Who is at risk of lung nodules on low-dose CT in a Western country? A population-based approach.

BACKGROUND: This population-based study aimed to identify the risk factors for lung nodules in a Western European general population. METHODS: We quantified the presence or absence of lung nodules among 12 055 participants of the Dutch population-based ImaLife (Imaging in Lifelines) study (age ≥45 years) who underwent low-dose chest computed tomography. Outcomes included the presence of 1) at least one solid lung nodule (volume ≥30 mm3) and 2) a clinically relevant lung nodule (volume ≥100 mm3). Fully adjusted multivariable logistic regression models were applied overall and stratified by smoking status to identify independent risk factors for the presence of nodules. RESULTS: Among the 12 055 participants (44.1% male; median age 60 years; 39.9% never-smokers; 98.7% White), we found lung nodules in 41.8% (5045 out of 12 055) and clinically relevant nodules in 11.4% (1377 out of 12 055); the corresponding figures among never-smokers were 38.8% and 9.5%, respectively. Factors independently associated with increased odds of having any lung nodule included male sex, older age, low educational level, former smoking, asbestos exposure and COPD. Among never-smokers, a family history of lung cancer increased the odds of both lung nodules and clinically relevant nodules. Among former and current smokers, low educational level was positively associated with lung nodules, whereas being overweight was negatively associated. Among current smokers, asbestos exposure and low physical activity were associated with clinically relevant nodules. CONCLUSIONS: The study provides a large-scale evaluation of lung nodules and associated risk factors in a Western European general population: lung nodules and clinically relevant nodules were prevalent, and never-smokers with a family history of lung cancer were a non-negligible group.

Prevalence of pulmonary nodules detected incidentally on noncancer-related imaging: a review.

Pulmonary nodules are common incidental findings requiring surveillance. Follow-up recommendations vary depending on risk factors, size and solid or subsolid characteristics. This review aimed to evaluate the prevalence of clinically significant nodules detected on noncancer-dedicated imaging and the prevalence of part-solid and ground-glass nodules. We conducted a systematic search of literature and screened texts for eligibility. Clinically significant nodules were noncalcified nodules >4-6 mm. Prevalence estimates were calculated for all studies and risk of bias was assessed by one reviewer. Twenty-four studies were included, with a total of 30 887 participants, and 21 studies were cross-sectional in design. Twenty-two studies used computed tomography (CT) imaging with cardiac-related CT being the most frequent. Prevalence of significant nodules was highest in studies with large field of view of the chest and low size thresholds for reporting nodules. The prevalence of part-solid and ground-glass nodules was only described in two cardiac-related CT studies. The overall risk of bias was low in seven studies and moderate in 17 studies. While current literature frequently reports incidental nodules on cardiovascular-related CT, there is minimal reporting of subsolid characteristics. Unclear quantification of smoking history and heterogeneity of imaging protocol also limits reliable evaluation of nodule prevalence in nonscreening cohorts.

Does obstructive sleep apnea-induced intermittent hypoxia increase the incidence of solitary pulmonary nodules, thyroid nodules, and other disorders? A retrospective study based on 750 cardiovascular disease patients.

BACKGROUND: Obstructive sleep apnea (OSA) has been shown to be an important risk factor for cardiovascular disease (CVD), and intermittent hypoxia is an important pathogenetic factor for it. In the clinic, it was found that most CVD patients combined with OSA were also combined with solitary pulmonary nodules (SPN) or thyroid nodules (TN). Are these disorders related to intermittent hypoxia? One study showed that intermittent hypoxia is a pathogenic factor for lung cancer in mice, but there have been no clinical reports. So we conducted a retrospective study to explore whether intermittent hypoxia caused by OSA increases the incidence of SPN, TN, and other disorders. METHODS: We selected 750 patients with cardiovascular disease (CVD), who were divided into the control group and the OSA group according to the result of portable sleep monitoring. Retrospectively analyzed the comorbidities that patients with OSA are prone to and explored the correlation between OSA and those comorbidities. RESULTS: The incidence of SPN, TN, cervical spondylosis, and carotid-artery plaques was higher in the OSA group than in the control group. These diseases are significantly associated with OSA (p < 0.05), and their incidence increased with an elevated apnea-hypopnea index. After excluding interference from age, gender, BMI, smoking history, history of lung disease, and history of tumors, OSA showed a significant correlation with SPN. After excluding age, gender, BMI, and thyroid disease, OSA was associated with TN. Patients with comorbidities have lower nocturnal oxygen saturation and more extended periods of apnea. Logistic multiple regression results revealed that male, advanced age, obesity, CS, and nasal septum deviation were independent risk factors for OSA. CONCLUSIONS: Patients combined with OSA may further develop more comorbidities, such as SPN, TN, and carotid-artery plaques. It may be related to intermittent hypoxia caused by OSA.

Trends in the incidence of pulmonary nodules in chest computed tomography: 10-year results from two Dutch hospitals.

