Prospective validation of the role of PET/CT in detecting disease after neoadjuvant chemotherapy in advanced ovarian cancer.

OBJECTIVES: The study aimed to compare the diagnostic accuracies of 2-[18F]FDG PET/CT and contrast-enhanced CT (ceCT) after neoadjuvant chemotherapy (NACT) in advanced ovarian cancer (OC). MATERIALS AND METHODS: This study consisted historical observational cohort and prospective validation cohort. Patients with newly diagnosed stage III-IV OC scheduled for NACT were recruited, with imaging performed after three to six cycles of NACT before interval debulking surgery. Nineteen regions in the abdominopelvic cavity were scored for the presence and absence of disease, referenced to the intra-operative findings or histological specimens. Diagnostic metrics were compared using McNemar's test. RESULTS: In the historical cohort (23 patients, age 58 ± 13), 2-[18F]FDG PET had an overall accuracy (Acc) 82%, sensitivity (Sen) 38%, specificity (Spe) 97%, positive predictive value (PPV) 79% and negative predictive value (NPV) 82%; ceCT had an overall Acc 86%, Sen 64%, Spe 93%, PPV 75% and NPV 89%. In the prospective cohort (46 patients, age 59 ± 9), 2-[18F] FDG PET had an overall Acc 87%, Sen 48%, Spe 98%, PPV 84% and NPV 88%; ceCT had an overall Acc 89%, Sen 66%, Spe 95%, PPV 77% and NPV 91%. No significant difference was demonstrated between the two imaging modalities (p > 0.05). High false-negative rates were observed in the right subdiaphragmatic space, omentum, bowel mesentery and serosa. High omental metabolic uptake after NACT was associated with histological non-responders (p < 0.05). CONCLUSION: 2-[18F]FDG PET/CT had no additional value over ceCT with comparable diagnostic accuracy in detecting disease after NACT in advanced OC. CLINICAL RELEVANCE STATEMENT: 2-[18F]FDG PET/CT is not superior to contrast-enhanced CT in determining disease after neoadjuvant chemotherapy in advanced ovarian cancer; contrast-enhanced CT should be suffice for surgical planning before interval debulking surgery. KEY POINTS: • Additional value of 2-[18F]FDG PET/CT over contrast-enhanced CT is undefined in detecting disease after neoadjuvant chemotherapy. • 2-[18F]FDG PET/CT has comparable diagnostic accuracy compared to contrast-enhanced CT. • Contrast-enhanced CT will be suffice for surgical planning after neoadjuvant chemotherapy.

MRI with DWI improves detection of liver metastasis and selection of surgical candidates with pancreatic cancer: a systematic review and meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis to evaluate if magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) adds value compared to contrast-enhanced computed tomography (CECT) alone in the preoperative evaluation of pancreatic cancer. METHODS: MEDLINE, EMBASE, and Cochrane databases were searched for relevant published studies through October 2022. Studies met eligibility criteria if they evaluated the per-patient diagnostic performance of MRI with DWI in the preoperative evaluation of newly diagnosed pancreatic cancer compared to CECT. Our primary outcome was the number needed to treat (NNT) to prevent one futile surgery using MRI with DWI, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis (i.e., surgical intervention in metastatic disease missed by CECT). The secondary outcomes were to determine the diagnostic performance and the NNT of MRI with DWI to change management in pancreatic cancer. RESULTS: Nine studies met the inclusion criteria with a total of 1121 patients, of whom 172 had liver metastasis (15.3%). The proportion of futile surgeries reduced by MRI with DWI was 6.0% (95% CI, 3.0-11.6%), yielding an NNT of 16.6. The proportion of cases that MRI with DWI changed management was 18.1% (95% CI, 9.9-30.7), corresponding to an NNT of 5.5. The per-patient sensitivity and specificity of MRI were 92.4% (95% CI, 87.4-95.6%) and 97.3% (95% CI, 96.0-98.1). CONCLUSION: MRI with DWI may prevent futile surgeries in pancreatic cancer by improving the detection of occult liver metastasis on preoperative CECT with an NNT of 16.6. CLINICAL RELEVANCE STATEMENT: MRI with DWI complements the standard preoperative CECT evaluation for liver metastasis in pancreatic cancer, improving the selection of surgical candidates and preventing unnecessary surgeries. KEY POINTS: • The NNT of MRI with DWI to prevent potential futile surgeries due to occult liver metastasis on CECT, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis, in patients with pancreatic cancer was 16.6. • The higher performance of MRI with DWI to detect liver metastasis occult on CECT can be attributed to an increased detection of subcentimeter liver metastasis.

