Multimodality Imaging of Postmastectomy Breast Reconstruction Techniques, Complications, and Tumor Recurrence.

For women undergoing mastectomy, breast reconstruction can be performed by using implants or autologous tissue flaps. Mastectomy options include skin- and nipple-sparing techniques. Implant-based reconstruction can be performed with saline or silicone implants. Various autologous pedicled or free tissue flap reconstruction methods based on different tissue donor sites are available. The aesthetic outcomes of implant- and flap-based reconstructions can be improved with oncoplastic surgery, including autologous fat graft placement and nipple-areolar complex reconstruction. The authors provide an update on recent advances in implant reconstruction techniques and contemporary expanded options for autologous tissue flap reconstruction as it relates to imaging modalities. As breast cancer screening is not routinely performed in this clinical setting, tumor recurrence after mastectomy and reconstruction is often detected by palpation at physical examination. Most local recurrences occur within the skin and subcutaneous tissue. Diagnostic breast imaging continues to have a critical role in confirmation of disease recurrence. Knowledge of the spectrum of benign and abnormal imaging appearances in the reconstructed breast is important for postoperative evaluation of patients, including recognition of early and late postsurgical complications and breast cancer recurrence. The authors provide an overview of multimodality imaging of the postmastectomy reconstructed breast, as well as an update on screening guidelines and recommendations for this unique patient population. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Perceived Stress among Iranians during COVID-19 Pandemic; Stressors and Coping Mechanisms: A Mixed-methods Approach.

OBJECTIVE: New coronavirus (COVID-19) pandemic socioeconomically affected the world. In this study, we measured the perceived stress in response to the COVID-19 pandemic among Iranians to determine the groups at both extremes of the spectrum followed by identifying the stressors and coping mechanisms. METHODS: This study was a mixed-methods study. We distributed a web-based 10-item perceived stress scale (PSS-10), to measure perceived stress score (PSS), through social networks from March 12 to 23, 2020. Then, we interviewed 42 students, 31 homemakers, 27 healthcare providers, and 21 male participants to identify the sources of stress and coping mechanisms. RESULTS: Finally, 13,454 participants completed the questionnaires. The median and interquartile range (IQR) of the participants' PSS was 21 (15-25). Students, homemakers, and healthcare workers (HCWs) showed a higher median (IQR) of PSS compared to other groups (23 [18 to 27], 22 [16 to 26], and 19 [14 to 24], respectively). Male participants showed a lower median (IQR) PSS (17 [12 to 23]). Content analysis of 121 participants' answers showed that the most common stressors were school-related issues mentioned by students, family-related issues mentioned by homemakers, and COVID-19-related issues mentioned by healthcare providers. Male participants' coping mechanisms were mostly related to the perception of their abilities to cope with the current crisis. CONCLUSION: Our participants clinically showed a moderate level of PSS. The main stressors among students, homemakers, and HCWs were related to their principal role in this period, and male participants' coping mechanisms were inspired by the self-image retrieved from the social perspectives.

Imaging Evaluation of Abdominopelvic Gunshot Trauma.

Firearm-related injuries, or gunshot wounds (GSWs), are among the most important worldwide public health problems, resulting in considerable annual morbidity, disability, and mortality. GSWs to the abdomen and pelvis are associated with substantial injuries to multiple organs and tissues. Imaging plays an important role in identifying these injuries, dictating nonoperative management, and determining imaging and clinical follow-up, as well as helping manage potential long-term complications. CT is the primary imaging modality used to evaluate these injuries and their complications, including use of reconstructed multiplanar volume-rendered images. The authors discuss the ballistics and mechanisms of firearm injury, CT findings, trajectory analysis, and applications of different imaging modalities above and beyond CT in evaluation of GSWs. Imaging findings and classifications of the severity of injuries to solid and hollow organs and vascular, musculoskeletal, and neurologic systems are reviewed. Key complications associated with gunshot injuries to the abdomen and pelvis are presented. The challenges of imaging in the acute trauma setting and potential pitfall mimics at imaging, particularly at CT, are also described. A step-by-step guide for thorough and comprehensive evaluation of GSWs to the abdomen and pelvis is introduced, with tips for optimizing effective communication with the clinical team. Online supplemental material is available for this article. ©RSNA, 2020.

