation on vulnerable coronary plaques in HIV-infected patients based on coronary CTA / 中国医学影像技术

Objective: To explore whether vulnerable coronary plaques in HIV-infected patients are different with those in non-HIV-infected ones, and to analyze the relative risk factors. Methods: A total of 167 HIV-infected patients (HIV-infected group) and 185 non-HIV-infected patients(non-HIV-infected group) who underwent coronary CTA (CCTA) were collected. Vulnerable plaques were defined as those with two or more high-risk morphological features. The type, location and incidence of vulnerable coronary plaques were analyzed and compared between 2 groups, and the risk factors of vulnerable coronary plaques in HIV-infected patients were analyzed. Results: There was no significant difference of baseline clinical data between the two groups. The most common types of vulnerable coronary plaques in 2 groups were both low attenuation plaques+positive remodeling, most located in the proximal segment of left anterior descending artery (segment 6). The incidence of vulnerable coronary plaques ≥1 coronary segments in HIV-infected patients was higher than that in non-HIV-infected patients (34.73% vs 24.32%,P<0.05). Vulnerable coronary plaques in HIV-infected patients were independently correlated with the duration of antiretroviral therapy (ART) drug (OR=1.29, 95%CI [1.04,1.59], P=0.02). Conclusion: The incidence of vulnerable coronary plaques in HIV-infected patients was higher than that in non-HIV-infected patients. ART drug may be an independent risk factor for coronary plaque vulnerability in HIV-infected patients.

Analysis of the components of carotid plaque and relationship with cerebral infarction with spectral CTA / 中国医学影像技术

Objective: To investigate the feasibility of energy spectrum CT angiography (CTA) in distinguishing the components of atherosclerosis plaque in carotid artery, and to analyze the relationship of different type atherosclerosis plaque with cerebral infarction. Methods: Energy spectrum CTA and head MRI were performed on 60 patients with carotid artery stenosis detected with ultrasound. CT value and effective atomic number of plaque, fat, muscle and bone tissue were measured, respectively. The characteristic energy spectrum curve of average CT value in 40-140 keV single energy image were obtained, and slope of energy spectrum curve was calculated. Cerebral infarction was evaluated based on MRI results. According to the results of energy spectrum CTA, the plaques were divided into lipid plaque, lipid core-dominated mixed plaque, fibrous composites-dominated mixed plaque, fibrous plaque and calcified plaque. The lipid plaque and lipid/fiber mixed plaque were classified as unstable plaque, and the fibrous plaque and calcified plaque were classified as stable plaque. The differences of the slope of energy spectrum curve and effective atomic number in patients of each type plaques were compared. The incidences of cerebral infarction in patients with various types of plaques were correlated. Results: A total of 109 carotid plaques were enrolled, including 21 lipid plaque, 11 lipid core-dominated mixed plaque, 30 fibrous composites-dominated mixed plaque, 15 fibrous plaque and 32 calcified plaque. Statistical differences of the corresponding energy curve slope and effective atomic number wer found among different type plaques (F=1 494. 83, 2 108. 74, both P<0.01). Totally 19, 11, 19, 10 and 20 patients were found with lipid plaque, lipid core-dominated mixed plaque, fibrous composites-dominated mixed plaque, fibrous plaque and calcified plaque, among them MRI detected cerebral infarction in 13, 6, 7, 2 and 1 patient, and the incidence of cerebral infarction was 68.42% (13/19), 54.55% (6/11), 36.84% (7/19), 11.11% (1/9), and 0 (0/20), respectively. The incidence of cerebral infarction in all 60 patients was 45.00%(27/60, in those with unstable plaque or stable plaque was 53.06% (26/49) and 3.33% (1/30), respectively. Conclusion: Energy spectrum CTA could be used for detailed analysis on the components and types of carotid plaques. The more the lipid components of plaque, the worse its stability, and the higher the risk of cerebral infarction.

