Prone position PET/CT is useful in reducing gravity-dependent opacity-related [18F]fluorodeoxyglucose uptake.

OBJECTIVES: This study aimed to investigate whether performing [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) in the prone position could reduce [18F]FDG uptake in dependent lungs. METHODS: Patients who underwent [18F]FDG PET/CT in both supine and prone positions from October 2018 to September 2021 were reviewed retrospectively. [18F]FDG uptake of dependent and nondependent lungs was analysed visually and semi-quantitatively. A linear regression analysis was performed to examine the association between the mean standardised uptake value (SUVmean) and the Hounsfield unit (HU). RESULTS: A total of 135 patients (median age, 66 years [interquartile range: 58-75 years]; 80 men) were included. Dependent lungs showed significantly higher SUVmean and HU than nondependent lungs on supine position PET/CT (sPET/CT, 0.59 ± 0.14 vs. 0.36 ± 0.09, p < 0.001; - 671 ± 66 vs. - 802 ± 43, p < 0.001, respectively) and prone position PET/CT (pPET/CT, 0.45 ± 0.12 vs. 0.42 ± 0.08, p < 0.001; - 731 ± 67 vs. - 790 ± 40, p < 0.001, respectively). Linear regression analysis revealed a strong association between the SUVmean and HU in sPET/CT (R = 0.86, p < 0.001) and moderate association in pPET/CT (R = 0.65, p < 0.001). One hundred and fifteen patients (85.2%) had visually discernible [18F]FDG uptake in the posterior lung on sPET/CT, which disappeared on pPET/CT in all but one patient (0.7%, p < 0.001). CONCLUSIONS: [18F]FDG uptake of the lung had moderate-to-strong associations with HU. Gravity-dependent opacity-related [18F]FDG uptake can be effectively reduced on prone position PET/CT. CLINICAL RELEVANCE STATEMENT: Prone position PET/CT effectively reduces gravity-dependent opacity-related [18F]fluorodeoxyglucose uptake in the lung, potentially improving diagnostic accuracy in evaluating nodules in dependent lungs and offering a more accurate assessment of lung inflammation parameters in interstitial lung disease evaluations. KEY POINTS: • The study evaluated whether performing [18F]fluorodeoxyglucose ([18F]FDG) PET/CT could reduce [18F]FDG uptake in lungs. • In prone and supine position PET/CT, the [18F]FDG uptake and Hounsfield unit were moderately to strongly associated. • Prone position PET/CT can reduce gravity-dependent opacity-related [18F]FDG uptake by the posterior lung.

Preoperative Helical Dynamic Enhanced Multidetector Row Computed Tomography: Can It Be a Prognostic Indicator in Early-Stage Non-small Cell Lung Cancer?

OBJECTIVE: This study aimed to investigate the prognostic significance of dynamic contrast-enhanced computed tomography in patients with stage IA non-small cell lung cancer (NSCLC). METHODS: We retrospectively enrolled 139 patients (77 men, 62 women; mean age, 59 years) with stage IA NSCLC who underwent dynamic contrast-enhanced computed tomography. Data on age, pathologic subtype, peak enhancement, and net enhancement of primary lung cancer were collected and correlated with 5-year survival. RESULTS: Peak enhancement had a significant correlation with overall survival in the univariable analysis (hazard ratio [HR], 1.18, confidence interval [CI], 1.01-1.38; P = 0.04) and in the multivariable analysis (HR, 1.19; CI, 1.01-1.39; P = 0.04). Patients with peak enhancement of 90 Hounsfield unit or higher had a significantly increased risk of death compared with patients with less enhancement after curative surgery (HR, 4.15; CI, 1.23-13.95; P = 0.02). CONCLUSIONS: Our study confirmed the prognostic significance of peak enhancement as an indicator for the overall survival of stage IA NSCLC.

Prone position [18F]FDG PET/CT to reduce respiratory motion artefacts in the evaluation of lung nodules.

