Added value of 40 keV virtual monoenergetic images for diagnosing malignant pleural effusion on chest CT.

OBJECTIVE: This study aimed to evaluate the added value of 40 keV virtual mono-energetic images (VMIs) obtained from dual-layer detector CT (DLCT) for diagnosing malignant pleural effusion (MPE) in patients presenting with unilateral pleural effusion on chest CT. MATERIALS AND METHODS: This retrospective study included 75 patients with unilateral pleural effusion who underwent contrast-enhanced chest CT scans using DLCT. Quantitative and qualitative assessments of the visibility of pleural thickening were conducted on both conventional 120 kVp images and 40 keV VMIs. Two independent radiologists reviewed chest CT scans with or without 40 keV VMIs to detect pleural nodules or nodular thickening for the diagnosis of MPE. Diagnostic performances were compared and independent predictors of MPE were identified through multivariate logistic regression analysis using CT and clinicopathologic findings. RESULTS: Pleural thickening associated with MPE demonstrated a higher contrast-to-noise ratio value and greater visual conspicuity in 40 keV VMIs compared to benign effusions (p < 0.05). For both readers, the use of 40 keV VMIs significantly improved (p < 0.05) the diagnostic performance in terms of sensitivity and area under the curve (AUC) for diagnosing MPE through the detection of pleural nodularity. Inter-observer agreements between the two readers were substantial for both 120 kVp images alone and the combined use of 40 keV VMIs. Initial cytology results and pleural nodularity at 40 keV were identified as independent predictors of MPE. CONCLUSION: The use of 40 keV VMIs from DLCT can improve diagnostic performance of readers in detecting MPE among patients with unilateral pleural effusion.

High-Grade Surface Osteosarcoma of the Rib Mimicking a Neurogenic Tumor: Radiologic and Pathologic Findings.

Osteosarcoma commonly occurs in the intramedullary cavity of long bones such as the femur, tibia, and humerus in children and adolescents. Osteosarcoma occurring as a primary tumor in the chest wall is rare. Only a limited number of such cases have been documented in the existing literature. Herein, we present radiologic and pathologic findings of a high-grade surface osteosarcoma of the rib mimicking a neurogenic tumor in a 44-year-old woman.

Left-Side Contrast-Injection-Induced Pseudopathologic Vertebral Enhancement in Oncology Patients without Venous Obstruction: A Report of Two Cases.

The appearance of sclerotic bone lesions in contrast-enhanced computed tomography (CT) scans is often a significant concern for the possible presence of metastatic disease, especially in individuals with a known history of cancer. Prior research has demonstrated that in cases where patients suffer from thrombosis in major veins like the superior vena cava or the brachiocephalic vein, vertebral venous congestion can create imaging patterns on CT scans that resemble sclerotic bone metastases. However, instances of such imaging findings in patients without any form of venous obstruction are not commonly reported. In this study, we present cases of pseudopathologic vertebral enhancement observed consistently following left-side contrast injections in cancer patients devoid of venous obstruction. We aim to discuss and propose a potential mechanism for this phenomenon, drawing attention to a less commonly recognized diagnostic consideration in oncological imaging.

Airspace Enlargement with Fibrosis in a Young Heavy Smoker Mimicking Diffuse Cystic Lung Disease.

The widespread use of computed tomography (CT) has led to the increased recognition of cystic lung lesions. Multiple pulmonary cysts can be observed in heterogeneous disorders called diffuse cystic lung diseases (DCLDs), which include pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, lymphocytic interstitial pneumonia, and Birt-Hogg-Dubé syndrome. Recently, airspace enlargement with fibrosis (AEF) has been recognized as an entity on the spectrum of smoking-related lung diseases. We report a young male heavy smoker presenting diffuse pulmonary cysts on chest CT with suspected DCLD. However, histopathological examination of the surgical biopsy specimen revealed dilated emphysematous cysts with prominent mural fibrosis, consistent with AEF.

Application of Highly Flexible Adaptive Image Receive Coil for Lung MR Imaging Using Zero TE Sequence: Comparison with Conventional Anterior Array Coil.