A cycle generative adversarial network for generating synthetic contrast-enhanced computed tomographic images from non-contrast images in the internal jugular lymph node-bearing area.

The objectives of this study were to create a mutual conversion system between contrast-enhanced computed tomography (CECT) and non-CECT images using a cycle generative adversarial network (cycleGAN) for the internal jugular region. Image patches were cropped from CT images in 25 patients who underwent both CECT and non-CECT imaging. Using a cycleGAN, synthetic CECT and non-CECT images were generated from original non-CECT and CECT images, respectively. The peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) were calculated. Visual Turing tests were used to determine whether oral and maxillofacial radiologists could tell the difference between synthetic versus original images, and receiver operating characteristic (ROC) analyses were used to assess the radiologists' performances in discriminating lymph nodes from blood vessels. The PSNR of non-CECT images was higher than that of CECT images, while the SSIM was higher in CECT images. The Visual Turing test showed a higher perceptual quality in CECT images. The area under the ROC curve showed almost perfect performances in synthetic as well as original CECT images. In conclusion, synthetic CECT images created by cycleGAN appeared to have the potential to provide effective information in patients who could not receive contrast enhancement.

Comparison of [18F]-OC PET/CT and contrast-enhanced CT/MRI in the detection and evaluation of neuroendocrine neoplasms.

OBJECTIVES: Gallium-68 (68Ga)-labeled somatostatin analog (SSA) PET imaging has been widely used in clinical practice of neuroendocrine neoplasms (NENs). Compared with 68Ga, 18F has a great practical and economic advantage. Although a few studies have shown the characteristics of [18F] AlF-NOTA-octreotide ([18F]-OC) in healthy volunteers and small NEN patient groups, its clinical value needs further investigation. Herein, this retrospective study aimed to evaluate the diagnostic accuracy of [18F]-OC PET/CT in detecting NENs, as well as to compare it with contrast-enhanced CT/MRI. METHODS: We retrospectively reviewed the data of 93 patients who had undergone [18F]-OC PET/CT and CT or MRI scans. Of these patients, there were 45 patients with suspected NENs for diagnostic evaluation, and 48 patients with pathologically confirmed NENs for detecting metastasis or recurrence. [18F]-OC PET/CT images were evaluated visually and semi-quantitatively by measuring maximum standardized uptake value of tumor (SUVmax), tumor-to-background SUVmax ratio (TBR), and SUVmax of hypophysis (SUVhypophysis). A total of 276 suspected NEN lesions were found in these 93 patients. The results of histopathology or radiographic follow-up served as the reference standard for the final diagnosis. RESULTS: Forty-five patients with suspected NENs were confirmed by histopathological examination via resection or biopsy. [18F]-OC PET/CT showed high radiotracer uptake in the lesions of G1-G3 NENs. [18F]-OC PET/CT showed superior performance with 96.3% of sensitivity, 77.8% of specificity, and 88.9% of accuracy in diagnosing NENs compared to CT/MRI. When cutoffs of SUVmax, TBR, and SUVhypophysis were 8.3, 3.1, and 15.4, [18F]-OC PET/CT had the best equilibrium between sensitivity and specificity for differentiating NEN from non-NEN lesions. For a total of 276 suspected NEN lesions, the sensitivity, specificity, and accuracy of [18F]-OC PET/CT for diagnosis of NENs were 90.5%, 82.1%, and 88.8%, respectively, and were higher than those of CT and MRI. G1 and G2 NENs had higher TBR and lower CT enhancement intensity than G3. The SUVmax and TBR had a positive correlation with CT enhancement intensity in G2 rather than in G1 or G3. CONCLUSIONS: [18F]-OC PET/CT is a promising imaging modality for initial diagnosis and detecting metastasis or postoperative recurrence in NENs.

Radiomics nomogram for preoperative differentiation of pulmonary mucinous adenocarcinoma from tuberculoma in solitary pulmonary solid nodules.

