ObjectiveTo analyze the relationship between image development types and delay time in computed tomography urography (CTU) examination and to investigate the value of choosing reasonable delay time to get the best images. MethodWe collected the data of 62 patients who underwent multi-slice CTU examination without fully developed images within 8 minutes from January 2010 to May 2014. There were 35 unilateral and 27 bilateral delayed imaging patients with a total of 89 cases. According to the degree of imaging development after the delayed 8 minutes, we divided it into 4 levels as follows:level 0 (no development), levelⅠ (light development), levelⅡ (partial development) and levelⅢ (full development). LevelⅢ was not included in this study. For level 0 to levelⅡ, we delayed scan for 15 to 1 440 minutes. ResultsAs the imaging development degree decreased, the delay time obviously extended. LevelⅡ could be fully displayed after 15 to 150 minutes of delayed scan. LevelⅠ could be fully displayed after 150 to 720 minutes. Level 0 still had no imaging development after 120 minutes, so there was no need to continue scanning. ConclusionsSelecting appropriate delay time of CTU based on the type of delayed imaging development can avoid unnecessary repeated delay scans, get the best development images, and estimate the kidney secretion functions, which is most helpful for accurate diagnosis of urinary system related diseases.
Objective To summarize the imaging manifestation and identification of ectopic pancreas (EP), so as to improve clinicians and radiologists’ knowledge of EP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate and avoiding unnecessary surgery. Methods Combined with clinical experience and relevant literatures in recent years, the histopathology, common imaging manifestations and main differential diagnosis of ectopic pancreas were summarized. Results EP is a rare congenital developmental anomaly of pancreas, the most common location is the upper digestive system. At present, the commonly used imaging technology is computed tomography. The imaging findings of ectopic pancreas were similar to those of normal pancreas, and its density and enhancement characteristics were related to its histopathological composition. The specific signs of ectopic pancreas include “central umbilical sign” “ductal structure” and “flat/adherent sign”. Heterotopic pancreas should be differentiated from submucosal tumor of gastrointestinal tract. Conclusions The imaging findings of EP have certain characteristics. For some cases with atypical imaging findings, imaging diagnosis is difficult.
ObjectiveTo investigate the radiomics features to distinguish invasive lung adenocarcinoma with micropapillary or solid structure. MethodsA retrospective analysis was conducted on patients who received surgeries and pathologically confirmed invasive lung adenocarcinoma in our hospital from April 2016 to August 2019. The dataset was randomly divided into a training set [including a micropapillary/solid structure positive group (positive group) and a micropapillary/solid structure negative group (negative group)] and a testing set (including a positive group and a negative group) with a ratio of 7∶3. Two radiologists drew regions of interest on preoperative high-resolution CT images to extract radiomics features. Before analysis, the intraclass correlation coefficient was used to determine the stable features, and the training set data were balanced using synthetic minority oversampling technique. After mean normalization processing, further radiomics features selection was conducted using the least absolute shrinkage and selection operator algorithm, and a 5-fold cross validation was performed. Receiver operating characteristic (ROC) curves were depicted on the training and testing sets to evaluate the diagnostic performance of the radiomics model. ResultsA total of 340 patients were enrolled, including 178 males and 162 females with an average age of 60.31±6.69 years. There were 238 patients in the training set, including 120 patients in the positive group and 118 patients in the negative group. There were 102 patients in the testing set, including 52 patients in the positive group and 50 patients in the negative group. The radiomics model contained 107 features, with the final 2 features selected for the radiomics model, that is, Original_ glszm_ SizeZoneNonUniformityNormalized and Original_ shape_ SurfaceVolumeRatio. The areas under the ROC curve of the training and the testing sets of the radiomics model were 0.863 (95%CI 0.815-0.912) and 0.857 (95%CI 0.783-0.932), respectively. The sensitivity was 91.7% and 73.7%, the specificity was 78.8% and 84.0%, and the accuracy was 85.3% and 78.4%, respectively. ConclusionThere are differences in radiomics features between invasive pulmonary adenocarcinoma with or without micropapillary and solid structures, and the radiomics model is demonstrated to be with good diagnostic value.