Pre-operation MSCTA combined with intraoperative ultrasound for application of laparoscopic kidney-preserving surgery for treatment of small renal cancer / 中国介入影像与治疗学

Objective: To observe the value of preoperative multi-slice spiral CT angiography (MSCTA) and intraoperative assisted ultrasound in application of laparoscopic kidney-preserving surgery for treating small renal cancer (tumor diameter ≤4 cm). Methods: A total of 85 patients with small kidney cancer underwent retroperitoneal laparoscopic nephron-sparing surgery, including 43 underwent preoperative MSCTA and intraoperative assisted ultrasound (observe group) and 42 underwent preoperative routine renal ultrasound and CT examination (control group). The relevant indicators were compared between the two groups. Results: Preoperative MSCTA findings of observe group were consistent with intraoperative findings. The operative time, intraoperative heat ischemia time, intraoperative blood loss and postoperative hospital stay in observe group were all less than those in control group (all P0.05), while the postoperative GFR of control group was lower than that before surgery (P=0.040). Conclusion: Preoperative MSCTA and intraoperative auxiliary ultrasound during retroperitoneal laparoscopic nephron-sparing surgery for patients with small renal carcinoma can reduce intraoperative blood loss and positive rate of resection margin, reserve as much nephrons as possible to promote the recovery of renal function.

Preoperative CTA evaluation on renal arteriovenous anatomy and tumor thrombi of massive renal carcinoma / 中国介入影像与治疗学

Objective To observe the value of renal artery plus renal vein CTA in preoperative evaluation on renal arteriovenous anatomy and tumor thrombi of massive renal carcinoma. Methods Renal artery + renal vein CTA obtained with 256-slice spiral CT of 56 patients with renal carcinoma confirmed by postoperative pathology were retrospectively analyzed, and the images were reconstructed. The anatomical situation of renal artery and renal vein, the location and type of tumor thrombi were observed and compared with surgical operation findings. Results All 56 patients had single tumor, located in the left kidney in 26 cases, while in the right kidney in 30 cases. The maximum diameter of tumor was 71-144 mm ([84.33±20.59]mm). There was no significant difference of the variation rate between the healthy side and the affected side of renal arteries nor veins (all P>0.05). CTA showed totally 117 tumor feeding arteries, while 118 tumor feeding arteries were found during operation, and the coincidence rate was 99.15% (117/118). CTA showed 69 draining veins, so did surgical operation, and the coincidence rate was 100% (69/69). CTA showed tumor thrombi infiltrating renal vein in 5 cases (5/56, 8.93%), infiltration of renal vein and inferior vena cava in 9 cases (9/56, 16.07%), including 5 cases of Mayo type 0, 3 cases of type , 4 cases of type Ⅱ, 2 cases of type III, whereas 42 cases (42/56, 75,00%) were found without infiltrating renal vein. Conclusion Preoperative renal artery plus renal vein CTA can accurately evaluate renal arteriovenous anatomy and location and type of tumor thrombi of renal mass renal carcinoma.

CT and MRI Imaging Findings of Gallbladder Neuroendocrine Tumor / 中山大学学报(医学科学版)

