Dual-phase Computed Tomography Research Articles

Pediatric Neuroendocrine Neoplasia of the Parathyroid Glands: Delving into Primary Hyperparathyroidism.

Our objective was to overview the most recent data on primary hyperparathyroidism (PHP) in children and teenagers from a multidisciplinary perspective. Methods: narrative review based on full-length, English-language papers (from PubMed, between January 2020 and July 2023). Results: 48 papers (14 studies of ≥10 subjects/study, and 34 case reports/series of <10 patients/study). Study-sample-based analysis: except for one case-control study, all of the studies were retrospective, representing both multicenter (n = 5) and single-center (n = 7) studies, and cohort sizes varied from small (N = 10 to 19), to medium-sized (N = 23 to 36) and large (N = 63 to 83); in total, the reviewed studies covered 493 individuals with PHP. Case reports/series (n = 34, N = 41): the mean ages studied varied from 10.2 to 14 years in case reports, and the mean age was 17 years in case series. No clear female predominance was identified, unlike that observed in the adult population. Concerning the assessments, there were four major types of endpoints: imaging data collection, such as ultrasound, 99mTc Sestamibi, or dual-phase computed tomography (CT); gene testing/familial syndrome identification; preoperative findings; and exposure to surgical outcome/preoperative drugs, like cinacalcet, over a 2.2-year median (plus two case reports of denosumab used as an off-label calcium-lowering agent). Single-gland cases (representing 85% of sporadic cases and 19% of genetic PHP cases) showed 100% sensitivity for neck ultrasounds, with 98% concordance with 99mTc Sestamibi, as well as a 91% sensitivity for dual-phase CT, with 25% of the lesions being ectopic parathyroids (mostly mediastinal intra-thymic). Case reports included another 9/41 patients with ectopic parathyroid adenomas, 3/41 with parathyroid carcinomas, and 8/41 subjects with brown tumors. Genetic PHP (which has a prevalence of 5-26.9%) mostly involved MEN1, followed by CDC73, CASR, RET, and CDKN1B, as well as one case of VHL. Symptomatic PHP: 70-100% of all cases. Asymptomatic PHP: 60% of genetic PHP cases. Renal involvement: 10.5% of a cohort with genetic PHP, 71% of sporadic PHP cases; 50% (in a cohort with a mean age of 16.7), 29% (in a cohort with a mean age of 15.2); 0% (in infancy) to 50-62% (in teenagers). Bone anomalies: 83% of the children in one study and 62% of those in two other studies. Gastrointestinal issues: 40% of one cohort, but the data are heterogeneous. Cure rate through parathyroidectomy: 97-98%. Recurrent PHP: 2% of sporadic PHP cases and 38% of familial PHP cases. Hungry bone syndrome: maximum rate of 34-40%. Case reports identified another 7/41 subjects with the same post-parathyroidectomy condition; a potential connection with ectopic presentation or brown tumors is suggested, but there are limited data. Minimally invasive thoracoscopic approaches for ectopic tumors seemed safe. The current level of statistical evidence on pediatric PHP qualifies our study- and case-sample-based analysis (n = 48, N = 534) as one of the largest of its kind. Awareness of PHP is the key factor to benefit our young patients.

Evaluation of the normal gastrointestinal tract in cats using dual-phase computed tomography.

In cats, although ultrasonography remains the preferred modality to evaluate the gastrointestinal tract, computed tomographic (CT) examination of the abdomen is commonly performed. However, a normal description of the gastrointestinal tract is lacking. This study describes the conspicuity and contrast enhancement pattern of the normal gastrointestinal tract in cats using dual-phase CT. Pre- and dual-phase postcontrast (early scan at 30 seconds and late scan mean at 84seconds) abdominal CT exams of 39 cats without history, clinical signs or diagnosis of gastrointestinal disease were reviewed. The gastrointestinal tract was examined for conspicuity and enhancement pattern using commercially available viewing software (Osirix, v.6.5.2), and diameters of 16 gastrointestinal segments were recorded and compared with published radiographic and ultrasonographic reference values. Of the 624 gastrointestinal segments, 530 (84.9%) were identified on precontrast studies and 545 (87.3%) segments on postcontrast studies. Of the gastrointestinal wall segments, 257 (41.2%) were identified on precontrast studies and 314 (50.3%) on postcontrast studies. Gastrointestinal segment diameters correlated well with published normal values, whereas wall thickness measurements usually were smaller compared with sonographic normal values. Early mucosal surface enhancement was frequently seen in the gastric cardia and fundus and ileocolic junction, and a mainly transmural wall enhancement in other gastrointestinal segments. Dual-phase CT allows for the identification of gastrointestinal tract segments and walls in cats. Contrast enhancement improves conspicuity and demonstrates wall layering in the cardia, fundus and ileocolic junction.