OBJECTIVE: To develop and validate predictive models using clinical parameters, radiomic features and a combination of both for preoperative differentiation of pulmonary nodular mucinous adenocarcinoma (PNMA) from pulmonary tuberculoma (PTB). METHOD: A total of 124 and 53 patients with PNMA and PTB, respectively, were retrospectively analyzed from January 2017 to November 2022 in The Fourth Affiliated Hospital of Hebei Medical University (Ligang et al., A machine learning model based on CT and clinical features to distinguish pulmonary nodular mucinous adenocarcinoma from tuberculoma, 2023). A total of 1037 radiomic features were extracted from contrast-enhanced computed tomography (CT). The patients were randomly divided into a training group and a test group at a ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) algorithm was used for radiomic feature selection. Three radiomics prediction models were applied: logistic regression (LR), support vector machine (SVM) and random forest (RF). The best performing model was adopted, and the radiomics score (Radscore) was then computed. The clinical model was developed using logistic regression. Finally, a combined model was established based on clinical factors and radiomics features. We externally validated the three models in a group of 68 patients (46 and 22 patients with PNMA and PTB, respectively) from Xing Tai People's Hospital (30 and 14 patients with PNMA and PTB, respectively) and The First Hospital of Xing Tai (16 and 8 patients with PNMA and PTB, respectively). The area under the receiver operating characteristic (ROC) curve (AUC) value and decision curve analysis were used to evaluate the predictive value of the developed models. RESULTS: The combined model established by the logistic regression method had the best performance. The ROC-AUC (also a decision curve analysis) of the combined model was 0.940, 0.990 and 0.960 in the training group, test group and external validation group, respectively, and the combined model showed good predictive performance for the differentiation of PNMA from PTB. The Brier scores of the combined model were 0.132 and 0.068 in the training group and test group, respectively. CONCLUSION: The combined model incorporating radiomics features and clinical parameters may have potential value for the preoperative differentiation of PNMA from PTB.

Construction of a radiogenomic association map of pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) persists as a malignancy with high morbidity and mortality that can benefit from new means to characterize and detect these tumors, such as radiogenomics. In order to address this gap in the literature, constructed a transcriptomic-CT radiogenomic (RG) map for PDAC. METHODS: In this Institutional Review Board approved study, a cohort of subjects (n = 50) with gene expression profile data paired with histopathologically confirmed resectable or borderline resectable PDAC were identified. Studies with pre-operative contrast-enhanced CT images were independently assessed for a set of 88 predefined imaging features. Microarray gene expression profiling was then carried out on the histopathologically confirmed pancreatic adenocarcinomas and gene networks were constructed using Weighted Gene Correlation Network Analysis (WCGNA) (n = 37). Data were analyzed with bioinformatics analyses, multivariate regression-based methods, and Kaplan-Meier survival analyses. RESULTS: Survival analyses identified multiple features of interest that were significantly associated with overall survival, including Tumor Height (P = 0.014), Tumor Contour (P = 0.033), Tumor-stroma Interface (P = 0.014), and the Tumor Enhancement Ratio (P = 0.047). Gene networks for these imaging features were then constructed using WCGNA and further annotated according to the Gene Ontology (GO) annotation framework for a biologically coherent interpretation of the imaging trait-associated gene networks, ultimately resulting in a PDAC RG CT-transcriptome map composed of 3 stage-independent imaging traits enriched in metabolic processes, telomerase activity, and podosome assembly (P < 0.05). CONCLUSIONS: A CT-transcriptomic RG map for PDAC composed of semantic and quantitative traits with associated biology processes predictive of overall survival, was constructed, that serves as a reference for further mechanistic studies for non-invasive phenotyping of pancreatic tumors.

Presumed radiological diagnosis of solid pseudopapillary tumors: do we really know what we are watching?

OBJECTIVES: Little is known about the clinicians' ability to ascertain the identity of a pancreatic lesion as solid pseudopapillary tumors (SPT)preoperatively. We led this retrospective study to figure out the disease spectrum that mimic SPT, the key features of SPT and the accuracy of CT and MRI in characterizing them. METHODS: Radiological and clinical database at a tertiary pancreatic disease center (Peking Union Medical College Hospital) was searched for patients who received CT or MRI with a presumed radiological diagnosis of SPT. Those patients' clinical information and final pathological diagnosis were collected. RESULTS: During 2018.10-2021.12, 200 patients had a presumed radiological diagnosis of SPT, and 132 of them had unambiguous pathological diagnosis. SPT were confirmed in only 63.6% (84/132), while the others had a variety of neoplastic and nonneoplastic lesions, including pancreatic neuroendocrine tumors (n = 15), pseudocysts (n = 4), mucinous cystic neoplasms (n = 4), serous cystadenomas (n = 3), neural sheath tumors (n = 3), lymphoepithelial cysts (n = 2), and several very rare pathologies (n = 17). Of note, 11.4% (15/132) of those were benign or nonneoplastic lesions, while 6.8% (9/132) were neoplasms with highly aggressive nature, or pancreatic metastases, which require systematic evaluation and staging instead of upfront surgery. Retrospective radiological analysis based on key imaging features, clinical history and laboratory findings had an improved diagnostic accuracy of 78.5% with CT and 77.8% with MRI. CONCLUSIONS: There is a broad disease spectrum mimicking SPT at CT and MRI. Key imaging features, clinical information and laboratory findings must be integrated to improve the diagnostic accuracy.

