Low Daily Step Count Associated with Small Erector Spinae Muscle Area and Sarcopenia in Idiopathic Pulmonary Fibrosis

Objective The daily step count is associated with mortality in idiopathic pulmonary fibrosis (IPF). However, the factors associated with this phenomenon are not yet fully understood. We therefore clarified its association with clinical parameters. Methods Fifty-nine patients with IPF with available data for daily step counts; 6-minute walk distance (6MWD); chest, abdominal, and pelvic computed tomography (CT); pulmonary function; psychological evaluations; and sarcopenia assessments were prospectively enrolled. The daily step count was measured continuously for seven consecutive days. The cross-sectional areas of the erector spinae muscles at the level of the 12th vertebra (ESMCSA) and psoas major muscle volume (PMV) obtained by CT were assessed. Results The average age of the patients was 73.3±8.1 years old, and the percent predicted forced vital capacity was 81.6%±15.8%. The median daily step count was 4,258 (2,155-6,991) steps. The average 6MWD, ESMCSA, and PMV were 413±97 m, 25.5±6.7 cm2, and 270±75.6 cm3, respectively. A linear regression analysis for daily step count showed that the ESMCSA and 6MWD were independent factors for the daily step count, whereas the PMV and skeletal muscle index were not. The daily step count, ESMCSA, and 6MWD were lower in patients with sarcopenia than in those without sarcopenia. Conclusion A lower daily step count was associated with a smaller erector spinae muscle area and sarcopenia in patients with IPF. Further studies are warranted to confirm the importance of physical therapy for muscle strengthening in patients with IPF.

Compressed sensing with deep learning reconstruction: Improving capability of gadolinium-EOB-enhanced 3D T1WI

PURPOSE

The purpose of this study was to determine the utility of compressed sensing (CS) with deep learning reconstruction (DLR) for improving spatial resolution, image quality and focal liver lesion detection on high-resolution contrast-enhanced T1-weighted imaging (HR-CE-T1WI) obtained by CS with DLR as compared with conventional CE-T1WI with parallel imaging (PI).

METHODS

Seventy-seven participants with focal liver lesions underwent conventional CE-T1WI with PI and HR-CE-T1WI, surgical resection, transarterial chemoembolization, and radiofrequency ablation, followed by histopathological or >2-year follow-up examinations in our hospital. Signal-to-noise ratios (SNRs) of liver, spleen and kidney were calculated for each patient, after which each SNR was compared by means of paired t-test. To compare focal lesion detection capabilities of the two methods, a 5-point visual scoring system was adopted for a per lesion basis analysis. Jackknife free-response receiver operating characteristic (JAFROC) analysis was then performed, while sensitivity and false positive rates (/data set) for consensus assessment of the two methods were also compared by using McNemar's test or the signed rank test.

RESULTS

Each SNR of HR-CE-T1WI was significantly higher than that of conventional CE-T1WI with PI (p < 0.05). Sensitivities for consensus assessment showed that HR-CE-MRI had significantly higher sensitivity than conventional CE-T1WI with PI (p = 0.004). Moreover, there were significantly fewer FP/cases for HR-CE-T1WI than for conventional CE-T1WI with PI (p = 0.04).

CONCLUSION

CS with DLR are useful for improving spatial resolution, image quality and focal liver lesion detection capability of Gd-EOB-DTPA enhanced 3D T1WI without any need for longer breath-holding time.

Deep Learning Reconstruction for DWIs by EPI and FASE Sequences for Head and Neck Tumors

BACKGROUND

Diffusion-weighted images (DWI) obtained by echo-planar imaging (EPI) are frequently degraded by susceptibility artifacts. It has been suggested that DWI obtained by fast advanced spin-echo (FASE) or reconstructed with deep learning reconstruction (DLR) could be useful for image quality improvements. The purpose of this investigation using in vitro and in vivo studies was to determine the influence of sequence difference and of DLR for DWI on image quality, apparent diffusion coefficient (ADC) evaluation, and differentiation of malignant from benign head and neck tumors.

METHODS

For the in vitro study, a DWI phantom was scanned by FASE and EPI sequences and reconstructed with and without DLR. Each ADC within the phantom for each DWI was then assessed and correlated for each measured ADC and standard value by Spearman's rank correlation analysis. For the in vivo study, DWIs obtained by EPI and FASE sequences were also obtained for head and neck tumor patients. Signal-to-noise ratio (SNR) and ADC were then determined based on ROI measurements, while SNR of tumors and ADC were compared between all DWI data sets by means of Tukey's Honest Significant Difference test.

RESULTS

For the in vitro study, all correlations between measured ADC and standard reference were significant and excellent (0.92 ≤ ρ ≤ 0.99, p < 0.0001). For the in vivo study, the SNR of FASE with DLR was significantly higher than that of FASE without DLR (p = 0.02), while ADC values for benign and malignant tumors showed significant differences between each sequence with and without DLR (p < 0.05).

CONCLUSION

In comparison with EPI sequence, FASE sequence and DLR can improve image quality and distortion of DWIs without significantly influencing ADC measurements or differentiation capability of malignant from benign head and neck tumors.

Computed tomography radiomic feature analysis of thymic epithelial tumors: Differentiation of thymic epithelial tumors from thymic cysts and prediction of histological subtypes

PURPOSE

To investigate the value of computed tomography (CT) radiomic feature analysis for the differential diagnosis between thymic epithelial tumors (TETs) and thymic cysts, and prediction of histological subtypes of TETs.

MATERIALS AND METHODS

Twenty-four patients with TETs (13 low-risk and 9 high-risk thymomas, and 2 thymic carcinomas) and 12 with thymic cysts were included in this study. For each lesion, the radiomic features of a volume of interest covering the lesion were extracted from non-contrast enhanced CT images. The Least Absolute Shrinkage and Selection Operator (Lasso) method was used for the feature selection. Predictive models for differentiating TETs from thymic cysts (model A), and high risk thymomas + thymic carcinomas from low risk thymomas (model B) were created from the selected features. The receiver operating characteristic curve was used to evaluate the effectiveness of radiomic feature analysis for differentiating among these tumors.

RESULTS

In model A, the selected 5 radiomic features for the model A were NGLDM_Contrast, GLCM_Correlation, GLZLM_SZLGE, DISCRETIZED_HISTO_Entropy_log2, and DISCRETIZED_HUmin. In model B, sphericity was the only selected feature. The area under the curve, sensitivity, and specificity of radiomic feature analysis were 1 (95% confidence interval [CI]: 1-1), 100%, and 100%, respectively, for differentiating TETs from thymic cysts (model A), and 0.76 (95%CI: 0.53-0.99), 64%, and 100% respectively, for differentiating high-risk thymomas + thymic carcinomas from low-risk thymomas (model B).

CONCLUSION

CT radiomic analysis could be utilized as a non-invasive imaging technique for differentiating TETs from thymic cysts, and high-risk thymomas + thymic carcinomas from low-risk thymomas.

