[Management of anticoagulant-related soft tissue bleeding]. / Management von Antikoagulanzien-induzierten Weichteilblutungen.

BACKGROUND AND OBJECTIVE: Spontaneous, severe, and life-threatening soft tissue bleeding (STB) in patients taking anticoagulants is associated with high morbidity and mortality due to the substantial blood loss and nonspecific clinical symptoms. The optimal management of these predominantly older patients with multiple comorbidities has not yet been unanimously clarified. MATERIALS AND METHODS: This work comprises a literature search and analysis of the pertinent retrospective studies and case series. RESULTS: Structured diagnostic workup with contrast-enhanced computed tomography (CT) is essential for planning transarterial embolization (TAE). Contrast agent extravasation, the signal flare phenomenon, and the hematocrit effect are all indicative of active bleeding or an anticoagulant-related hematoma. For TAE, coils, particles, and liquid embolic agents can be used alone or in combination. A back door/front door embolization should be strived for. CONCLUSION: Transarterial embolization is the method of choice for managing anticoagulant-related localized or diffuse spontaneous soft tissue bleeding in the context of hemodynamic stabilization of the patient.

Tumor pseudopapilar sólido de páncreas, una neoplasia inusual / Solid Pseudopapillary Tumor of the Pancreas, an Unusual Neoplasm

Presentación del caso. Se trata de una mujer de 26 años que presentó dolor en epigastrio e hipocondrio izquierdo, con aumento del perímetro abdominal y pérdida de 5 kg de peso corporal. En el examen físico se detectó una masa de gran tamaño en el epigastrio, con bordes regulares, ligeramente dolorosa al tacto y no móvil. Los estudios de imagen revelaron una neoplasia mixta en el cuerpo y cola pancreática. Intervención terapéutica. Se practicó una esplenopancreatectomía corpo-caudal, con extirpación completa del tumor. Evolución clínica. La paciente recibió cuidados especializados y vigilancia estrecha posquirúrgica en la unidad de cuidados intensivos, sin presentar complicaciones relevantes. Tras el alta hospitalaria, la paciente refirió un buen estado general en los controles de seguimiento, que incluyeron una tomografía realizada a los 12 meses, donde no se evidenciaron restos o recidivas tumorales

Case presentation. A 26-year-old woman who presented with pain in the epigastrium and left hypochondrium, with increased abdominal perimeter and loss of 5 kg of body weight. Physical examination revealed a large mass in the epigastrium, with regular borders, slightly painful to the touch and non-mobile. Imaging studies revealed a mixed neoplasm in the pancreatic body and tail. Treatment. A corpo-caudal splenopancreatectomy was performed, with complete removal of the tumor. Outcome. The patient received specialized care and close postoperative surveillance in the intensive care unit, with no relevant complications. After hospital discharge, the patient reported a good general condition in the follow-up controls, which included a computed tomography scan performed after 12 months, where no tumor remnants or recurrences were evidenced

Diagnostic Value Analysis of Multi-Slice Helical Computed Tomography Reconstruction Parameters Combined with 3.0 T Magnetic Resonance in Clear Cell Renal Cell Carcinoma.