OBJECTIVES: 2-Deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron-emission tomography/computed tomography (PET/CT) is widely used to evaluate lung nodules, although respiratory motion artefacts may occur. We investigated the value of prone position PET/CT (pPET/CT) in lung nodule evaluation compared with standard supine position PET/CT (sPET/CT). METHODS: We retrospectively reviewed 28 consecutive patients (20 men; age, 65.6 ± 12.1 years) with a lung nodule (size, 16.8 ± 5.5 mm) located below the sub-carinal level who underwent [18F]FDG PET/CT in a standard supine position and additional prone position. The maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), difference of diaphragm position between PET and CT (DDP), Dice's similarity coefficient (DSC) and occurrence of mis-registration were analysed. The [18F]FDG uptake of 20 biopsy-confirmed (15 malignant) nodules was evaluated visually. RESULTS: pPET/CT yielded a significantly higher SUVmax, lower MTV and shorter DDP than with sPET/CT (p = 0.043, 0.007 and 0.021, respectively). Mis-registration occurred in 53.6% of cases in sPET/CT and in 28.6% of cases in pPET/CT (p = 0.092). Among the 15 patients with mis-registration in sPET/CT, 10 patients (66.7%) did not show mis-registration in pPET/CT. DSC was higher in pPET/CT than in sPET/CT in 18 out of 28 patients (64.3%). In visual analysis, malignant nodules exhibited a higher [18F]FDG uptake positivity than benign nodules in pPET/CT (93.3% vs. 40.0%, p = 0.032) but not in sPET/CT (80.0% vs. 40.0%, p = 0.131). CONCLUSIONS: pPET/CT reduces respiratory motion artefact and enables more-precise measurements of PET parameters. KEY POINTS: • In prone position PET/CT, the decrease in the blurring effect caused by reduced respiratory motion resulted in a higher SUVmax and lower MTV in lung nodules than that with supine position PET/CT. • Prone position PET/CT was useful to interpret correctly malignant lung nodules as being positive in individual cases that had a negative result in supine position PET/CT.

Association of FUT2 and ABO with Crohn's disease in Koreans.

BACKGROUND AND AIM: Fucosyltransferase 2 (FUT2) at 19q13 is a well-established susceptibility locus for Crohn's disease (CD) in Caucasians. FUT2 encodes α-1,2-fucosyltransferase that regulates the secretion of the α-1-2-N-acetylgalactosaminyltransferase and α-1-3-galactosyltransferase (ABO) antigens in both the gastrointestinal mucosa and secretory glands. Given that CD is thought to arise from dysregulated mucosal immune responses to the gut flora and both the ABO blood group and the FUT2 secretor status affect the composition of the gut microbiota, the goal of this study was to evaluate the associations of variants of FUT2 and ABO with CD in Koreans. METHODS: Three single-nucleotide polymorphisms from the FUT2 and ABO genes were genotyped in 1735 patients with CD and 8074 healthy controls. RESULTS: The FUT2 non-secretor allele showed genome-wide significant association with CD in Koreans (rs1047781, odds ratio [OR] = 1.30, Pcombined  = 3.52 × 10-12 ). The ABO locus showed genome-wide significant association with CD in Asians (Pmeta  = 2.35 × 10-8 ). A moderate association was observed with the A and B groups (OR = 1.40, P = 2.26 × 10-6 ; and OR = 1.32, P = 1.92 × 10-4 , respectively) compared with the O group. Following stratification on the basis of FUT2 genotype, carriers of the secretor O blood group were significantly protective against CD than were those of the secretor non-O blood group (OR = 0.63, 95% confidence interval = 0.54-0.73, P = 2.86 × 10-9 ). CONCLUSIONS: These are the first results indicating that the O blood group and FUT2 secretor status are protective factors against CD in Asians.

Effects of smoking on the association of human leukocyte antigen with ulcerative colitis.

