Yoshiyuki Ozawa

OBJECTIVES: The purpose of this study was to determine the utility of conjugate gradient reconstruction (CG Recon) and deep learning reconstruction (DLR) for reducing scan time while maintaining the image quality and nodule detection capability on lung MRI with ultrashort TE (UTE-MRI) as compared with grid reconstruction (Grid Recon). MATERIALS AND METHODS: In the in vitro and in vivo studies, the NEMA phantom and 35 patients with pulmonary nodules were scanned by UTE-MRI with original (TEoriginal), 1/2 (UTE1/2), and 1/4 (UTE1/4) spoke numbers obtained by both methods and reconstructed with and without DLR. In this study, the standard protocol was UTEoriginal obtained by Grid Recon without DLR. Then, signal-to-noise ratios (SNR) of the phantom, lung and lesion were assessed. In the in vivo study, overall image quality and nodule detection capability were visually assessed on each UTE-MRI. Quantitative and qualitative indices were then compared between the standard protocol and others. Finally, a receiver operating characteristic (ROC) analysis was performed to compare the standard and other protocols. RESULTS: In in vitro and in vivo studies, all SNRs were significantly different between the standard protocol and each UTE-MRI with CG Recon and DLR (p < 0.05). Overall image quality of the standard protocol differed significantly from that of all UTE1/4s (p < 0.05). The area under the curve of each UTEOriginal obtained by CG Recon was significantly larger than that of the standard protocol (p < 0.05). CONCLUSION: CG Recon and DLR can reduce scan time while maintaining image quality and nodule detection capabilities on lung UTE-MRI. KEY POINTS: Question To determine the utility of conjugate gradient reconstruction (CG Recon) to reduce scan time without nodule detection capability on MRI with ultrashort TE (UTE-MRI). Findings Nodule detection capability was not significantly decreased by CG Recon with or without deep learning reconstruction when reducing scan time from the standard UTE-MRI protocol. Clinical relevance Conjugate gradient reconstruction (CG Recon) and deep learning reconstruction (DLR) have the potential to reduce scan time while maintaining image quality and nodule detection capability in lung MR imaging with ultrashort TE.

Chest CT has become a key component of the diagnostic approach to a wide range of airway and vascular diseases, including asthma, emphysema, chronic airways disease, and pulmonary vascular disorders such as pulmonary embolism. The interaction between ventilation and perfusion is complex but is always aimed at optimal matching to enable efficient gas exchange. If either one or both of these are affected by disease, they have a negative effect on the other. CT is able to define the structure of lung parenchyma, airways, and pulmonary vasculature in great detail. Beyond morphology, increasingly sophisticated scanner and software technology increase the diagnostic scope of CT toward obtaining comprehensive functional information. This paves the way for new understanding of lung function, the effects of various diseases, and the way in which therapeutic interventions have an effect. Greater understanding of the principal components of chest CT and how they are developing into clinical practice is relevant to anyone with an interest in diagnostic chest imaging. Keywords: CT-Spectral Imaging (Dual Energy), Applications-CT, CT-Quantitative, CT-Perfusion, Thorax, Lung © RSNA, 2025.

Background: When considering the effects of dupilumab on severe chronic rhinosinusitis with nasal polyps (CRSwNPs), dupilumab is expected to achieve CRSwNPs remission. The aim of this study was to assess the rate of remission of CRSwNPs with comorbid asthma and its predictors on a 24-month course of dupilumab. Methods: Adult patients with severe CRSwNPs and comorbid asthma who had completed a 24-month course of dupilumab were included in this post hoc analysis. The primary outcome was the rate of CRSwNPs remission at 12 and 24 months of dupilumab. The secondary outcome was to identify factors associated with CRSwNPs remission at 12 and 24 months. Based on the European criteria and a previous definition, remission was defined as the absence of symptoms, improved quality of life, no need for surgery, no exacerbations, recovery of olfactory function, and inactive disease by nasal endoscopy for ≥12 months. A rigorous six-component remission, including olfactory testing, was initially used. Results: Of 16 patients, 4 (25%) and 5 (31%) achieved six-component remission of CRSwNPs at 12 and 24 months, respectively. Patients with shorter disease duration and better olfactory function at baseline achieved six-component remission of CRSwNPs more frequently than those without at 24 months (both p < 0.05). Conclusions: Remission of severe CRSwNPs with comorbid asthma is attainable with a 24-month course of dupilumab.

OBJECTIVES: To determine the capability of dynamic contrast-enhanced (CE-) perfusion area-detector CT (ADCT) for detecting pathological structural changes in stage I non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: Sixty-three consecutive stage I NSCLC patients with progressive fibrosing interstitial lung disease (PF-ILD) underwent dynamic CE-perfusion ADCT analyzed by dual-input maximum slope (DMS) methods for total, pulmonary arterial and systemic arterial perfusion (TPDMS, PAPDMS and SAPDMS) maps, surgical treatment and pathological examination. Multicentric ROIs were then placed over sites assessed as normal lung, pulmonary emphysema, GGO or reticular pattern without traction bronchiectasis, reticular pattern with traction bronchiectasis and honeycombing in the resected lung. Next, an analysis of variance (ANOVA) followed by Tukey's honest significant difference (HSD) multiple comparison test was performed for a comparison of each of the perfusion parameters for five groups. Finally, discrimination accuracy for evaluation of lung parenchymal change was compared for all indexes and combined methods. RESULTS: PAPDMSs of abnormal lungs were significantly lower than that of normal lungs (p < 0.0001). SAPDMSs of normal or emphysematous lungs were significantly lower than those of others (p < 0.0001). SAPDMS of GGO or reticular pattern without traction bronchiectasis was significantly lower than that for reticular pattern with traction bronchiectasis and honeycombing (p < 0.0001). Discrimination accuracy of combined perfusion index was significantly higher than that of each index (p < 0.0001). CONCLUSION: Dynamic CE-perfusion ADCT is useful for detecting pathological structural changes in stage I NSCLC patients with PF-ILD. KEY POINTS: Question Can dynamic first-pass contrast-enhanced perfusion matrices evaluate parenchymal lung changes and disease severity of parenchymal diseases in stage I non-small cell lung cancer (NSCLC) patients? Findings Perfusion indexes differentiated significantly among normal lung, emphysema, GGO or reticular pattern without traction bronchiectasis, reticular pattern with traction bronchiectasis and honeycombing and significantly improved discrimination accuracy by combined methods. Clinical relevance Dynamic first-pass contrast-enhanced perfusion area-detector CT has the potential to assess underlying pathologies and pulmonary functional changes in stage I non-small cell carcinoma patients with progressive fibrosing interstitial lung disease.