Validation of a computed tomography diagnostic model for differentiating fibrotic hypersensitivity pneumonitis from idiopathic pulmonary fibrosis.

BACKGROUND: The diagnosis of fibrotic hypersensitivity pneumonitis (fHP) from other interstitial lung diseases, particularly idiopathic pulmonary fibrosis (IPF), is often difficult. This study aimed to examine computed tomography (CT) findings that were useful for differentiating between fHP and IPF and to develop and validate a radiological diagnostic model. METHODS: In this study, 246 patients (fHP, n = 104; IPF, n = 142) from two institutions were included and randomly divided into the test (n = 164) and validation (n = 82) groups (at a 2:1 ratio). Three radiologists evaluated CT findings, such as pulmonary fibrosis, small airway disease, and predominant distribution, and compared them between fHP and IPF using binomial logistic regression and multivariate analysis. A prognostic model was developed from the test group and validated with the validation group. RESULTS: Ground-glass opacity (GGO) with traction bronchiectasis (TB), honeycombing, hypoattenuation area, three-density pattern, diffuse craniocaudal distribution, peribronchovascular opacities in the upper lung, and random distribution were more common in fHP than in IPF. In multivariate analysis, GGO with TB, peribronchovascular opacities in the upper lung, and random distribution were significant features. The area under the curve of the fHP diagnostic model with the three aforementioned CT features was 0.733 (95% confidence interval [CI], 0.655-0.811, p < 0.001) in the test group and 0.630 (95% CI, 0.504-0.755, p < 0.047) in the validation group. CONCLUSION: GGO with TB, peribronchovascular opacities in the upper lung, and random distribution were important CT features for differentiating fHP from IPF.

Comparison of PDD-TURBT alone versus white light TURBT plus intravesical BCG therapy: A propensity-score matching study.

BACKGROUND: Although photodynamic-diagnosed transurethral resection of bladder cancer (PDD-TURBT) and Bacillus Calmette-Guérin (BCG) intravesical instillation are the two representative therapies for non-muscle invasive bladder cancer (NMIBC), no studies directly compare their efficacy. We evaluated the outcome of PDD-TURBT alone compared with white light TURBT with intravesical BCG therapy and analyzed the efficacy of both therapies depending on the characteristics of the tumors. METHODS: We retrospectively analyzed intermediate- and high-risk NMIBC patients treated with PDD-TURBT alone (the PDD group) or white light TURBT with BCG therapy (the white light group) using propensity score matched analysis. RESULTS: In the propensity score matched cohort, the 1-, 2-, and 3-year recurrence-free survival rates for the PDD group were 77.6 %, 64.1 %, and 48.1 %, respectively, compared to 84.6 %, 75.1 %, and 75.1 % for the white light group (p = 0.44, 0.27, 0.17, respectively). The difference in recurrence rates between the two groups tended to become more pronounced over time, although there was no significant difference. In the univariate and multivariate analysis, recurrence, multiplicity, and tumor grade were the significant prognostic factors of recurrence in the PDD group (p = 0.010, 0.047, 0.048, respectively). Long-term RFS was similar in the PDD and white light groups when the population was limited to the primary and single tumors, suggesting that PDD-TURBT alone may be sufficient in this spectrum of patients. CONCLUSIONS: PDD-TURBT alone is insufficient to control the long-term recurrence of bladder cancer but can be effective in selected cases such as primary and single tumors.

PRRX1 upregulates PD-L1 in human mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have been demonstrated to be efficacious in clinical applications for the amelioration of immune disorders, including graft-versus-host disease (GvHD) and Crohn's disease. The immunosuppressive role of Programmed death-ligand 1 (PD-L1) in MSCs is pivotal, yet the regulatory mechanisms governing its expression remain to be fully elucidated. In this study, we explored the influence of paired-related homeobox (PRRX1), a determinant of multipotency and self-renewal in MSCs, on the expression of various surface antigens, notably PD-L1. Multiple isoforms of PRRX1 were found to augment the mRNA levels of MSC markers, such as CD26 and CD317, with all isoforms elevating PD-L1 expression at both mRNA and protein levels. This study reveals that PRRX1 may act as a potential immunomodulatory factor in MSCs by regulating the PD-L1 pathway.

Upper extremity contact pressure measurement in robot-assisted pelvic surgery.

