Objective: To compare the effects of bone suppression imaging using deep learning (BSp-DL) based on a generative adversarial network (GAN) and bone subtraction imaging using a dual energy technique (BSt-DE) on radiologists’ performance for pulmonary nodule detection on chest radiographs (CXRs). Materials and Methods: A total of 111 adults, including 49 patients with 83 pulmonary nodules, who underwent both CXR using the dual energy technique and chest CT, were enrolled. Using CT as a reference, two independent radiologists evaluated CXR images for the presence or absence of pulmonary nodules in three reading sessions (standard CXR, BSt-DE CXR, and BSp-DL CXR). Person-wise and nodule-wise performances were assessed using receiver-operating characteristic (ROC) and alternative free-response ROC (AFROC) curve analyses, respectively. Subgroup analyses based on nodule size, location, and the presence of overlapping bones were performed. Results: BSt-DE with an area under the AFROC curve (AUAFROC) of 0.996 and 0.976 for readers 1 and 2, respectively, and BSp-DL with AUAFROC of 0.981 and 0.958, respectively, showed better nodule-wise performance than standard CXR (AUAFROC of 0.907 and 0.808, respectively; p ≤ 0.005). In the person-wise analysis, BSp-DL with an area under the ROC curve (AUROC) of 0.984 and 0.931 for readers 1 and 2, respectively, showed better performance than standard CXR (AUROC of 0.915 and 0.798, respectively; p ≤ 0.011) and comparable performance to BSt-DE (AUROC of 0.988 and 0.974; p ≥ 0.064). BSt-DE and BSp-DL were superior to standard CXR for detecting nodules overlapping with bones (p < 0.017) or in the upper/middle lung zone (p < 0.017). BSt-DE was superior (p < 0.017) to BSp-DL in detecting peripheral and sub-centimeter nodules. Conclusion BSp-DL (GAN-based bone suppression) showed comparable performance to BSt-DE and can improve radiologists’ performance in detecting pulmonary nodules on CXRs. Nevertheless, for better delineation of small and peripheral nodules, further technical improvements are required.

Objective: To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patientswith breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventionaldiffusion-weighted imaging (cDWI). Materials and Methods: Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm2 (cDWI800and cDWI1500) and sDWI at b-values of 1000 and 1500 s/mm2 (sDWI1000 and sDWI1500). Qualitative analysis (normal glandulartissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI setsand the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI setin 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test,one-way analysis of variance, and Cochran’s Q test. Results: All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasingb-values, regardless of the type of imaging (synthetic or conventional) (p< 0.001). Additionally, sDWI1500 provided better lesionconspicuity than cDWI1500 (3.52 ± 0.92 vs. 3.39 ± 0.90, p< 0.05). Although cDWI1500 showed better normal glandular tissuesuppression and overall image quality than sDWI1500 (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively;p< 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater insDWI1500 than in cDWI1500 (0.63 ± 0.17 vs. 0.55 ± 0.18, p< 0.001). Conclusion sDWI1500 can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity,better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI1500.

Dermoid cysts are benign congenital tumors composed of keratinizing squamous epithelium and dermal derivatives. They account for less than 1% of all intracranial tumors and are rarely exhibited at the base of the skull. To the best of our knowledge, only one case report has presented computed tomography and conventional T1-weighted magnetic resonance (MR) findings that revealed an infratemporal dermoid cyst. In the present study, we report an unusual case of a dermoid cyst in the right infratemporal fossa, which was incidentally detected by MR imaging with the Dixon technique. This article also highlights the importance of meticulous radiological review and the usefulness of the Dixon technique in everyday clinical practice.
Dermoid Cyst* ; Epithelium ; Magnetic Resonance Imaging ; Skull Base* ; Skull*

Dermoid cysts are benign congenital tumors composed of keratinizing squamous epithelium and dermal derivatives. They account for less than 1% of all intracranial tumors and are rarely exhibited at the base of the skull. To the best of our knowledge, only one case report has presented computed tomography and conventional T1-weighted magnetic resonance (MR) findings that revealed an infratemporal dermoid cyst. In the present study, we report an unusual case of a dermoid cyst in the right infratemporal fossa, which was incidentally detected by MR imaging with the Dixon technique. This article also highlights the importance of meticulous radiological review and the usefulness of the Dixon technique in everyday clinical practice.
Dermoid Cyst* ; Epithelium ; Magnetic Resonance Imaging ; Skull Base* ; Skull*

Arachnoid cysts (AC) are intraarachnoidal cerebrospinal fluid collections, and account for 1% of all intracranial space-occupying lesions. Intracystic hemorrhage of the AC can occur spontaneously, but this is an extremely rare event. Herein, we present a case of hemorrhagic AC in a nontraumatic patient in the left middle cranial fossa. We also performed relevant literature review on this disease.
Arachnoid Cysts ; Arachnoid* ; Cerebrospinal Fluid ; Cranial Fossa, Middle ; Hemorrhage* ; Humans ; Magnetic Resonance Imaging ; Rupture