OBJECTIVE: The diagnostic value of multi-slice helical computed tomography (MSCT) reconstruction parameters combined with 3.0 T magnetic resonance (MR) in clear cell renal cell carcinoma (CCRCC) was analysed. METHODS: A total of 158 patients with renal tumours were selected in First Hospital in Zibo city from February 2018 to March 2023 for the retrospective study and divided into CCRCC and non-CCRCCs groups according to the final results of pathological diagnosis. MSCT detection and 3.0 T MR detection were performed in both groups for imaging manifestation analysis. The receiver operating characteristic (ROC) curve was used in analysing the clinical efficacy of each single and combined diagnosis. RESULTS: The results of pathological diagnosis showed 115 patients with CCRCC and 43 non-CCRCC patients, accounting for 72.78% and 27.22%, respectively. Patients with CCRCC had higher proportions of calcification, necrosis, cystic degeneration and more pseudocapsules than non-CCRCC patients (p < 0.05). Patients with CCRCC mainly showed peripheral and heterogeneous enhancement, whereas non-CCRCC patients mainly showed homogeneous enhancement, and the difference was significant (p < 0.05). The cortical phase, parenchymal phase and excretion stage had higher computed tomography (CT) values in the CCRCC group (p < 0.001), and no significant difference in the CT value of plain scan phase was found between the groups (p > 0.05). The CCRCC group had obviously higher apparent diffusion coefficient value and incidence of necrosis and cystic degeneration (p < 0.001), lower incidence of haemorrhage (p < 0.05) and distinctly higher cortical enhancement indexes in the cortical phase, parenchymal phase and delay period (p < 0.001). The ROC analysis showed that the area under the curve, specificity, sensitivity and 95% CI of combined detection were higher than those of each single detection. CONCLUSIONS: The combination of MSCT reconstruction parameters and 3.0 T MR has a certain diagnostic value for CCRCC. The combined diagnosis has higher area under the curve, specificity, sensitivity and 95% CI, which can provide effective reference for clinical diagnosis and treatment, with a certain clinical application value.

Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans.

This study evaluated the effect of pitch on 256-slice helical computed tomography (CT) scans. Cylindrical water phantoms (CWP) were measured using axial and helical scans with various pitch values. The surface dose distributions of CWP were measured, and reconstructed images were obtained using filtered back-projection (FBP) and iterative model reconstruction (IMR). The image noise in each reconstructed image was decomposed into a baseline component and another component that varied along the z-axis. The baseline component of the image noise was highest at the center of the reconstructed image and decreased toward the edges. The normalized 2D power spectra for each pitch were almost identically distributed. Furthermore, the ratios of the 2D power spectra for IMR and FBP at different pitch values were obtained. The magnitudes of the components varying along the z-axis were smallest at the center of the reconstructed image and increased toward the edge. The ratios of the 3D power spectra on the fx axis for IMR and FBP at different pitch values were obtained. The results showed that the effect of the pitch was related to the component that varied along the z-axis. Furthermore, the pitch had a smaller effect on IMR than on FBP.

Digitized and structured informed patient consent before contrast-enhanced computed tomography: feasibility and benefits in clinical routine.

BACKGROUND: To evaluate the feasibility and benefits of digitized informed patient consent (D-IPC) for contrast-enhanced CT and compare digitized documentation with paper-based, conventional patient records (C-PR). METHODS: We offered D-IPC to 2016 patients scheduled for a CT. We assessed patient history (e.g., CT examinations, malignant or cardiovascular diseases) and contraindications (red flags) for a CT (e.g., thyroid hyperfunction, allergies) using a tablet device. We evaluated the success rate of D-IPC and compared patient age between the subgroups of patients who were able or unable to complete D-IPC. We analyzed the prevalence of marked questions and red flags (RF). RF were compared with the documentation from C-PR. We estimated greenhouse gas (GHG) emissions for paperless workflow and provide a cost-benefit analysis. RESULTS: Overall, 84.4% of patients completed D-IPC. They were younger (median 61 years) than unsuccessful patients (65 years; p < 0.001). Patients who marked questions (21.7%) were older than patients without inquiries (median 63.9 vs 59.5 years; p < 0.001). The most prevalent RF was thyroid disease (23.8%). RF were considered critical for contrast-agent injection in 13.7%, requiring personalized preparation. The detection rate for RF documented with D-IPC was higher than for C-PR (n = 385 vs. 43). GHG emissions for tablet production are 80-90 times higher than for paper production. The estimated costs were slightly higher for D-IPC (+ 8.7%). CONCLUSION: D-IPC is feasible, but patient age is a relevant factor. Marked questions and RF help personalize IPC. The availability of patient history by D-IPC was superior compared to C-PR.

A method for labelling lesions for machine learning and some new observations on osteochondrosis in computed tomographic scans of four pig joints.