(1) Background: Highly flexible adaptive image receive (AIR) coil has become available for clinical use. The present study aimed to evaluate the performance of AIR anterior array coil in lung MR imaging using a zero echo time (ZTE) sequence compared with conventional anterior array (CAA) coil. (2) Methods: Sixty-six patients who underwent lung MR imaging using both AIR coil (ZTE-AIR) and CAA coil (ZTE-CAA) were enrolled. Image quality of ZTE-AIR and ZTE-CAA was quantified by calculating blur metric value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of lung parenchyma. Image quality was qualitatively assessed by two independent radiologists. Lesion detection capabilities for lung nodules and emphysema and/or lung cysts were evaluated. Patients' comfort levels during examinations were assessed. (3) Results: SNR and CNR of lung parenchyma were higher (both p < 0.001) in ZTE-AIR than in ZTE-CAA. Image sharpness was superior in ZTE-AIR (p < 0.001). Subjective image quality assessed by two independent readers was superior (all p < 0.05) in ZTE-AIR. AIR coil was preferred by 64 of 66 patients. ZTE-AIR showed higher (all p < 0.05) sensitivity for sub-centimeter nodules than ZTE-CAA by both readers. ZTE-AIR showed higher (all p < 0.05) sensitivity and accuracy for detecting emphysema and/or cysts than ZTE-CAA by both readers. (4) Conclusions: The use of highly flexible AIR coil in ZTE lung MR imaging can improve image quality and patient comfort. Application of AIR coil in parenchymal imaging has potential for improving delineation of low-density parenchymal lesions and tiny nodules.

Bone Suppression on Chest Radiographs for Pulmonary Nodule Detection: Comparison between a Generative Adversarial Network and Dual-Energy Subtraction.

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.

Prediction of the possibility of laparoscopic reduction of Petersen's hernia after gastrectomy: multicenter observational cohort study.

INTRODUCTION: Petersen's hernia (PH) is a potentially fatal complication of bowel infarction that is difficult to treat by laparoscopic reduction. AIM: To define predictive computed tomography (CT) profiles to identify PH patients who would be suitable for laparoscopic reduction by a comparative analysis between patients treated by laparoscopic and open reduction. MATERIAL AND METHODS: We retrospectively collected the clinical data of patients (n = 28) who underwent PH reduction surgery after minimally invasive gastrectomy for gastric cancer in the period 2015-2018 at four training hospitals. We examined the preoperative CT scans to identify the indications for laparoscopic PH reduction. RESULTS: We compared the laparoscopic reduction group (laparoscopic group, n = 15) and the open reduction group (open group, n = 13). Patients in the laparoscopic group were younger (55.7 ±10.4) than those in the open group (69.3 ±9.1), but there were no differences in clinical or laboratory findings. We found that there were two CT profiles with significant differences between the open and laparoscopic groups: superior mesenteric vein (SMV) narrowing and small bowel dilation. We found that small bowel dilatation was an independent factor on multivariate analysis for laparoscopic PH reduction. CONCLUSIONS: We found that small bowel dilatation is the most important CT profile for identifying PH patients contraindicated for laparoscopic reduction. Despite the retrospective design of this study, these CT profiles are expected to define the scope of laparoscopic reduction in PH patients and to establish indications for the laparoscopic approach.

Transcatheter Arterial Embolization for Spontaneous Hepatic Rupture Associated with HELLP Syndrome: A Case Report.

Background: Spontaneous hepatic rupture associated with the syndrome characterized by hemolysis, elevated liver enzymes, and a low platelet count (HELLP syndrome) is a rare and life-threatening condition, and only a few cases regarding the management of this condition through transcatheter arterial embolization (TAE) have been previously reported. Case summary: Herein, we report a case involving a 35-year-old pregnant woman who presented at 28 weeks of gestation with right upper quadrant pain, hypotension, and elevated levels of liver enzymes. Transabdominal ultrasound revealed fetal death. She required an emergency cesarean section, and hepatic rupture was identified after the fetus had been delivered. Hepatic packing and TAE were performed. The postprocedural course was uneventful, and the patient was discharged 14 days after she had been admitted to our hospital. Conclusions: Spontaneous hepatic rupture associated with HELLP syndrome is a very serious condition that requires prompt and decisive management. The high maternal and fetal mortality rates associated with this condition can be reduced through early accurate diagnosis and adequate management. The findings in the reported case indicate that TAE may be an attractive alternative to surgery for the management of spontaneous hepatic rupture associated with HELLP syndrome.