Dual-phase computed tomography for localization of parathyroid lesions in children and adolescents with primary hyperparathyroidism

BackgroundChildhood and adolescent primary hyperparathyroidism (PHPT) is a rare disease caused by single adenomas in 65–94% of patients. In this patient group, there is no data on computed tomography (CT) for pre-operative parathyroid localization that may facilitate focused parathyroidectomy. MethodsTwo radiologists reviewed dual-phase (nonenhanced and arterial) CT images of twenty-three operated children and adolescents [20:single-gland disease(SGD), 3:multi-glandular disease(MGD)] with proven histopathological PHPT. Percentage arterial enhancement (PAE) was calculated as [100*{arterial-phase Hounsfield unit (HU)-nonenhanced phase HU}/nonenhanced HU] of the parathyroid lesion(s), thyroid, and lymph node. ResultsDual-phase CT lateralized 100%, localized to the correct quadrant/site 85% SGD (including 3/3 ectopic), and identified 1/3 MGD. PAE (cutoff ≥ 112.3%) was sensitive (91.3%) and specific (99.5%) in distinguishing parathyroid lesions from local mimics (P<0.001). The average effective dose was 3.16±1.01mSv, comparable to the planar/single photon emission CT (SPECT) Technetium 99m(Tc)-sestamibi and choline positron emission tomography (PET)/CT scans. Solid-cystic morphology identified in 4 patients harboring pathogenic germline variants (3:CDC73, 1:CASR) may serve as a radiological clue to molecular diagnosis. Nineteen out of 20 (95%) patients with SGD who had undergone single gland resection based on pre-operative CT findings were in remission over a median follow-up of 18 months. ConclusionAs most children/adolescents with PHPT have SGD, dual-phase CT protocols which reduce the effective radiation dose with high localization sensitivity for single parathyroid lesions may be a sustainable pre-operative imaging modality in this patient group.

Computed tomography can differentiate vaginal-origin from uterine-origin lesions in bitches.

To investigate typical computed tomography (CT) features for the differentiation of vaginal from the uterine origin in dogs. 7 healthy Beagles in the prospective study and 5 bitches in the retrospective study. In the prospective study, dual-phase CT images were obtained from sexually intact female Beagles (n = 7) during anestrus and estrus. On the CT images, the vagina and uterine horns, body, and cervix were assessed for diameter, attenuation, and contrast enhancement pattern. In the retrospective study, CT features of large vaginal lesions (leiomyoma, leiomyosarcoma, adenocarcinoma, hematocolpos, and Gartner's duct cyst) were assessed in 5 bitches. In normal bitches, the cervix was thicker with strong central enhancement compared to the uterus and vagina. The uterine artery, which enters the mesometrium at the level of the cervix, was clearly visualized and assisted in identifying the cervix. In bitches with large vaginal masses, uterine arteries were displaced by the lesions and could not be used to locate the cervix. In 4/5 dogs with vaginal masses, identification of the cervix allowed the determination of the organ of origin. In 1 dog with adenocarcinoma, CT vaginography was additionally required for determining the origin of mass. Results from this study indicate that the cervix, recognized in CT as focal thickening of the uterus with central enhancement, may be used as a landmark for the differentiation between the uterus and vagina in bitches.

Percentage arterial enhancement on 2D CT in the diagnosis of primary hyperparathyroidism: A prospective validation study and potential pitfalls.

Parathyroid lesions are identified by subjective enhancement and washout patterns on computed tomography (CT). We have previously proposed "percentage arterial enhancement" (PAE) as an objective index and now aim to validate its performance prospectively. Dual-phase CT was performed in 40 consecutive primary hyperparathyroidism patients. PAE was calculated as [{arterial phase Hounsfield unit (HU)-unenhanced phase HU}/unenhanced phase HU] × 100. PAE > 128.9% was considered parathyroid. PAE had 94.2% sensitivity, 100% positive predictive value (PPV) in lateralization, and sensitivity and PPV of 93.9% in quadrant localization of single-gland disease. PAE failed to identify two lesions: an intrathyroidal parathyroid carcinoma in the background of multinodular goiter and another lower enhancing cystic parathyroid adenoma. PAE had 60% sensitivity, and 100% PPV to identify multigland disease. The mean effective dose was 2.74 mSV. PAE is a specific CT index for parathyroid lesions with less radiation exposure. Areas of caution include intrathyroidal and cystic lesions.