Efficacy of dupilumab for airway hypersecretion and airway wall thickening in patients with moderate-to-severe asthma: A prospective, observational study

BACKGROUND

Dupilumab has clinical effects in patients with moderate-to-severe asthma. When considering interleukin (IL)-4 and IL-13 signaling, effects of dupilumab on airway mucus hypersecretion and airway remodeling are expected, but they have been reported in only a few short-term studies. Its efficacy for airway hyperresponsiveness (AHR) remains unknown. We comprehensively assessed the efficacy of dupilumab, especially for subjective and objective measures of airway mucus hypersecretion and airway dimensions in moderate-to-severe asthmatic patients.

METHODS

In 28 adult patients with moderate-to-severe uncontrolled asthma, the comprehensive efficacy of 48-week dupilumab treatment, including the Cough and Sputum Assessment Questionnaire (CASA-Q), radiological mucus scores and airway dimensions on computed tomography (CT), was assessed prospectively. Treatment responsiveness to dupilumab was analyzed.

RESULTS

With 48-week dupilumab treatment, all four cough and sputum domain scores of CASA-Q improved significantly. Radiological mucus scores and airway wall thickening on CT were significantly decreased. The decreases in mucus scores were significantly associated with improvements in Asthma Control Questionnaire scores, Asthma Quality of Life Questionnaire (AQLQ) overall scores, airway obstruction, and airway type 2 inflammation. When defined by > 0.5 improvement in AQLQ overall scores, 18 patients (64%) were identified as responders.

CONCLUSIONS

Dupilumab reversed subjective and objective measures of airway mucus hypersecretion and some aspects of airway remodeling in patients with moderate-to-severe uncontrolled asthma.

Pulmonary MRI with ultra-short TE using single- and dual-echo methods: comparison of capability for quantitative differentiation of non- or minimally invasive adenocarcinomas from other lung cancers with that of standard-dose thin-section CT

OBJECTIVE

The purpose of this study was thus to compare capabilities for quantitative differentiation of non- and minimally invasive adenocarcinomas from other of pulmonary MRIs with ultra-short TE (UTE) obtained with single- and dual-echo techniques (UTE-MRISingle and UTE-MRIDual) and thin-section CT for stage IA lung cancer patients.

METHODS

Ninety pathologically diagnosed stage IA lung cancer patients who underwent thin-section standard-dose CT, UTE-MRISingle, and UTE-MRIDual, surgical treatment and pathological examinations were included in this retrospective study. The largest dimension (Dlong), solid portion (solid Dlong), and consolidation/tumor (C/T) ratio of each nodule were assessed. Two-tailed Student's t-tests were performed to compare all indexes obtained with each method between non- and minimally invasive adenocarcinomas and other lung cancers. Receiver operating characteristic (ROC)-based positive tests were performed to determine all feasible threshold values for distinguishing non- or minimally invasive adenocarcinoma (MIA) from other lung cancers. Sensitivity, specificity, and accuracy were then compared by means of McNemar's test.

RESULTS

Each index showed significant differences between the two groups (p < 0.0001). Specificities and accuracies of solid Dlong for UTE-MRIDual2nd echo and CTMediastinal were significantly higher than those of solid Dlong for UTE-MRISingle and UTE-MRIDual1st echo and all C/T ratios except CTMediastinal (p < 0.05). Moreover, the specificities and accuracies of solid Dlong and C/T ratio were significantly higher than those of Dlong for each method (p < 0.05).

CONCLUSION

Pulmonary MRI with UTE is considered at least as valuable as thin-section CT for quantitative differentiation of non- and minimally invasive adenocarcinomas from other stage IA lung cancers.

CLINICAL RELEVANCE STATEMENT

Pulmonary MRI with UTE's capability for quantitative differentiation of non- and minimally invasive adenocarcinomas from other lung cancers in stage IA lung cancer patients is equal or superior to that of thin-section CT.

KEY POINTS

• Correlations were excellent for pathologically examined nodules with the largest dimensions (Dlong) and a solid component (solid Dlong) for all indexes (0.95 ≤ r ≤ 0.99, p < 0.0001). • Pathologically examined Dlong and solid Dlong obtained with all methods showed significant differences between non- and minimally invasive adenocarcinomas and other lung cancers (p < 0.0001). • Solid tumor components are most accurately measured by UTE-MRIDual2nd echo and CTMediastinal, whereas the ground-glass component is imaged by UTE-MRIDual1st echo and CTlung with high accuracy. UTE-MRIDual predicts tumor invasiveness with 100% sensitivity and 87.5% specificity at a C/T threshold of 0.5.

Diffusion weighted imaging with reverse encoding distortion correction: Improvement of image quality and distortion for accurate ADC evaluation in in vitro and in vivo studies

PURPOSE

The purpose of this in vivo study was to determine the effect of reverse encoding direction (RDC) on apparent diffusion coefficient (ADC) measurements and its efficacy for improving image quality and diagnostic performance for differentiating malignant from benign tumors on head and neck diffusion-weighted imaging (DWI).

METHODS

Forty-eight patients with head and neck tumors underwent DWI with and without RDC and pathological examinations. Their tumors were then divided into two groups: malignant (n = 21) and benign (n = 27). To determine the utility of RDC for DWI, the difference in the deformation ratio (DR) between DWI and T2-weighted images of each tumor was determined for each tumor area. To compare ADC measurement accuracy of DWIs with and without RDC for each patient, ADC values for tumors and spinal cord were determined by using ROI measurements. To compare DR and ADC between two methods, Student's t-tests were performed. Then, ADC values were compared between malignant and benign tumors by Student's t-test on each DWI. Finally, sensitivity, specificity and accuracy were compared by means of McNemar's test.

RESULTS

DR of DWI with RDC was significantly smaller than that without RDC (p < 0.0001). There were significant differences in ADC between malignant and benign lesions on each DWI (p < 0.05). However, there were no significant difference of diagnostic accuracy between the two DWIs (p > 0.05).

CONCLUSION

RDC can improve image quality and distortion of DWI and may have potential for more accurate ADC evaluation and differentiation of malignant from benign head and neck tumors.

Lung Magnetic Resonance Imaging: Technical Advancements and Clinical Applications

ABSTRACT

Since lung magnetic resonance imaging (MRI) became clinically available, limited clinical utility has been suggested for applying MRI to lung diseases. Moreover, clinical applications of MRI for patients with lung diseases or thoracic oncology may vary from country to country due to clinical indications, type of health insurance, or number of MR units available. Because of this situation, members of the Fleischner Society and of the Japanese Society for Magnetic Resonance in Medicine have published new reports to provide appropriate clinical indications for lung MRI. This review article presents a brief history of lung MRI in terms of its technical aspects and major clinical indications, such as (1) what is currently available, (2) what is promising but requires further validation or evaluation, and (3) which developments warrant research-based evaluations in preclinical or patient studies. We hope this article will provide Investigative Radiology readers with further knowledge of the current status of lung MRI and will assist them with the application of appropriate protocols in routine clinical practice.