Machine learning-based radiomics analysis of preoperative functional liver reserve with MRI and CT image.

OBJECTIVE: The indocyanine green retention rate at 15 min (ICG-R15) is a useful tool to evaluate the functional liver reserve before hepatectomy for liver cancer. Taking ICG-R15 as criteria, we investigated the ability of a machine learning (ML)-based radiomics model produced by Gd-EOB-DTPA-enhanced hepatic magnetic resonance imaging (MRI) or contrast-enhanced computed tomography (CT) image in evaluating functional liver reserve of hepatocellular carcinoma (HCC) patients. METHODS: A total of 190 HCC patients with CT, among whom 112 also with MR, were retrospectively enrolled and randomly classified into a training dataset (CT: n = 133, MR: n = 78) and a test dataset (CT: n = 57, MR: n = 34). Then, radiomics features from Gd-EOB-DTPA MRI and CT images were extracted. The features associated with the ICG-R15 classification were selected. Five ML classifiers were used for the ML-model investigation. The accuracy (ACC) and the area under curve (AUC) of receiver operating characteristic (ROC) with 95% confidence intervals (CI) were utilized for ML-model performance evaluation. RESULTS: A total of 107 different radiomics features were extracted from MRI and CT, respectively. The features related to ICG-R15 which was classified into 10%, 20% and 30% were selected. In MRI groups, classifier XGBoost performed best with its AUC = 0.917 and ACC = 0.882 when the threshold was set as ICG-R15 = 10%. When ICG-R15 = 20%, classifier Random Forest performed best with AUC = 0.979 and ACC = 0.882. When ICG-R15 = 30%, classifier XGBoost performed best with AUC = 0.961 and ACC = 0.941. For CT groups, the classifier XGBoost performed best when ICG-R15 = 10% with AUC = 0.822 and ACC = 0.842. When ICG-R15 = 20%, classifier SVM performed best with AUC = 0.860 and ACC = 0.842. When ICG-R15 = 30%, classifier XGBoost performed best with AUC = 0.938 and ACC = 0.965. CONCLUSIONS: Both the MRI- and CT-based machine learning models are proved to be valuable noninvasive methods for functional liver reserve evaluation.

Simultaneous spatial and temporal regularization in low-dose dynamic contrast-enhanced CT cerebral perfusion studies.

PURPOSE: To apply total generalized variation (TGV) and its combination with low-rank and sparse decomposition (LRSD) (LTGV) to cerebral perfusion studies using low-dose dynamic contrast-enhanced (DCE) CT and to quantitatively evaluate their performances through comparisons with those without any regularizers and those of total variation (TV) and its combination with LRSD (LTV) using simulation and clinical data. METHODS: The simulation study used a realistic digital brain phantom. Low-dose DCE-CT images were reconstructed using the regularizers and primal-dual algorithm. Subsequently, cerebral perfusion parameter (CPP) images were generated from them. Thereafter, their quality was evaluated based on the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). Further, the accuracy of CPP estimation was evaluated through a linear regression analysis between the CPP values obtained by the above regularizers and those obtained from the noise-free DCE-CT images. In addition, the mean and standard deviation of the CPP were calculated (region analysis). In the clinical study, low-dose DCE-CT images were generated using normal-dose images acquired from a patient, and CPP images were generated from them similar to that in the simulation study. RESULTS: When using LTV and LTGV, both PSNR and SSIM were higher than those of the other methods with increasing regularization parameter values. The results of the linear regression and region analyses demonstrated that TGV generally exhibited the best performance, followed by LTGV, and finally that of TV was significantly different from those of the other regularizers. Despite an overall consistency between the simulation and clinical results, certain inconsistencies appeared owing to the difference in generating low-dose DCE-CT images. CONCLUSIONS: The results implied that TGV and LTGV were useful in improving the accuracy of CPP estimation using low-dose DCE-CT. This study provides an improved understanding of the performance of regularizers and is expected to aid in the selection of a suitable regularizer for low-dose DCE-CT perfusion studies.

Association between acute adverse reactions to iodinated contrast media and anxiety in patients undergoing contrast-enhanced CT examination. / CTå¢žå¼ºæ£€æŸ¥ä¸­ç¢˜å¯¹æ¯”å‰‚æ€¥æ€§ä¸è‰¯ååº”ä¸Žç„¦è™‘çŠ¶æ€çš„ç›¸å ³æ€§.