Blunt splenic injury in adults: Association between volumetric quantitative CT parameters and intervention.

Computed tomography volumetry of blunt splenic injury-related features predicts splenectomy and angioembolization in adults and identifies clinically important target features for computer vision and automation research. BACKGROUND Several ordinal grading systems are used in deciding whether to perform angioembolization (AE) or splenectomy following blunt splenic injury (BSI). The 2018 American Association for the Surgery of Trauma (AAST) Organ Injury Scale incorporates vascular lesions but not hemoperitoneum, which is considered in the Thompson classifier. Granular and verifiable quantitative measurements of these features may have a future role in facilitating objective decision making. PURPOSE The purpose of this study is to compare performance of computed tomography (CT) volumetry-based quantitative modeling to the 1994 and 2018 AAST Organ Injury Scale and Thompson classifier for the following endpoints: decision to perform splenectomy (SPY), and the composite of SPY or AE. MATERIALS AND METHODS Adult BSI patients (age ≥18 years) scanned with dual-phase CT prior to intervention at a single Level I trauma center from 2017 to 2019 were included in this retrospective study (n = 174). Scoring using 2018 AAST, 1994 AAST, and Thompson systems was performed retrospectively by two radiologists and arbitrated by a third. Endpoints included (1) SPY and (2) the composite of SPY or AE. Logistic regression models were developed from segmented active bleed, contained vascular lesion, splenic parenchymal disruption, and hemoperitoneum volumes. Area under the receiver operating characteristic curve (AUC) for ordinal systems and volumetric models were compared. RESULTS Forty-seven BSI patients (27%) underwent SPY, and 87 patients (50%) underwent SPY or AE. Quantitative model AUCs (0.85—SPY, 0.82—composite) were not significantly different from 2018 AAST AUCs (0.81, 0.88, p = 0.66, 0.14) for both endpoints and were significantly improved over Thompson scoring (0.76, p = 0.02; 0.77, p = 0.04). CONCLUSION Quantitative CT volumetry can be used to model intervention for BSI with accuracy comparable to 2018 AAST scoring and significantly higher than Thompson scoring. LEVEL OF EVIDENCE Prognostic and Epidemiological; Level IV.

Unidentified bright objects of spleen on arterial phase CT: mimicker of splenic vascular injury in blunt abdominal trauma.

We have described unidentified bright objects of spleen (UBOS), a hitherto undescribed entity, as hyperdense areas on arterial phase (AP) computed tomography (CT) seen in relation to splenic lacerations and are isodense to the normal parenchyma on portal venous phase with no correlate on digital subtraction angiography (DSA). UBOS mimic splenic vascular injuries like active contrast extravasation and pseudoaneurysm and need to be differentiated from them as it would have implications on patient management. We undertook this study to identify CT features of UBOS that can differentiate them from splenic vascular injuries and to calculate their diagnostic accuracy. This retrospective study was approved by the institutional ethical committee and the need for informed consent was waived. Patients with splenic injury who had undergone dual-phase CT and DSA were included. All the lesions that were hyperdense on AP were evaluated for their outline, their relation to the adjacent/parallel margins of a laceration (margin sign), string of beads appearance, and the presence of adjacent normal parenchyma (adjacent parenchyma sign). The Hounsfield unit (HU) of the lesion and the aorta on the AP were also noted. The diagnostic accuracy of various signs for distinguishing UBOS from splenic vascular injuries was calculated using DSA as the reference standard. Of 48 patients, 5 were excluded due to suboptimal quality of the examination or a time difference of more than 6 hours between the CT and DSA. A total of 54 hyperdense lesions were detected on AP in 43 patients. These were classified as vascular injuries (pseudoaneurysm, n=11; active contrast extravasation, n=11) and UBOS (n=32) based on DSA. The margin sign, string of beads appearance, and ill-defined outline had high specificity (95%, 86%, and 82%, respectively) but low sensitivity (50%, 65%, and 63%, respectively). The adjacent parenchyma sign had a moderate sensitivity and specificity of 84% and 77%, respectively. ROC analysis showed that a difference of 50 HU between the aorta and the lesion had a high sensitivity and specificity of 88.9% and 90.6%, respectively, with an area under the curve of 0.90. An attenuation difference of over 50 HU between the aorta and the lesion and the presence of normal adjacent parenchyma had the highest diagnostic accuracy, while an ill-defined outline, string of beads appearance, and margin sign had high specificity but low sensitivity for differentiating UBOS from splenic vascular injuries.