Reactions to Both Nonionic Iodinated and Gadolinium-Based Contrast Media: Incidence and Clinical Characteristics.

OBJECTIVE: The objective or our study was to assess the incidence rate and clinical characteristics of allergiclike reactions in patients who received both nonionic iodinated contrast medium (ICM) and gadolinium-based contrast medium (GBCM). MATERIALS AND METHODS: Acute allergiclike reactions in patients who received both ICM and GBCM to nonionic ICM or GBCM injections during a 5-year period were analyzed. Allergy preparation was not administered when patients received a different type of contrast material. Acute allergiclike reactions to both ICM and GBCM were evaluated. RESULTS: Of 302,858 contrast injections (155,234 ICM and 147,624 GBCM) during a 5-year period, 1006 (752 ICM and 254 GBCM) acute allergiclike contrast reactions were reported. The overall rate of reaction to ICM was 0.48% (95% CI, 0.45-0.52%), and the overall rate of reaction to GBCM was 0.17% (95% CI, 0.15-0.19%). A total of 19,237 patients received at least one ICM injection and one GBCM injection, with a total of 56,310 injections (19,237 initial injections and 37,073 subsequent injections). Nine patients had reactions to both ICM and GBCM with the primary reaction rate of 9/19,237 (incidence rate, 0.047%; 95% CI, 0.044-0.050%), and the secondary reaction rate of 9/37,073 (incidence rate, 0.024%; 95% CI, 0.023-0.026%). All secondary reactions in patients who had a reaction to both ICM and GBCM were mild. None of the patients required medication for the treatment of the secondary reaction. CONCLUSION: An allergiclike reaction to both nonionic ICM and GBCM was an extremely rare event that presented as a mild acute reaction without significant clinical consequences despite the fact that an allergy preparation was not administered.

Current Guidelines for the Diagnosis and Management of Hepatocellular Carcinoma: A Comparative Review.

OBJECTIVE: The purpose of this article is to review aspects of guidelines pertinent to radiologists involved in the diagnosis or treatment of hepatocellular carcinoma. CONCLUSION: Early diagnosis and treatment of hepatocellular carcinoma are important because only 10% of patients meet the criteria for curative therapy at the time of diagnosis. Several organizations have developed guidelines for screening, diagnosis, and treatment of hepatocellular carcinoma. Radiologists play a pivotal role in every aspect of these guidelines.

Threshold for Enhancement in Treated Hepatocellular Carcinoma on MDCT: Effect on Necrosis Quantification.

OBJECTIVE: The objective of our study was to determine whether the conventionally used enhancement threshold of 10 HU for assessing tumor viability in treated hepatocellular carcinoma (HCC) lesions is valid. MATERIALS AND METHODS: To distinguish pseudoenhancement from enhancement in a tumor, we used an in vivo model: The attenuation of 54 hepatic cysts during the unenhanced and portal venous phases of MDCT, similar to what may be observed in HCC with central necrosis, was used to determine the threshold for pseudoenhancement. To validate this model, we compared the attenuation value of liver parenchyma in this cohort with that of 22 HCCs during the late arterial phase of enhancement. We tested the effect of this pseudoenhancement on quantifying necrosis in HCC compared with the conventionally used threshold of 10 HU. RESULTS: Values of enhancing HCC tissue on arterial phase MDCT (mean, 121.3 HU) were comparable with normal liver parenchyma on venous phase MDCT (117.3 HU) (p = 0.27). The threshold of 17.1 HU was the best threshold for the detection of pseudoenhancement in cysts (99% accuracy, 100% sensitivity, and 98% specificity). When this threshold was used instead of the conventional threshold of 10 HU, the mean necrosis proportion of treated HCC increased from 34.0% to 42.6% and the mean viable tumor proportion decreased from 66.0% to 57.4%. The quantification of viable HCC tissue based on 10 HU and the quantification of viable HCC tissue based on 17.1 HU were found to be significantly different (p < 0.0001). CONCLUSION: The threshold of 17.1 HU may be the appropriate cutoff for nonenhancement in a necrotic HCC. Use of this threshold may potentially affect how response to therapy is quantified and categorized.

Diagnostic accuracy of sonoelastography in detecting malignant thyroid nodules: a systematic review and meta-analysis.

