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Background Lung cancer is the leading cause of cancer-related deaths throughout the world. Chest computed tomography (CT) is now widely used in the screening and diagnosis of lung cancer due to its effectiveness. Radiologists must identify each small nodule shadow from 3D volume images, which is very burdensome and often results in missed nodules. To address these challenges, we developed a computer-aided detection (CAD) system that automatically detects lung nodules in CT images. Methods A total of 1997 chest CT scans were collected for algorithm development. The algorithm was designed using deep learning technology. In addition to evaluating detection performance on various public datasets, its robustness to changes in radiation dose was assessed by a phantom study. To investigate the clinical usefulness of the CAD system, a reader study was conducted with 10 doctors, including inexperienced and expert readers. This study investigated whether the use of the CAD as a second reader could prevent nodular lesions in lungs that require follow-up examinations from being overlooked. Analysis was performed using the Jackknife Free-Response Receiver-Operating Characteristic (JAFROC). Results The CAD system achieved sensitivity of 0.98/0.96 at 3.1/7.25 false positives per case on two public datasets. Sensitivity did not change within the range of practical doses for a study using a phantom. A second reader study showed that the use of this system significantly improved the detection ability of nodules that could be picked up clinically (p = 0.026). Conclusions We developed a deep learning-based CAD system that is robust to imaging conditions. Using this system as a second reader increased detection performance.

Digital subtraction angiography (DSA) is frequently applied in interventional radiology (IR). When DSA is not useful due to misregistration, digital angiography (DA) as an alternative option is used. In DA, the harmonization function (HF) works in real time by harmonizing the distribution of gray steps or reducing the dynamic range; thus, it can compress image gradations, decrease image contrast, and suppress halation artifacts. DA with HF as a good alternative to DSA is clinically advantageous in body IR for generating DSA-like images and simultaneously reducing various motion artifacts and misregistrations caused by patient body motion, poor breath-holding, bowel and ureter peristalsis, and cardiac pulsation as well as halation artifacts often stemming from the lung field. Free-breath DA with HF can improve body IR workflow and decrease the procedure time by reducing the risk of catheter dislocation and using background structures as anatomical landmarks, demonstrating reduced radiation exposure relative to DSA. Thus, HF should be more widely and effectively utilized for appropriate purposes in body IR. This article illustrates the basic facts and principles of HF in DA, and demonstrates clinical advantages and limitations of this function in body IR. Electronic supplementary material The online version of this article (10.1007/s11604-020-00990-w) contains supplementary material, which is available to authorized users.

A hand hygiene behavior questionnaire and environmental survey were conducted regarding the mobile X-ray system used in the emergency room. As a result, among a total of 22 radiological technologists at this hospital who replied to the questionnaire, 18 wore disposable gloves when performing X-ray imaging using the mobile system. Among those 18, 11 were found to touch computed radiology (CR) consoles and HIS/RIS terminals while still wearing the gloves, thus creating the potential for spreading pathogens to other medical equipment and systems. According to the results of an environmental survey of the emergency imaging preparation room, the highest levels of bacteria were detected on CR consoles and HIS/RIS terminals. A possible reason for this is that these locations are not wiped down and cleaned as a part of routine cleaning and disinfection protocols, thus demonstrating the importance of cleaning and disinfection. Hand hygiene by medical personnel and appropriate cleaning and disinfecting of the working environment are important for preventing the spread of nosocomial infections. Radiological technologists are also required to take effective measures against infections in consideration of the high frequency of contact with both infected patients and patients susceptible to infections.

We describe computed tomographic (CT) findings in two patients with cardiac injury who required emergency surgery. Chest CT revealed an unexpected low-density area, indicating pericardial effusion. We emphasize that, given the situation of trauma, an incidental low-density area covering more than two slices along the inferior border of the heart suggests pericardial effusion, which may be caused by cardiac injury.

Metastatic calcifications according to histopathologic and scintigraphic findings have been well-defined. The authors report a postoperative case of hyperparathyroidism with multiple metastatic calcifications in the lung, kidney, stomach, heart, and vessels that were primarily detected by bone scintigraphy and demonstrated by CT. Tc-99m MDP bone scintigraphy showed a markedly increased accumulation of radioactivity diffusely throughout the lung, left ventricular wall, both kidneys, and the gastric cardia and body. In the lung, plain films showed almost normal lung. CT, however, demonstrated patchy, slightly increased densities in the lung bilaterally. Cardiac CT indicated a considerably increased density of the ventricular myocardium and remarkable calcification in or near the atrioventricular septum or annulus fibrosus. Upper abdominal CT demonstrated increased densities diffusely throughout the gastric mucosa and renal cortex. Only vascular calcifications were depicted by plain films. Using both bone scintigraphy and CT provides accurate information about each lesion and each tissue, allowing precise diagnosis of even a questionable lesion in the early stage of metastatic calcification. Early diagnosis and early therapy offer the best chance for cure or palliative therapy.