BACKGROUND: Osteochondrosis is a major cause of leg weakness in pigs. Selection against osteochondrosis is currently based on manual scoring of computed tomographic (CT) scans for the presence of osteochondrosis manifesta lesions. It would be advantageous if osteochondrosis could be diagnosed automatically, through artificial intelligence methods using machine learning. The aim of this study was to describe a method for labelling articular osteochondrosis lesions in CT scans of four pig joints to guide development of future machine learning algorithms, and to report new observations made during the labelling process. The shoulder, elbow, stifle and hock joints were evaluated in CT scans of 201 pigs. RESULTS: Six thousand two hundred fifty osteochondrosis manifesta and cyst-like lesions were labelled in 201 pigs representing a total volume of 211,721.83 mm3. The per-joint prevalence of osteochondrosis ranged from 64.7% in the hock to 100% in the stifle joint. The lowest number of lesions was found in the hock joint at 208 lesions, and the highest number of lesions was found in the stifle joint at 4306 lesions. The mean volume per lesion ranged from 26.21 mm3 in the shoulder to 42.06 mm3 in the elbow joint. Pigs with the highest number of lesions had small lesions, whereas pigs with few lesions frequently had large lesions, that have the potential to become clinically significant. In the stifle joint, lesion number had a moderate negative correlation with mean lesion volume at r = - 0.54, p < 0.001. CONCLUSIONS: The described labelling method is an important step towards developing a machine learning algorithm that will enable automated diagnosis of osteochondrosis manifesta and cyst-like lesions. Both lesion number and volume should be considered during breeding selection. The apparent inverse relationship between lesion number and volume warrants further investigation.

[Low-dose helical CT projection data restoration using noise estimation].

OBJECTIVE: To build a helical CT projection data restoration model at random low-dose levels. METHODS: We used a noise estimation module to achieve noise estimation and obtained a low-dose projection noise variance map, which was used to guide projection data recovery by the projection data restoration module. A filtering back-projection algorithm (FBP) was finally used to reconstruct the images. The 3D wavelet group residual dense network (3DWGRDN) was adopted to build the network architecture of the noise estimation and projection data restoration module using asymmetric loss and total variational regularization. For validation of the model, 1/10 and 1/15 of normal dose helical CT images were restored using the proposed model and 3 other restoration models (IRLNet, REDCNN and MWResNet), and the results were visually and quantitatively compared. RESULTS: Quantitative comparisons of the restored images showed that the proposed helical CT projection data restoration model increased the structural similarity index by 5.79% to 17.46% compared with the other restoration algorithms (P < 0.05). The image quality scores of the proposed method rated by clinical radiologists ranged from 7.19% to 17.38%, significantly higher than the other restoration algorithms (P < 0.05). CONCLUSION: The proposed method can effectively suppress noises and reduce artifacts in the projection data at different low-dose levels while preserving the integrity of the edges and fine details of the reconstructed CT images.

Osteochondrosis and other lesions in all intervertebral, articular process and rib joints from occiput to sacrum in pigs with poor back conformation, and relationship to juvenile kyphosis.

BACKGROUND: Computed tomography (CT) is used to evaluate body composition and limb osteochondrosis in selection of breeding boars. Pigs also develop heritably predisposed abnormal curvature of the spine including juvenile kyphosis. It has been suggested that osteochondrosis-like changes cause vertebral wedging and kyphosis, both of which are identifiable by CT. The aim of the current study was to examine the spine from occiput to sacrum to map changes and evaluate relationships, especially whether osteochondrosis caused juvenile kyphosis, in which case CT could be used in selection against it. Whole-body CT scans were collected retrospectively from 37 Landrace or Duroc boars with poor back conformation scores. Spine curvature and vertebral shape were evaluated, and all inter-vertebral, articular process and rib joints from the occiput to the sacrum were assessed for osteochondrosis and other lesions. RESULTS: Twenty-seven of the 37 (73%) pigs had normal spine curvature, whereas 10/37 (27%) pigs had abnormal curvature and all of them had wedge vertebrae. The 37 pigs had 875 focal lesions in articular process and rib joints, 98.5% of which represented stages of osteochondrosis. Five of the 37 pigs had focal lesions in other parts of vertebrae, mainly consisting of vertebral body osteochondrosis. The 10 pigs with abnormal curvature had 21 wedge vertebrae, comprising 10 vertebrae without focal lesions, six ventral wedge vertebrae with ventral osteochondrosis lesions and five dorsal wedge vertebrae with lesions in the neuro-central synchondrosis, articular process or rib joints. CONCLUSIONS: Computed tomography was suited for identification of wedge vertebrae, and kyphosis was due to ventral wedge vertebrae compatible with heritably predisposed vertebral body osteochondrosis. Articular process and rib joint osteochondrosis may represent incidental findings in wedge vertebrae. The role of the neuro-central synchondrosis in the pathogenesis of vertebral wedging warrants further investigation.