Upper extremity complications are often a problem in robot-assisted pelvic surgery (RAPS) with the lithotomy-Trendelenburg position (LT-position). This study focused on upper extremity contact pressure (UEP) and examined the relationship between UEP and upper extremity complications. From May 2020 to April 2022 at the University of Tokyo Hospital, UEP was measured in 155 patients undergoing RARP and 20 patients undergoing RARC. A total of 350 sets of UEP were investigated in this study. UEP was measured using a portable interface pressure sensor (Palm Q, Cape CO., Kanagawa, Japan) in the preoperative lithotripsy position (L-position), preoperative LT-position, and postoperative L-position. UEP was increased in the preoperative LT-position than in the preoperative L-position (right side 5.2 mmHg vs. 17.1 mmHg, left side 5.3 mmHg vs. 17.1 mmHg, P < 0.001, respectively), and was decreased in the postoperative L-position than in preoperative LT-position (right side 17.1 mmHg vs. 10.8 mmHg, left side 17.1 mmHg vs. 10.6 mmHg, P < 0.001, respectively). Eleven upper extremities developed shoulder pain. UEP of the preoperative LT-position tended to be higher in the upper extremity exhibiting shoulder pain (25.6 mmHg (15.4-30.3) vs. 17.1 mmHg (12.0-24.4) P = 0.0901). UEP measurements may help prevent postoperative shoulder pain.

Multimodal modeling with low-dose CT and clinical information for diagnostic artificial intelligence on mediastinal tumors: a preliminary study.

BACKGROUND: Diagnosing mediastinal tumours, including incidental lesions, using low-dose CT (LDCT) performed for lung cancer screening, is challenging. It often requires additional invasive and costly tests for proper characterisation and surgical planning. This indicates the need for a more efficient and patient-centred approach, suggesting a gap in the existing diagnostic methods and the potential for artificial intelligence technologies to address this gap. This study aimed to create a multimodal hybrid transformer model using the Vision Transformer that leverages LDCT features and clinical data to improve surgical decision-making for patients with incidentally detected mediastinal tumours. METHODS: This retrospective study analysed patients with mediastinal tumours between 2010 and 2021. Patients eligible for surgery (n=30) were considered 'positive,' whereas those without tumour enlargement (n=32) were considered 'negative.' We developed a hybrid model combining a convolutional neural network with a transformer to integrate imaging and clinical data. The dataset was split in a 5:3:2 ratio for training, validation and testing. The model's efficacy was evaluated using a receiver operating characteristic (ROC) analysis across 25 iterations of random assignments and compared against conventional radiomics models and models excluding clinical data. RESULTS: The multimodal hybrid model demonstrated a mean area under the curve (AUC) of 0.90, significantly outperforming the non-clinical data model (AUC=0.86, p=0.04) and radiomics models (random forest AUC=0.81, p=0.008; logistic regression AUC=0.77, p=0.004). CONCLUSION: Integrating clinical and LDCT data using a hybrid transformer model can improve surgical decision-making for mediastinal tumours, showing superiority over models lacking clinical data integration.

Fourth national Japanese antimicrobial susceptibility pattern surveillance program: Bacterial isolates from patients with complicated urinary tract infections.

INTRODUCTION: Antimicrobial susceptibility patterns of bacterial pathogens isolated from patients with complicated urinary tract infections were analyzed using the national surveillance data, comprising 793 bacterial strains from eight clinically relevant species. MATERIALS AND METHODS: Data were collected for the fourth national surveillance project from July 2020 to December 2021 by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Disease, and the Japanese Society of Clinical Microbiology. Surveillance was supervised with the cooperation of 43 medical institutions throughout Japan. RESULTS: Fluoroquinolone required a minimum inhibitory concentration (MIC) of 2-64 mg/L to inhibit the 330 tested Escherichia coli strains. The proportion of levofloxacin-resistant E. coli strains increased from 28.6% in 2008 to 29.6% in 2011, 38.5% in 2015, and 44.5% in 2021. The proportion of levofloxacin-resistant strains of Pseudomonas aeruginosa also increased from previous survey results, showing a continuing downward trend. Conversely, the proportion of levofloxacin-resistant strains of Enterococcus faecalis decreased relative to previous reports. Neither multidrug-resistant P. aeruginosa nor carbapenem-resistant Enterobacteriaceae were detected. For methicillin-resistant Staphylococcus aureus (MRSA), the proportion of vancomycin-susceptible strains (MIC of 2 µg/mL) decreased from 14.7% to 7.7%. DISCUSSION: Bacterial strains that produced extended-spectrum ß-lactamase included E. coli (82/330 strains, 24.8%), Klebsiella pneumoniae (11/68 strains, 16.2%), and Proteus mirabilis (4/26 strains, 15.4%). As compared to previous surveillance reports, these strains showed an increase in proportion over the years.

