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*

A thymoma often occurs in patients with myasthenia gravis, but the development of multiple thymoma is very rare. The authors report the radiologic and pathologic findings of multiple invasive thymoma in a 59-year-old male with myasthenia gravis.
Humans ; Male ; Middle Aged ; Myasthenia Gravis* ; Thymoma*

Pneumothorax, pneumomediastinum and pneumopericardium usually develop during emergency situations and these conditions may result in cardiopulmonary compromise, so an early and accurate diagnosis is seen as crucial for proper treatment. For diagnosis of pneumothorax, pneumomediastinum and pneumopericardium, chest radiography is a primary modality and CT can help for diagnosing them earlier and detecting associated abnormalities. The purpose of this pictorial essay is to describe the pathophysiology, various radiographic signs and diagnostic pitfalls of pneumothorax, pneumomediastinum and peumopericardium on chest radiographs that are correlated with CTs, and to aid the physician in the radiographic diagnosis.
Diagnosis ; Emergencies ; Mediastinal Emphysema* ; Pneumopericardium* ; Pneumothorax* ; Radiography ; Radiography, Thoracic ; Thorax

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.

PURPOSE: The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. MATERIALS AND METHODS: From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. RESULTS: 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration (p < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn (p < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. CONCLUSION: Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules or focal GGA are found on the low-dose CT performed in asymptomatic patients with peripheral blood eosinophilia. Short interval follow-up should be recommended to avoid invasive procedures or unnecessary aggressive treatment due to mistaking these lesions as lung cancer or metastatic malignancy.
Early Detection of Cancer ; Eosinophilia ; Eosinophils ; Female ; Follow-Up Studies ; Health Promotion ; Humans ; Lung Neoplasms* ; Lung* ; Male ; Mass Screening* ; Parasites ; Pulmonary Eosinophilia* ; Seasons ; Smoke ; Smoking ; 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

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

Extragastrointestinal stromal tumor (EGIST) has been reported to occur only rarely, and the cases of this disease appearing as cystic masses are also known to be very infrequent. Along with a review of the related articles, we report here on a case of EGIST arising from the omentum that was seen as a multiloculated large cystic mass with multiple thick septa and a solid component.
Omentum*

PURPOSE: To evaluate the NMR relaxation properties and imaging characteristics of tissue-specificity for a newly developed macromolecular MR agent. MATERIALS AND METHODS: Phthalocyanine (PC) was chelated with paramagnetic ion, Mn. 2.01g(5.2 mmol) of Phthalocyanine was mixed with 0.37g (1.4 mmol) of Mn chloride at 310 degrees C for 36 hours and then purified by chromatography (CHC13/CH3OH 98/2 v/v, Rf, 0.76) to obtain 1.04g (46%) of MnPC (molecular weight = 2000d), The T1/T2 relaxivity of MnPC was measured in 1.5T(64 MHz) MR using 0.1 mM MnPC. The MR image characteristics of MnPC was evaluated using spin-echo (TR/TE = 500/14 msec) and gradient-echo (FLASH) (TR/TE = 80/4 msec, flip angle = 60) techniques in 1.5T MR scanner. The images of rabbit liver were obtained every 10 minutes up to 4 hours. To study the effect of concentration on image, 20 mM, 50 mM, 100 mM of MnPC were tested. RESULTS: The relaxivities of MnPC at 1.5T (64MHz) were R1 = 7.28 mM-1S-1, R2 = 55.56 mM-1S-1. Compared to the values of Gd-DTPA (R1[= 4.8 mM-1S-1), R2[= 5.2 mM-1S-1]), both T1/T2 relaxivities of MnPC were higher than those of Gd-DTPA. For both of SE and FLASH techniques, the contrast enhancement reached maximum at 10 minutes after bolus injection and the enhancement continued for more than 2 hours. When compared with small molecular weight liver agents such as Gd-EOB-DTPA, Gd-BOPTA and MnDPDP, MnPC was characterized by more prolonged enhancement time. The time course of MR images also revealed biliary excretion of MnPC. CONCLUSION: We developed a new macromolecular MR agent, MnPC. The relaxivities of MnPC were higher than those of small molecular weight Gd-chelate. Hepatic uptake and biliary excretion of MnPC suggests that this agent is a new liver-specific MR agent.
Chromatography ; Gadolinium DTPA ; Liver ; Molecular Weight ; Relaxation

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.