BACKGROUND AND AIM: Tobacco smoking is a risk factor for gastrointestinal disorders, causing mucosal damage and impairing immune responses. However, smoking has been found to be protective against ulcerative colitis (UC). Human leukocyte antigen (HLA) is a major susceptibility locus for UC, and HLA-DRB1*15:02 has the strongest effect in Asians. This study investigated the effects of smoking on the association between HLA and UC. METHODS: The study enrolled 882 patients with UC, including 526 never, 151 current, and 205 former smokers, and 3091 healthy controls, including 2124 never, 502 current, and 465 former smokers. Smoking-stratified analyses of HLA data were performed using a case-control approach. RESULTS: In a case-control approach, HLA-DRB1*15:02 was associated with UC in never smokers (ORnever smokers  = 3.20, Pnever smokers  = 7.88 × 10-23 ) but not in current or former smokers (Pcurrent smokers  = 0.72 and Pformer smokers  = 0.33, respectively). In current smokers, HLA-DQB1*06 was associated with UC (ORcurrent smokers  = 2.59, Pcurrent smokers  = 6.39 × 10-12 ). No variants reached genome-wide significance in former smokers. CONCLUSIONS: An association between UC and HLA-DRB1*15:02 was limited to never smokers. Our findings highlight that tobacco smoking modifies the effects of HLA on the risk of UC.

Association of TRAP1 with infliximab-induced mucosal healing in Crohn's disease.

BACKGROUND AND AIM: Anti-tumor necrosis factor (TNF) agents, such as infliximab (IFX), have been increasingly used to induce and maintain disease remission in patients with Crohn's disease (CD). Despite a considerable non-response rate, little is known about the genetic predictors of response to anti-TNF therapy in CD. Our aim in this study was to investigate the genetic factors associated with response to anti-TNF therapy in patients with CD. METHODS: We performed a two-stage genome-wide association study (GWAS) to identify loci influencing the response to IFX among Korean patients with CD, comprising 42 good responders with mucosal healing and 70 non-responders. The achievement of mucosal healing was assessed by endoscopy and imaging. The functional significance of TRAP1 (TNF receptor associated protein 1) was examined using dextran sodium sulfate-induced colitis model in TRAP1 transgenic mice. RESULTS: The GWAS identified rs2158962, an intronic single nucleotide polymorphism (SNP) of TRAP1, significantly associated with mucosal healing (odds ratio = 4.94; Pcombined  = 1.35 × 10-7 ). In the dextran sodium sulfate-induced acute colitis, TRAP1 transgenic mice showed a better response to IFX than the wild-type mice. CONCLUSIONS: The TRAP1 gene is associated with mucosal healing in CD patients following IFX therapy. Identifying the genetic predictors of mucosal healing to anti-TNF therapy can prevent patients from exposure to ineffective therapies.

JOURNAL CLUB: Doubling Time of Thymic Epithelial Tumors Correlates With World Health Organization Histopathologic Classification.

OBJECTIVE: Awareness of volume doubling times (VDTs) of different thymic epithelial tumors (TETs), including low- and high-grade thymomas and thymic carcinomas, is important for their management. The purpose of this study was to evaluate the VDTs of incidentally found TETs using 3D volumetry (3D-VDT) and longest diameter (LD-VDT). MATERIALS AND METHODS: This retrospective study included 50 patients (30 men, 20 women) who had histologically proven TETs and who underwent at least two serial CT studies at greater than 2-month intervals. TETs were classified into World Health Organization subtypes and further divided into low-grade (group A [A-B1]) and high-grade (group B [B2, B3]) thymoma and thymic carcinoma (group C). Tumor volumetry was performed by either manual segmentation (3D-VDT) or longest diameter measurement (LD-VDT). RESULTS: Groups A, B, and C accounted for 15, 26, and nine tumors. The median LDVDT in group A was 703.6 days (range, 286.7-1855.9 days); group B, 412.1 days (range, 130.9-716.9 days), and group C, 146.3 days (range, 68.9-448.3 days) (p < 0.01). The median 3D-VDTs were 1138.8 days (range, 350.1-3915.3 days), 711.0 days (range, 145.5-7209.5 days), and 203.1 days (range, 58.9-766.9 days) (p < 0.01). In ROC analysis, both LD-VDT (AUC, 0.873; p < 0.01; optimal cutoff value, 222.6 days; 90.2% sensitivity, 77.8% specificity) and 3DVDT (AUC, 0.859; p < 0.01; optimal cutoff value, 218.0 days; 92.7% sensitivity; 66.7% specificity) differentiated group C from groups A and B. CONCLUSION: VDTs differ among TETs according to tumor grade. Measurement of either LD-VDT or 3D-VDT is sensitive for differentiating carcinomas from thymomas (cutoff value, ≈ 220 days).