Hollow adrenal gland sign on dual-phase contrast-enhanced CT in critically ill patients with sepsis.

We aimed to describe the clinical manifestations of patients with sepsis who had the hollow adrenal gland sign (HAGS) during the acute phase of resuscitation and evaluated its value in predicting in-hospital mortality. We performed a single-center, retrospective study of patients with sepsis who visited the emergency department (ED) from November 2015 to December 2018. The patients were categorized into the positive HAGS (pHAGS) and negative HAGS (nHAGS) groups, based on its presence in initial dual-phase contrast-enhanced abdominal computed tomography (CT). The primary outcome was in-hospital mortality. A multiple logistic regression model was developed to assess variables related to in-hospital mortality. In all, 156 patients were included, and 36.5% (n = 57) was assigned to the pHAGS group. Both the maximal Sequential Organ Failure Assessment score within 24 h after ED arrival (10, interquartile range [IQR] 7-13 vs. 8, IQR 6-10, p < 0.01) and APACHE II score (24, IQR 20-31 vs. 20, IQR 17-25, p < 0.01) were significantly higher in the pHAGS than in the nHAGS group; the former group received significantly more interventions including vasopressors, renal replacement therapy, mechanical ventilation, and transfusions; in-hospital mortality was significantly higher in the former than in the latter group (29.8% vs. 10.1%, p < 0.01). pHAGS was an independent predictor of in-hospital mortality (adjusted odds ratio, 2.89; 95% confidence interval, 1.08-7.78; p = 0.04). Patients with sepsis who showed the HAGS had more severe illness than those who did not, and had an increased need for organ-supportive interventions. Presence of the HAGS was independently associated with in-hospital mortality.

The value of bronchial and cavity contraction rates in differentiating benign and malignant pulmonary cavities

BackgroundThe present study aimed to assess the value of bronchial and cavity contraction percentages in differentiating benign and malignant pulmonary cavities.MethodsForty-two patients with pulmonary cavities were scanned by dual-phase computed tomography (CT). Then, the cavity and bronchial contraction percentages were respectively measured, the differences between the benign and malignant cavities were compared, and the best diagnostic critical point for differentiating benign and malignant cavities was obtained through the receiver operator characteristic (ROC) curve of the diagnostic test.ResultsThe contraction percentage of the bronchial end with benign cavities was significantly higher than that of the bronchial end with malignant cavities (P < 0.001). The contraction percentage was significantly higher in the benign group than in the malignant group (P < 0.001). The ROC analysis revealed that the sensitivity and specificity of the bronchial contraction percentage was 90.50 and 86.40%, respectively, while the sensitivity and specificity of the cavity contraction percentage was 90.50 and 90.90%, respectively.ConclusionThe dual-phase CT scanning of the bronchial and cavity contraction percentage can distinguish between benign and malignant cavities.

Differentiating autoimmune pancreatitis from pancreatic ductal adenocarcinoma with CT radiomics features

PurposeThe purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). Materials and MethodsEighty-nine patients with AIP (65 men, 24 women; mean age, 59.7±13.9 [SD] years; range: 21–83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1±12.3 [SD] years; range: 36–86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5mm thickness/increment) were compared with thick-slices images (3 or 5mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing. ResultsThe pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8–100%), 83.9% (52:67; 95% CI: 74.7–93.0%) and 77.4% (48/62; 95% CI: 67.0–87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6–100%) and 100% specificity (33/33; 95% CI: 93–100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8–100%) and area under the curve of 0.975 (95% CI: 0.936–1.0). ConclusionsRadiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.