OBJECTIVE: The aim of this systematic review was to determine the diagnostic accuracy of sonoelastography in detecting malignant thyroid nodules. MATERIALS AND METHODS: A systematic search in MEDLINE and bibliographic databases was performed for the terms "thyroid nodule" and "sonoelastography." The inclusion criteria were the report of a 4- or 5-point scoring scale for elasticity score by qualitative sonoelastography as the index test and fine-needle aspiration (FNA) cytology or histopathology for thyroid nodules as the reference standard. Studies in which only the strain ratio was reported and studies of patients with underlying medical conditions were excluded. The methodologic quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. A meta-analysis of diagnostic accuracy measures for sonoelastography was performed using Meta-DiSc freeware software (version 1.4). RESULTS: A total of 12 studies assessing 1180 thyroid nodules (817 benign and 363 malignant) were included. The most commonly used threshold for characterizing malignancy--that is, elasticity scores between 2 and 3--showed a sensitivity of 86.0% (95% CI, 81.9-89.4%) and specificity of 66.7% (95% CI, 63.4-69.9%) with positive and negative likelihood ratios and a diagnostic odds ratio of 3.82 (95% CI, 2.38-6.13), 0.16 (95% CI, 0.08-0.32), and 27.51 (95% CI, 9.21-82.18), respectively. The highest sensitivity of the test was achieved by a threshold elasticity score of between 1 and 2 with a sensitivity of 98.3% (95% CI, 96.2-99.5%). CONCLUSION: Sonoelastography can be considered as a reliable screening tool for characterizing thyroid nodules. An elasticity score of 1 is indicative of benign pathology in almost all cases and can be used to exclude many patients from further invasive assessments.

Quality of published Iranian medical education research studies: a systematic review.

BACKGROUND: Research in medical education has been paid more attention than before; however the quality of research reporting has not been comprehensively appraised. To evaluate the methodological and reporting quality of Iranian published medical education articles. METHODS: Articles describing medical students, residents, fellows or program evaluation were included. Articles related to continuing medical education or faculty development, review articles and reports, and studies considering both medical and nonmedical students were excluded. We searched MEDLINE through PubMed in addition to major Iranian medical education search engines and databases including Scientific Information Database (SID) from March 2003 to March 2008. The Medical Education Research Quality Index (MERSQI) scale and the Consolidated Standards of Reporting Trials (CONSORT 2001) were used for experimental studies and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) was utilized for observational studies. RESULTS: Ninety five articles were found to be related to the medical education research in Iran including 16 (16.8%) experimental studies. Total MERSQI scores ranged between 3.82 and 13.09 with the mean of 8.39 points. Mean domain scores were highest for data analysis (1.85) and lowest for validity (0.61). The most frequently reported item was background (96%) and the least reported was the study limitations (16%). CONCLUSION: The quality of published medical education research in Iran seems to be suboptimal.

A Survey of Practicing Radiologists on the Use of Premedication Before Intravenous Iodinated Contrast Medium Administration.

OBJECTIVE: To determine whether updated guidance by the ACR in 2017 advocating use of intravenous (IV) premedication in emergency department (ED) patients and inpatients with reported iodinated contrast allergy was associated with a change in clinical practice. METHODS: An anonymous survey was distributed via e-mail in October 2020 to practicing radiologist members of the ACR interrogating use of corticosteroid premedication for two clinical vignettes: an indicated routine (perform within 24 hours) inpatient contrast-enhanced CT (CE-CT) and an indicated urgent (perform within 6 hours) ED CE-CT. In both scenarios, the patient had a prior moderate hypersensitivity reaction to iodinated contrast media. Clinical management was evaluated. Data were compared to historical controls from 2009. RESULTS: The response rate was 11% (724 of 6,616). For the inpatient scenario, 72% (518 of 724) would use corticosteroid premedication with CE-CT, and 28% (200 of 724) would perform noncontrast CT. For the ED scenario, 67% (487 of 724) would use corticosteroid premedication with CE-CT, and 30% (217 of 724) would perform noncontrast CT. Oral premedication (85%, 439 of 518) was preferred for routine inpatients, and rapid IV premedication (89%, 433 of 487) was preferred for urgent ED patients. Of those who provided rapid IV dosing data in the ED, two doses of corticosteroids were used by 53% (216 of 410) and one dose was used by 45% (185 of 410), with academic radiologists more likely than private or hybrid practice radiologists to administer two doses (74% [74 of 100] versus 48% [151 of 312], P < .001, odds ratio, 3.03; 95% confidence interval, 1.84-5.00). Rapid IV premedication was more commonly used in 2020 than in 2009 (60% [433 of 724] versus 29% [20 of 69], P < .001, odds ratio, 3.65; 95% confidence interval, 2.12-6.26). Antihistamine use was common in both inpatient (93%, 480 of 518) and ED settings (92%, 447 of 487). Only 32% (229 of 721) of radiologists practiced in accordance with ACR guidelines, suggesting no need for routine premedication before CE-CT in patients with prior severe hypersensitivity reaction to gadolinium-based contrast media. Nonetheless, most (93%, 670 of 724) said the ACR Manual on Contrast Media was a major determinant of their practice. CONCLUSIONS: Use of rapid IV premedication in urgent settings has increased since 2009, following updated ACR guidelines, but there is disagreement over whether one or two corticosteroid doses is required. Despite reported high reliance on ACR guidelines, deviations from those guidelines remain common. In general, when ACR guidelines were not followed, it was in a risk-averse direction.