Development of risk-score model in patients with negative surgical margin after robot-assisted radical prostatectomy.

A total of 739 patients underwent RARP as initial treatment for PCa from November 2011 to October 2018. Data on BCR status, clinical and pathological parameters were collected from the clinical records. After excluding cases with neoadjuvant and/or adjuvant therapies, presence of lymph node or distant metastasis, and positive SM, a total of 537 cases were eligible for the final analysis. The median follow-up of experimental cohort was 28.0 (interquartile: 18.0-43.0) months. We identified the presence of International Society of Urological Pathology grade group (ISUP-GG) ≥ 4 (Hazard ratio (HR) 3.20, 95% Confidence Interval (95% CI) 1.70-6.03, P < 0.001), lymphovascular invasion (HR 2.03, 95% CI 1.00-4.12, P = 0.049), perineural invasion (HR 10.7, 95% CI 1.45-79.9, P = 0.020), and maximum tumor diameter (MTD) > 20 mm (HR 1.9, 95% CI 1.01-3.70, P = 0.047) as significant factors of BCR in the multivariate analysis. We further developed a risk model according to these factors. Based on this model, 1-year, 3-year, and 5-year BCR-free survival were 100%, 98.9%, 98.9% in the low-risk group; 99.1%, 94.1%, 86.5% in the intermediate-risk group; 93.9%, 84.6%, 58.1% in the high-risk group. Internal validation using the bootstrap method showed a c-index of 0.742 and an optimism-corrected c-index level of 0.731. External validation was also carried out using an integrated database derived from 3 other independent institutions including a total of 387 patients for the final analysis. External validation showed a c-index of 0.655. In conclusion, we identified risk factors of biochemical failure in patients showing negative surgical margin after RARP and further developed a risk model using these risk factors.

PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumours.

BACKGROUND: Paired related-homeobox 1 (PRRX1) is a transcription factor in the regulation of developmental morphogenetic processes. There is growing evidence that PRRX1 is highly expressed in certain cancers and is critically involved in human survival prognosis. However, the molecular mechanism of PRRX1 in cancer malignancy remains to be elucidated. METHODS: PRRX1 expression in human Malignant peripheral nerve sheath tumours (MPNSTs) samples was detected immunohistochemically to evaluate survival prognosis. MPNST models with PRRX1 gene knockdown or overexpression were constructed in vitro and the phenotype of MPNST cells was evaluated. Bioinformatics analysis combined with co-immunoprecipitation, mass spectrometry, RNA-seq and structural prediction were used to identify proteins interacting with PRRX1. RESULTS: High expression of PRRX1 was associated with a poor prognosis for MPNST. PRRX1 knockdown suppressed the tumorigenic potential. PRRX1 overexpressed in MPNSTs directly interacts with topoisomerase 2 A (TOP2A) to cooperatively promote epithelial-mesenchymal transition and increase expression of tumour malignancy-related gene sets including mTORC1, KRAS and SRC signalling pathways. Etoposide, a TOP2A inhibitor used in the treatment of MPNST, may exhibit one of its anticancer effects by inhibiting the PRRX1-TOP2A interaction. CONCLUSION: Targeting the PRRX1-TOP2A interaction in malignant tumours with high PRRX1 expression might provide a novel tumour-selective therapeutic strategy.

Antitumor activity of α-pinene in T-cell tumors.

T-cell acute leukemia and lymphoma have a poor prognosis. Although new therapeutic agents have been developed, their therapeutic effects are suboptimal. α-Pinene, a monoterpene compound, has an antitumor effect on solid tumors; however, few comprehensive investigations have been conducted on its impact on hematologic malignancies. This report provides a comprehensive analysis of the potential benefits of using α-pinene as an antitumor agent for the treatment of T-cell tumors. We found that α-pinene inhibited the proliferation of hematologic malignancies, especially in T-cell tumor cell lines EL-4 and Molt-4, induced mitochondrial dysfunction and reactive oxygen species accumulation, and inhibited NF-κB p65 translocation into the nucleus, leading to robust apoptosis in EL-4 cells. Collectively, these findings suggest that α-pinene has potential as a therapeutic agent for T-cell malignancies, and further investigation is warranted.