Differential diagnosis of chromophobe renal cell carcinoma and papillary renal cell carcinoma with dual-energy spectral computed tomography

Computed tomography (CT) image features of chromophobe renal cell carcinoma (ChRCC) and papillary renal cell carcinoma (PRCC) are, occasionally, sometimes difficult to identify. However, spectral CT might provide quantitative parameters to differentiate them. To differentiate between ChRCC and PRCC with quantitative parameters using spectral CT. Forty cases of RCC confirmed with pathological tests were analyzed retrospectively (27 cases of PRCC and 13 cases of ChRCC). All patients underwent non-enhanced CT and dual-phase contrast-enhanced CT scans. For each lesion, the CT value of monochromatic images as well as iodine and water concentrations were measured, and the slope of spectrum curve was calculated. Data were analyzed using Student's t-test. Sensitivity and specificity of the quantitative parameters were analyzed using the receiver operating characteristic (ROC) curve. During the cortex phase (CP) and parenchyma phase (PP), the CT value and slope of spectrum curve of ChRCC were higher than those of PRCC, and significant differences were observed at low energy levels (40-70 keV). Normalized iodine concentration of ChRCC and that of PRCC was significantly different during CP and PP (P < 0.05). The water (iodine) concentrations of ChRCC and PRCC in CP and PP were not statistically different (P > 0.05). All the ROCs for parameters were above the reference line. Spectral CT may help increase the diagnostic accuracy of differentiating PRCC from ChRCC using a quantitative analysis.

Discrimination of mediastinal metastatic lymph nodes in NSCLC based on radiomic features in different phases of CT imaging

BackgroundWe aimed to develop radiomic models based on different phases of computed tomography (CT) imaging and to investigate the efficacy of models for diagnosing mediastinal metastatic lymph nodes (LNs) in non-small cell lung cancer (NSCLC).MethodsEighty-six NSCLC patients were enrolled in this study, and we selected 231 mediastinal LNs confirmed by pathology results as the subjects which were divided into training (n = 163) and validation cohorts (n = 68). The regions of interest (ROIs) were delineated on CT scans in the plain phase, arterial phase and venous phase, respectively. Radiomic features were extracted from the CT images in each phase. A least absolute shrinkage and selection operator (LASSO) algorithm was used to select features, and multivariate logistic regression analysis was used to build models. We constructed six models (orders 1–6) based on the radiomic features of the single- and dual-phase CT images. The performance of the radiomic model was evaluated by the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV).ResultsA total of 846 features were extracted from each ROI, and 10, 9, 5, 2, 2, and 9 features were chosen to develop models 1–6, respectively. All of the models showed excellent discrimination, with AUCs greater than 0.8. The plain CT radiomic model, model 1, yielded the highest AUC, specificity, accuracy and PPV, which were 0.926 and 0.925; 0.860 and 0.769; 0.871 and 0.882; and 0.906 and 0.870 in the training and validation sets, respectively. When the plain and venous phase CT radiomic features were combined with the arterial phase CT images, the sensitivity increased from 0.879 and 0.919 to 0.949 and 0979 and the NPV increased from 0.821 and 0.789 to 0.878 and 0.900 in the training group, respectively.ConclusionsAll of the CT radiomic models based on different phases all showed high accuracy and precision for the diagnosis of LN metastasis (LNM) in NSCLC patients. When combined with arterial phase CT, the sensitivity and NPV of the model was be further improved.

2409 A Rare Complication of Gastric Bypass in the Setting of Chronic Liver Disease

INTRODUCTION: Porto-mesenteric venous thrombosis (PMVT) is a known and potentially fatal complication of general surgery. However, it has been rarely reported as a complication of worsening liver disease after undergoing bariatric surgery. This is a case of a patient who presented with mesenteric thrombosis following Roux-en-y gastric bypass (RYGB). CASE DESCRIPTION/METHODS: Patient is a 42-year-old African American female with a history of RYGB who presented with episodes of post-operative abdominal pain for 5 years. She was found to have recurrent high-grade small bowel obstruction's (SBO) necessitating a small bowel resection. Her course was further complicated by intra-abdominal abscesses requiring computed tomography (CT)-guided drainage, and wound dehiscence requiring open surgical intervention and debridement. Four months after discharge, she presented with right-sided abdominal pain and acute encephalopathy. Liver enzymes were elevated. Abdominal ultrasound revealed portal vein thrombosis (PVT). Dual-phase CT of the abdomen revealed sub-acute to chronic complete diffuse mesenteric thrombosis with collateralizations involving the portal, splenic, and distal superior mesenteric veins. Given that previous imaging suggested steatosis and hepatomegaly, sub-acute liver injury secondary to thrombosis was established in the setting of chronic liver disease. The patient's underlying non-alcoholic fatty liver disease was likely worsened by severe malnutrition and short gut syndrome following the RYGB. Her hepatic encephalopathy resolved after initiating lactulose and rifaximin. Outpatient hematology evaluation for all causes of thrombophilia remained inconclusive and the patient had no recurrences of thrombosis. DISCUSSION: RYGB remains the gold standard for bariatric surgery as it results in the most durable weight loss. However, complications may occur such as gastrointestinal leak, fistulas, marginal ulcers, SBO, and dumping syndrome. Mechanisms of thrombosis formation in this setting could be related to intra-operative vascular manipulation, increased intra-abdominal pressure, venous stasis, and possibly deteriorating liver function secondary to rapid weight loss and malnutrition. PMVT hasn't been reported consistently as a complication in various bariatric surgery studies, which leads us to conclude that it's either under or mis-diagnosed. It is extremely important to consider PMVT as a complication of RYGB in patients who have evidence of underlying liver disease prior to undergoing RYGB.