Effectiveness of deep learning reconstruction on standard to ultra-low-dose high-definition chest CT images

PURPOSE

Deep learning reconstruction (DLR) has been introduced by major vendors, tested for CT examinations of a variety of organs, and compared with other reconstruction methods. The purpose of this study was to compare the capabilities of DLR for image quality improvement and lung texture evaluation with those of hybrid-type iterative reconstruction (IR) for standard-, reduced- and ultra-low-dose CTs (SDCT, RDCT and ULDCT) obtained with high-definition CT (HDCT) and reconstructed at 0.25-mm, 0.5-mm and 1-mm section thicknesses with 512 × 512 or 1024 × 1024 matrixes for patients with various pulmonary diseases.

MATERIALS AND METHODS

Forty age-, gender- and body mass index-matched patients with various pulmonary diseases underwent SDCT (CT dose index volume : mean ± standard deviation, 9.0 ± 1.8 mGy), RDCT (CTDIvol: 1.7 ± 0.2 mGy) and ULDCT (CTDIvol: 0.8 ± 0.1 mGy) at a HDCT. All CT data set were then reconstructed with 512 × 512 or 1024 × 1024 matrixes by means of hybrid-type IR and DLR. SNR of lung parenchyma and probabilities of all lung textures were assessed for each CT data set. SNR and detection performance of each lung texture reconstructed with DLR and hybrid-type IR were then compared by means of paired t tests and ROC analyses for all CT data at each section thickness.

RESULTS

Data for each radiation dose showed DLR attained significantly higher SNR than hybrid-type IR for each of the CT data (p < 0.0001). On assessments of all findings except consolidation and nodules or masses, areas under the curve (AUCs) for ULDCT with hybrid-type IR for each section thickness (0.91 ≤ AUC ≤ 0.97) were significantly smaller than those with DLR (0.97 ≤ AUC ≤ 1, p < 0.05) and the standard protocol (0.98 ≤ AUC ≤ 1, p < 0.05).

CONCLUSION

DLR is potentially more effective for image quality improvement and lung texture evaluation than hybrid-type IR on all radiation dose CTs obtained at HDCT and reconstructed with each section thickness with both matrixes for patients with a variety of pulmonary diseases.

Deep Learning Reconstruction to Improve the Quality of MR Imaging: Evaluating the Best Sequence for T-category Assessment in Non-small Cell Lung Cancer Patients

PURPOSE

Deep learning reconstruction (DLR) has been recommended as useful for improving image quality. Moreover, compressed sensing (CS) or DLR has been proposed as useful for improving temporal resolution and image quality on MR sequences in different body fields. However, there have been no reports regarding the utility of DLR for image quality and T-factor assessment improvements on T2-weighted imaging (T2WI), short inversion time (TI) inversion recovery (STIR) imaging, and unenhanced- and contrast-enhanced (CE) 3D fast spoiled gradient echo (GRE) imaging with and without CS in comparison with thin-section multidetector-row CT (MDCT) for non-small cell lung cancer (NSCLC) patients. The purpose of this study was to determine the utility of DLR for improving image quality and the appropriate sequence for T-category assessment for NSCLC patients.

METHODS

As subjects for this study, 213 pathologically diagnosed NSCLC patients who underwent thin-section MDCT and MR imaging as well as T-factor diagnosis were retrospectively enrolled. SNR of each tumor was calculated and compared by paired t-test for each sequence with and without DLR. T-factor for each patient was assessed with thin-section MDCT and all MR sequences, and the accuracy for T-factor diagnosis was compared among all sequences and thin-section CT by means of McNemar's test.

RESULTS

SNRs of T2WI, STIR imaging, unenhanced thin-section Quick 3D imaging, and CE-thin-section Quick 3D imaging with DLR were significantly higher than SNRs of those without DLR (P < 0.05). Diagnostic accuracy of STIR imaging and CE-thick- or thin-section Quick 3D imaging was significantly higher than that of thin-section CT, T2WI, and unenhanced thick- or thin-section Quick 3D imaging (P < 0.05).

CONCLUSION

DLR is thus considered useful for image quality improvement on MR imaging. STIR imaging and CE-Quick 3D imaging with or without CS were validated as appropriate MR sequences for T-factor evaluation in NSCLC patients.

Capability for dose reduction while maintaining nodule detection: Comparison of silver and copper X-ray spectrum modulation filters for chest CT using a phantom study with different reconstruction methods

PURPOSE

To compare the capability of CTs obtained with a silver or copper x-ray beam spectral modulation filter (Ag filter and Cu filter) and reconstructed with FBP, hybrid-type IR and deep learning reconstruction (DLR) for radiation dose reduction for lung nodule detection using a chest phantom study.

MATERIALS AND METHODS

A chest CT phantom was scanned with a 320-detector row CT with Ag filter at 0.6, 1.6 and 2.5 mGy and Cu filters at 0.6, 1.6, 2.5 and 9.6 mGy, and reconstructed with the aforementioned methods. To compare image quality of all the CT data, SNRs and CNRs for any nodule were calculated for all protocols. To compare nodule detection capability among all protocols, the probability of detection of any nodule was assessed with a 5-point visual scoring system. Then, ROC analyses were performed to compare nodule detection capability of Ag and Cu filters for each radiation dose data with the same method and of the three methods for any radiation dose data and obtained with either filter.

RESULTS

At any of the doses, SNR, CNR and area under the curve for the Ag filter were significantly higher or larger than those for the Cu filter (p < 0.05). Moreover, with DLR, those values were significantly higher or larger than all the others for CTs obtained with any of the radiation doses and either filter (p < 0.05).

CONCLUSION

The Ag filter and DLR can significantly improve image quality and nodule detection capability compared with the Cu filter and other reconstruction methods at each of radiation doses used.

Area-Detector Computed Tomography for Pulmonary Functional Imaging

An area-detector CT (ADCT) has a 320-detector row and can obtain isotropic volume data without helical scanning within an area of nearly 160 mm. The actual-perfusion CT data within this area can, thus, be obtained by means of continuous dynamic scanning for the qualitative or quantitative evaluation of regional perfusion within nodules, lymph nodes, or tumors. Moreover, this system can obtain CT data with not only helical but also step-and-shoot or wide-volume scanning for body CT imaging. ADCT also has the potential to use dual-energy CT and subtraction CT to enable contrast-enhanced visualization by means of not only iodine but also xenon or krypton for functional evaluations. Therefore, systems using ADCT may be able to function as a pulmonary functional imaging tool. This review is intended to help the reader understand, with study results published during the last a few decades, the basic or clinical evidence about (1) newly applied reconstruction methods for radiation dose reduction for functional ADCT, (2) morphology-based pulmonary functional imaging, (3) pulmonary perfusion evaluation, (4) ventilation assessment, and (5) biomechanical evaluation.