ObjectiveTo explore the application of pulmonary ventilation and perfusion imaging (V/P SPECT/CT) in quantitative evaluation of ventilation and perfusion function and its potential value in guiding local treatment of lung in patients with asthma.MethodsA total of 20 patients with asthma were included in this study. All patients underwent V/P SPECT/CT and pulmonary function test, and symptoms were assessed by the ACT questionnaire. Patients were graded for degree of airway obstruction according to V/ P SPECT/CT image visual scoring criteria. The comprehensive lung function (%) of the patients was quantitatively evaluated by combining the ventilation and perfusion defect of each lung segment in V/P imaging. The correlation between the degree of airway obstruction, comprehensive lung function, pulmonary function test and ACT score was analyzed.ResultsV/P SPECT/CT imaging can be used to grade the degree of airway obstruction in asthma patients (0-3 grade). Airway obstruction grading by V/P SPECT/CT visual score was associated with predictive forced expiratory volume in one second (FEV1%pred) of patients (r=–0.74, P<0.001). V/P SPECT/CT can also comprehensively evaluate ventilation and perfusion function in patients with asthma, and comprehensive lung function measured by this method was also correlated with FEV1%pred (r=0.629, P=0.003). V/P SPECT/CT can be used to quantitatively analyze the percentage of ventilation and perfusion function in each lung lobe. Compared with V/P SPECT/CT results, the CT volume overestimates the contribution in the upper lobes, and underestimates the lower lobes contribution to overall function.ConclusionsV/P SPECT/CT can be used as a new method to directly reflect the degree of airway obstruction in patients with asthma. Moreover, it can comprehensively and quantitatively evaluate the ventilation and perfusion function of asthma patients. V/P SPECT/CT can also be used to evaluate lobe function in patients with asthma, helping to identify the heterogeneity of changes in pulmonary function in patients with asthma, and has potential value for future treatment targeting specific areas of the lung.
According to the inclusion and exclusion criteria, we searched for relevant original articles in some big Chinese and English databases.The qualities of the studies were evaluated with QUADAS quality assessment tool. A software program, Meta-disc, was used to obtain the pooled estimates and heterogeneity test for sensitivity, specificity, SROC curve, and so on. Finally the 17 article were included. On a per-patient basis, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (LR+), negative likelihood ratio (LR-), diagnostic odds ratio (DOR), Q*, SROC area under curve for 99mTc-MDP bone scan and computed tomography (CT) were 0.87 and 0.99, 0.81 and 0.98, 3.88 and 13.86, 0.2 and 0.03, 27.73 and 612.17, 0.8418 and 0.9732, 0.9097 and 0.9952, respectively. On a per-focus basis, the pooled SEN, SPE, LR+, LR-, DOR, Q*, SROC area under curve for 99mTc-MDP bone scan was 0.86, 0.97, 13.32, 0.16, 102.4, 0.8944, 0.9528, respectively. For CT, only 1 article were included. This paper demonstrate: whether 99mTc-MDP or CT both have high diagnostic efficiency for bone metastase of breast cancer.
In recent years, photon-counting computed tomography (PCD-CT) based on photon-counting detectors (PCDs) has become increasingly utilized in clinical practice. Compared with conventional CT, PCD-CT has the potential to achieve micron-level spatial resolution, lower radiation dose, negligible electronic noise, multi-energy imaging, and material identification, etc. This advancement facilitates the promotion of ultra-low dose scans in clinical scenarios, potentially detecting minimal and hidden lesions, thus significantly improving image quality. However, the current state of the art is limited and issues such as charge sharing, pulse pileup, K-escape and count rate drift remain unresolved. These issues could lead to a decrease in image resolution and energy resolution, while an increasing in image noise and ring artifact and so on. This article systematically reviewed the physical principles of PCD-CT, and outlined the structural differences between PCDs and energy integration detectors (EIDs), and the current challenges in the development of PCD-CT. In addition, the advantages and disadvantages of three detector materials were analysed. Then, the clinical benefits of PCD-CT were presented through the clinical application of PCD-CT in the three diseases with the highest mortality rate in China (cardiovascular disease, tumour and respiratory disease). The overall aim of the article is to comprehensively assist medical professionals in understanding the technological innovations and current technical limitations of PCD-CT, while highlighting the urgent problems that PCD-CT needs to address in the coming years.