PURPOSE: Before laparoscopic gastrectomy for gastric cancer can be planned, it is very important to know the precise location of the tumor. The aim of this study was to evaluate 3 methods of predicting the exact location of the tumor: preoperative gastrofibroscopy (GFS), preoperative computed tomography gastroscopy (CT), and intraoperative gastroscopy-guided laparoscopy (Lap). METHODS: In this study, 15 patients were prospectively identified, and endoscopic clips were preoperatively placed on the proximal 1 cm of the tumor, at the angle on the greater curvature and opposite the angle on the greater curvature. The distances between the pylorus and the proximal tumor clip (PT), the angle clip (PA), the greater curvature clip (PG), and the gastroesophageal junction were measured by preoperative GFS, preoperative CT, intraoperative Lap, and visual inspection (Vis). RESULTS: PT, PA, and PG values measured by preoperative GFS differed significantly from the Vis values (P < 0.01). However, preoperative CT measurements of PT, PA, and PG did not differ from the Vis values (P = 0.78, P = 0.48, and P = 0.53, respectively). Intraoperative Lap and Vis PT values differed by only 1.1 cm on an average (P = 0.10), but PA and PG values varied by 1.9 and 3.4 cm, respectively (P = 0.01 for both). CONCLUSION: Endoscopic clipping combined with preoperative CT gastroscopy is more useful than preoperative GFS for preoperatively predicting the location of early gastric cancers and will be helpful for planning laparoscopic gastrectomy.
Esophagogastric Junction ; Gastrectomy ; Gastroscopy ; Humans ; Laparoscopy ; Prospective Studies ; Pylorus ; Stomach Neoplasms ; Tomography, X-Ray Computed

A trocar site hernia is a rare complication. We report a patient who had an abdominal wall mass at a previous trocar site after laparoscopic distal gastrectomy. It was diagnosed as omental herniation and fat necrosis. We conclude that patients with trocar site masses exhibiting fat density on a computed tomography scan could be followed up without surgery, and that fascial defects located at 10-mm or larger trocar sites should be closed whenever possible to prevent hernia formation.
Abdominal Wall ; Fat Necrosis ; Gastrectomy ; Hernia ; Humans ; Laparoscopy ; Omentum ; Stomach Neoplasms ; Surgical Instruments

PURPOSE: To describe the CT and clinical features of tuberculosis involving the right middle lobe of the lung. MATERIALS AND METHODS: Among patients diagnosed with pulmonary tuberculosis at our hospital during the past three years, 16 cases (mean age of patients: 72 years) were reviewed for radiological and clinical presentation of patients that underwent CT and chest radiography and showed mainly right middle lobe involvement. RESULTS: Middle lobe collapse or consolidation (n=16) and bronchial stenosis or obstruction without the presence of soft tissue masses (n=15) were the main findings. Enlarged mediastinal or hilar lymph nodes (n=15), cavities within consolidated tissue (n=2), ill-defined centrilobular nodules (n=12), a tree-in-bud appearance (n=10), focal consolidations (n=7) and small nodules (n=4) were found. All patients were older than 64 years and most complained of non-specific symptoms. A sputum smear for AFB was positive in four cases. CONCLUSION: A diagnosis of tuberculosis in the right middle lobe is suggested in older patients with following CT findings: 1) middle lobe collapse or consolidation; 2) middle lobe bronchus stenosis or obstruction without the presence of soft tissue masses; 3) mediastinal or hilar lymphadenopathy; 4) cavities within consolidation, and centrilobular nodules with branching linear structure in the adjacent lungs. Further evaluation such as bronchoscopy is recommended for confirmation even when the sputum smear for AFB is negative.
Bronchi ; Bronchoscopy ; Constriction, Pathologic ; Diagnosis ; Humans ; Lung* ; Lymph Nodes ; Lymphatic Diseases ; Radiography ; Sputum ; Thorax ; Tuberculosis ; Tuberculosis, Pulmonary*

PURPOSE: To evaluate the imaging findings of abdominal extraosseous plasma cell neoplasm. MATERIALS AND METHODS: From April 2000 to January 2005, eight patients (four men, four women; mean age, 50.6 years) with pathologically proved, extraosseous plasma cell neoplasm involving the abdominal organs were included in this study. The diagnoses were based on consensus agreement between two radiologists who retrospectively reviewed CT, ultrasonography, and enteroclysis findings. We evaluated the findings by focusing on the location, size, margin, and enhancement pattern of the lesion, and lymphadenopathy on each image. RESULTS: There were multiple myeloma in four patients and extramedullary plasmacytoma in the remaining four. Involved abdominal organs were the liver (n = 4), spleen (n = 4), lymph node (n = 3), stomach (n = 1), small bowel (n = 1), and colon (n = 1). The hepatic involvement of plasma cell neoplasm presented as a homogeneous, well-defined, solitary mass (n = 1), multiple nodules (n = 1), and hepatomegaly (n = 2). Its involvement of the spleen and lymph node appeared as splenomegaly and lymphadenopathy, respectively. Its involvement of the gastrointestinal tract including the stomach, small bowel, and colon, presented as a homogeneous, diffuse wall thickening or mass in the gastrointestinal tract. CONCLUSION: Abdominal extraosseous plasma cell neoplasm involves occasionally the liver, spleen, and lymph node, and rarely the gastrointestinal tract. When we encounter a well-defined, homogeneous lesion of the abdominal organs in patients diagnosed or suspected as having plasma cell neoplasm, we should consider its involvement of the abdominal organs.
Colon ; Consensus ; Diagnosis ; Female ; Gastrointestinal Tract ; Hepatomegaly ; Humans ; Liver ; Lymph Nodes ; Lymphatic Diseases ; Male ; Multiple Myeloma ; Neoplasms, Plasma Cell* ; Plasma Cells* ; Plasma* ; Plasmacytoma ; Retrospective Studies ; Spleen ; Splenomegaly ; Stomach ; Ultrasonography

Intussusception is rare in adults accounting for 5% of all cases. It can be caused by various lesions but is rarely the result of trauma. Recently we encountered a case of adult intussusception after blunt abdominal trauma without any other leading causes. We report this case with a review of the relevant literatures.
Abdomen, Acute ; Adult* ; Humans ; Intussusception*