Diagnosis of multiple pulmonary cavernous hemangiomas via dual-layer spectral CT: A case report.

RATIONALE: Cavernous hemangioma is a benign vascular tumor, which very rarely occurs in the lung. When appearing as multiple nodules on chest CT, this tumor can be misdiagnosed as metastatic malignancy. PATIENT CONCERNS: A 72-year-old woman presented with incidentally found multiple lung nodules on chest radiograph. DIAGNOSES: Based on information derived from dual-layer spectral CT images, the possibility of slow flow vascular tumor such as cavernous hemangioma was suggested. A pathologic diagnosis of pulmonary cavernous hemangioma was made via video-assisted thoracoscopic biopsy. INTERVENTIONS: After tissue confirmation, the patient was discharged without further intervention. OUTCOMES: The patient recovered without any event. Follow-up chest CT performed 6 months later showed no significant interval change in nodule size and distribution. LESSONS: Material decomposition images obtained from dual energy CT can help physicians understand the character of tumor vascularity for an accurate diagnosis of pulmonary cavernous hemangioma.

Pneumothorax after CT-guided transthoracic lung biopsy: A comparison between immediate and delayed occurrence.

BACKGROUND: In CT-guided transthoracic lung biopsy (CTLB), pneumothorax can occur as a late complication (delayed pneumothorax). The incidence, risk factors, and clinical significance of delayed pneumothorax are not well known. OBJECTIVES: To compare the risk factors for immediate and delayed pneumothorax after CTLB and to know their clinical significance. METHODS: Images and medical records of 536 consecutive patients who underwent CTLB were reviewed. All biopsies were performed as inpatient procedures. Follow-up chest radiographs were obtained at least twice at 4 h after procedure and before discharge. Risk factors for immediate and delayed pneumothorax were assessed based on patient-, lesion-, and procedure-related variables. Rates of chest tube insertion were also compared. RESULTS: Pneumothorax developed in 161 patients (30.0%) including 135 (25.2%) immediate and 26 (4.9%) delayed cases. Lesion size was an independent risk factor for both immediate and delayed pneumothorax (OR = 0.813; CI = 0.717-0.922 and OR = 0.610; CI = 0.441-0.844, respectively). While emphysema, lower lobe location, and long intrapulmonary biopsy track were risk factors (OR = 1.981; CI = 1.172-3.344, OR = 3.505; CI = 2.718-5.650, and OR = 1.330; CI = 1.132-1.563, respectively) for immediate pneumothorax, upper lobe location and increased number of pleural punctures were independent risk factors (OR = 5.756; CI = 1.634-20.274 and OR = 3.738; CI = 1.860-7.511, respectively) for delayed pneumothorax. The rate of chest tube insertion was significantly (p < 0.001) higher in delayed pneumothorax. CONCLUSION: Pneumothorax tends to occur immediately after CTLB in patients with emphysema, lower lobe lesion, and long intrapulmonary biopsy track. Further attention and warnings are needed for those with multiple punctures of small lesions involving upper lobes due to the possibility of delayed development of pneumothorax and higher requirement for chest tube drainage.

Feasibility Study of Synthetic Diffusion-Weighted MRI in Patients with Breast Cancer in Comparison with Conventional Diffusion-Weighted MRI.

OBJECTIVE: To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patients with breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventional diffusion-weighted imaging (cDWI). MATERIALS AND METHODS: Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm² (cDWI800 and cDWI1500) and sDWI at b-values of 1000 and 1500 s/mm² (sDWI1000 and sDWI1500). Qualitative analysis (normal glandular tissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI sets and the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI set in 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 increasing b-values, regardless of the type of imaging (synthetic or conventional) (p < 0.001). Additionally, sDWI1500 provided better lesion conspicuity than cDWI1500 (3.52 ± 0.92 vs. 3.39 ± 0.90, p < 0.05). Although cDWI1500 showed better normal glandular tissue suppression 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 in sDWI1500 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.