Six-year outcomes of robot-assisted radical prostatectomy versus volumetric modulated arc therapy for localized prostate cancer: A propensity score-matched analysis.

BACKGROUND: Although robot-assisted radical prostatectomy (RARP) and intensity-modulated radiotherapy are the leading respective techniques of prostatectomy and radiotherapy for localized prostate cancer, almost no study has directly compared their outcomes; none have compared mortality outcomes. METHODS: We compared 6­year outcomes of RARP (n = 500) and volumetric modulated arc therapy (VMAT, a rotational intensity-modulated radiotherapy, n = 360) in patients with cT1-4N0M0 prostate cancer. We assessed oncological outcomes, namely overall survival (OS), cancer-specific survival (CSS), radiological recurrence-free survival (rRFS), and biochemical recurrence-free survival (bRFS), using propensity score matching (PSM). We also assessed treatment-related complication outcomes of prostatectomy and radiotherapy. RESULTS: The median follow-up duration was 79 months (> 6 years). PSM generated a matched cohort of 260 patients (130 per treatment group). In the matched cohort, RARP and VMAT showed equivalent results for OS, CSS, and rRFS: both achieved excellent 6­year outcomes for OS (> 96%), CSS (> 98%), and rRFS (> 91%). VMAT had significantly longer bRFS than RARP, albeit based on different definitions of biochemical recurrence. Regarding complication outcomes, patients who underwent RARP had minimal (2.6%) severe perioperative complications and achieved excellent continence recovery (91.6 and 68.8% of the patients achieved ≤ 1 pad/day and pad-free, respectively). Patients who underwent VMAT had an acceptable rate (20.0%) of grade ≥ 2 genitourinary complications and a very low rate (4.4%) of grade ≥ 2 gastrointestinal complications. CONCLUSION: On the basis of PSM after a 6-year follow-up, RARP and VMAT showed equivalent and excellent oncological outcomes, as well as acceptable complication profiles.

Efficacy and safety of intravesical dimethyl sulfoxide treatment for patients with refractory Hunner-type interstitial cystitis: Real-world data postofficial approval in Japan.

OBJECTIVES: To examine real-world data regarding intravesical dimethyl sulfoxide (DMSO) therapy after official approval as a treatment for Hunner-type interstitial cystitis (HIC) in Japan. METHODS: This single institution, retrospective observational study was conducted between 2021 and 2022 to evaluate the outcomes of 30 patients with refractory HIC who received intravesical DMSO therapy according to the approved standardized regimen: administration of DMSO every 2 weeks for a total of 12 weeks. Treatment outcomes were evaluated using a 7-graded global response assessment scale, O'Leary and Sant's symptom and problem indices (OSSI/OSPI), the overactive bladder symptom score (OABSS), an 11-point pain intensity numerical rating scale, quality of life (QOL) score, and frequency volume chart variables. Related complications were also documented. RESULTS: The response rates at 2, 4, 6, 8, 10, and 12 weeks were 36.7%, 43.3%, 53.3%, 60.0%, 70.0%, and 70.0%, respectively. Compared with baseline, OSSI/OSPI, pain intensity, urinary frequency, and the QOL score improved significantly from 4 weeks of treatment. The OABSS score and functional bladder capacity also showed a tendency toward moderate improvement, but the difference was not significant. The mean duration of symptom relapse after termination of treatment was 6.4 ± 3.9 months. No patients discontinued treatment due to adverse events, although acute bladder irritation during infusion was noted in 21 patients (70%), which disappeared within 3 days. CONCLUSIONS: This study verifies the safety, moderately durable efficacy, and tolerability of the standard intravesical treatment with DMSO for HIC in Japan.

Review of clinical and diagnostic imaging of the thymus: from age-related changes to thymic tumors and everything in between.

The thymus, a primary lymphoid organ of the immune system, undergoes several changes due to a variety of reasons, ranging from aging to pathological conditions. These changes can make distinguishing between benign and neoplastic changes in the thymus challenging, thereby complicating the histopathological diagnoses of thymic tumors. Moreover, most patients with thymic tumors are asymptomatic at the time of diagnosis. Therefore, imaging plays an extremely important role in the evaluation of thymic lesions. In this review, we introduced the imaging characteristics of the thymus, ranging from benign findings, such as normal maturation and benign lesions, to neoplasms.