Impact of Morphotype on Image Quality and Diagnostic Performance of Ultra-Low-Dose Chest CT.

OBJECTIVES: The image quality of an Ultra-Low-Dose (ULD) chest CT depends on the patient's morphotype. We hypothesize that there is a threshold beyond which the diagnostic performance of a ULD chest CT is too degraded. This work assesses the influence of morphotype (Body Mass Index BMI, Maximum Transverse Chest Diameter MTCD and gender) on image quality and the diagnostic performance of a ULD chest CT. METHODS: A total of 170 patients from three prior prospective monocentric studies were retrospectively included. Renewal of consent was waived by our IRB. All the patients underwent two consecutive unenhanced chest CT acquisitions with a full dose (120 kV, automated tube current modulation) and a ULD (135 kV, fixed tube current at 10 mA). Image noise, subjective image quality and diagnostic performance for nine predefined lung parenchyma lesions were assessed by two independent readers, and correlations with the patient's morphotype were sought. RESULTS: The mean BMI was 26.6 ± 5.3; 20.6% of patients had a BMI > 30. There was a statistically significant negative correlation of the BMI with the image quality (ρ = -0.32; IC95% = (-0.468; -0.18)). The per-patient diagnostic performance of ULD was sensitivity, 77%; specificity, 99%; PPV, 94% and NPV, 65%. There was no statistically significant influence of the BMI, the MTCD nor the gender on the per-patient and per-lesion diagnostic performance of a ULD chest CT, apart from a significant negative correlation for the detection of emphysema. CONCLUSIONS: Despite a negative correlation between the BMI and the image quality of a ULD chest CT, we did not find a correlation between the BMI and the diagnostic performance of the examination, suggesting a possible use of the ULD protocol in obese patients.

Correlation between pleural tags on CT and visceral pleural invasion of peripheral lung cancer that does not appear touching the pleural surface.

OBJECTIVES: To evaluate the association between a sign and visceral pleural invasion (VPI) of peripheral non-small-cell lung cancer (NSCLC) that does not appear touching the pleural surface. METHODS: A total of 221 consecutive patients with NSCLC that did not appear touching the pleural surface, ≤ 3 cm in solid tumor diameter, and was surgically resected between January 2009 and December 2015 were included. We focused on the flat distortion of the tumor caused by an arch-shaped linear tag between the tumor and the pleura on CT and named it a bridge tag sign. We evaluated the associations between the clinicopathological features of the tumor, including the bridge tag sign, and VPI. We also evaluated the associations between histopathological findings and the bridge tag sign. The utility of the bridge tag sign in the diagnosis of VPI was statistically assessed. RESULTS: The bridge tag sign was observed in 48 (20.8%) patients. VPI was positive in 9 (4.1%) patients; among these, the bridge tag sign was positive in 8 patients. In multivariate analysis, a bridge tag sign was significantly associated with VPI. The bridge tag sign was associated with longer contact length of the pleura with the tumor and trapezoid type pleural retraction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of VPI were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively. CONCLUSIONS: A bridge tag sign on CT might improve the accuracy of the prediction of VPI. KEY POINTS: • We present the bridge tag sign which is defined as a flat distortion of an NSCLC tumor by an arch-shaped linear tag between the tumor and chest wall or interlobar fissure. • The bridge tag sign was an independent predictive factor for visceral pleural invasion. • The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of visceral pleural invasion were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

Vascular assessment in small bowel obstruction: can CT predict requirement for surgical intervention?