@#【Objective】 To summarize the CT and MRI imaging features of gallbladder neuroendocrine tumor.【Methods】 CT and MRI data of 10 patients with gallbladder neuroendocrine tumors proven by surgical pathology between January 2010 and May 2018 were retrospectively analyzed. Among them，6 patients underwent CT examination，3 underwent MRI examination，and 1 patient underwent both CT and MRI examinations. The size，morphologic features and contrast enhancement pattern of gallbladder tumors，and the presence of liver metastasis，bile duct and perihepatic metastasis，lymph node metastasis，and the presence of gallbladder stone were assessed.【Results】Among these 10 cases of gallbladder neuroendocrine tumor，the largest dimension of tumors ranged from 39 mm to 120 mm. The tumors manifest? ed as a mass protruding into the lumen with a broad base adhering to the wall of the gallbladder. In 7 patients who had undergone CT examination，the tumors manifested as an irregular mass with soft tissue density on CT. In 4 patients who had undergone MRI，the tumors showed homogeneous iso-intense signal on T1-weightedimaging，heterogenous hyper-intense signal on T2- weighted imaging，and limited diffusion on diffusion- weighted imaging. All tumors in 10 patients showed moderate，heterogeneous and persistent enhancement. Eight patients had liver metastasis，among whom 7 had metastases in liver segments 4 and 5，and 1 had multiple metastases in other liver segments. Six patients had bile duct invasion and 3 had hilar fat invasion. Seven patients had lymph node metastasis. One patient had gallstone.【Conclusion】Gallbladder neuroendocrine tumor has certain characteristic CT and MRI findings，such as a large mass in gallbladder，which tends to invade adjacent liver parenchyma，and extend along gallbladder neck and gallbladder ducts，accompanied with hepatic portal and retroperitoneal lymph node metastasis，and hilar fat invasion.

256-slice spiral CT manifestations and pathological analysis of gastrointestinal stromal tumors / 中国基层医药

Objective To analyze the CT manifestations of gastrointestinal stromal tumors(GIST),and compared with the pathological results,in order to improve the value of CT in clinical diagnosis of GIST.Methods 256 slice spiral CT manifestations of 35 cases with GIST confirmed by surgery and pathology were analyzed retrospectively.Results 30 cases with GIST tumors were located in the stomach,duodenum in 2 cases,ileum in 2 cases,1 case with multiple tumors (located in mesentery,retinal).The tumor size ranged from 1.0 to 11.2 cm.11 cases of lumps showed soft tissue mass,24 cases showed uneven density with cystic and necrosis,including 10 cases with ulceration in surface.There were 5 cases with hemorrhage,2 cases with scattered calcification.After enhancement scan,11 cases of tumors were homogeneous enhancement and 24 cases showed uneven enhancement.The solid composition was shown more rich blood supply,especially in the venous phase.There were 9 cases out of the digestive tract,22 cases in the digestive tract,4 cases were mixed growth.There were 35 cases with CD117 positive expression by immunohistochemistry,34 cases with CD34 positive expression.After postoperative pathological risk assessment,there were 21 cases with low risk malignant tumor,moderate malignant tumor in 7 cases,highly malignant tumor in 7 cases.Conclusion 256 layers spiral CT scan can accurately offer the morphology of gastrointestinal stromal tumor,location,size and internal structure,and evaluate the risk level of tumor,it is helpful for clinical preoperative treatment,and determination of the prognosis.

[The facial nerve study of multi-slice spiral computed tomography in congenital abnormality of external and middle ear].

Objective:Images of temporal bone are obtained on Siemens 64 slices spiral CT scanner with high resolution scanning to describe the course of facial nerve for better preoperative evaluation of CAEMA.Method:To describe the course of facial nerve on rectangular coordinate system from three silce on HRCT, 29 patients(35 ears) are enrolled in our study in ENT department from November 2005 to March 2007 in the second affiliated hospital of sun yan sen university, who are all diagnosed not acquired deformity but CAEME, associated with no congenital deformity syndromes and no middle ear or mastoid operations before. Patients with bilateral ears deformity are 6, and unilateral ears deformity are 23 (13 right and 10 left) in the study group. The control group is the normal ears of unilateral ear deformity.Result:In the study group, the shortest distance from FN tympanic segment to oval window is shorter than that of the normal group (P< 0.05). In CAEME of unilateral ears the FN mastoid segment displaces anteriorly about 2.7 mm, and in CAEME of bilateral ears displaces 3.0mm, compared with the normal ears (P< 0.05). The deformity degree of auricle has correlations with anteriorly displacement of facial nerve mastoid segment (P< 0.05).Conclusion:The FN mastoid segment is anteriorly displacement in both bilateral and unilateral ear deformity. The deformity degree of auricle has correlations with anteriorly displacement of facial nerve mastoid segment. The lateral displacement of facial nerve doesn't occur usually in CAEME. The shortest distance between oval window and tympanic segment of FN become shorter than normal ears.