Annotated normal CT data of the abdomen for deep learning: Challenges and strategies for implementation

PurposeThe purpose of this study was to report procedures developed to annotate abdominal computed tomography (CT) images from subjects without pancreatic disease that will be used as the input for deep convolutional neural networks (DNN) for development of deep learning algorithms for automatic recognition of a normal pancreas. Materials and methodsDual-phase contrast-enhanced volumetric CT acquired from 2005 to 2009 from potential kidney donors were retrospectively assessed. Four trained human annotators manually and sequentially annotated 22 structures in each datasets, then expert radiologists confirmed the annotation. For efficient annotation and data management, a commercial software package that supports three-dimensional segmentation was used. ResultsA total of 1150 dual-phase CT datasets from 575 subjects were annotated. There were 229 men and 346 women (mean age: 45±12years; range: 18–79years). The mean intra-observer intra-subject dual-phase CT volume difference of all annotated structures was 4.27mL (7.65%). The deep network prediction for multi-organ segmentation showed high fidelity with 89.4% and 1.29mm in terms of mean Dice similarity coefficients and mean surface distances, respectively. ConclusionsA reliable data collection/annotation process for abdominal structures was developed. This process can be used to generate large datasets appropriate for deep learning.

Identification of the feeding arteries of hepatocellular carcinomas by performing dual arterial phase CT during pre-transarterial chemoembolization angiography

This study evaluated the usefulness of performing dual arterial phase computed tomography (CT) during pre-transarterial chemoembolization (TACE) angiography for identifying the feeding arteries of hepatocellular carcinomas (HCC). Dual arterial phase CT was performed during pre-TACE angiography in 73 patients with 139 HCC. Ten HCC underwent this procedure twice, so the total number of examined HCC was 149. Early and late arterial phase images were obtained 6 seconds after injection of an iodinated contrast material serially during a single breath-hold. The feeding artery was defined as the branch of the hepatic artery that was connected to the enhanced areas of the tumor. For HCC that could not be visualized on the early arterial phase images, fusion images superimposing the early and late arterial phase images were constructed. Furthermore, technical success defined as successful catheterization of the subsegmental or more distal feeding artery was evaluated. The feeding artery was correctly identified on dual arterial phase CT in 146 of the 149 tumors (98.0%). In two HCC, the feeding arteries could not be identified due to severe motion artifacts, and in one, due to the presence of anastomosis between the right and left hepatic arteries. Catheterization of the subsegmental feeding artery was successful in all TACE procedures (technical success rate: 100%). Performing dual arterial phase CT during angiography appears to be useful for identifying the feeding arteries of HCC.

Thermal Ablation in the Management of Adrenal Metastasis Originating from Non-small Cell Lung Cancer: A 5-year Single-center Experience.