Advances for Pulmonary Functional Imaging: Dual-Energy Computed Tomography for Pulmonary Functional Imaging

Dual-energy computed tomography (DECT) can improve the differentiation of material by using two different X-ray energy spectra, and may provide new imaging techniques to diagnostic radiology to overcome the limitations of conventional CT in characterizing tissue. Some techniques have used dual-energy imaging, which mainly includes dual-sourced, rapid kVp switching, dual-layer detectors, and split-filter imaging. In iodine images, images of the lung's perfused blood volume (PBV) based on DECT have been applied in patients with pulmonary embolism to obtain both images of the PE occluding the pulmonary artery and the consequent perfusion defects in the lung's parenchyma. PBV images of the lung also have the potential to indicate the severity of PE, including chronic thromboembolic pulmonary hypertension. Virtual monochromatic imaging can improve the accuracy of diagnosing pulmonary vascular diseases by optimizing kiloelectronvolt settings for various purposes. Iodine images also could provide a new approach in the area of thoracic oncology, for example, for the characterization of pulmonary nodules and mediastinal lymph nodes. DECT-based lung ventilation imaging is also available with noble gases with high atomic numbers, such as xenon, which is similar to iodine. A ventilation map of the lung can be used to image various pulmonary diseases such as chronic obstructive pulmonary disease.

Chemical Exchange Saturation Transfer MRI: Capability for Predicting Therapeutic Effect of Chemoradiotherapy on Non-Small Cell Lung Cancer Patients

BACKGROUND

Amide proton transfer (APT) weighted chemical exchange saturation transfer CEST (APTw/CEST) magnetic resonance imaging (MRI) has been suggested as having the potential for assessing the therapeutic effect of brain tumors or rectal cancer. Moreover, diffusion-weighted imaging (DWI) and positron emission tomography fused with computed tomography by means of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG-PET/CT) have been suggested as useful in same setting.

PURPOSE

To compare the capability of APTw/CEST imaging, DWI, and FDG-PET/CT for predicting therapeutic effect of chemoradiotherapy (CRT) on stage III non-small cell lung cancer (NSCLC) patients.

STUDY TYPE

Prospective.

POPULATION

Eighty-four consecutive patients with Stage III NSCLC, 45 men (age range, 62-75 years; mean age, 71 years) and 39 women (age range, 57-75 years; mean age, 70 years). All patients were then divided into two groups (Response Evaluation Criteria in Solid Tumors [RECIST] responders, consisting of the complete response and partial response groups, and RECIST non-responders, consisting of the stable disease and progressive disease groups).

FIELD STRENGTH/SEQUENCE

3 T, echo planar imaging or fast advanced spin-echo (FASE) sequences for DWI and 2D half Fourier FASE sequences with magnetization transfer pulses for CEST imaging.

ASSESSMENT

Magnetization transfer ratio asymmetry (MTRasym ) at 3.5 ppm, apparent diffusion coefficient (ADC), and maximum standard uptake value (SUVmax, ) on PET/CT were assessed by means of region of interest (ROI) measurements at primary tumor.

STATISTICAL TESTS

Kaplan-Meier method followed by log-rank test and Cox proportional hazards regression analysis with multivariate analysis. A P value <0.05 was considered statistically significant.

RESULTS

Progression-free survival (PFS) and overall survival (OS) had significant difference between two groups. MTRasym at 3.5 ppm (hazard ratio [HR] = 0.70) and SUVmax (HR = 1.41) were identified as significant predictors for PFS. Tumor staging (HR = 0.57) was also significant predictors for OS.

DATA CONCLUSION

APTw/CEST imaging showed potential performance as DWI and FDG-PET/CT for predicting the therapeutic effect of CRT on stage III NSCLC patients.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

Reverse encoding distortion correction for diffusion-weighted MRI: Efficacy for improving image quality and ADC evaluation for differentiating malignant from benign areas in suspected prostatic cancer patients

PURPOSE

The purpose of this study was to determine the influenceof reverse encoding distortion correction (RDC) on ADC measurement and its efficacy for improving image quality and diagnostic performance for differentiating malignant from benign prostatic areas on prostatic DWI.

METHODS

Forty suspected prostatic cancer patients underwent DWI with or without RDC (i.e. RDC DWI or DWI) using a 3 T MR system as well as pathological examinations. The pathological examination results indicated 86 areas were malignant while 86 out of 394 areas were computationally selected as benign. SNR for benign areas and muscle and ADCs for malignant and benign areas were determined by ROI measurements on each DWI. Moreover, overall image quality was assessed with a 5-point visual scoring system on each DWI. Paired t-test or Wilcoxon's signed rank test was performed to compare SNR and overall image quality for DWIs. ROC analysis was then used to compare the diagnostic performance, and sensitivity (SE), specificity (SP) and accuracy (AC) of ADC were compared between two DWI by means of McNemar's test.

RESULTS

SNR and overall image quality of RDC DWI showed significant improvements when compared with those of DWI (p < 0.05). Areas under the curve (AUC), SP and AC of DWI RDC DWI (AUC: 0.85, SP: 72.1%, AC: 79.1%) were significantly better than those of DWI (AUC: 0.79, p = 0.008; SP: 64%, p = 0.02; AC: 74.4%, p = 0.008).

CONCLUSION

RDC technique has the potential to improve image quality and ability to differentiate malignant from benign prostatic areas on DWIs of suspected prostatic cancer patients.

Serum creatinine/cystatin C ratio is a surrogate marker for sarcopenia in patients with idiopathic pulmonary fibrosis

BACKGROUND

The serum creatinine/cystatin C (Cr/CysC) ratio has attracted attention as a marker for sarcopenia, but has not been studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to confirm the utility of the serum Cr/CysC ratio in predicting sarcopenia and investigate its clinical relevance.

METHODS

This cross-sectional pilot study prospectively enrolled patients with stable IPF. IPF was diagnosed through multidisciplinary discussions according to the 2018 international guidelines, and sarcopenia was diagnosed according to the 2019 consensus report of the Asian Working Group for Sarcopenia. Patient-reported outcomes (PROs) were evaluated using the modified Medical Research Council (mMRC) dyspnea scale, chronic obstructive pulmonary disease assessment test (CAT), and King's Brief Interstitial Lung Disease (K-BILD) questionnaire. The associations between serum Cr/CysC ratio and the presence of sarcopenia and other clinical parameters, including PROs scores, were examined.

RESULTS

The study enrolled 49 Japanese patients with IPF with a mean age of 73.0 ± 7.7 years and a mean percentage of predicted forced vital capacity of 80.4 ± 15.5%. Sarcopenia was diagnosed in 18 patients (36.7%), and the serum Cr/CysC ratio was 0.86 [0.76-0.94] (median [interquartile range]). The receiver operating characteristic curve analyses for the detection of sarcopenia according to the serum Cr/CysC showed that the area under the curve, optimal cutoff value, specificity, and sensitivity were 0.85, 0.88, 0.65, and 0.94, respectively. Sarcopenia was identified in 13% of patients with a high serum Cr/CysC ratio (≥ 0.88) and 60% of patients with a low serum Cr/CysC ratio (< 0.88) (P < 0.001). Multiple linear regression analysis showed that the serum Cr/CysC ratio was an independent predictive marker of worse PROs evaluated using mMRC (P < 0.05), CAT (P < 0.05), and K-BILD (P < 0.05).