Cyclophosphamide for scleroderma lung disease: a systematic review and meta-analysis.

To assess the effectiveness of cyclophosphamide in the management of scleroderma-related interstitial lung disease (ILD). In this systematic review study, the primary outcome measures were change in forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (D(L)CO) of the patients after 6 and 12 months. To assess the effect of cyclophosphamide on early stage of ILD, alveolitis, in SSc patients, we selected the studies that used the BAL findings or HRCT or recent deterioration of PFT with minimal chest X-ray finding in early stage of disease as diagnosis of alveolitis. A sensitive systematic search strategy was used to find all relevant studies. Finally, 17 trials were included in the analysis that was performed using STATA. (Version 8) and Review Manager (version 4.1; MetaView version 4.1) softwares. Results from 10 studies were pooled for the outcome variable of FVC after 12 months. The summary WMD (random effects) was 2.45 (95% CI, 0.760-4.149 P = 0.005), which means that cyclophosphamide was able to prevent deterioration of FVC after 12 months. In pooled data of 13 studies, about DLCO after 12 months WMD (random effects) was 2.003 2.96 (95% CI, -0.228 to 6.159 P = 0.069), which means that cyclophosphamide was not able to prevent deterioration of D(L)CO after 12 months. If we considered clinically sensible improvement as absolute value ≥10% in DLCO and VC, then result of treatment with cyclophosphamide treatment in scleroderma patients with ILD was not significant.

Feasibility of sub-second CT angiography of the abdomen and pelvis with very low volume of contrast media, low tube voltage, and high-pitch technique, on a third-generation dual-source CT scanner.

BACKGROUND: Concerns about potential risks of using contrast media in patients with chronic renal insufficiency limit the utilization of CT angiography in this population. PURPOSE: To evaluate the feasibility of abdominopelvic CTA with very low volumes of contrast media. MATERIAL AND METHODS: In this retrospective study, 20 patients with chronic renal insufficiency underwent high-pitch abdominopelvic (AP) CTA on a third-generation dual-source CT scanner with 30 mL of nonionic iodinated contrast. The homogeneity of intravascular attenuation at the suprarenal aorta, infrarenal aorta, and the right common iliac artery was measured. Image noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were used to assess objective image quality. Subjective image quality was evaluated on a 5-point scale (1 = unacceptable; 5 = excellent). RESULTS: Twelve male and eight female patients underwent CTA of the abdomen and pelvis at 80 kVp. Five CTAs also included the chest (CAP). The mean scan duration was 0.78 ± 0.19 s for AP and 0.96 ± 0.06 s for CAP CTAs. The mean ± SD of attenuation at suprarenal aorta, infrarenal aorta, and right common iliac artery were 235.1 ± 68.0, 249.2 ± 61.3, and 254.4 ± 67.7 HU, respectively. The attenuation was homogeneous across vascular levels (P = 0.06). All scans had diagnostic subjective image quality with the median (IQR) of 3.5 (1.75). CNR and SNR were homogeneous across vascular levels (P = 0.08 and P = 0.14, respectively). CONCLUSION: Sub-second, high-pitch abdominopelvic CTA with a low volume of contrast in patients with chronic renal insufficiency is technically and clinically feasible with good diagnostic image quality and homogenous attenuation across vascular levels.