Perfusion- and pattern-based quantitative CT indexes using contrast-enhanced dual-energy computed tomography in diffuse interstitial lung disease: relationships with physiologic impairment and prediction of prognosis.

OBJECTIVES: To evaluate automated texture-based segmentation of dual-energy CT (DECT) images in diffuse interstitial lung disease (DILD) patients and prognostic stratification by overlapping morphologic and perfusion information of total lung. METHODS: Suspected DILD patients scheduled for surgical biopsy were prospectively included. Texture patterns included ground-glass opacity (GGO), reticulation and consolidation. Pattern- and perfusion-based CT measurements were assessed to extract quantitative parameters. Accuracy of texture-based segmentation was analysed. Correlations between CT measurements and pulmonary function test or 6-minute walk test (6MWT) were calculated. Parameters of idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) and non-IPF/UIP were compared. Survival analysis was performed. RESULTS: Overall accuracy was 90.47% for whole lung segmentation. Correlations between mean iodine values of total lung, 50-97.5th (%) attenuation and forced vital capacity or 6MWT were significant. Volume of GGO, reticulation and consolidation had significant correlation with DLco or SpO2 on 6MWT. Significant differences were noted between IPF/UIP and non-IPF/UIP in 6MWT distance, mean iodine value of total lung, 25-75th (%) attenuation and entropy. IPF/UIP diagnosis, GGO ratio, DILD extent, 25-75th (%) attenuation and SpO2 on 6MWT showed significant correlations with survival. CONCLUSION: DECT combined with pattern analysis is useful for analysing DILD and predicting survival by provision of morphology and enhancement. KEY POINTS: • Dual-energy CT (DECT) produces morphologic and parenchymal enhancement information. • Automated lung segmentation enables analysis of disease extent and severity. • This prospective study showed value of DECT in DILD patients. • Parameters on DECT enable characterization and survival prediction of DILD.

Clinical correlation of a new and practical magnetic resonance grading system for cervical foraminal stenosis assessment.

BACKGROUND: No systematic and quantitative system for evaluation of cervical neural foraminal stenosis (CNFS) has been reported. PURPOSE: To evaluate whether the new magnetic resonance (MR) grading system for CNFS correlates with clinical manifestations and to propose a modified grading system more useful for clinical practice. MATERIAL AND METHODS: We examined 356 patients who underwent MR imaging (MRI) of the cervical spine. The presence and grade of cervical foraminal stenosis at the maximal narrowing point were assessed using the new grading system suggested by Kim et al. (Kim system) and a modification of this grading system (modified Kim system) based on T2 axial images. Grade 0: narrowest neural foramen > extraforaminal root; Grade 1: ≤ extraforaminal root; Grade 2: <50% of extraforaminal root. Modified Kim system: Grade 0: >80%, Grade 1: <80% but >50%, Grade 2 as for the Kim system. Results were correlated with clinical manifestations and neurologic physical examination findings (positive neurologic manifestation [PNM]). RESULTS: Analysis of correlation coefficients (Rs) showed moderate correlation between grades and clinical manifestations using the Kim system (0.484-0.562) and moderate to high correlation between grades and PNMs using the modified Kim system (0.517-0.782). CONCLUSION: The Kim system showed moderate correlation clinical findings, while the modified Kim system still showed moderate but slightly stronger correlation. In both systems, grade 0 could denote negative neurologic manifestations. Although a considerable number of grade 1 and 2 cases in both systems had PNM, fulfilling the criteria for grades 1 and 2 CNFS, it does not perfectly predict PNM.