CONCLUSIONS

This study showed that the serum Cr/CysC ratio may be a surrogate marker of sarcopenia in patients with IPF. Furthermore, it is important to pay attention to the serum Cr/CysC ratio because a lower serum Cr/CysC ratio is associated with worse PROs. Further studies are required to validate these observations to determine whether the Cr/CysC ratio can be used to detect sarcopenia in patients with IPF.

Decreased peak expiratory flow rate associated with mortality in idiopathic pulmonary fibrosis: A preliminary report

Objectives

The peak expiratory flow rate (PEFR) is known to decrease in patients with sarcopenia. However, little is known about the clinical impact of the PEFR in idiopathic pulmonary fibrosis (IPF). This study aimed to confirm whether a decrease in PEFR over 6 months was associated with survival in IPF patients.

Methods

Consecutive IPF patients who had been assessed at a single center were retrospectively analyzed. The relative decline in PEFR over 6 months was assessed. Survival analyses were performed by univariate and multivariate Cox proportional hazard models.

Results

A total of 61 eligible cases (average age 70 years) were examined, and 21 patients (34.4%) died. The univariate Cox regression analysis showed that the body mass index, baseline % predicted forced vital capacity (FVC), baseline % predicted PEFR, % predicted diffusion capacity for carbon monoxide (DL_CO), relative decline in FVC, and relative decline in PEFR were prognostic factors. On multivariate analyses, relative decline in PEFR (hazard ratio [HR] 1.037, p < .05) and baseline % predicted FVC (HR 0.932, p < .001) were independent prognostic factors, whereas relative decline in FVC was not.

Conclusion

A decrease in PEFR after 6 months may predict worse survival in patients with IPF.

Frequency and impact on clinical outcomes of sarcopenia in patients with idiopathic pulmonary fibrosis

Objectives

Sarcopenia is a syndrome characterized by reduced muscle mass and function. It is well-recognized as a complication in chronic diseases such as chronic obstructive pulmonary disease. However, little is known about sarcopenia in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to investigate the clinical characteristics of sarcopenia and the association between quality of life and sarcopenia in patients with IPF.

Methods

In this pilot cross-sectional study, 56 Japanese outpatients with IPF (49 men) were enrolled prospectively. Sarcopenia was diagnosed according to the criteria of the Asian Working Group for Sarcopenia 2019. Its associations with clinical parameters including age, pulmonary functions, physical performance, and patient-reported outcomes (PROs) were examined.

Results

The frequency of sarcopenia was 39.3% (n = 22) in this cohort. There were significant differences in St George’s Respiratory Questionnaire (p = .005), modified Medical Research Council score (p = .004), and Hospital and Anxiety Depression Scale depression score (p = .030) between the sarcopenic and non-sarcopenic groups. On multivariate regression analysis, 6-min walk distance (6MWD) was an independent factor associated with sarcopenia (odds ratio 1.241, 95% confidence interval 1.016–1.515, p = .034).

Conclusion

Sarcopenia was associated with PROs and physical performance in patients with IPF.

Spontaneous improvement of interstitial pneumonia with autoimmune features: A case report

Interstitial pneumonia with autoimmune features (IPAF) was proposed to describe patients with interstitial lung disease who do not meet the classification criteria for a defined connective tissue disease. Here, we report a spontaneous improvement case of IPAF. A 58-year-old man developed dry cough and dyspnoea. Positive result was obtained for the anti-centromere antibody. High-resolution computed tomography (HRCT) showed reticular abnormalities and ground-glass opacities. Cryobiopsy specimens revealed cellular non-specific interstitial pneumonia. The patient displayed periungual erythema and nail fold bleeding, but no sclerosis. He did not meet the criteria for systemic scleroderma, but did meet those for IPAF. Because symptoms slightly improved, the patient declined immunosuppressive treatment. After 6 months, repeated HRCT showed an apparent reduction in the area of ground-glass opacities. The forced vital capacity improved from 2.72 to 3.47 L and serum Krebs von den Lungen (KL)-6 decreased from 1977 to 531 U/ml, and symptoms disappeared.

Nasal polyp eosinophilia and FeNO may predict asthma symptoms development after endoscopic sinus surgery in CRS patients without asthma

BACKGROUND

Asthma is a significant comorbidity of eosinophilic chronic rhinosinusitis (CRS). Type2-driven biomarkers such as sinus tissue eosinophilia and fractional nitric oxide (FeNO) may be utilized to detect high risk patients who develop asthma symptoms after endoscopic sinus surgery (ESS) in CRS patients.

METHODS

Thirty-six CRS patients without asthma who agreed to undergo ESS between October 2015 and December 2017 were prospectively observed for 12 months following ESS. They were monitored for the development of typical asthma symptoms including dyspnea, wheezes, and cough which responded to anti-asthma medication. Biomarkers were compared between patients who developed asthma symptoms after ESS (asthma symptoms group) and those who did not (non-asthma group). Biomarker changes following ESS intervention were also evaluated.

RESULTS

Six patients were lost to follow after ESS. Thus, 30 CRS patients [16 with nasal polyps (NPs) proved by surgery] were followed. Seven (23%) newly complained of asthma symptoms during follow-up. Levels of FeNO and the prevalence of eosinophilic NPs (eosinophils ≥ 70/high power fields) were significantly higher in the asthma symptom group than in non-asthma group [50.7 ppb vs 22.4 ppb for FeNO levels, and 100% (n = 3) vs 23% (n = 3) for eosinophilic NP prevalence, both p < 0.05]. Levels of sputum periostin decreased significantly by ESS in the non-asthma group. However, changes of biomarkers after ESS were comparable between the two groups.

CONCLUSIONS

Eosinophils in NPs (≥70/high power fields) and preoperative FeNO may be significant biomarkers for predicting the development of asthma symptoms after ESS.

Imaging findings of lesions in the middle and posterior mediastinum

Lesions in the middle and posterior mediastinum are relatively rare, but there are some useful radiological clues that can be used to diagnose them precisely. It is useful to determine the affected mediastinal compartment and the locations of the main thoracic nerves on medical images for diagnosing such mediastinal lesions. Neurogenic tumors can occur in the middle mediastinum, although they generally arise as posterior mediastinal tumors. Based on the above considerations, we review various characteristic imaging findings of middle and posterior mediastinal lesions, and their differential diagnoses.