PURPOSE: Small bowel obstruction (SBO) is a common cause of emergency presentations for abdominal pain and can be complicated by mesenteric ischemia. Computed tomography is currently central to diagnosis and management planning. Currently accepted signs identify secondary effects of the root physiological insult, which is vascular obstruction. We hypothesized that with advancements in CT technology and reconstruction algorithms, we can now more closely interrogate the mesenteric vasculature for obstruction and more accurately predict the need for surgical intervention. METHODS: We retrospectively audited the charts of all patients presenting with a clinical diagnosis of SBO at a single institution in a 12-month period. Two blinded consultant radiologists were then asked to analyze 3D MIP reconstruction CT scans for vascular obstruction in addition to any currently accepted signs of ischemia. Comparison between vascular cutoff and accepted current signs in the need for surgical intervention and the presence of any signs of ischemia in theater were recorded. RESULTS: Vascular cutoff had a comparable, with a trend towards superiority, sensitivity and specificity and inter-observer agreement to currently accepted signs of ischemia. The absence of a cut off sign has an excellent negative predictive value for ischemia with only 2 (3.7%) patients demonstrating ischemia at surgery where the vascular cutoff sign was not seen to be present. CONCLUSION: Interrogating vascular obstruction using 3D MIP reconstructions in small bowel obstruction may be a more sensitive and specific sign for prediction of surgical intervention, possibly occurring earlier in the obstruction pathway.

Comparison of virtual computed tomography enteroscopy using carbon dioxide with small-bowel enteroclysis and capsule endoscopy in patients with small-bowel tuberculosis.

OBJECTIVE: Comparison of virtual CT enteroscopy (VCTE) using carbon dioxide with small-bowel enteroclysis (SBE) and capsule endoscopy (CE) in small-bowel tuberculosis (SBTB). METHODS: This prospective study comprised consecutive patients suspected to have SBTB. VCTE and SBE were performed on the same day and evaluated by independent radiologists. CE was performed within 2 weeks. VCTE was performed following insufflation of carbon dioxide via catheters in the jejunum and anorectum. A contrast-enhanced CT was followed by a delayed non-contrast CT. Image processing was done using virtual colonoscopy software. Findings on VCTE, SBE, and CE were compared. The final diagnosis of SBTB was based on either histopathological or cytological findings, response to antitubercular treatment, or a combination of these. RESULTS: Of the 55 patients in whom VCTE was performed, complete data was available in 52 patients. A final diagnosis of SBTB was established in 37 patients. All patients had VCTE and SBE. CE was performed in 34 patients. Adequate luminal distension was achieved in all patients with SBE and 35 patients with VCTE. SBE showed more strictures in jejunum (10.8%) and ileum (75.7%) compared with VCTE (jejunum, 8.1%, and ileum, 64.9%) and CE (jejunum, 5.9%, and ileum, 61.8%). However, difference was not statistically significant. VCTE revealed a greater length of strictures in both the jejunum and ileum compared with SBE and CE. CONCLUSION: VCTE allows adequate evaluation of the bowel in most patients with SBTB. It allows detection of greater length of abnormality in jejunum and ileum compared with SBE and CE. KEY POINTS: • The use of VCTE using CO2 bowel insufflation in patients with SBTB should be considered. • VCTE allows detection of a greater length of abnormality in the jejunum and ileum.

Association of quantitative CT lung density measurements and lung function decline in World Trade Center workers.

BACKGROUND: Occupational exposures at the WTC site after 11 September 2001 have been associated with presumably inflammatory chronic lower airway diseases. AIMS: In this study, we describe the trajectories of expiratory air flow decline, identify subgroups with adverse progression, and investigate the association of those trajectories with quantitative computed tomography (QCT) imaging measurement of increased and decreased lung density. METHODS: We examined the trajectories of expiratory air flow decline in a group of 1,321 former WTC workers and volunteers with at least three periodic spirometries, and using QCT-measured low (LAV%, -950 HU) and high (HAV%, from -600 to -250 HU) attenuation volume percent. We calculated the individual regression line slopes for first-second forced expiratory volume (FEV1 slope), identified subjects with rapidly declining ("accelerated decliners") and increasing ("improved"), and compared them to subjects with "intermediate" (0 to -66.5 mL/year) FEV1 slope. We then used multinomial logistic regression to model those three trajectories, and the two lung attenuation metrics. RESULTS: The mean longitudinal FEV1 slopes for the entire study population, and its intermediate, decliner, and improved subgroups were, respectively, -40.4, -34.3, -106.5, and 37.6 mL/year. In unadjusted and adjusted analyses, LAV% and HAV% were both associated with "accelerated decliner" status (ORadj , 95% CI 2.37, 1.41-3.97, and 1.77, 1.08-2.89, respectively), compared to the intermediate decline. CONCLUSIONS: Longitudinal FEV1 decline in this cohort, known to be associated with QCT proximal airway inflammation metric, is also associated with QCT indicators of increased and decreased lung density. The improved FEV1 trajectory did not seem to be associated with lung density metrics.