Pure ground-glass opacity neoplastic lung nodules: histopathology, imaging, and management.

OBJECTIVE: The purpose of this article is to discuss histologic diagnosis of pure pulmonary ground-glass opacity nodules (GGNs), high-resolution CT (HRCT) findings and pathologic correlation, and management. CONCLUSION: When pure GGNs are greater than 15 mm in diameter with nodularity or have high pixel attenuation (>-472 HU), the nodules are more likely to be invasive adenocarcinomas. Sublobar resection with a secured safety margin and without nodal dissection is performed for HRCT-suggested pure-GGN invasive adenocarcinomas and has a 100% 5-year survival rate.

[18F]FDG PET/CT is useful in discriminating invasive adenocarcinomas among pure ground-glass nodules: comparison with CT findings-a bicenter retrospective study.

PURPOSE: Predicting the malignancy of pure ground-glass nodules (GGNs) using CT is challenging. The optimal role of [18F]FDG PET/CT in this context has not been clarified. We compared the performance of [18F]FDG PET/CT in evaluating GGNs for predicting invasive adenocarcinomas (IACs) with CT. METHODS: From June 2012 to December 2020, we retrospectively enrolled patients with pure GGNs on CT who underwent [18F]FDG PET/CT within 90 days. Overall, 38 patients with 40 ≥ 1-cm GGNs were pathologically confirmed. CT images were analyzed for size, attenuation, uniformity, shape, margin, tumor-lung interface, and internal/surrounding characteristics. Visual [18F]FDG positivity, maximum standardized uptake value (SUVmax), and tissue fraction-corrected SUVmax (SUVmaxTF) were evaluated on PET/CT. RESULTS: The histopathology of the 40 GGNs were: 25 IACs (62.5%), 9 minimally invasive adenocarcinomas (MIA, 22.5%), and 6 adenocarcinomas in situ (AIS, 15.0%). No significant differences were found in CT findings according to histopathology, whereas visual [18F]FDG positivity, SUVmax, and SUVmaxTF were significantly different (P=0.001, 0.033, and 0.018, respectively). The size, visual [18F]FDG positivity, SUVmax, and SUVmaxTF showed significant diagnostic performance to predict IACs (area under the curve=0.693, 0.773, 0.717, and 0.723, respectively; P=0.029, 0.001, 0.018, and 0.013, respectively). In the multivariate logistic regression analysis, visual [18F]FDG positivity discriminated IACs among GGNs among various CT and PET findings (P=0.008). CONCLUSIONS: [18F]FDG PET/CT demonstrated superior diagnostic performance compared to CT in differentiating IAC from AIS/MIA among pure GGNs, thus it has the potential to guide the proper management of patients with pure GGNs.

Predicting Non-Small-Cell Lung Cancer Survival after Curative Surgery via Deep Learning of Diffusion MRI.