OBJECTIVES: As the use of iodinated contrast media has become more widely with advances in imaging, several guidelines have suggested that anxiety increases the risk of acute adverse reactions associated with iodinated contrast media. This study aims to evaluate the impact of anxiety on the occurrence of acute adverse reactions (AAR) to iodinated contrast media in patients undergoing contrast-enhanced CT examinations. METHODS: Inpatients who underwent contrast-enhanced CT examinations at the Third Xiangya Hospital between February and October 2021 were prospectively recruited. Prior to the imaging examinations, all patients completed the Generalized Anxiety Disorder Scale-7 (GAD-7) assessment before the imaging examinations to determine the severity of anxiety, which was categorized as mild, moderate, or severe. Based on the occurrence of AAR, patients were classified into an AAR group and a non-AAR group. The difference in anxiety was compared between the 2 groups. Multivariate logistic regression analysis was used to identify independent risk factors associated with AAR. To ensure comparability between the 2 groups, propensity score matching (PSM) was utilized to align the clinical characteristics. Subsequently, the difference in anxiety within the matched groups was analyzed. RESULTS: The study comprised 880 patients, with 80 patients in the AAR group and 800 patients in the non-AAR group. There was a significant difference in proportion of patients with mild-severe anxiety between the 2 groups (75% in the AAR group and 36% in the non-AAR group, P<0.001). Additionally, differences were also observed in occupation, income, underlying diseases, and allergy history (all P<0.001). The results of multivariate logistic regression analysis revealed that patients' income, allergy history, and anxiety were independent risk factors for AAR to iodinated contrast media (all P<0.05). Following PSM, each matched group included 66 cases, and no significant differences in clinical characteristics were observed between the 2 groups (all P>0.05). However, the proportion of patients with mild-severe anxiety remained significantly higher in the AAR group compared to the non-AAR group (75% in the AAR group and 31% in the non-AAR group, P<0.001). CONCLUSIONS: Anxiety is associated with an increased risk of AAR to iodinated contrast media in patients undergoing contrast-enhanced CT examinations, suggesting the clinical importance of screening for anxiety before imaging examinations.

Diagnosis and staging of cardiac masses: additional value of CMR with 18F-FDG-PET compared to CMR with CECT.

PURPOSE: Characterization of malignant cardiac masses is usually performed with cardiac magnetic resonance (CMR) and staging with whole-body contrast-enhanced computed tomography (CECT). In this study, our objective was to evaluate the role of 18Fluor-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) with CMR for both characterization and staging of cardiac masses. METHODS: Patients with cardiac masses who underwent CMR, CECT, and 18F-FDG-PET were retrospectively identified. For the characterization of cardiac masses, we calculated the respective performances of CMR alone, 18F-FDG-PET alone, and the combination of 18F-FDG-PET and CMR. For staging, we compared head-to-head the respective performances of 18F-FDG-PET and CECT. Histology served as gold standard for malignancy, and response to anticoagulation for thrombus. RESULTS: In a total of 28 patients (median age 60.5 years, 60.7% women), CMR accurately distinguished malignant from benign masses with sensitivity (Se) of 86.7%, specificity (Sp) of 100%, positive predictive value (PPV) of 100%, negative predictive value (NPV) of 86.7%, and accuracy of 92.9%. 18F-FDG-PET demonstrated 93.3% Se, 84.6% Sp, 87.5% PPV, 91.7% NPV, and 89.3% accuracy. Combining CMR with 18F-FDG-PET allowed to benefit from the high sensitivity of 18F-FDG-PET (92.9%) and the excellent specificity of CMR (100%) for malignant diseases. For staging, 18F-FDG-PET outperformed CECT on per-patient (66.7% vs 55.6% correct diagnosis, respectively), per-organ (10 vs 7 organs, respectively), and per-lesion basis (> 29 vs > 25 lesions, respectively). CONCLUSION: Combining 18F-FDG-PET with CMR improved the characterization of cardiac masses compared to each modality alone. Additionally, the diagnostic performance of 18F-FDG-PET was better than CECT for staging. This study suggests that the combination of CMR and 18F-FDG-PET is the most effective for the characterization of cardiac masses and the staging of these lesions.

Rapid identification of source of delayed hemobilia following endoscopic metallic stenting for malignant biliary obstruction.

