Postoperative pulmonary complications (PPCs)—including pneumonia, respiratory failure, atelectasis, bronchospasm, and aspiration—remain among the most frequent causes of perioperative morbidity and mortality, contributing significantly to prolonged hospitalization and healthcare costs [1]. Reported incidence varies from 5–15% depending on patient comorbidities, anesthetic approach, and surgical procedure [2, 3]. Risk factors include advanced age, smoking, preexisting lung disease, and thoracic or upper abdominal surgery [2]. Several validated indices, such as the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score, provide reliable prediction of PPCs [4]. These scores incorporate patient demographics, comorbidities, and procedural factors, and have been externally validated in diverse surgical populations. Despite this, many institutions continue to request routine preoperative chest imaging, often as part of longstanding surgical checklists, even in the absence of symptoms or abnormal clinical findings [5]. The predictive value of preoperative chest imaging—including chest radiography (CXR), computed tomography (CT), and, more recently, lung ultrasound (LUS)—remains uncertain. Historical data suggest limited impact of CXR on perioperative decision-making [6], while CT and LUS have been proposed as potential tools in selected populations [8, 9]. This systematic review evaluates whether preoperative chest imaging provides incremental prognostic information for PPCs beyond established clinical risk assessments.

This review was conducted in accordance with the PRISMA 2020 guideline [7] and prospectively registered in PROSPERO. PubMed and guideline repositories were searched through October 3, 2025, without language restrictions. Eligible studies included randomized trials, observational cohorts, and systematic reviews evaluating preoperative CXR, CT, or LUS in adult surgical populations. Two reviewers independently screened abstracts and full texts, extracted data, and assessed study quality. The Cochrane Risk of Bias 2 (RoB-2) tool was used for randomized trials, the Newcastle–Ottawa Scale (NOS) for observational studies, and AMSTAR-2 for systematic reviews. Disagreements were resolved by consensus or a third reviewer.

Thirty-two studies met inclusion criteria. • Chest radiograph (CXR): Abnormal findings were reported in 2.5–37% of patients but led to management changes in ≤2% [6]. After adjusting for clinical risk indices, CXR findings did not independently predict PPCs. • Computed tomography (CT): CT demonstrated incremental value primarily in thoracic surgery and in patients with COPD or interstitial lung disease, where functional indices such as predicted postoperative FEV1 and DLCO were enhanced by radiologic assessment [8]. In unselected surgical populations, CT had minimal predictive contribution. • Lung ultrasound (LUS): Evidence was limited but promising. A multicenter study reported modest predictive accuracy (AUROC ≈0.65) for PPCs [9]. LUS was more consistently useful for postoperative monitoring than preoperative risk prediction. Across modalities, clinical indices such as ARISCAT consistently outperformed imaging for predicting PPCs [4]. Table 1: Summary of Evidence by Imaging Modality Imaging Modality Main Findings Guideline/Review Consensus Chest Radiograph (CXR) Abnormalities detected in 2.5–37% of patients; only ≤2% resulted in management changes. No independent predictive value after adjustment for clinical risk scores. Not recommended for routine use. Routine use discouraged. Selective imaging justified only for new/unexplained symptoms, abnormal findings, or high-risk surgeries. Computed Tomography (CT) Not useful in unselected patients. Provides prognostic value in thoracic surgery and in patients with COPD/ILD. Predictive contribution often indirect through functional indices (ppoFEV1, ppoDLCO). Reserved for thoracic surgery or significant underlying disease. Not recommended for general screening. Lung Ultrasound (LUS) Feasible, portable, radiation-free. Modest predictive value (AUROC ≈0.65). Operator dependence and heterogeneous scoring limit generalization. Stronger evidence for postoperative monitoring than preoperative prediction. Promising but still investigational. Not yet included in guidelines for preoperative prediction.

This systematic review confirms that routine preoperative chest imaging offers minimal predictive value for PPCs. • CXR adds little beyond the clinical exam and validated risk scores, and its routine use is not justified [5, 6]. • CT may assist in risk stratification in selected populations (thoracic surgery, COPD, ILD), but routine use in general surgical candidates is not supported [8]. • LUS remains investigational; its portability and absence of radiation are attractive, but existing studies are small, heterogeneous, and operator dependent [9]. The findings align with current professional society guidelines, which discourage routine preoperative imaging in asymptomatic patients [5]. Clinical indices remain the cornerstone of PPC risk prediction [4]. Limitations of the evidence include heterogeneity in PPC definitions, variable imaging protocols, and limited high-quality LUS data. Future research should explore: • Integration of LUS into validated risk scores, • CT-derived radiomic phenotypes for PPC risk in non-thoracic populations, and • Prospective multicenter trials comparing imaging-augmented vs. clinical prediction models.

Routine preoperative chest imaging does not improve prediction of PPCs. Imaging should be reserved for patients with new or unexplained respiratory symptoms, abnormal clinical findings, or high-risk surgical contexts. Clinical risk indices such as ARISCAT remain essential for perioperative planning [4].

1. Canet J, Gallart L, Gomar C, et al. Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology. 2010;113(6):1338-1350. 2. Mazo V, Sabaté S, Canet J. Predicting postoperative pulmonary complications in the general population. Curr Opin Anaesthesiol. 2014;27(2):107-115. 3. Qaseem A, Snow V, Fitterman N, et al. Risk assessment for and strategies to reduce perioperative pulmonary complications for patients undergoing noncardiothoracic surgery: a guideline from the ACP. Ann Intern Med. 2006;144(8):575-580. 4. Canet J, Gallart L, Gomar C, et al. Development and validation of a score to predict risk of postoperative pulmonary complications (ARISCAT). Anesthesiology. 2010;113(6):1338-1350. 5. American College of Radiology. ACR Appropriateness Criteria® Routine Chest Radiography. Reston, VA: ACR; 2023. 6. Archer C, Levy AR, McGregor M. Value of routine preoperative chest x-rays: a meta-analysis. Can J Anaesth. 1993;40(11):1022-1027. 7. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. 8. Brunelli A, Charloux A, Bolliger CT, et al. ERS/ESTS clinical guidelines on fitness for radical therapy in lung cancer patients. Eur Respir J. 2009;34(1):17-41. 9. Zieleskiewicz L, Muller L, Lakhal K, et al. Point-of-care lung ultrasound in perioperative medicine: a prospective multicentre observational study. Anesthesiology. 2018;128(3):432-444.