BACKGROUND: the objective of this study is to evaluate the predictive power of the survival model using deep learning of diffusion-weighted images (DWI) in patients with non-small-cell lung cancer (NSCLC). METHODS: DWI at b-values of 0, 100, and 700 sec/mm2 (DWI0, DWI100, DWI700) were preoperatively obtained for 100 NSCLC patients who underwent curative surgery (57 men, 43 women; mean age, 62 years). The ADC0-100 (perfusion-sensitive ADC), ADC100-700 (perfusion-insensitive ADC), ADC0-100-700, and demographic features were collected as input data and 5-year survival was collected as output data. Our survival model adopted transfer learning from a pre-trained VGG-16 network, whereby the softmax layer was replaced with the binary classification layer for the prediction of 5-year survival. Three channels of input data were selected in combination out of DWIs and ADC images and their accuracies and AUCs were compared for the best performance during 10-fold cross validation. RESULTS: 66 patients survived, and 34 patients died. The predictive performance was the best in the following combination: DWI0-ADC0-100-ADC0-100-700 (accuracy: 92%; AUC: 0.904). This was followed by DWI0-DWI700-ADC0-100-700, DWI0-DWI100-DWI700, and DWI0-DWI0-DWI0 (accuracy: 91%, 81%, 76%; AUC: 0.889, 0.763, 0.711, respectively). Survival prediction models trained with ADC performed significantly better than the one trained with DWI only (p-values < 0.05). The survival prediction was improved when demographic features were added to the model with only DWIs, but the benefit of clinical information was not prominent when added to the best performing model using both DWI and ADC. CONCLUSIONS: Deep learning may play a role in the survival prediction of lung cancer. The performance of learning can be enhanced by inputting precedented, proven functional parameters of the ADC instead of the original data of DWIs only.

CT detection of dry peritoneal seeding in patients with advanced gastric cancer.

BACKGROUND/AIMS: To determine the significant CT findings of dry peritoneal seeding (DPS) in patients with advanced gastric cancer (AGC) and to assess whether radiologists' performance in the detection of DPS can be improved using these significant CT findings. METHODOLOGY: Two radiologists reviewed CT images of AGC patients with DPS and without seeding for the presence or absence of various CT findings suggesting peritoneal seeding, in consensus. Significant CT findings for DPS were determined using Fisher's exact test. Two other observers, blinded to the results of the consensus review during the first session but not during the second session, evaluated the presence or absence of DPS independently on a five-point scale. Each observer's performance was evaluated using a pair-wise comparison of the receiver operating characteristic (ROC) curves. RESULTS: Soft tissue nodule or plaque on the peritoneal surface was the only significant CT finding of DPS (p=0.014). The areas under the ROC curves of the two observers were not significantly different between the two review sessions. CONCLUSIONS: Soft tissue nodule or plaque on the peritoneal surface was a significant CT finding for the detection of DPS. However, radiologists' performance for the detection of DPS did not improve despite knowledge of this finding.

CT Findings of Thymic Epidermoid Cyst in the Anterior Mediastinum: A Case Report and Literature Review.

An epidermoid cyst is a benign tumor found anywhere in the body. However, the occurrence of epidermoid cysts in the thymus is extremely rare, with only six cases reported worldwide. The correct diagnosis of thymic epidermoid cysts is often difficult due to the unusual location and nonspecific imaging findings. Herein, we present a case of a thymic epidermoid cyst in a 37-year-old female with clinical information and chest CT findings. Further, we have reviewed previous literature reports describing imaging findings of thymic epidermoid cysts.

Tissue Fraction Correction and Visual Analysis Increase Diagnostic Sensitivity in Predicting Malignancy of Ground-Glass Nodules on [18F]FDG PET/CT: A Bicenter Retrospective Study.

We investigated the role of [18F]FDG positron emission tomography/computed tomography (PET/CT) in evaluating ground-glass nodules (GGNs) by visual analysis and tissue fraction correction. A total of 40 pathologically confirmed ≥1 cm GGNs were evaluated visually and semiquantitatively. [18F]FDG uptake of GGN distinct from background lung activity was considered positive in visual analysis. In semiquantitative analysis, we performed tissue fraction correction for the maximum standardized uptake value (SUVmax) of GGN. Of the 40 GGNs, 25 (63%) were adenocarcinomas, 9 (23%) were minimally invasive adenocarcinomas (MIAs), and 6 (15%) were adenocarcinomas in situ (AIS). On visual analysis, adenocarcinoma showed the highest positivity rate among the three pathological groups (88%, 44%, and 17%, respectively). Both SUVmax and tissue-fraction−corrected SUVmax (SUVmaxTF) were in the order of adenocarcinoma > MIA > AIS (p = 0.033 and 0.018, respectively). SUVmaxTF was significantly higher than SUVmax before correction (2.4 [1.9−3.0] vs. 1.3 [0.8−1.8], p < 0.001). When using a cutoff value of 2.5, the positivity rate of GGNs was significantly higher in SUVmaxTF than in SUVmax (50% vs. 5%, p < 0.001). The diagnostic sensitivity of [18F]FDG PET/CT in predicting the malignancy of lung GGN was improved by tissue fraction correction and visual analysis.