Quantification of liver extracellular volume using dual-energy CT: utility for prediction of liver-related events in cirrhosis.

OBJECTIVES: To determine whether quantification of liver extracellular volume fraction (fECV) using dual-energy CT (DECT) allows prediction of liver-related events (LREs) in cirrhotic patients. METHODS: This retrospective study included 305 cirrhotic patients who underwent dual-source DECT imaging and had serum markers analyzed within 2 weeks of initial CT imaging. The fECV score was measured using an iodine map of equilibrium-phase images obtained 3 min after contrast injection at 100/140 Sn kVp. The association of the fECV score and serum markers with LREs was investigated. A risk model combining the fECV score (< 27 versus ≥ 27%) and serum albumin level (< 4 versus ≥ 4 g/dL) was constructed for LRE prediction. RESULTS: An increased fECV score (odds ratio, 1.27; 95% confidence interval (CI), 1.15, 1.40) was independently associated with decompensated cirrhosis at baseline (n = 85) along with the Model for End-Stage Liver Disease score (odds ratio, 1.32; 95% CI, 1.07, 1.63). Among patients with compensated cirrhosis, 10.5% (23 of 220) experienced LREs during the median follow-up period of 2.0 years (decompensation, n = 14; hepatocellular carcinoma, n = 9). The fECV score (hazard ratio, 1.40; 95% CI, 1.22, 1.62) and serum albumin level (hazard ratio, 0.26; 95% CI, 0.09, 0.73) were independent predictors of LRE. The mean times to LRE among the high (16.5 months, n = 18)-, intermediate (25.6 months, n = 44)-, and low (30.5 months, n = 158)-risk groups were significantly different (p < 0.001). CONCLUSIONS: The fECV score derived from DECT allows prediction of LREs in cirrhotic patients. KEY POINTS: • The extracellular volume fraction (fECV) score derived from the iodine map of dual-energy CT (DECT) was independently associated with the presence of hepatic decompensation. • The fECV score derived from the iodine map of DECT can predict liver-related events (LREs) in patients with cirrhosis. • Equilibrium-phase scanning in dual-energy mode is recommended as part of liver CT in cirrhotic patients because it can provide a prognostic indicator for LRE development.

Coexistence of nontuberculous mycobacterium and IgG4-related disease in a solitary pulmonary nodule: A case report.

RATIONALE: Immunoglobulin G4-related disease (IgG4-RD) is regarded as an immune-mediated systemic fibroinflammatory disease. Several studies have linked IgG4-RD to infections such as tuberculosis and actinomycosis. However, the coexistence of IgG4-RD and non-tuberculous mycobacterium (NTM) in a single pulmonary nodule has not been reported yet. PATIENT CONCERNS: A 76-year-old male patient presented with cough and sputum. A solitary pulmonary nodule suspicious of lung cancer was found on chest CT. DIAGNOSIS: Through video-assisted thoracoscopic biopsy, a diagnosis of co-existing NTM and IgG4-RD in a single nodule was made. INTERVENTIONS: Antibiotic treatment was applied for pneumonia developed after surgery. The patient was also supported by extracorporeal membrane oxygenation and mechanical ventilation since his pneumonia was refractory to medical treatment. OUTCOMES: The patient expired on the 60th postoperative day due to multiple organ failure. LESSONS: IgG4-RD can occur singularly or accompanied by other diseases. We report a solitary pulmonary nodule caused by NTM and concurrent IgG4-RD, suggesting a possible association between these 2 entities. Immunologic relations between IgG4-RD and accompanying infection should be further investigated.

The investigation of diet recovery after distal gastrectomy.