Delayed hemobilia, a rare but potentially fatal complication of endoscopic metallic stenting for malignant biliary obstruction, requires prompt identification of the source of bleeding and subsequent embolization. However, hemobilia is characteristically intermittent, and computed tomography (CT) often fails to show pseudoaneurysms or extravasations. In particular, because the posterior superior pancreaticoduodenal artery (PSPDA) runs alongside the common bile duct for its whole length, it is readily obscured by metallic artifacts in that duct, such as stents, making identification of the source of bleeding by CT difficult. We have encountered three patients with delayed hemobilia from the PSPDA following endoscopic biliary stenting for malignant biliary obstruction in whom no extravasation or pseudoaneurysms were detected by contrast-enhanced CT during bleeding. However, when we identified that the PSPDA had a smaller diameter than in previous CTs in all three cases, we suspected that the PSPDA was the source of the bleeding. No extravasation or pseudoaneurysms were detected with celiac arteriography or superior mesenteric arteriography; however, extravasation and pseudoaneurysms were detected by direct PSPDA angiography. Hemostasis was achieved through embolization. Detecting a large decrease in the diameter of the PSPDA on contrast-enhanced CT during biliary bleeding may help to identify the source of that bleeding.

Assessment of glomerular filtration rate measurement in dogs using dynamic contrast CT compared to serum iohexol clearance.

Dynamic contrast CT with Patlak plot analysis can be used to determine the glomerular filtration rate (GFR). However, several studies have shown different GFR values and they are most likely less than the values by the standard techniques. The purpose of this prospective, experimental, and method comparison study was to evaluate the GFR using a CT technique (CT-GFR) in 12 healthy dogs compared to serum iohexol clearance (SIC-GFR). All dogs were anesthetized and placed in the right lateral recumbency position and the caudal part was lifted inside the CT gantry. A single-slice dynamic CT of the aorta and both kidneys was scanned sequentially every 2 s for 2 min after a bolus injection (3 mL/s) of iohexol (300 mg/kg). Time attenuation curves (TAC) were constructed and the GFR per volume of kidney was calculated using the Patlak plot analysis method based on 30-120 s time intervals, and results were compared to global GFR from SIC that was determined with eight blood samples for up to 240 min. The CT-GFR value (1.85 ± 0.48 mL/min/kg) was significantly less than the SIC-GFR value (3.40 ± 0.80 mL/min/kg; P < .05). The CT-GFR was correlated with SIC-GFR by the coefficient of correlation (r) at 0.61 (P = .046). In conclusion, the CT-GFR underestimated SIC-GFR and should be used carefully. We suggest that the GFR should be calculated using the equation derived from linear regression between CT-GFR and the standard GFR method. With its own particular parameters, each institute should have its own prediction equation.

An audit of contrast extravasation in patients undergoing contrast enhanced CTs at radiology department in a tertiary care hospital in Pakistan.

OBJECTIVE: To audit the radiology department of a health facility, focusing on contrast extravasations management pre- and post-implementation of a standard protocol. METHODS: The audit was conducted at the Radiology Department of Shifa International Hospital, Islamabad, Pakistan and comprised reported computed tomography contrast extravasation incidents from January 2017 to December 2019 in the retrospective phase before the implementation of a standard protocol. Post-implementation, re-audit was done prospectively to assess compliance from January 2020 to May 2021. Overall score of >80% was chosen arbitrarily as a qualifying standard for adequate documentation. RESULTS: Of the 49 total cases, 26(53%) related to the first phase and 23(47%) to the second. In the first phase, 2(20%) of the 10 parameters cleared the cut-off mark; 'study performed' 25(96%) and 'limb assessment by technician' 26(100%). In the second phase, 2(20%) parameters failed to clear the cut-off mark; site of cannula/extravasation' 18(78.3%) and 'volume of contrast' 15(65%). CONCLUSIONS: Lack of early identification and appropriate management, especially in cases of large-volume extravasation, may result in significant morbidity.

Successful endoscopic hemostasis compared to transarterial embolization in patients with colonic diverticular bleeding.

Transarterial embolization (TAE) is performed in patients with colonic diverticular bleeding after difficult endoscopic hemostasis or rebleeding. A total of 375 patients with hematochezia at our hospital from 1 April 2016 to 31 March 2020 were retrospectively analysed. Firstly, we compared the group in which hemostasis was achieved by endoscopy alone with the group that eventually underwent TAE. Secondly, we compared the group in which hemostasis was achieved by endoscopy alone, with the group switched to TAE after endoscopic hemostasis failed. The group that eventually underwent TAE had a higher shock index and lower Alb and PT% than the endoscopic hemostasis group. The shock index was correlated with Alb and PT%. When the cut-off value for the shock index was defined as more than 0.740, an OR of 9.500, a positive predictive value (PPV) of 40.0%, a negative predictive value (NPV) of 93.4%, and an accuracy of 80.3% were obtained for predicting a switch to TAE treatment. The greatest risk for TAE was the presence of shock and extravasation on contrast-enhanced CT. A switch to TAE treatment was likely when the shock index was more than 0.740. TAE should be considered in cases with a high shock index and showing extravasation on contrast-enhanced CT.