Angiographic Findings of an Isolated Meandering Pulmonary Vein: A Case Report.

A meandering pulmonary vein (MPV) is a rare pulmonary vascular anomaly characterized by an abnormal course of the pulmonary vein draining into the left atrium. We report the case of a 55-year-old female who was diagnosed with a right MPV on pulmonary angiography. Enhanced chest CT revealed a vascular structure with an abnormal course that drained into the right superior pulmonary vein in the right upper lobe, which resembled a pulmonary arteriovenous malformation (AVM). Pulmonary angiography performed to discriminate between an MPV and pulmonary AVM showed no feeding artery, normal parenchymal staining, and drainage to the left atrium via the culprit vessel. Thus, the patient was diagnosed with MPV. When an MPV is difficult to differentiate from other vascular anomalies on enhanced chest CT, pulmonary angiography can be helpful. By recognizing the angiographic findings of an MPV, unnecessary treatment can be prevented.

Dynamic contrast-enhanced MRI for response evaluation of non-small cell lung cancer in therapy with epidermal growth factor receptor tyrosine kinase inhibitors: a pilot study.

BACKGROUND: It is important to identify candidates who would benefit from target agent chemotherapy in advanced NSCLC patients. The purpose of this study is to evaluate the feasibility of DCE-MRI for early response evaluation in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment in patients with NSCLC. METHODS: Seven patients were prospectively enrolled who have pathologically-proven NSCLC with EGFR mutations or at least 2 of the following factors; adenocarcinoma, female, or never-smokers. Patients were treated with gefitinib or erlotinib and the start of chemotherapy was denoted day 0. DCE-MRI was performed at day-1, day+7, and day+28. Longitudinal changes of perfusion parameters were quantified and compared to Response Evaluation Criteria in Solid Tumors (RECIST) results. RESULTS: Quantitative perfusion parameters; Ktrans, ve and vp of the lung cancer showed a significant decrease at day+7 (P=0.016), but no further significant decrease between day+7 and day+28 (P>0.05). Semiquantitative markers for tumor enhancement curve pattern; EA (enhancement amplitude), MS (maximum slope), and AUC (area under the curve) also showed a significant decrease at day+7 (P=0.016, 0.031, and 0.016, respectively), but no further significant decrease between day+7 and day+28 (P>0.05). When RECIST applied, all patient was in the stable disease at day+7 and three patients showed partial response (PR) at day+28. All seven patients showed PR by the 3-month follow-up. CONCLUSIONS: Perfusion parameters may be used as an early non-invasive imaging biomarker for the response evaluation of target agent treatment in NSCLC.

Lung Nodule Malignancy Prediction in Sequential CT Scans: Summary of ISBI 2018 Challenge.