Background:Treatment of adrenal metastasis from lung carcinoma may prolong survival in the selected patients. However, not all patients can undergo surgery; thus, minimally invasive ablation procedures such as radiofrequency ablation (RFA) and microwave ablation (MWA) have gained acceptance as alternative treatment methods. This study summarized a 5-year single-center experience regarding the evaluation of safety and efficacy of computed tomography (CT)-guided thermal ablation in the management of adrenal metastasis originating from non-small cell lung cancer (NSCLC).Methods:The data of NSCLC patients ablated for adrenal metastasis at the Department of Diagnostic Imaging and Interventional Radiology, General Hospital Sotiria, were retrospectively analyzed. Patients were divided into two groups: RFA group and MWA group according to the therapeutic approaches. Preprocedural blood tests included measurement of international normalized ratio, partial thromboplastin time, and platelet enumeration. A dual-phase contrast-enhanced spiral CT was performed immediately after the procedure to assess the immediate response after ablation and to screen for related complications. Follow-up was performed with CT or magnetic resonance imaging at 1, 3, 6 months and 1 year after ablation and every 6 months thereafter.Results:A total of 99 ablation sessions in 71 patients with adrenal metastasis originating from NSCLC were included in the final analysis. Self-limited, postablation syndrome occurred in 16/99 (16.1%) of ablation sessions. All procedures were technically successful. Immediate postablation imaging showed no contrast enhancement of the ablated tumor in all patients. Follow-up imaging at 3 months revealed local tumor progression in 8 (22.8%) patients of the RFA group and 7 (19.4%) patients of MWA group, all of them underwent a second session successfully. The 1-year assessment revealed local recurrence of the ablated tumor in six patients (17.1%) of RFA group and seven patients (19.4%) of MWA group. Among these 71 patients, those with tumor size >3.5 cm had a higher local recurrence rate (65.2%, 15/23) than those with tumors ≤3.5 cm (16.7%, 8/48; P = 0.012). There was no significant difference in the median survival time between RFA (14.0 months) and MWA (14.6 months) groups (P > 0.05).Conclusions:RFA and MWA showed comparable efficacy and safety in adrenal metastasis treatment.

IMPROVING CONSPICUITY OF THE CANINE GASTROINTESTINAL WALL USING DUAL PHASE CONTRAST-ENHANCED COMPUTED TOMOGRAPHY: A RETROSPECTIVE CROSS-SECTIONAL STUDY.

Gastrointestinal (GI) disease is a common clinical complaint in small animal patients; computed tomography (CT) examinations enable a global overview of the GI tract and associated structures. Previously, the GI wall has been reportedly identified from serosa to mucosa in 77% of standard postcontrast CT studies and wall layers seen in ultrasound have not been distinguished. Inconsistent strong contrast enhancement of the inner layer of the GI mucosal surface was noted on dual phase CT studies acquired in our institution, which increased the visibility of the GI tract and disease processes. The aim of this retrospective, observational, cross-sectional study was to determine the optimal portal vein attenuation for maximizing GI wall conspicuity using dual phase contrast-enhanced CT. Patients with abdominal CT for a non-GI related disease were included. In a pilot study, 175 GI segments from 35 CT studies were graded for presence of mucosal surface enhancement (MSE). The strongest mucosal surface enhancement grade correlated with portal vein attenuation of 43-150HU; this value was used as inclusion criterion in the main study. A total of 441 GI segments were evaluated in 42 CT studies postcontrast for GI wall conspicuity. The GI wall was conspicuous in 56.7% precontrast, 84.5% at 30s, and 77.3% late postcontrast; 4.7% of segments were removed due to motion blur. At 30 s distinct mucosal surface enhancement was seen in the small intestine and gastric mucosal surface enhancement was poor. Findings supported the use of dual phase contrast-enhanced CT for improving conspicuity of the GI wall.

Small Bowel Gastrointestinal Stromal Tumors: Multidetector Computed Tomography Enhancement Pattern and Risk of Progression.

Small bowel gastrointestinal stromal tumors (SB-GISTs) are rare lesions with a variable appearance on computed tomography (CT). This case series analyzes the CT enhancement pattern with the histologic risk assessment of tumor progression. Local institutional pathology database was searched for SB-GISTs from 2000 to 2015. Pathology reports and clinical notes were reviewed. Imaging was qualitatively reviewed for pattern of enhancement categorized into homogeneous or heterogeneous groups. Nonparametric statistical analysis was performed comparing enhancement to segment of bowel involved, presence of necrosis, tumor size, histologic grade (ie, G1 or G2), and histologic risk of progression (ie low, moderate, high). For simplicity, risk of progression was binned into low-risk or non-low-risk groups. Twenty-six pathology-proven, first presentation, nonmetastatic SB-GISTs were included into study. Seventeen were located in duodenum, 7 in jejunum, and 2 within the ileum. Dual phase (arterial and venous) CT imaging was available for 22 cases. Four cases did not have dual phase (three venous phase and one arterial phase only). Seventeen cases demonstrated heterogeneous enhancement and 9 cases homogeneous enhancement. Statistically significant difference was found between size versus enhancement groups (3.1 cm for homogeneous versus 6.8 cm for heterogeneous) (Mann-Whitney U test, n = 26, P = 0.002). Presence of necrosis versus enhancement group was statistically significant (Pearson χ, P = 0.001). Low-risk and non-low-risk groups versus enhancement groups was very significant (P = 0.001). Bowel segment involvement and histologic grading versus enhancement group did not reach statistical significance (P = 0.174 and P = 0.07, respectively). This case series reveals an important significant association between heterogeneous enhancement and non-low risk (ie, moderate/high) SB-GISTs. Beyond just describing the tumor, using enhancing pattern, the interpreting radiologist can preoperatively suggest additional prognostic information, potentially helpful for surgical planning.