Clinical evaluation of contrast-enhanced CT combined with PET/CT in diagnosis of mediastinal lymph node metastasis of non-small-cell lung cancer.

Objectives: To investigate the clinical value of contrast-enhanced CT combined with PET/CT in the differential diagnosis of mediastinal lymph node metastasis (MLNM) of non-small-cell lung cancer (NSCLC). Methods: A total of 120 patients with NSCLC combined with mediastinal lymphadenopathy hospitalized in our hospital were selected. All the patients received radical resection of lung cancer and mediastinal lymphadenectomy. After pathological diagnosis, they were divided into MLNM group (malignant group, undergoing contrast-enhanced CT) and non-MLNM group (benign group, receiving contrast-enhanced CT combined with PET-CT). The results were judged by two senior radiologists independently. The results of different scanning methods and postoperative pathology were compared using the t test, χ2 test and Pearson correlation coefficient test. Results: Compared with the pathological results, contrast-enhanced CT diagnosed 31 cases, with a coincidence rate of 62%, and contrast-enhanced CT combined with PET-CT diagnosed 42 cases, with a coincidence rate of 84%, presenting a statistically significant difference (P = 0.02). Among the 120 patients with lung cancer, pathological examination confirmed MLNM in 50 patients and benign enlargement in 70 patients, contrast-enhanced CT alone detected metastasis in 40 patients and benign enlargement in 80 patients, and contrast-enhanced CT combined with PET-CT detected metastasis in 47 patients and benign enlargement in 73 patients. The sensitivity and accuracy of the latter were significantly higher than those of the former (sensitivity, P = 0.01; accuracy, P = 0.01). With the increase in the malignancy of lymph nodes, the degree of CT enhancement, the concentration of radioactive substances and SUV value increased, showing positive correlations. Conclusion: Contrast-enhanced CT combined with PET/CT in the diagnosis of MLNM of NSCLC presents higher coincidence rate, sensitivity and accuracy. With the increase in tumor malignancy, the enhancement degree and radioactive substance concentration increase. The two methods are synergistic and complementary in diagnosing MLNM.

Feasibility and outcomes of bronchial artery embolization in patients with non-massive hemoptysis.

PURPOSE: To evaluate the safety, efficacy, and long-term outcome of bronchial artery embolization (BAE) in the treatment of non-massive hemoptysis and the prognostic factors associated with recurrent bleeding. MATERIALS AND METHODS: From March 2005 to September 2014, BAE was performed in 233 patients with non-massive hemoptysis. All patients had a history of persistent or recurrent hemoptysis despite conservative medical treatment. We assessed the technical and clinical success, recurrence, prognostic factors related to recurrent bleeding, recurrence-free survival rate, additional treatment, and major complications in all the patients. RESULTS: Technical success was achieved in 224 patients (96.1%), and clinical success was obtained in 219 (94.0%) of the 233 patients. In addition, 64 patients (27.5%) presented hemoptysis recurrence with median time of 197 days after embolization. Tuberculosis sequelae and presence of aberrant bronchial artery or non-bronchial systemic collaterals were significantly related to recurrent bleeding (p < 0.05). The use of Histoacryl-based embolic materials significantly reduced the recurrent bleeding rate (p < 0.05). Patient who had a tuberculosis sequelae showed a significantly lower recurrence-free survival rate (p = 0.013). Presence of aberrant bronchial artery or non-bronchial systemic collaterals showed a statistically significant correlation with recurrence-free survival rate (p = 0.021). No patients had major complications during follow-up. CONCLUSIONS: BAE is a safe and effective treatment to manage non-massive hemoptysis. The procedure may offer a better long-term control of recurrent hemoptysis and quality of life than conservative therapy alone.

Application of low dose pancreas perfusion CT combined with enhancement scanning in diagnosis of pancreatic neuroendocrine tumors.

PURPOSE: To explore the diagnostic value of pancreatic perfusion CT combined with contrast-enhanced CT in one-time scanning (PCECT) in pancreatic neuroendocrine tumors (PNETs) and to evaluate the difference of perfusion parameters between different grades of PNETs. MATERIALS AND METHODS: From October 2016 to December 2018, forty consecutive patients with histopathological-proven PNETs were identified retrospectively that received PCECT for the preoperative PNETs evaluation. Two board certified radiologists who were blinded to the clinical data evaluated the images independently. The image characters of PNETs vs. tumor-free pancreatic parenchymal and different grades of PNETs were analyzed. RESULTS: One-time PCECT scanning had a detection rate of 89.1% for PNETs, which was higher than the detection accuracy of the perfusion CT only (83.6%). The perfusion parameters of PNETs including blood volume (BV), blood flow (BF), mean slope of increase (MSI), and capillary surface permeability (PS) were significantly increased than those of tumor-free pancreatic parenchyma (p < 0.05, respectively). For differential comparison between grade I (G1) and grade II (G2) tumors, the parameters of BF and impulse residue function (IRF) of tumor tissue were significantly higher in the G2 tumors (p < 0.05, for both). In this study, the total radiation dose of the whole PCECT scan was 16.241 ± 2.289 mSv. CONCLUSION: The one-time PCECT scan may improve the detection of PNETs according to morphological features and perfusion parameters with a relative small radiation dose. The perfusion parameters of BF and IRF may be used to help distinguish G1 and G2 tumors in the preoperative evaluation.