Roles of cytokines and T cells in the pathogenesis of myasthenia gravis

Myasthenia gravis (MG) is characterized by muscle weakness and fatigue caused by the presence of autoantibodies against the acetylcholine receptor (AChR) or the muscle-specific tyrosine kinase (MuSK). Activated T, B and plasma cells, as well as cytokines, play important roles in the production of pathogenic autoantibodies and the induction of inflammation at the neuromuscular junction in MG. Many studies have focused on the role of cytokines and lymphocytes in anti-AChR antibody-positive MG. Chronic inflammation mediated by T helper type 17 (Th17) cells, the promotion of autoantibody production from B cells and plasma cells by follicular Th (Tfh) cells and the activation of the immune response by dysfunction of regulatory T (T_reg ) cells may contribute to the exacerbation of the MG pathogenesis. In fact, an increased number of Th17 cells and Tfh cells and dysfunction of T_reg cells have been reported in patients with anti-AChR antibody-positive MG; moreover, the number of these cells was correlated with clinical parameters in patients with MG. Regarding cytokines, interleukin (IL)-17; a Th17-related cytokine, IL-21 (a Tfh-related cytokine), the B-cell-activating factor (BAFF; a B cell-related cytokine) and a proliferation-inducing ligand (APRIL; a B cell-related cytokine) have been reported to be up-regulated and associated with clinical parameters of MG. This review focuses on the current understanding of the involvement of cytokines and lymphocytes in the immunological pathogenesis of MG, which may lead to the development of novel therapies for this disease in the near future.

Serum level of soluble urokinase plasminogen activator receptor (suPAR) as a disease severity marker of myasthenia gravis: a pilot study

Myasthenia gravis (MG) is an autoantibody-mediated inflammatory disease of the neuromuscular junction. Biomarkers indicating disease activity in MG are warranted. Recently, the soluble urokinase plasminogen activator receptor (suPAR) has been reported to be associated with inflammation, tissue damage, disease activity and prognosis in various diseases, including autoimmune diseases. In this study, serum suPAR levels were measured in 40 patients with anti-acetylcholine receptor antibody-positive MG and 30 controls, and their correlations with clinical variables and severity scale scores were investigated. We identified that serum suPAR levels significantly correlated with MG activities of daily living scale (Spearman's ρ = 0·45; P = 0·004) and MG Foundation of America classification (Spearman's ρ = 0·37; P = 0·02) at serum sampling, but not with anti-acetylcholine receptor antibody titers. In conclusion, serum suPAR levels can be a candidate for a novel biomarker of disease activity in anti-acetylcholine receptor antibody-positive MG.

Moulds and Staphylococcus aureus enterotoxins are relevant allergens to affect Type 2 inflammation and clinical outcomes in chronic rhinosinusitis patients

Background

Sensitisation to moulds and Staphylococcus aureus enterotoxins (SEs) is associated with the pathophysiology of both asthma and chronic rhinosinusitis (CRS). The purpose of this study was to clarify the contribution of sensitisation to these allergens to Type 2 inflammation in the blood, nose and the lower airways, and clinical outcomes in CRS patients.

Methods

We prospectively enrolled 56 CRS patients who underwent endoscopic sinus surgery (ESS) (20 with comorbid asthma) and 28 healthy controls between October 2015 and December 2017. CRS patients were followed up for 12 months after surgery. Type 2 inflammation-related biomarkers were analysed using blood, resected tissue samples and sputum. 10 allergens including Alternaria, Aspergillus and SEs were measured. Type 2 inflammation-related biomarkers and clinical outcomes were compared in the stratification with the presence or absence of allergen sensitisation.

Results

Sensitisation rate to moulds and SEs in asthmatic patients was increased when changing the cut-off value of specific IgE titre from 0.35 UA·mL⁻¹ to 0.10 UA·mL⁻¹ (1.7- and 4.5-fold, respectively). Moulds and SEs affected the prevalence of asthma and eosinophilic CRS by interacting with each other. All Type 2 inflammation-related biomarkers except for eosinophils in sinus tissue were significantly higher in patients with mould or SE (mould/SE) sensitisation (≥0.10 UA·mL⁻¹) (n=19) than in those without (n=37) and healthy subjects (all p<0.05). Meanwhile, mould/SE sensitisation did not affect longitudinal changes in clinical outcomes after ESS. Changes in serum mould/SE-IgE levels after ESS remained unclear.

Conclusion

Mould/SE sensitisation (≥0.10 UA·mL⁻¹) may affect the development of Type 2 inflammation and clinical outcomes in CRS patients.

Alternaria,Aspergillusand S. aureus enterotoxins are important allergens affecting Type 2 inflammation and clinical outcomes in CRS patients. Sensitisation to moulds/SEs (≥0.10 UA·mL⁻¹) would be meaningful in the pathophysiology of CRS.https://bit.ly/3bUG8ZT

Changes in serum complements and their regulators in generalized myasthenia gravis

OBJECTIVE

To investigate changes in serum complements and their regulators in the pathogenesis of myasthenia gravis (MG).

METHODS

Forty-four patients with acetylcholine receptor antibody-positive MG, as well as 20 patients with non-inflammatory neurological disorders were enrolled. Serum complements (C3, C4 and soluble C5b-9) and complement regulators (vitronectin, clusterin and properdin) were extensively analysed by enzyme-linked immunosorbent assay and their associations with clinical profiles of MG were examined.

RESULTS

Serum C3, C4 and clusterin levels were not significantly different between patients with MG and controls. The patients with MG had higher soluble C5b-9 (P = 0.09) and vitronectin (P = 0.001) levels than the controls; moreover, vitronectin levels decreased after treatment (P = 0.09). Serum properdin (P = 0.03) levels were lower in the patients with MG than in the controls, and negatively correlated with the MG Activities of Daily Living score (rs = -0.26, P = 0.09) and with the presence of bulbar palsy (P = 0.04).

CONCLUSION

Our results show that activation of complements and an altered complement network could contribute to the inflammatory pathogenesis of MG.

A simple and reliable method to preoperatively detect a common trunk of the left pulmonary vein

Background

It is difficult to detect a common trunk of the left pulmonary vein (PV) preoperatively, which may cause intraoperative accidental complications. The purpose of this study is to establish a simple and reliable method of detecting a common trunk in preoperative computed tomography (CT) images.

Methods

A total of 428 patients who underwent thin-section CT preoperatively for left lung cancer at 4 institutions were reviewed. The characteristic findings of a common trunk in the axial view were considered by confirming the preoperative CT findings of cases that had been verified to have a common trunk based on intraoperative findings. The CT images were reviewed independently by two evaluators.

Results

We found that the distance between the mediastinal side of the left lower bronchus and the junction of two left PVs was extremely short in the cases with a common trunk in the axial view. In a typical case, the axial section of the bronchus is close to the junction. Of the 416 patients that were evaluable among the 428 total patients, 26 (6.3%) were diagnosed as having a common trunk by both evaluators, and the diagnosis was coincident in 413 patients (99.2%). We were able to evaluate the surgical videos of 16 of the 26 patients, and a common trunk was confirmed in 15 patients (94%).

Conclusions

We established a simple and reliable method of detecting a common trunk of the left PV in the axial view on chest CT that was routinely performed prior to lung cancer surgery.

Incorporation of a computer-aided vessel-suppression system to detect lung nodules in CT images: effect on sensitivity and reading time in routine clinical settings

PURPOSE

To evaluate whether a computer-aided vessel-suppression system improves lung nodule detection in routine clinical settings.