Differentiating benign from malignant pancreatic cysts on computed tomography.

PURPOSE: It is important to identify features on computed tomography (CT) that can distinguish between benign and premalignant or malignant pancreatic cysts to avoid unnecessary surgeries. This study investigated the preoperative diagnostic evaluation of cystic pancreatic lesions to determine how advanced imaging and clinical factors should guide management. METHODS: In total, 53 patients with 27 benign and 26 premalignant or malignant cysts were enrolled. CT features of the cysts were compared using univariate and multivariate analyses. RESULTS: On univariate analysis, a solid component (p < 0.01), septation (p < 0.01), location (p < 0.01), border (p < 0.01), wall enhancement (p = 0.01), lesion margins (p < 0.01), pancreatic atrophy (p = 0.04), and a cystic wall (p < 0.01) were all significantly different between benign and premalignant or malignant cysts. On multivariate analysis, only a solid component (p < 0.01) and septation (p < 0.01) were significant. CONCLUSION: A thin cystic wall, uniform homogeneity, a clear border, the presence of septation, pancreatic atrophy, and the absence of both wall enhancements and solid components were more frequently seen in benign cysts. A thick wall, lack of homogeneity, the presence of wall enhancements and solid components, absence of septation, only a small degree of pancreatic atrophy, and unclear borders were more frequent among premalignant or malignant cysts. The only CT features to differentiate benign from premalignant or malignant cysts were a solid component and septation.

[Progress of Lung Cancer Screening with Low Dose Helical Computed Tomography].

Lung cancer which represents characteristics of a heavy disease burden, a large proportion of advanced lung cancer and a low five-year survival rate is a threat to human health. It is essential to implement population-based lung cancer screening to improve early detection and early treatment. The National Lung Screening Trial (NLST) demonstrated that screening with low dose helical computed tomography (LDCT) may decrease lung cancer mortality, which brings hope for the early diagnosis and treatment of lung cancer. In recent years, great progresses have been made on research of lung cancer screening with LDCT. However, whether LDCT could be applied to large population-based lung cancer screening projects is still under debate. In this paper, we review the recent progresses on history of lung cancer screening with LDCT, selection of high-risk individuals, management of pulmonary nodules, performance of screening, acceptance of LDCT and cost-effectiveness.
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Initial Results from Mobile Low-Dose Computerized Tomographic Lung Cancer Screening Unit: Improved Outcomes for Underserved Populations.