The delta opioid receptor agonist KNT-127 relieves innate anxiety-like behavior in mice by suppressing transmission from the prelimbic cortex to basolateral amygdala.

AIM: Excitatory projections from the prelimbic cortex (PL) to the basolateral nucleus of the amygdala (BLA) are implicated in the regulation of anxiety-like behaviors, and we previously demonstrated that anxiolytic-like effects of the selective delta-opioid receptor (DOP) agonist KNT-127 is involved in suppressing glutamate neurotransmission in the PL. Here, we investigated the mechanisms underlying the anxiolytic-like effect of KNT-127 in mice by combining optogenetic stimulation of the PL-BLA pathway with behavioral analyses. METHODS: Four-week-old male C57BL/6J mice received bilateral administration of adeno-associated virus (AAV)2-CaMKIIa-hChR2(H134R)-enhanced yellow fluorescent protein (EYFP) into the PL to induce expression of the light-activated excitatory ionic channel ChR2. Subsequently, an optic fiber cannula connected to a wireless photo-stimulator was implanted into the BLA for optogenetic PL-BLA pathway stimulation. We evaluated innate anxiety using the elevated plus maze (EPM) and open field (OF) tests as well as learned anxiety using the contextual fear conditioning (CFC) test. RESULTS: Optogenetic activation of the PL-BLA pathway enhanced anxiety-like behaviors in the EPM and OF, while prior subcutaneous administration of KNT-127 (10 mg/kg) reduced this anxiogenic effect. In contrast, optogenetic activation of the PL-BLA pathway had no significant effect on conditioned fear. CONCLUSION: Our findings indicate that the PL-BLA circuit contributes to innate anxiety and that the anxiolytic-like effects of KNT-127 are mediated at least in part by suppression of PL-BLA transmission. The PL delta-opioid receptor may thus be an effective therapeutic target for anxiety disorders.

Oxytocinergic projection from the hypothalamus to supramammillary nucleus drives recognition memory in mice.

Oxytocin (OXT) neurons project to various brain regions and its receptor expression is widely distributed. Although it has been reported that OXT administration affects cognitive function, it is unclear how endogenous OXT plays roles in cognitive function. The present study examined the role of endogenous OXT in mice cognitive function. OXT neurons were specifically activated by OXT neuron-specific excitatory Designer Receptors Exclusively Activated by Designer Drug expression system and following administration of clozapine-N-oxide (CNO). Object recognition memory was assessed with the novel object recognition task (NORT). Moreover, we observed the expression of c-Fos via immunohistochemical staining to confirm neuronal activity. In NORT, the novel object exploration time percentage significantly increased in CNO-treated mice. CNO-treated mice showed a significant increase in the number of c-Fos-positive cells in the supramammillary nucleus (SuM). In addition, we found that the OXT-positive fibers from paraventricular hypothalamic nucleus (PVN) were identified in the SuM. Furthermore, mice injected locally with CNO into the SuM to activate OXTergic axons projecting from the PVN to the SuM showed significantly increased percentage time of novel object exploration. Taken together, we proposed that object recognition memory in mice could be modulated by OXT neurons in the PVN projecting to the SuM.

Development of cartilage tissue using a stirred bioreactor and human iPSC-derived limb bud mesenchymal cells.

Production of cartilaginous particles for regenerative medicine requires a large supply of chondrocytes and development of suitable production techniques. Previously, we successfully produced human induced pluripotent stem cell (hiPSC)-derived limb bud mesenchymal cells (ExpLBM cells) with a high chondrogenic differentiation potential that stably proliferate. It may be possible to use these cells in combination with a stirred bioreactor to develop a tissue-engineered cell culture technology with potential for scale-up to facilitate production of large amounts of cartilaginous particles. ExpLBM cells derived from 414C2 and Ff-I 14s04 (human leukocyte antigen homozygous) hiPSCs were seeded into a stirred bioreactor containing cartilage induction medium. To characterize the cartilaginous particles produced, we performed real-time quantitative reverse transcription-polymerase chain reaction and histological analyses. Additionally, we transplanted the cartilage tissue into osteochondral defects of immunocompromised rats to assess its functionality, and evaluated engraftment of the grafted tissue. We successfully produced large amounts of cartilaginous particles via cartilage induction culture in a stirred bioreactor. This tissue exhibited significantly increased expression levels of type II collagen (COL2), aggrecan (ACAN), and SRY-box transcription factor 9 (SOX9), as well as positive Safranin O and Toluidine blue staining, indicating that it possesses characteristics of hyaline cartilage. Furthermore, engrafted tissues in osteochondral knee defects of immunodeficient rats were positively stained for human vimentin, COL2, and ACAN as well as with Safranin O. In this study, we successfully generated large amounts of hiPSC-derived cartilaginous particles using a combination of tissue engineering techniques. This method is promising as a cartilage regeneration technology with potential for scale-up.