OBJECTIVE: To study trends in the incidence of reported pulmonary nodules and stage I lung cancer in chest CT. METHODS: We analyzed the trends in the incidence of detected pulmonary nodules and stage I lung cancer in chest CT scans in the period between 2008 and 2019. Imaging metadata and radiology reports from all chest CT studies were collected from two large Dutch hospitals. A natural language processing algorithm was developed to identify studies with any reported pulmonary nodule. RESULTS: Between 2008 and 2019, a total of 74,803 patients underwent 166,688 chest CT examinations at both hospitals combined. During this period, the annual number of chest CT scans increased from 9955 scans in 6845 patients in 2008 to 20,476 scans in 13,286 patients in 2019. The proportion of patients in whom nodules (old or new) were reported increased from 38% (2595/6845) in 2008 to 50% (6654/13,286) in 2019. The proportion of patients in whom significant new nodules (≥ 5 mm) were reported increased from 9% (608/6954) in 2010 to 17% (1660/9883) in 2017. The number of patients with new nodules and corresponding stage I lung cancer diagnosis tripled and their proportion doubled, from 0.4% (26/6954) in 2010 to 0.8% (78/9883) in 2017. CONCLUSION: The identification of incidental pulmonary nodules in chest CT has steadily increased over the past decade and has been accompanied by more stage I lung cancer diagnoses. CLINICAL RELEVANCE STATEMENT: These findings stress the importance of identifying and efficiently managing incidental pulmonary nodules in routine clinical practice. KEY POINTS: • The number of patients who underwent chest CT examinations substantially increased over the past decade, as did the number of patients in whom pulmonary nodules were identified. • The increased use of chest CT and more frequently identified pulmonary nodules were associated with more stage I lung cancer diagnoses.

Prevalence and clinical characteristics of malignant lung nodules in tuberculosis endemic area in a single tertiary centre.

BACKGROUND: Lung nodule management remains a challenge to clinicians, especially in endemic tuberculosis areas. Different guidelines are available with various recommendations; however, the suitability of these guidelines for the Asian population is still unclear. Our study described the prevalence of malignant lung nodules among nodules measuring 2-30 mm, the demographic and characteristics of lung nodules between benign and malignant groups, and the clinician's clinical practice in managing lung nodules. METHOD: Retrospective review of lung nodules from the computed tomography archiving and communication system (PACS) database and clinical data from January 2019 to January 2022. The data was analysed by using chi square, mann whitney test and simple logistic regression. RESULTS: There were 288 nodules measuring 2-30 mm identified; 49 nodules underwent biopsy. Twenty-seven (55%) biopsied nodules were malignant, (prevalence of 9.4%). Among the malignant lung nodules, 74% were adenocarcinoma (n = 20). The commonest benign nodules were granuloma n = 12 (55%). In nodules > 8 mm, the median age of malignant and benign was 72 ± 12 years and 66 ± 16 years, respectively (p = 0.024). There was a significant association of benign nodules (> 8 mm) in subjects with previous or concurrent tuberculosis (p = 0.008). Benign nodules are also associated with nodule size ≤ 8 mm, without spiculation (p < 0.001) and absence of emphysema (p = 0.007). The nodule size and the presence of spiculation are factors to make the clinicians proceed with tissue biopsy. Spiculated nodules and increased nodule size had 11 and 13 times higher chances of undergoing biopsy respectively (p < 0.001).) Previous history of tuberculosis had a 0.874 reduced risk of progression to malignant lung nodules (p = 0.013). These findings implied that these three factors are important risk factors for malignant lung nodules. There was no mortality association between benign and malignant. Using Brock's probability of malignancy, nodules ≤ 8 mm had a low probability of malignancy. CONCLUSION: The prevalence of malignant lung nodules in our centre was comparatively lower than non-Asian countries. Older age, the presence of emphysema, and spiculation are associated with malignancy. Clinical judgment is of utmost importance in managing these patients. Fleishner guideline is still being used as a reference by our clinician.

Evaluating the Patient With a Pulmonary Nodule: A Review.

IMPORTANCE: Pulmonary nodules are identified in approximately 1.6 million patients per year in the US and are detected on approximately 30% of computed tomographic (CT) images of the chest. Optimal treatment of an individual with a pulmonary nodule can lead to early detection of cancer while minimizing testing for a benign nodule. OBSERVATIONS: At least 95% of all pulmonary nodules identified are benign, most often granulomas or intrapulmonary lymph nodes. Smaller nodules are more likely to be benign. Pulmonary nodules are categorized as small solid (<8 mm), larger solid (≥8 mm), and subsolid. Subsolid nodules are divided into ground-glass nodules (no solid component) and part-solid (both ground-glass and solid components). The probability of malignancy is less than 1% for all nodules smaller than 6 mm and 1% to 2% for nodules 6 mm to 8 mm. Nodules that are 6 mm to 8 mm can be followed with a repeat chest CT in 6 to 12 months, depending on the presence of patient risk factors and imaging characteristics associated with lung malignancy, clinical judgment about the probability of malignancy, and patient preferences. The treatment of an individual with a solid pulmonary nodule 8 mm or larger is based on the estimated probability of malignancy; the presence of patient comorbidities, such as chronic obstructive pulmonary disease and coronary artery disease; and patient preferences. Management options include surveillance imaging, defined as monitoring for nodule growth with chest CT imaging, positron emission tomography-CT imaging, nonsurgical biopsy with bronchoscopy or transthoracic needle biopsy, and surgical resection. Part-solid pulmonary nodules are managed according to the size of the solid component. Larger solid components are associated with a higher risk of malignancy. Ground-glass pulmonary nodules have a probability of malignancy of 10% to 50% when they persist beyond 3 months and are larger than 10 mm in diameter. A malignant nodule that is entirely ground glass in appearance is typically slow growing. Current bronchoscopy and transthoracic needle biopsy methods yield a sensitivity of 70% to 90% for a diagnosis of lung cancer. CONCLUSIONS AND RELEVANCE: Pulmonary nodules are identified in approximately 1.6 million people per year in the US and approximately 30% of chest CT images. The treatment of an individual with a pulmonary nodule should be guided by the probability that the nodule is malignant, safety of testing, the likelihood that additional testing will be informative, and patient preferences.