This study aims to investigate the adaptation process of the alimentary tract after distal gastrectomy and understand the impact of remnant stomach volume (RSV) on diet recovery.One year after gastrectomy, although patients' oral intake had increased, the RSV was decreased and small bowel motility was enhanced. Patients with a larger RSV showed no additional benefits regarding nutritional outcomes.We prospectively enrolled patients who underwent distal gastrectomy with Billroth II reconstruction to treat gastric cancer at a tertiary hospital cancer center between September 2009 and February 2012. Demographic data, diet questionnaires, computed tomography (CT), and contrast fluoroscopy findings were collected. Patients were divided into 2 groups according to the RSV calculated using CT gastric volume measurements (large vs small). Dietary habits and nutritional status were compared between the groups.Seventy-eight patients were enrolled. Diet volume recovered to 90% of baseline by the 36 postoperative month, and RSV was 70% of baseline at 6 months after surgery and gradually decreased over time. One year after surgery, small bowel transit time was 75% compared to the 1st postoperative month (P < .05); however, transit time in the esophagus and remnant stomach showed no change in any studied interval. Compared to patients with a small RSV, those with a large RSV showed no differences in diet volume, habits, or other nutritional benefits (P > .05).Diet recovery for distal gastrectomy patients was achieved by increased small bowel motility. The size of the remnant stomach showed no positive impact on nutritional outcomes.

Pulmonary tuberculosis mimicking radiation pneumonitis in a patient with neck malignancy: A case report.

RATIONALE: Primary or reactivation pulmonary tuberculosis (TB) is frequent in immunocompromised patients such as those with human immunodeficiency virus (HIV) infection, chronic renal failure, poorly controlled diabetes, and hematologic malignancy. Immune system of patients with solid-organ cancer can be also altered by malignancy itself or chemotherapy. However, information on the effect of radiation on patient's immunity is scarce. Herein, we present a case of pulmonary TB occurring in a radiation field that mimics focal radiation pneumonitis in a patient who has received curative chemoradiation therapy for neck malignancy. We also performed literature review to understand the impact of radiation therapy on patients' immunity. PATIENT CONCERN: A 56-year-old male patient visited our hospital with a palpable mass in the right supraclavicular fossa which was later confirmed as metastatic squamous cell carcinoma. After completion of concurrent chemoradiation therapy, a focal consolidation was developed in the right upper lobe apex where radiation was applied. The patient did not have any symptoms or signs of infectious disease. DIAGNOSIS: Pulmonary TB was diagnosed through polymerase chain reaction (PCR) test and culture of sputum. INTERVENTION: Anti-TB medication was started. OUTCOME: The patient was tolerable to anti-TB medication and the size of TB lesion gradually decreased. LESSON: A suspicion of pulmonary TB should be given to patients with new infiltrates in radiation port due to impact of radiation therapy on local infection barriers and patients' immune system.

Quantitative severity of pulmonary emphysema as a prognostic factor for recurrence in patients with surgically resected non-small cell lung cancer.

BACKGROUND: Pulmonary emphysema is a major component of chronic obstructive pulmonary disease and lung cancer. However the prognostic significance of quantitative emphysema severity in patients with lung cancer is unclear. We analyzed whether numerical emphysema value is a prognostic factor for recurrence in patients with surgically resected non-small cell lung cancer. METHODS: We quantified emphysema severity of the whole lung and regional lobes in 45 patients (mean age 68.0 years) using an automated chest computed tomography-based program. Predictive factors for recurrence were investigated using a Cox proportional hazards model. Recurrence-free and overall survival was compared after dichotomization of patients according to whole lung emphysema severity. RESULTS: The mean percentage emphysema ratio of the whole lung was 1.21 ± 2.04. Regional lobar emphysema severity was highest in the right middle lobe (1.93 ± 0.36), followed by right upper (1.35 ± 2.50), left upper (1.34 ± 2.12), left lower (1.05 ± 2.52), and right lower (0.78 ± 2.28) lobes. The low severity group showed significantly longer overall survival compared to the high severity group (log-rank test, P = 0.018). Quantitative emphysema severity of the whole lung (hazard ratio 1.36; 95% confidence interval 1.0-1.73) and stage III (hazard ratio 6.17; 95% confidence interval 1.52-25.0) were independent predictors of recurrence after adjusting for age, gender, smoking status, and forced expiratory volume in one second. CONCLUSION: The severity of whole lung emphysema was independently associated with recurrence. Patients with non-small cell lung cancer and marginal pulmonary emphysema at lower severity survive longer after curative-intent surgery.