Ruptured aneurysms at the distal superior cerebellar artery successfully treated by combining occipital artery-superior cerebellar artery anastomosis and endovascular therapy: illustrative case.

BACKGROUND: Distal superior cerebellar artery (SCA) aneurysms are rare and are treated using various treatment strategies. Treatment often requires parent artery occlusion, which raises concerns regarding the potential risk of ischemia in the distal territory. OBSERVATIONS: An 81-year-old woman presented with subarachnoid hemorrhage. Diagnostic cerebral angiography revealed two tiny distal SCA aneurysms. Because significant ischemic damage following parent artery occlusion was concerned, two bypasses between the occipital artery and SCA branches were first performed with the patient in the prone position in a hybrid operating room. Each aneurysm was successively treated in the same position with endovascular internal trapping and intra-aneurysmal embolization. After adequate hemostasis was confirmed, the wound was closed. Both aneurysms were successfully occluded without symptomatic ischemic complications. LESSONS: This combined surgical and endovascular approach would be helpful in cases with notable concerns regarding ischemia after sacrificing the parent artery.

The Role of Oxytocin in Alzheimer's Disease and Its Relationship with Social Interaction.

Alzheimer's disease (AD)-the most common cause of dementia in the elderly-is characterized by progressive memory loss and ß-amyloid protein (Aß) accumulation in the brain. Recently, loneliness was found to be a high risk factor for AD, and social isolation has become a major cause of AD. AD. Oxytocin (OXT), the main hormone involved in social bonding, has been implicated in social interactions, notably in building trust and relationships. Moreover, social isolation or social enrichment modulates the activation of neurons related to OXT. Recently, we reported that OXT reverses learning and memory impairment in AD animal models. Based on the limited number of studies currently available, OXT might be a therapeutic target for AD. Further studies are necessary in order to better understand the role of oxytocin in AD. In this review, we described the relationships between OXT, AD, and social interaction.

Stepwise diagnostic algorithm for high-attenuation pulmonary abnormalities on CT.

High-attenuation pulmonary abnormalities are commonly seen on CT. These findings are increasingly encountered with the growing number of CT examinations and the wide availability of thin-slice images. The abnormalities include benign lesions, such as infectious granulomatous diseases and metabolic diseases, and malignant tumors, such as lung cancers and metastatic tumors. Due to the wide spectrum of diseases, the proper diagnosis of high-attenuation abnormalities can be challenging. The assessment of these abnormal findings requires scrutiny, and the treatment is imperative. Our proposed stepwise diagnostic algorithm consists of five steps. Step 1: Establish the presence or absence of metallic artifacts. Step 2: Identify associated nodular or mass-like soft tissue components. Step 3: Establish the presence of solitary or multiple lesions if identified in Step 2. Step 4: Ascertain the predominant distribution in the upper or lower lungs if not identified in Step 2. Step 5: Identify the morphological pattern, such as linear, consolidation, nodular, or micronodular if not identified in Step 4. These five steps to diagnosing high-attenuation abnormalities subdivide the lesions into nine categories. This stepwise radiologic diagnostic approach could help to narrow the differential diagnosis for various pulmonary high-attenuation abnormalities and to achieve a precise diagnosis.Critical relevance statement Our proposed stepwise diagnostic algorithm for high-attenuation pulmonary abnormalities may help to recognize a variety of those high-attenuation findings, to determine whether the associated diseases require further investigation, and to guide appropriate patient management. Key points • To provide a stepwise diagnostic approach to high-attenuation pulmonary abnormalities.• To familiarize radiologists with the varying cause of high-attenuation pulmonary abnormalities.• To recognize which high-attenuation abnormalities require scrutiny and prompt treatment.