ObjectiveTo analyze and conclude CT and MRI imaging features of ectopic pancreas in gastrointestinal tract so as to improve the understanding of the features.MethodsThe clinical, imaging, and pathological data of 12 patients with ectopic pancreas in the gastrointestinal tract confirmed by the pathology in the Sichuan Provincial People’s Hospital from November 2016 to June 2019 were retrospectively analyzed. The characteristics of image presentation were summarized.Results① The anatomical distribution: all patients had a single lesion. Of the 12 cases, 6 cases located in the gastric body lesser curvature, 3 cases located in the gastric angle, 1 case located in the posterior wall of gastric antrum, 1 case occurred in the upper jejunum, and 1 case occurred in the terminal ileum; 8 cases located in the submucosa, 2 cases located in the submucosa and muscular layer simultaneously, 1 case located in the submucosa, muscular and serous layer simultaneously, and 1 case located in the muscular layer. ② Size of the lesions: the maxium dimensions of the lesions were all 3 cm or less, and the long axes of the lesions were parallel to the gastrointestinal tract wall in 10 cases. ③ The internal characteristics: the results of 9 of 11 cases showed the isodensity compared to main pancreas on the plain CT scan. The results of 8 patients with enhanced CT showed the moderate to obvious enhancement, with 2 cases showed the slightly enhanced flaky or tube-like foci. In the arterial phase and portal venous phase, 6 cases showed the isodensity compared to main pancreas respectively. The result of MRI in 1 patient showed the isointensity compared to main pancreas on the plain scan and obviously heterogeneous enhancement.ConclusionCT and MRI could provide some information about location, size, and internal density or intensity of ectopic pancreas, and could be helpful for diagnosis.
Objective To investigate the CT and MR imaging manifestation of rare pancreatic tumors in order to deepen the understanding of their imaging characteristics and improve the diagnostic accuracy. Methods Clinical and image date of 34 cases with rare pancreatic tumors proved by surgery and histopathologically were analyzed retrospectively. Including neuroendocrine tumors of the pancreas (NETP,n=13), solid-pseudopapillary tumors of pancreas (SPTP,n=10), intraductal papillary mucinous neoplasms (IPMN,n=2), serous cystadenoma (SCA,n=7), and mucinous cystadenoma (MCA,n=2). Examined by CT in 19 cases, by MRI in 11 cases, examined by CT and MRI at the same time in 4 cases. The characterized imaging features of each kind of tumors were analyzed emphatically. Results Of the 13 cases of NETP, solid lesions in 6 cases, predominantly soild in 4 cases, predominantly cystic in 3 cases. Homogenous enhancement in 6 cases, heterogeneous enhancement in 7cases, the soild constituent of all cases were showed moderate to marked enhancement. Of the 10 cases of SPTP, predominantly soild in 2 cases, soild and cystic in 5 cases, predominantly cystic in 3 cases. The solid part of 10 cases presented as gradually enhancement, 2 cases appeared hemorrhage, 1 case appeared stippled calcification. Of the 2 cases of IPMN, both of them were combined type, showed multilocular cystic tumors due to the dilated of the pancreatic duct. Of the 7 cases of SCA, microcystic partten in 3 cases and single cyst partten in 4 cases, showed unilocular or multilocular cystic with clear boundary. The 2 cases of MCA, showed unilocular cystic with clear boundary. Conclusion Different histological types of pancreatic rare tumor appeared different kinds of imaging characteristic, we may improve the diagnostic accuracy by analyzing their features.
ObjectiveTo summarize the research progress of CT related to esophageal varices of cirrhotic patients complicated with portal hypertension.MethodsRelevant CT literatures of esophageal varices of cirrhotic patients complicated with portal hypertension were collected to make an review,then summarized the research status and progress of CT in the diagnosis and evaluation of lower esophageal varices.ResultCT had a good correlation with endoscopic diagnosis of esophageal varices, and CT was of great value in evaluating the presence, degree, and risk of esophageal varicose veins, especially in predicting the risk of esophageal varicose veins, which could be used as an effective modality to assist endoscopic examination to a certain extent.ConclusionsCT is an important examination method for esophageal varices, which has important value in diagnosis and evaluation. In the future, more further researches can be carried out to provide more strong and accurate support for the diagnosis and treatment of esophageal varices.
ObjectiveTo summarize the methods and research progress of imaging evaluation of liver iron concentration.MethodsThe current status and progress of different imaging techniques in liver iron overload research were reviewed by studying the relevant literatures at home and abroad. The methods for determining liver iron concentration and their advantages and disadvantages were summarized.ResultsThe imaging methods for determining liver iron concentration mainly included traditional non-enhanced CT and dual energy CT examination, magnetic resonance signal intensity ratio, relative signal intensity index, T2 and R2 values, magnetic resonance spectroscopy, T2* and R2* values, susceptibility weighted imaging, and quantitative susceptibility mapping.ConclusionLiver iron quantification imaging method, including dual-energy CT and magnetic resonance imaging could non-invasively and accurately assess the liver iron overload.