Invasive thymoma with multiple ring calcifications and osseous metaplasia: A case report.

An 8.0 × 7.0 × 3.0 cm calcified anterior mediastinal mass was found in a 57-year-old man during a regular health checkup. The tumor had invaded the pericardium and phrenic nerve. The Masaoka-Koga classification was stage III. Multiple ring calcifications were present in the gross feature, and osseous metaplasia was observed in the histologic examination. World Health Organization histologic classification of the tumor was type B2. The patient is currently undergoing chemotherapy and radiation therapy to prevent tumor recurrence. To our knowledge, this is the first case of multiple ring calcifications and osseous metaplasia in invasive thymoma.

Clinical importance of cross-sectional area of intercostal muscles in patients with chronic obstructive pulmonary disease.

INTRODUCTION: Limb muscle wasting is one of main systemic manifestation of chronic obstructive pulmonary disease (COPD). However, the change of respiratory muscle is unclear. OBJECTIVES: This study assessed the cross-sectional area (CSA) of the intercostal muscles (ICMs) in patients with COPD, using chest computed tomography (CT) and determined its association with the clinical characteristics of COPD. METHODS: They retrospectively reviewed 60 patients with stable COPD and compared them with 30 controls. CSA (mm2 ) of the ICM on chest CT was measured at the midline level of the lateral arch of the bilateral first rib with a 3-mm slice thickness by using CT histogram software. The association with the clinical characteristics of COPD and with the control groups was assessed. RESULTS: CSA of the ICM and the CSA/body mass index (BMI) were lower in the COPD group than in the control group. Patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 4 had a significantly lower CSA of the ICM than patients with stage 1, 2, and 3. CSA of the ICM was positively associated with FEV1 , %FEV1 predicted, FEV1 /FVC ratio, and BMI and negatively associated with age. However, there were no associations with PaO2 , PaCO2 , smoking status, 6-minute walk test, frequency of acute exacerbation of COPD, and serum C-reactive protein level. CONCLUSION: Intercostal muscle atrophy occurs in COPD patients and is associated with severity of airway obstruction, BMI, and increasing age.

Initial clinical experience with dual-layer detector spectral CT in patients with acute intracerebral haemorrhage: A single-centre pilot study.

PURPOSE: The purpose of this study was to investigate the clinical feasibility of spectral analyses using dual-layer detector spectral computed tomography (CT) in acute intracerebral haemorrhage (ICH). MATERIAL AND METHODS: We retrospectively reviewed patients with acute ICH who underwent CT angiography on a dual-layer detector spectral CT scanner. A spectral data analysis was performed to detect contrast enhancement in or adjacent to acute ICH by using spectral image reconstructions including monoenergetic (MonoE), virtual noncontrast (VNC), and iodine overlay fusion images. We also acquired a spectral plot to assess material differentiation within lesions. RESULTS: Among the 30 patients, the most common cause of acute ICH was chronic hypertension (18/30, 60%) followed by trauma (5/30, 16.7%), brain tumour (3/30, 10%), Moyamoya disease (2/30, 6.7%), and haemorrhagic diathesis from anticoagulation therapy (2/30, 6.7%). Of 30 patients, 13 showed suboptimal iodine suppression in the subcalvarial spaces on VNC images compared with true noncontrast images. The CT angiographic spot sign within the acute ICH was detected in four patients (4/30, 13.3%). All three tumours were metastatic and included lung cancer (n = 2) and hepatocellular carcinoma (n = 1) which showed conspicuous delineation of an enhancing tumour portion in the spectral analysis. Spectral analyses allowed the discrimination of acute haemorrhage and iodine with enhanced lesion visualization on the MonoE images obtained at lower keVs (less than 70 keV) and spectral plot. CONCLUSIONS: Even though the image quality of VNC is perceived to be inferior, it is feasible to evaluate acute ICH in clinical settings using dual-layer detector spectral CT. The MonoE images taken at lower keVs were useful for depicting contrast enhancing lesion, and spectral plot might be helpful for material differentiation in patients with acute ICH.