MATERIALS AND METHODS

We used computer software that automatically suppresses pulmonary vessels on chest CT while preserving pulmonary nodules. Sixty-one chest CT images were included in our study. Three radiologists independently read either standard CT images alone or both computer-aided CT and standard CT images randomly to detect a pulmonary nodule ≥ 4 mm in diameter. After an interval of at least 15 days to avoid recall bias, the three radiologists interpreted the counterpart images of the same patients. The reference standard was decided by an expert panel. The primary endpoint was sensitivity. The secondary endpoint was interpretation time.

RESULTS

The average sensitivity improved with computer-aided CT (72% for standard CT vs. 84% for computer-aided CT, p = 0.02). There was no difference in the false-positive rate (21% for both standard CT and computer-aided CT, p = 0.98). Although the average reading time was 9.5% longer for computer-aided plus standard CT compared with standard CT alone, the difference was not significant (p = 0.11).

CONCLUSION

Vessel-suppressed CT images helped radiologists to improve the sensitivity of pulmonary nodule detection without compromising the false-positive rate.

Increased Serum Periostin Levels and Eosinophils in Nasal Polyps Are Associated with the Preventive Effect of Endoscopic Sinus Surgery for Asthma Exacerbations in Chronic Rhinosinusitis Patients

BACKGROUND

Eosinophilic nasal polyps (NPs) are associated with the presence of asthma in chronic rhinosinusitis (CRS) patients. Serum periostin has been considered a relevant biomarker for unified airway diseases.

OBJECTIVE

To determine the utility of biomarkers including serum periostin that reflects reduction of exacerbations of comorbid asthma in CRS patients.

METHODS

We prospectively recruited 56 CRS patients who were subjected to undergo endoscopic sinus surgery (ESS) (20 with asthma) between October 2015 and December 2017 and followed them for 1 year after ESS. Blood eosinophil count, serum periostin, and fractional nitric oxide (FeNO) were measured at enrollment. How these type 2-driven biomarkers reflect comorbid asthma was determined using receiver operating characteristic (ROC) analysis. The frequency of asthma exacerbations during 1 year was counted both before and after ESS. Associations between preoperative biomarkers including eosinophils in NPs and asthma exacerbations were evaluated.

RESULTS

Blood eosinophil count, FeNO, and serum periostin levels were significantly higher in CRS patients with asthma than in those without (p < 0.01 for all) and discriminated comorbid asthma among CRS patients (p < 0.05; AUC > 0.80 for all). The increased preoperative serum periostin correlated with lower absolute number of postoperative exacerbations (ρ = -0.49, p = 0.03) and its relative reduction after ESS (ρ = 0.53, p = 0.03) in asthmatic patients. Increased eosinophils in NPs were also associated with reduced asthma exacerbations.

CONCLUSION

Preoperative increased serum periostin and eosinophils in NPs are associated with the preventive effect of ESS for asthma exacerbations in CRS patients comorbid with asthma.

Definitive chemoradiotherapy for squamous cell carcinoma of the esophagus: outcomes for borderline-resectable disease

Definitive chemoradiotherapy (dCRT) is the standard treatment for unresectable esophageal cancer. Induction chemotherapy has been actively investigated for borderline-resectable and unresectable disease, but the superiority over dCRT has yet to be confirmed. The purpose of this study was to evaluate the outcome of dCRT with special interest in borderline-resectable disease. Patients with esophageal cancer treated with dCRT between January 2004 and November 2016 were included in this retrospective analysis. Chemotherapy consisted of two cycles of cisplatin (70-75 mg/m2) on day 1 and 5-fluorouracil (700-1000 mg/m2 per day) on days 1-4 or low-dose cisplatin (10 mg/m2 per day) and 5-fluorouracil (175 mg/m2 per day) for 20 days. Radiotherapy was given with a daily fraction of 1.8-2 Gy to a total dose of 50-70 Gy. A total of 104 patients were included: 34 were resectable, 35 were borderline-resectable and 35 were unresectable. Complete response was achieved in 44 patients (42%). Eighteen patients (17%) suffered Grade 2 or greater cardiopulmonary toxicity and seven patients (7%) suffered Grade 3 cardiopulmonary toxicity. At the time of this analysis, 59 patients were dead and 45 were censored. The 3-year overall survival proportions for resectable, borderline-resectable and unresectable patients were 64%, 46% and 21%, respectively. The overall survival for borderline-resectable patients with complete response and noncomplete response was significantly different (P < 0.001), with 3-year survival of 70% and 8%, respectively. The overall survival for complete response patients with borderline-resectable disease was encouraging. Further investigation to find a subgroup fit for esophagus-preserving treatment is warranted.

Usefulness of the advanced monoenergetic image reconstruction in dual-energy computed tomography for detecting the perforator vein of lower extremity varix

Background

Identification of the perforator vein is important for treating lower extremity varix.

Purpose

We evaluated the ability of 40-keV advanced monoenergetic images to depict the perforator vein in patients with lower extremity varix.

Material and Methods

Thirty-three patients aged 52–86 years were examined with contrast-enhanced dual-energy computed tomography (CT) and advanced virtual monoenergetic images (40 keV) were reconstructed. For evaluating enhancement of a lower extremity vein and the difference in CT number between the vein and muscle, we set the region of interest on the popliteal vein (PV). We also evaluated the ability of 100-kVp and 40-keV volume-rendering (VR) images to depict the perforator veins.

Results

The mean CT numbers of the PV at 100 kVp and 40 keV were 113 ± 16 and 321 ± 63 HU, respectively (P < 0.01). In 40-keV transverse images of 33 patients, 84 of the perforator veins were detected. In those 84 veins, 70 (83%) were depicted and 14 (17%) were not depicted on VR images that were reconstructed from 40-keV transverse images. At 100 kVp, 10 (12%) of the perforator veins could be depicted in VR images because the muscles buried them or the PVs were blurred due to insufficient enhancement.

Conclusion

The advanced monoenergetic reconstruction technique is useful for evaluating the perforator vein in patients with lower extremity varix.

Reasons for Undergoing CT During Childhood: Can CT-Exposed and CT-Naive Populations Be Compared?

Several epidemiological studies suggested an increased risk of cancer and other tumors in individuals undergoing computed tomography (CT) examination during childhood; however, it was questioned whether the group undergoing CT was comparable to that not undergoing CT. To address this issue, we investigated the reasons for undergoing CT in 763 children aged 0 to 19 years in 2013. Their medical records were fully evaluated and symptoms, underlying conditions, reasons for CT, and clinical courses after CT were investigated. Among the 763 children, 66.1% underwent repeat CT after the first examination, and 19.3% underwent CT 8 times or more. Among all the examined children, 8.8% had cancer and 4.7% had cancer-prone conditions such as Down syndrome, tuberous sclerosis, and cirrhosis. Only 11.4% of the 763 children underwent CT because of trauma, and 32.2% of the children had some types of congenital anomaly. The rate of trauma decreased with an increase in the frequency of CT examinations. Since the incidence of congenital anomalies is below 2.5% in the general population, it was concluded that the population of children undergoing CT is completely different from that not undergoing CT. The 2 groups should not be compared.