Geographic Trends in Publications and Submissions in Radiology Journals: Decade Report (2010 - 2020).

RATIONALE AND OBJECTIVE: The Radiology Research Alliance (RRA) of the Association of University Radiologists (AUR) organized a task force to quantify geographic changes in submissions to and publications within radiology journals over time. MATERIALS AND METHODS: Twenty journals were selected: 7 US-based general, 4 European-based general, and 9 subspecialty radiology journals. Journals were solicited for submissions and publications based on country of origin from 2010 -2020. Regression models assessed changes over time across countries, and by continent, with an emphasis on the US and China, for each journal category. RESULTS: There were 104,679 publications and 92,446 submissions from 149 countries. Overall, there were significant increases in numbers of publications from Asia (R2 = 0.66, p <0.01), and specifically, China (R2 = 0.87, p <0.01). For US journals, there were increased numbers of publications from Asia (R2 = 0.72, p <0.01) and China (R2 = 0.98, p <0.01), but decreased numbers from North America (R2 = 0.41, p = 0.03). For European journals, there were increased numbers of publications from Asia (R2 = 0.79, p <0.01), North America (R2 = 0.75, p <0.01), and China (R2 = 0.82, p <0.01). For subspecialty journals, there were increased numbers of publications from North America (R2 = 0.38, p = 0.04) and China (R2 = 0.73, p <0.01). There was an acute COVID spike in submissions during 2020, with a continuous increase most notable in China (R2 = 0.96, p <0.01). CONCLUSION: In the last decade, the numbers of submissions to and publications within general and subspecialty US and European radiology journals have generally increased around the world, with the largest growth in Asia and in particular China.

Pulmonary survival study in 91 patients with systemic sclerosis.

In systemic sclerosis (SSc), major determinant of morbidity and mortality is pulmonary complication including pulmonary interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). In this study, the natural course of pulmonary involvement in SSc patients was investigated. This was a historical cohort study of SSc patients at a referral center for SSc in Iran between February 1998 and December 2007. Patients had a standardized initial evaluation, and interstitial pulmonary involvement was established by high-resolution CT scan (HRCT). Pulmonary hypertension was assessed by tricuspid gradient on echocardiography. Development of abnormal FVC or DLCO was considered as secondary outcome. Analysis of pulmonary survival was performed for primary and secondary outcomes. Ninety-one SSc patients were included in the study with the mean age of 44.1 (14.8). Among these, 65 (71.4%) patients were classified as limited subtype (lcSSc) and 84 (93.3%) were women. PAH was investigated in 8 (8.2%) patients, 1 (6.7%) in dcSSc and 7 (15.9%) in lcSSc subtype of disease. ILD had developed after a median of 107 (SE = 24.4) months after the first symptom of SSc, and 29 patients (31.9%) developed pulmonary fibrosis. Alveolitis and fibrosis had developed after a median of 129.0 (22.9) and 259.0 (74.2) months, respectively. There was a significant difference in Alveolitis-free pulmonary survival between two subgroups of the disease, which showed pulmonary alveolitis developed later in limited SSc (P = 0.03). The difference was not significant in two subtypes when Cox regression model was used to identify the effect of other prognostic factors on pulmonary survival in patients. In the present study, clinical manifestations of two subtypes of disease were divergent at first; however they became convergent in late stages, and this was the same as results in previous studies. Echocardiography for evaluation of pulmonary hypertension and pulmonary function tests for early detection of ILD and PAH is recommended for SSc patients to detect early stages of pulmonary involvement before significant vascular and fibrotic changes occur.

Pediatric Emergency Imaging Studies in Academic Radiology Departments: A Nationwide Survey of Staffing Practices.