INTRODUCTION: The National Lung Screening Trial (NLST) demonstrated that screening high-risk patients with low-dose computed tomography (CT) of the chest reduces lung cancer mortality compared with screening with chest x-ray. Uninsured and Medicaid patients usually lack access to this hospital-based screening test because of geographic and socioeconomic factors. We hypothesized that a mobile screening unit would improve access and confer the benefits demonstrated by the NLST to this underserved group, which is most at risk of lung cancer deaths. PATIENTS AND METHODS: We created a mobile unit by building a Samsung BodyTom portable 32-slice low-dose CT scanner into a 35-foot coach; it delivers high-quality images for both soft tissue and bone and includes a waiting area and high-speed wireless internet connection for fast image transfer. The unit was extensively tested to show robustness and stability of mobile equipment. This project was designed to screen uninsured and underinsured patients, otherwise with eligibility criteria identical to that of the National Lung Screening Trial, with the only difference being exclusion of patients eligible for Medicare (which provides financial coverage for CT-based lung cancer screening). RESULTS: We screened 550 patients (20% black, 3% Hispanic, 70% rural) with a male-to-female ratio of 1.1:1, median age 61 years (range, 55-64), and found 12 lung cancers at initial screen (2.2%), including 6 at stage I-II (58% of total lung cancers early stage) and 38 Lung-RADS 4 (highly suspicious) lesions that are being followed closely. Incidental findings included nonlung cancers and coronary artery disease. DISCUSSION: In this initial pilot study, using the first mobile low-dose whole body CT screening unit in the U.S., the initial cancer detection rate is comparable to that reported in the NLST, despite excluding patients over the age of 64 years who have Medicare coverage, but with marked improvement of screening rates specifically in underserved sociodemographic, racial, and ethnic groups and with better outcomes than conventionally found in the underserved and at lower cost per case. IMPLICATIONS FOR PRACTICE: This study shows clearly that a mobile low-dose CT scanning unit allows effective lung cancer screening for underserved populations, such as impoverished African Americans, Hispanics, Native Americans, or isolated rural groups, and has a pick-up rate of 1% for early stage disease. If confirmed in a planned randomized trial, this will be policy changing, as these groups usually present with advanced disease; this approach will produce better survival data at lower cost per case.

Computed tomographic development of physeal osteochondrosis in pigs.

BACKGROUND: Articular osteochondrosis follows a dynamic development pattern. Lesions arise, in incidence peaks compatible with failure of cartilage canal vessels during incorporation into bone, and can also resolve. Lesions that resolve before examination at a single time point will constitute false-negative diagnoses. The aim of the study was to identify physeal osteochondrosis lesions in pigs and monitor their development by computed tomography (CT), to determine if they follow a similar dynamic development pattern to articular osteochondrosis. RESULTS: Thirteen physes were evaluated bilaterally in up to eight biweekly CT scans from 18 male Landrace pigs age 70-180 days (total: 112 scans), generating 2912 scores. There were 1754 (60%) lesion-negative scores and 1158 (40%) lesion-positive scores. Positive scores comprised 138 lesions present at the start and 235 lesions that developed during the study, from 4 to 32 lesions per physis (median: 15 lesions). There were 1-2 peaks in the incidence curves for 12/13 examined physes, the exception being the proximal humerus. Positive scores also included 785 times that lesions persisted, from 1.3-4.8 examination intervals per lesion (median: 2.8 intervals). Negative scores included 190 times that lesions resolved, from 19 to 100% of lesions per physis (median: 65%). Lesions resolved by filling with bone from marginal sclerosis and reparative ossification centres. In the distal scapula and distal fibula, perichondrial new bone formation occurred that led to permanent enlargement of physeal regions. Angular limb deformity was not identified in any pig. CONCLUSIONS: Physeal osteochondrosis followed a similar dynamic development pattern to articular osteochondrosis. There were peaks in the incidence curves, compatible with failure of vessels during incorporation into bone. In some physes, osteochondrosis led to permanent enlargement, potentially relevant for decubital ulcers. The relationship between physeal osteochondrosis and angular limb deformity must be examined further in pigs over 6 months old in future.

Characteristic CT features of pheochromocytomas - probability model calculation tool based on a multicentric study.

OBJECTIVES: The aim of the study was to evaluate the CT features of adrenal tumors in an effort to identify features specific to pheochromocytomas and second, to define a feasible probability calculation model. METHODS: This multicentric retrospective study included patients from the period 2003 to 2017 with an appropriate CT examination and a histological diagnosis of an adrenal adenoma, pheochromocytoma, adrenocortical carcinoma, or metastasis. In total, 346 patients were suitable for the CT image analysis, which included evaluation of the largest diameter, the shape of the lesion, the presence of central necrosis and its margins, and the presence of an enhancing peripheral rim ("ring sign"). RESULTS: Pheochromocytomas have a significantly more spherical shape (P<0.001), whereas an elliptical shape significantly reduces the probability of a pheochromocytoma (odds ratio = 0.015), as does another shape (odds ratio = 0.006). A "ring sign" is also more frequent in pheochromocytomas compared to other adrenal tumors (P=0.001, odds ratio = 6.49). A sharp necrosis also increases the probability of a pheochromocytoma more than unsharp necrosis (odds ratio 231.6 vs. 20.2). The probability calculation model created on the basis of the results confirms a high sensitivity and specificity (80% and 95%). CONCLUSION: This study confirms the value of anatomical features in the assessment of adrenal masses with the ability to significantly improve the identification of pheochromocytomas. Advanced assessment of the tumor shape was defined and a original comprehensive calculating tool of the pheochromocytoma probability was created on the basis of the results presented here and could be used in clinical routine.