Advanced monoenergetic reconstruction technique in dual-energy computed tomography for evaluation of vascular anatomy before adrenal vein sampling

Background

In adrenal vein sampling, selecting the right adrenal vein is technically difficult and it is important to evaluate the right adrenal vein anatomy before adrenal vein sampling. The advanced monoenergetic reconstruction technique has recently become available and we hypothesized that this technique may be useful.

Purpose

To evaluate the usefulness of the advanced monoenergetic reconstruction technique in dual-energy computed tomography (CT; advanced monoenergetic images) for evaluation of vascular anatomy before adrenal vein sampling.

Material and Methods

Twenty-one patients underwent three-phase (20, 30, and 70 s) contrast-enhanced CT before adrenal vein sampling. Advanced monoenergetic images were reconstructed at 40 keV and analyzed objectively and subjectively in comparison with the standard 120-kVp images. As objective evaluation, the signal-to-noise ratio and contrast-to-noise ratio of the right adrenal vein were assessed. As subjective evaluation, two radiologists assessed the delineation of the right adrenal vein using a 5-point Likert scale (1 = poor, 5 = excellent). Furthermore, the technical success rate of adrenal vein sampling and procedure time were also evaluated.

Results

There was no difference in the signal-to-noise ratio between the two groups. The contrast-to-noise ratios of the right adrenal vein of advanced monoenergetic images were higher than those of the standard images ( P < 0.05). The Likert scores of advanced monoenergetic images were higher than those of the standard images ( P < 0.05). The technical success rate of adrenal vein sampling was 95% (20/21) and the median of procedure time was 103 min (range = 59–197 min).

Conclusion

Advanced monoenergetic imaging appears to be useful in the delineation of the right adrenal vein before adrenal vein sampling.

A novel pathophysiologic link between upper and lower airways in patients with chronic rhinosinusitis: Association of sputum periostin levels with upper airway inflammation and olfactory function

Background

Chronic rhinosinusitis (CRS) and asthma are collectively called unified airway diseases. Periostin has been implicated in the pathophysiologic link of these conditions but only by serum measurements. We sought to investigate sputum levels of periostin and their association with upper airway inflammation and olfactory function in CRS patients.

Methods

We prospectively recruited 56 CRS patients who underwent endoscopic sinus surgery (20 with and 36 without comorbid asthma), and 28 healthy controls between October 2015 and December 2017. Lower and upper airway indices such as sputum periostin levels and eosinophil and neutrophil counts, exhaled fractional nitric oxide (FeNO) levels, and olfactory function were evaluated in the three groups. Radiological severity of CT images and tissue eosinophilia of surgical specimens were also assessed in the CRS patients.

Results

Sputum periostin levels were highest, and olfactory function was most impaired, in the CRS patients with comorbid asthma, followed by those without asthma and controls in this order. CRS with asthma group showed higher sputum eosinophils and FeNO levels than the other two groups, while CRS patients without asthma showed significantly higher neutrophils in sputum than the other two groups. When confined to CRS patients, olfactory dysfunction was correlated with sputum eosinophil counts. Eosinophil counts of nasal polyps showed a significant positive correlation with sputum periostin and FeNO levels. Radiological severity of CRS was correlated with sputum eosinophil counts and FeNO levels.

Conclusions

Periostin levels and inflammatory cells such as eosinophils and neutrophils in the lower airways are increased in patients with CRS, suggesting the presence of mutual interactions between upper and lower airways even if asthma does not coexist. Olfactory dysfunction and eosinophilic nasal polyps may be potential indicators of Th2-driven inflammation in the lower airways.

Trial registration

This study was registered on the UMIN Clinical Trials Registry (Registry ID UMIN000018672).

Visibility of the hilar lymph nodes using advanced virtual monoenergetic low-keV images for preoperative evaluation of lung cancer

OBJECTIVE

The purpose of our study was to evaluate the visibility of the hilar lymph nodes (LNs) using advanced virtual monoenergetic low-keV images compared with early-phase contrast-enhanced CT.

METHODS

Dual energy contrast-enhanced CT was performed for pre-operative evaluation of lung cancer at 20 and 60 s after administration of contrast media in 50 patients (32 males and 18 females; mean age, 69 years). Five kinds of images (A: 20 s/120 kV; B: 60 s/40 keV; C: 60 s/50 keV; D: 60 s/120 kV; E: 60 s/100 kV) were reconstructed. We measured the CT number of the bilateral main pulmonary arteries (PAs), pulmonary veins (PVs) and hilar LNs, and evaluated the differences in CT number (Hounsfield units, HUs) between the PA/PV and LNs (PA-LN and PV-LN contrast). Artifacts from the superior vena cava (SVC) were also evaluated.

RESULTS

The mean PA-LN contrast (HU) was 415 in image group A, 299 in B, 180 in C, 80 in D, and 100 in E. The mean PV-LN contrasts in each group were 306, 287, 177, 78, and 99, respectively. Image group B showed the second highest PA-LN contrast following image group A. There was no significant difference in the PV-LN contrast between image groups A and B. The PA-LN and PV-LN contrasts of image groups B and C were significantly higher than those of E. SVC artifacts were lower in the delayed-phase images (Group B-E) than in Group A.

CONCLUSION

To evaluate the hilar LNs with a single image series, advanced virtual monoenergetic 40-keV imaging at the delayed 60-s phase seems to be the most valuable.

ADVANCES IN KNOWLEDGE

Advanced virtual monoenergetic image is useful for evaluation of both hilar LNs and tumors in the delayed phase without artifact derived from the streak artifact from dense contrast media in the SVC.

Frequency and features of myasthenia gravis developing after thymectomy

BACKGROUND AND PURPOSE

Thymectomy is an effective treatment for myasthenia gravis (MG) with anti-acetylcholine receptor (AChR) antibodies. We rarely encounter patients who develop MG after surgery for thymic tumors. This study aimed to investigate the characteristics and frequency of post-thymectomy onset (PostTx) MG.

METHODS

We reviewed the clinical information of thymoma-associated MG in 158 patients. Of these, 18 (11%) patients with PostTx MG were identified.

RESULTS

The presence of anti-AChR antibodies (82%) and electrophysiological abnormalities (50%) was confirmed before thymectomy in patients with PostTx MG. The clinical characteristics of PostTx MG were similar to those of pre-thymectomy onset (PreTx) MG. In PostTx MG, the duration between thymectomy and MG onset were distributed as < 6 months (early-onset PostTx MG) and ≥ 6 months (late-onset PostTx MG). Notably, some patients with late-onset PostTx MG were associated with thymoma relapse.

CONCLUSION

Our results suggest that approximately 11% of patients with thymoma-associated MG were PostTx MG and pre-surgical assessment of anti-AChR antibody titer or electrophysiological testing may predict PostTx MG development. However, no difference in clinical manifestation and prognosis was observed between PreTx MG and PostTx MG.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.