ASSOCIATIONS BETWEEN DUAL-PHASE COMPUTED TOMOGRAPHY FEATURES AND HISTOPATHOLOGIC DIAGNOSES IN 52 DOGS WITH HEPATIC OR SPLENIC MASSES.

Ability to noninvasively differentiate malignant from nonmalignant abdominal masses would aid clinical decision making. The aim of this retrospective, cross-sectional study was to identify features in dual-phase computed tomographic (CT) studies that could be used to distinguish malignant from nonmalignant hepatic and splenic masses in dogs. Medical records were searched for dogs that had an abdominal dual-phase CT examination, a hepatic or splenic mass, and subsequent histopathologic diagnosis. Computed tomographic images for all included dogs were acquired prior to and <30 s (early phase) and >60 s (delayed phase) after intravenous contrast administration. Fifty-two dogs with 55 masses were studied: 24 hepatic, including 14 (58%) malignant and 10 (42%) non-malignant; 31 splenic, including 18 (58%) malignant and 13 (42%) nonmalignant. There was substantial overlap in the pre- and postcontrast CT features of malignant and nonmalignant hepatic and splenic masses. Regardless of histologic diagnosis, hepatic masses most frequently showed marked, generalized enhancement in early phase images that persisted in the delayed phase. Splenic hemangiosarcoma and nodular hyperplastic lesions most frequently showed marked, generalized enhancement in early phase images that persisted in delayed images whereas most splenic hematomas had slight enhancement in early phase images. All splenic hematomas and 77% of the hemangiosarcomas had contrast accumulation compatible with active hemorrhage. There were no other significant differences in quantitative or categorical CT data between malignant and nonmalignant hepatic or splenic masses. Dual-phase CT of dogs with hepatic or splenic masses provides limited specific diagnostic information.

Evaluation of the Effect of Intracoronary Attenuation on Coronary Plaque Measurements Using a Dual-phase Coronary CT Angiography Technique on a 320-row CT Scanner—In Vivo Validation Study

The characterization of plaques based on their computed tomography (CT) number is important for the detection of vulnerable atherosclerotic plaques. An earlier in vitro study showed that intravascular attenuation affected the attenuation of coronary atherosclerotic plaques. We attempted to validate this finding in vivo and here we introduce a dual-phase coronary CT angiography (CCTA) technique to address this issue. Institutional ethics committee approval and informed consent were obtained. Thirty patients (30 noncalcified plaques) underwent dual-phase CCTA. Two CT datasets were obtained, one with coronary artery enhancement and the other without coronary artery enhancement. The CT number of the plaque and the adjacent vessel lumen was measured in a circular region of interest on curved planar reconstruction images. The region of interest setting was consistent between the two CT datasets. We performed linear regression analysis of the changes in the CT numbers (ΔHounsfield unit), calculated by subtracting the two CT datasets, for the lumen and for the plaque. We also evaluated the relationship between plaque attenuation on nonenhanced coronary artery images and luminal attenuation with and without contrast enhancement. The ΔHounsfield unit for the plaque and the lumen showed a strong correlation (r = 0.61). There was no significant correlation between plaque attenuation on nonenhanced coronary artery images and luminal attenuation with and without contrast enhancement (r = 0.23 and 0.24, respectively). Intravascular attenuation changed the attenuation of coronary atherosclerotic plaques. Using the copy-paste technique, the CT number of identical plaques can be measured in registered dual-phase CCTA images for the evaluation of coronary plaques.