Wide-volume versus helical acquisition in unenhanced chest CT: prospective intra-patient comparison of diagnostic accuracy and radiation dose in an ultra-low-dose setting.

OBJECTIVES: Diagnostic performance and potential radiation dose reduction of wide-area detector CT sequential acquisition ("wide-volume" acquisition (WV)) in unenhanced chest examination are unknown. This study aims to assess the image quality, the diagnostic performance, and the radiation dose reduction of WV mode compared with the classical helical acquisition for lung parenchyma analysis in an ultra-low-dose (ULD) protocol. METHODS: After Institutional Review Board Approval and written informed consent, 64 patients (72% men; 67.6 ± 9.7 years old; BMI 26.1 ± 5.3 kg/m2) referred for a clinically indicated unenhanced chest CT were prospectively included. All patients underwent, in addition to a standard helical acquisition (120 kV, automatic tube current modulation), two ULD acquisitions (135 kV, fixed tube current at 10 mA): one in helical mode and one in WV mode. Image noise, subjective image quality (5-level Likert scale), and diagnostic performance for the detection of 9 predetermined parenchymal abnormalities were assessed by two radiologists and compared using the chi-square or Fisher non-parametric tests. RESULTS: Subjective image quality (4.2 ± 0.7 versus 4.2 ± 0.8, p = 0.56), image noise (41.7 ± 8 versus 40.9 ± 8.7, p = 0.3), and diagnostic performance were equivalent between ULD WV and ULD helical. Radiation dose was significantly lower for the ULD WV acquisition (mean dose-length product 14.1 ± 1.3 mGy cm versus 15.8 ± 1.3, p < 0.0001). CONCLUSION: An additional 11% dose reduction is achieved with the WV mode in ULD chest CT with fixed tube current, with equivalent image quality and diagnostic performance when compared with the helical acquisition. KEY POINTS: • Image quality and diagnostic performance of ultra-low-dose unenhanced chest CT are identical between wide-volume mode and the reference helical acquisition. • Wide-volume mode allows an additional radiation dose reduction of 11% (mean dose-length product 14.1 ± 1.3 mGy cm versus 15.8 ± 1.3, p < 0.0001).

Impact of transient hepatic attenuation differences on computed tomography scans in the diagnosis of acute gangrenous cholecystitis.

BACKGROUND: We examined the utility of transient hepatic attenuation differences (THADs) detected in the arterial phase of computed tomography for the diagnosis of acute gangrenous cholecystitis (AGC). METHODS: We examined 83 consecutive patients who underwent cholecystectomy within 72 h of undergoing three-phase dynamic computed tomography scans for acute cholecystitis between 2009 and 2018 (histopathological examination later confirmed 42 with AGC, 41 without). The THAD volume (cm3 ) was calculated by multiplying the total area of the enhancing lesions (traced on axial images) by the thickness of the scan (0.5-cm slices). We evaluated the sensitivity and specificity of the THAD volume and other computed tomography findings of AGC. RESULTS: The THAD volume was significantly larger in the AGC group than in the non-gangrenous acute cholecystitis group (P < 0.0001). The cutoff value of 78 cm3 , determined using a receiver operating characteristics curve, yielded a sensitivity of 88.1% and specificity of 75.6% for detecting AGC. Multivariate analysis revealed a THAD volume of >78 cm3 to be an independent predictor of AGC. CONCLUSIONS: Acute gangrenous cholecystitis can be diagnosed using THAD volume, resulting in improved treatment and fewer serious complications.