Primary cardiac lymphoma: the management and outcome of a single-centre cohort of 22 patients.

BACKGROUND: The incidence of primary cardiac lymphoma (PCL) is increasing, but the optimal management approach remains unclear. We assessed the clinical characteristics of a single-centre cohort with the goal of determining the optimal management approach. The treatment outcomes and prognostic factors are reported. MATERIAL AND METHODS: All PCL patients were diagnosed via biopsy guided by whole-body imaging (positron emission tomography/computed tomography [PET/CT] and/or contrast-enhanced CT]. Curative therapy involved either surgery or prephase steroids followed by definitive immunochemotherapy, depending on the histological type. The primary outcomes were overall survival (OS) and progression-free survival (PFS); the secondary outcome was the treatment response. RESULTS: Twenty-two PCL patients (14 males, 8 females; age: 59.5 ± 14.7 years [mean ± S.D.]) were histologically confirmed to have diffuse large B-cell lymphoma (DLBCL; n = 17 [77.3%]), fibrin-associated DLBCL (FA-DLBCL) (n = 4 [18.2%]) and Burkitt lymphoma (n = 1 [4.5%]). Seven patients underwent cardiotomy (three for biopsy, four with curative intent). The median and longest follow-up periods were 16.3 and 180.0 months, respectively. The 16 patients who received curative therapy (complete response [CR], n = 15 [93.8%]; partial response [PR], n = 1 [6.2%]) showed better survival than those who did not (5-year OS: 83.0 ± 11.3% vs. 0%; hazard ratio [HR]: 0.025[95% confidence interval, CI: 0.003-0.187], p < 0.001); 5-year PFS: 78.7 ± 11.0% vs. 0%, HR= 0.010[0.001-0.093], p < 0.001). The left ventricular ejection fractions (LVEF) before and after definitive treatment was 63.6 ± 2.4% and 64.6 ± 4.5%, respectively (p = 0.275, power = 0.318). Extrapericardial lesions were associated with poorer survival (5-year OS: 40.0 ± 29.7% vs. 100%, p = 0.027; 5-year PFS:40.0 ± 21.9% vs. 100%, p = 0.010). CONCLUSIONS: Whole-body imaging is essential for diagnosis and prognosis. Curative therapy provided reasonable outcomes and survival; extrapericardial lesions were associated with a poorer treatment response.

Quantification of Structural Heterogeneity Using Fractal Analysis of Contrast-Enhanced CT Image to Predict Survival in Gastric Cancer Patients.

BACKGROUND: Malignant tumor essentially implies structural heterogeneity. Fractal analysis of medical imaging has a potential to quantify this structural heterogeneity in the tumor AIMS: The purpose of this study is to quantify this structural abnormality in the tumor applying fractal analysis to contrast-enhanced computed tomography (CE-CT) image and to evaluate its biomarker value for predicting survival of surgically treated gastric cancer patients. METHODS: A total of 108 gastric cancer patients (77 men and 31 women; mean age: 69.1 years), who received curative surgery without any neoadjuvant therapy, were retrospectively investigated. Portal-phase CE-CT images were analyzed with use of a plug-in tool for ImageJ (NIH, Bethesda, USA), and the fractal dimension (FD) in the tumor was calculated using a differential box-counting method to quantify structural heterogeneity in the tumor. Tumor FD was compared with clinicopathologic features and disease-specific survival (DSS). RESULTS: High FD value of the tumor significantly associated with high T stage and high pathological stage (P = 0.009, 0.007, respectively). In Kaplan-Meier analysis, patients with higher FD tumors (FD > 0.9746) showed a significantly worse DSS (P = 0.009, log rank). Multivariate analysis demonstrated that tumor FD, T stage, and N stage were independent prognostic factors for DSS. In subset analysis of lymph-node positive gastric cancers, only tumor FD was an independent prognostic factor for DSS. CONCLUSION: CT fractal analysis can be a useful biomarker for gastric cancer patients, reflecting survival and clinicopathologic features.