[CT manifestations of squamous papilloma in adult nose, pharynx and throat].

Objective:Analyze the CT imaging characteristics of squamous papilloma in adult nose pharynx and throat to improve the diagnostic accuracy.Method:Retrospectively analyze clinical data and CT image data in 24 cases of squamous papilloma in adult nose, pharynx and throat, which were confirmed by endoscopic surgical pathology, and summarize CT imaging features including location, shape, enhancement, and its relationship with adjacent tissue, and so on.Result:The patients with squamous papilloma were characterized by diffusing thickening and uniform swelling of the mucosa of nose, pharynx and throat, narrowing near the cavity gap, swallow gap existing, and enhancement scanning manifested mild-to-moderate gradually uniform reinforcement (enhanced CT value with 20-45 HU), when accompanied with malignancy, apparent arterial enhancement (enhanced CT value >45 HU) was observed.Conclusion:The adult patients with papilloma of nose, pharynx and throat has special features in CT image, which can provide more information for clinical diagnosis.

[Computer-assisted anatomical evaluation of the nasal sinuses in 2-3 years old children].

Objective:To analyze the anatomical and developmental characteristics of nasal sinuses in 2-3 years old children.Method:Coronal CT scans of 62 cases (2-3 years old children) were studied with the imaging station. The gasification conditions of the sinuses were identified and measured.Result:The mean of the transverse and vertical diameters for the left side of the maxillary sinuse was (17.51±2.92)mm and (16.63±3.46)mm. Those for the right side were (17.28±2.51)mm and (17.24±3.72)mm. The mean for the left side of the anterior ethmoid sinus were (5.06±1.18)mm and (13.61±2.49)mm. Those for its right side were (5.00±1.45)mm and (13.64±2.30)mm. The mean for the left side of the posterior ethmoid sinus were (7.94±1.72)mm and (12.80±1.78)mm. Those for the right side were (7.88±1.85)mm and (12.64±.96)mm.96.77%(120 sides) of the sphenoid sinuses were developed. The mean for the left side of the sphenoid sinus were (7.38±3.11)mm and (8.67±3.14)mm. Those for the right side were (7.48±2.70)mm and (8.63±2.42)mm. 30.65% (38 sides) of the frontal sinuses were developed.Conclusion:The all nasal sinuses in 2-3 years old children have been already developed. The pneumatization of the frontal sinus was defined in some babies. It can help radiologist make correct diagnosis of paranasal sinuses in children.

Feasibility study of low concentration iso_osmolar contrast agent and low tube voltage for rabbit hepatic computed tomography perfusion scanning / 中华放射医学与防护杂志

Objective To investigate the feasibility of low-c oncentration iso_osmolar contrast agent together with low tube voltage and iterative reconstruction algorithm in rabbit liver computed tonography (CT) perfusion imaging.Methods A total of 15 bealthy New Zealand rabbits were scanned twice of liver CT perfusion scans each with 24 hours interval.The first scan (routine group) was acquired at 100 kV and 100 mAs with ultravist (370 mg/ml),while the second (double low group) was acquired at 80 kV and 100 mAs with iodixanol (270 mg/ml) at 24 hours after the first scan.The obtained images were reconstructed with filtered back projection (FBP) and adaptive iterative dose reduction (AIDR-3D)algorithms in the controlled and experimental groups,respectively.The perfusion parameters including hepatic artery perfusion(HAP),portal vein perfasion(PVP),hepatic perfusion index(HPI),and total liver perfusion(TLP) and image quality as image quality score,average CT value of abdomen aorta,signalto-noise ratio(SNR),carrier-to-noise ratio(CNR),and figure of merit(FOM) were compared used pair ttest or Mann-Whitney U-test between the two groups wherever appropriate.The effective radiation dose and iodine intake were also recorded and compared.Results The image quality and perfusion parameters had no significantly different between the two groups except for FOM.The effective radiation dose and iodine intake were 38.79％ and 27.03％ lower in the double low group.Conclusions Low concentration iso _osmolar contrast agent (iodixanol,270 mg/ml) together with low tube voltage (80 kV) helps to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