Lung cancer is by far the leading cause of cancer death in the US. Recent studies have demonstrated the effectiveness of screening using low dose CT (LDCT) in reducing lung cancer related mortality. While lung nodules are detected with a high rate of sensitivity, this exam has a low specificity rate and it is still difficult to separate benign and malignant lesions. The ISBI 2018 Lung Nodule Malignancy Prediction Challenge, developed by a team from the Quantitative Imaging Network of the National Cancer Institute, was focused on the prediction of lung nodule malignancy from two sequential LDCT screening exams using automated (non-manual) algorithms. We curated a cohort of 100 subjects who participated in the National Lung Screening Trial and had established pathological diagnoses. Data from 30 subjects were randomly selected for training and the remaining was used for testing. Participants were evaluated based on the area under the receiver operating characteristic curve (AUC) of nodule-wise malignancy scores generated by their algorithms on the test set. The challenge had 17 participants, with 11 teams submitting reports with method description, mandated by the challenge rules. Participants used quantitative methods, resulting in a reporting test AUC ranging from 0.698 to 0.913. The top five contestants used deep learning approaches, reporting an AUC between 0.87 - 0.91. The team's predictor did not achieve significant differences from each other nor from a volume change estimate (p =.05 with Bonferroni-Holm's correction).

Signal intensity change of the labyrinth in patients with surgically confirmed or radiologically diagnosed vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery MR imaging at 3 T.

OBJECTIVE: The purpose of this study was to evaluate the signal intensity (SI) change of the labyrinth in patients with vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery (FLAIR) imaging at 3 T. METHODS: Thirty-four patients with surgically confirmed or radiologically diagnosed vestibular schwannoma were included in this study. Retrospectively, we visually and quantitatively compared the SIs of the cochlea and vestibule on the affected side with those on the unaffected side. We also investigated whether there was correlation between the SI ratios (SIRs) of the labyrinth and the audiometric findings. RESULTS: On 3D FLAIR images, the SI of the cochlea and vestibule on the affected side was significantly increased in 97% (33/34) and 91% (31/34), respectively. While the SI of the cochlea was diffusely increased, that of the vestibule was only partially increased. Quantitative study also revealed statistically significantly higher SIRs of the cochlea (0.99 +/- 0.29) and vestibule (0.73 +/- 0.31) on the affected side, compared with the cochlea (0.47 +/- 0.20) and vestibule (0.19 +/- 0.10) on the unaffected side. There was no significant correlation of the SIRs of the labyrinth with the degree of hearing loss. CONCLUSION: In patients with vestibular schwannoma, isotropic 3D FLAIR imaging is a useful method for the evaluation of the SI changes of the labyrinth.

Extremity arteriovenous malformations involving the bone: therapeutic outcomes of ethanol embolotherapy.

PURPOSE: To assess retrospectively the therapeutic results, complications, and therapeutic approach to ethanol embolotherapy of extremity arteriovenous malformations (AVMs) involving the bone. MATERIALS AND METHODS: From December 1996 to May 2009, 22 patients (12 male, 10 female; eight children, 14 adults; age range, 1-64 years) with extremity AVMs involving the bone underwent staged ethanol embolotherapy (range, 1-12 procedures; mean, 4.4 procedures) under general anesthesia. Four patients had pure bone AVMs and 18 had mixed bone and soft-tissue AVMs. Pulmonary artery pressure and arterial blood pressure were monitored as ethanol was injected. Ethanol embolotherapy was performed by direct puncture and/or transcatheter approach. Therapeutic outcomes were established by evaluation of the clinical response of symptoms and signs, as well as the degree of devascularization at follow-up angiography or computed tomography. RESULTS: Ninety-six ethanol embolotherapy procedures were performed in 22 patients. Four (18%) were cured, 14 (64%) showed improvement, three (14%) showed no change, and one (4%) experienced treatment failure and amputation of the affected extremity. Ethanol embolotherapy was considered effective (ie, combined cure and improvement outcomes) in 18 patients (82%). Ten patients (45%) experienced complications. Twelve minor complications (skin and transient peripheral nerve injury; 13%) and one major complications (longstanding nerve palsy; 1%) occurred in 96 procedures. CONCLUSIONS: Ethanol embolotherapy of extremity AVMs involving the bone has the potential to eliminate or improve symptoms in a high percentage of patients, with an acceptable risk of minor and major complications.