Solutions of the qKZ equation associated with the quantum affine algebra $U_q(\hat{sl}_2)$ and its two dimensional evaluation representation are studied. The integral formulae derived from the free field realization of intertwining operators of $q$-Wakimoto modules are shown to coincide with those of Tarasov and Varchenko., Published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/

The indication, complication, diagnostic finding, pit fall of pulmonary angiogram(PAG) for the diagnosis of acute pulmonary embolism (PE) were described. Current non-invasive test such as V/Q scan, CT and MR have been accepted as useful tools for diagnosis and decision making of the treatment of PE. The indications of PAG seems to be limited as the cases with 1) discrepancy between clinical findings and the results of V/Q scan, 2) high suspicious of PE with some risk of anti-coagulant therapy or presenting complication of this therapy, 3) prior to IVR. However, the PAG is still accepted as final clinical test to make a decision of PE or not.

Purpose: To assess the efficacy of the Spring filter during interventional treatment of deep venous thrombosis in vivo. Material and Methods: A model of inferior vena cava thrombosis was used. Part I: the thrombus was treated by the pulse-spray technique (PT) (urokinase 250,000 IU; n=7) or a rotatory basket catheter, Thrombolizer (MT) (activated with compressed air at 7 atm; n=5). Part II: Following placement of a Spring filter, the animal underwent PT (n=5) or MT (n=5). Based on the results of part I, the treatment protocol was modified (PT, urokinase 500,000 IU; MT, compressed air at 8 atm). Embolus volumes trapped by the filter and found in the lungs were calculated and the filtering efficacy quantified. Results: Part I: Pulmonary emboli (1 to 4 mm in diameter) were observed in 3 animals in the PT group and 1 animal in the MT group, respectively. Median reduction in thrombus volume was 21% and 4% by PT and MT, respectively. Part II: In the PT group, 58% and 100% of the total embolus load was trapped in 2 animals, while the filter failed to trap emboli (1 to 1.5 mm in diameter) in 1 animal. In the remaining 2 animals, no embolus was found trapped by the filter or in the lungs. In the MT group, 55–97% (median 83%) of the embolus load was trapped. Emboli found in the lungs did not exceed 4 mm in diameter. Conclusion: Preceding interventional treatment of venous thrombosis with placement of the Spring filter reduced the embolic burden on the lungs.

To evaluate in vitro the functional efficacy of a new variable-sized, temporary venous filter, the Spring filter (SF). The SF was tested in a flow phantom, using flexible, thin-walled polyethylene tubes 12, 14, and 16 mm in diameter to simulate veins. Clots of three sizes were used: 6 × 10 mm, 6 × 20 mm, 9 × 20 mm. Filter deployment was performed, ensuring that its functional diameter after placement was a predetermined multiple of the radius ‘r’ of the tube: 3.0r, 2.8r, 2.6r, 2.4r. The terminal coil was visually examined for changes in configuration. Clot retention by the filter for a period of 3 min was recorded as a success. The baseline intraluminal pressure and the maximum pressure reached after clot introduction were recorded. The trapping ability was calculated from the results for 10 clots. The effect of the following parameters on filter function were studied: size of embolus, caliber of simulated vein, and functional diameter of filter. The filter configuration was stable. Not a single instance of axial tilting occurred on deployment. Functional diameter was the major determinant of filter function. One hundred percent of clots were trapped irrespective of clot size and tube caliber when the functional diameter was 3.0r. Only 73% (95% confidence interval (CI): 57%–88%) and 77% (95% CI: 61%–92%) of small emboli were held up by the filter when the functional diameters were 2.6r and 2.4r, respectively (p = 0.0001). A significant reduction in clot trapping was encountered even with medium clots when the functional diameter was 2.4r (p = 0.02). Against the background of available data on retrievable vena caval filters, the current model of SF warrants further investigation.

Four different polymers used in commercial angiographic catheters were compared in vitro with respect to their ability to activate the complement system.Commercially available angiographic catheters made from one of the following plastics were used: polyamide, polyethylene, polyurethane, and polytetrafluoroethylene. Silicone-coated latex urinary catheters served as the reference standard. Each catheter was cut into 20-mm segments, immersed in a polypropylene tube containing fresh serum from a volunteer donor, and incubated at 37 degrees C. Samples were drawn at 15 minutes, 1 hour, and 6 hours; C3 activation products (C3AP) and the terminal complement complex (TCC) content were estimated with enzyme immunoassays.By 1 hour, a significant increase in C3AP and TCC concentrations was observed with all angiographic catheters relative to controls (P.01-.001). The time-concentration plots for both C3AP and TCC were steepest for polyamide. C3AP concentrations relative to controls were significantly higher with exposure to polyamide compared with polyurethane at 1 hour (P.01), and with both polyethylene and polyurethane at 6 hours (P.01). Polytetrafluoroethylene induced larger amounts of C3AP formation by 6 hours than polyethylene and polyurethane (P.05). However, polytetrafluoroethylene was associated with the lowest relative median concentrations of TCC; the difference with polyamide was significant at 6 hours (P.001). As with C3AP, differences in TCC generation between polyethylene and polyurethane were marginal at all observation points (P.05).All the polymers tested activated the complement system. Activation was most prominent with exposure to polyamide and least marked with polyurethane.