OBJECTIVE: Particularly for pediatric patients presenting with acute conditions or challenging diagnoses, identifying variation in emergency radiology staffing models is essential in establishing a standard of care. We conducted a cross-sectional survey among radiology departments at academic pediatric hospitals to evaluate staffing models for providing imaging interpretation for emergency department imaging requests. METHODS: We conducted an anonymous telephone survey of academic pediatric hospitals affiliated with an accredited radiology residency program across the United States. We queried the timing, location, and experience of reporting radiologists for initial and final interpretations of emergency department imaging studies, during weekday, overnight, and weekend hours. We compared weekday with overnight, and weekday with weekend, using Fisher's exact test and an α of 0.05. RESULTS: Surveying 42 of 47 freestanding academic pediatric hospitals (89%), we found statistically significant differences for initial reporting radiologist, final reporting radiologist, and final report timing between weekday and overnight. We found statistically significant differences for initial reporting radiologist and final report timing between weekday and weekend. Attending radiologist involvement in initial reports was 100% during daytime, but only 33.3% and 69.0% during overnight and weekends. For initial interpretation during overnight and weekend, 38.1% and 28.6% use resident radiologists without attending radiologists, and 28.6% and 2.4% use teleradiology. All finalized reports as soon as possible during weekdays, but only 52.4% and 78.6% during overnight and weekend. DISCUSSION: A minority of hospitals use 24-hour in-house radiology attending radiologist coverage. During overnight periods, the majority of academic pediatric emergency departments rely on resident radiologists without attending radiologist supervision or outside teleradiology services to provide initial reports. During weekend periods, over a quarter rely on resident radiologists without attending radiologist supervision for initial reporting. This demonstrates significant variation in staffing practices at academic pediatric hospitals. Future studies should look to determine whether this variation has any impact on standard of care.

Gunshot injuries to the brachial plexus during wartime.

Gunshot injuries of the brachial plexus are a challenging issue among peripheral nerve lesions. Surgical reconstruction of such injuries is difficult and the clinical outcome depends on several factors. The aim of this study was to present the outcome of surgical management of gunshot injuries of the brachial plexus that occurred following Iran-Iraq war. Twenty patients with 55 injured elements of the brachial plexus underwent surgery in Loghman-Hakim Hospital during 1982 and 1992. Reconstructive procedures included neurolysis in 30 injured elements, nerve grafting in 17 and a combination of these two methods in 8 cases. Surgical procedure was selected based on the microscopic findings during the operation. Final recovery outcome was assessed at least 3 years after surgery on the basis of motor and sensory recoveries. Final outcome was defined as poor, intermediate, and good. Both good and intermediate outcomes were considered as useful recovery. An acceptable recovery was obtained in 28 of 30 (94%) injured elements undergone neurolysis, 15 of 17 (89%) elements in nerve graft group, and 7 of 8 (87.5%) elements reconstructed with neurolysis in combination with nerve graft. In neurolysis, good recovery was more frequent and obtained in 23 of 30 (77.5%) lesions. Best treatment outcome was observed in lesions of lateral cord to musculocutaneous nerve which all injured elements showed good recovery. Impairment in none of the lesions in the level of posterior cord and lower trunk or C8-T1 led to good recovery. In surgical reconstruction of gunshot injuries of the brachial plexus the most favorable results were observed in the neurolysis reconstruction of the lesions in the lateral cord to musculocutaneous nerve. In the absence of spontaneous improvement of neurologic deficit, surgical procedures should be done as soon as possible according to the type and location of injury.

Are Iranians aware of carbon monoxide poisoning: symptoms and its prevention strategies?

Carbon monoxide (CO) poisoning is still a health problem all over the world. Informing users about symptoms and suggesting annual inspection of CO producing devices will result in CO poisoning reduction. The goal of this study was to evaluate awareness about CO poisoning symptoms and its prevention ways in Iranian population. In this study, a total of 700 patients' family members attended Imam Khomeni hospital were asked to enroll in the study. A structured questionnaire was used including demographic characteristics, devices which were used at home, awareness of CO poisoning symptoms, awareness of CO detectors, the last time that tubal patency of devices are checked, if it is helpful to open the window to fix gas leak and if surveying devices by an expert at the beginning of the cold season is recommended. A total of 635 participants completed questionnaires. The most used device was gas water heater followed by gas heater. Five hundred and nine reported that they are aware of CO poisoning symptoms (80.1%), 398 (62.6%) stated that it is possible to detect CO leak and 566 (89.1%) told CO detectors would be helpful for reduction of mortality from CO poisoning. Fifty percent of participants had not checked their devices since they have bought their devices. Five hundred and thirty-six (84.4%) reported that opening window could help CO leak, and 596 (93.8%) agreed that an expert checked their fuel-burning devices at the beginning of the winter. Iranian people are not aware of all CO poisoning symptoms. Developing a national strategy for CO surveillance and people education will be helpful.