Analysis of characteristics of multi-slice spiral CT in primary splenic tumors / 中国基层医药

Objective To analyze the plain and enhanced features of multiple spiral CT in primary splenic tumors,and to evaluate the diagnostic value.Methods The spiral CT findings of 29 cases of splenic primary tumors proved by operation or biopsy were retrospectively analyzed.Results 23 cases of benign tumors (9 cases of splenic cyst,7 cases of hemangioma,3 cases of lymphangioma,2 cases of myofibroblastic tumor,hamartoma in 2 cases),clinical manifestations of mild abdominal discomfort or no symptoms;CT scan for spleen in single or multiple low density or mixed density mass.Hemangioma,wrong structure can show the tumor calcification spots,hamartoma with calcification or fat density.CT enhancement,no enhancement of splenic cyst,hemangioma and delayed enhancement,center filling;lymphangioma without slight strengthening or interval,myofibroblastic tumor or hamartoma to strengthen the characteristic of diversity.6 cases of malignant tumors (3 cases of lymphangioma,2 cases of lymphoma,1 case of malignant fibrous histiocytoma of angiosarcoma),malignant tumors had abdominal pain,weight loss and other symptoms,CT scan,spleen enlargement,mass was larger,the boundary was not clear,less calcification,can strengthen the CT,tumor metastasis;lymph enhanced slightly,angiosarcoma delayed enhancement,uneven enhancement of malignant fibrous histiocytoma.Conclusion Multi slice spiral CT scanning combined with enhancement has a high diagnostic value for primary splenic tumors.

Computed tomography in the diagnosis of portal venous and intestinal wall gas in patients with ischemic bowel disease / 中华肝胆外科杂志

Objective To investigate radiological features on computed tomography (CT) in the di agnosis of portal venous and intestinal wall gas in patients with ischemic bowel disease.Methods The clinic-pathological data of 17 patients with portal venous and intestinal gas associated with ischemic bowel diseases from Wenzhou People's Hospital (n =6),Yueqing People's Hospital (n =5),Shanghai Xuhui Dahua Hospital (n =3) and the Second Affiliated Hospital of Wenzhou Medical University (n =3) from January 2013 to October 2016 were analysed retrospectively.All the patients have been fasting for 8 h prior to CT scans.Enhanced CT study was performed following routine CT with no abdominal pressure for breath less scanting.Portal venous gas,intestinal wall gas,intestinal thickness and density,mesentery thickness,celiac effusion,and severity of intestinal wall enhancement were recorded.Results All the 17 patients ex perienced abdominal distension and pain.Additionally,nausea and vomiting was observed in 9 patients,di arrhea in 7,melena in 7,periumbilical tenderness in 11 and rebound tenderness in 8.CT scans of these 17 patients showed portal venous gas,including massiveprune-tree signs of hepatic vein and portal vein (n =11) and scanty gas shadows in distal hepatic vein (n =6).Intestinal gas sign was determined in all these patients (n =17),including single bubble shadow (n =8),multiple bubble shadow (n =7),and band-shaped bubble (n =2).Furthermore,CT study indicated extensive intestinal wall thickening with edema (n =13),predominate luminal extension of thinner bowels (n =4),scanty celiac effusion (n =3).Enhanced CT scans demonstrated 8 patients with decreased enhancement of intestinal wall and mesentery with diseases,target and halo signs observed in enhanced scans.Conclusions Portal venous and intestinal wall gas may demonstrate distinctive CT imaging.CT study could have superior sensitivity and spe cialty in clinical diagnoses of ischemic bowel diseases.