Prevalence of pulmonary nodules in dogs with malignant neoplasia as determined by CT.

In order to estimate the prevalence of pulmonary nodules in dogs with nonpulmonary malignant neoplasia, medical record descriptions of CT findings in dogs diagnosed with nonpulmonary malignant neoplasia were reviewed retrospectively. A total of 536 dogs were sampled from a single hospital. For malignant neoplasms with >10 affected individuals, prevalence of multiple pulmonary nodules at first CT was hemangiosarcoma 24 of 58 (41%), osteosarcoma 14 of 55 (26%), carcinoma 20 of 80 (25%), histiocytic sarcoma five of twenty-one (24%), soft tissue sarcoma 13 of 57 (23%), adenocarcinoma 11 of 60 (18%), melanoma five of thirty-seven (14%), lymphoma 10 of 76 (13%), mast cell tumor two of forty-seven (4%), and squamous cell carcinoma zero of seventeen (0%). A solitary pulmonary nodule was identified at first CT in 33 (6%) dogs. Of these, nine had follow-up CT, including two dogs in which the nodule disappeared, three dogs in which the size of the nodule did not change, and four dogs in which the nodule enlarged and additional pulmonary nodules appeared. Dogs with hemangiosarcoma were most likely to have signs of pulmonary metastasis at first CT, whereas dogs with mast cell tumor were infrequently affected, and no dog with squamous cell carcinoma had signs of pulmonary metastasis. A solitary pulmonary nodule at first CT was an indeterminate finding, potentially unassociated with neoplasia.

Incidental pulmonary nodule frequency in Turkey.

INTRODUCTION: Pulmonary nodules are common incidental findings on computed tomography (CT). In Turkey, there is no available data about the follow-up of the frequency of incidental nodules. Our aim is to assess the frequency and size distrubition of incidental pulmonary nodule in our country. MATERIALS AND METHODS: Between January 2015 and December 2016, computed tomographies, taken of all outpatient and emergency department that recorded in the screening database were examined retrospectively. Nodules and their characteristics (number, size, density, localization) and relationship between age and gender were evaluated. RESULT: The age range of the cases was mean 58.99 ± 16.20 years, 256 (42.5%) were women and 347 (57.5%) were men. A total of 288 (48.25%) cases had 420 nodules. Solid nodule was present in 184 cases (30.5%). The number of cases with one solid nodule was 119 (64.7%). There were 124 solid nodules (55.36%) of ≥ 4-< 6 mm diameter, 64 solid nodules (28.57%) of ≥ 6-< 8 mm diameter and 36 solid nodules (16.07%) of ≥ 8 mm diameter. Nodule frequency increased statistically significantly with the age (p= 0.001). CONCLUSIONS: The frequency of incidental nodule was found higher than in our country than in developed countries.

Combination diagnosis of multi-slice spiral computed tomography and secretary phospholipase A2-IIa for solitary pulmonary nodules.

INTRODUCTION: This study was aimed to compare the diagnostic value of multi-slice spiral computed tomography (CT) and secretary phospholipase A2-IIa (sPLA2-IIa) in differentiating between malignant and benign solitary pulmonary nodules (SPNs). METHODS: A total of 223 patients with SPNs (91 patients with malignant SPNs and 132 patients with benign SPNs) were included from Weihai Central Hospital during October 2014 to December 2016. SPN diagnosis was confirmed in all patients using needle biopsy, surgery and bronchoscopy. The patients were managed with dynamic multi-slice CT scans, and their sPLA2-IIa levels were also detected. By selecting the area of interest of focus, the perfusion parameters of multi-slice CT targeting the focus were obtained. RESULTS: The levels of MTT, PS, BV, BF and sPLA2-IIa significantly increased with increasing severity of SPNs (P<.05). Notably, BV (area under the ROC curve [AUC]=0.915; 95%CI: 0.88-0.95; sensitivity=91.21%; specificity=78.79%) showed a higher potential to discriminate patients with malignant SPNs from those with benign SPNs than did BF (AUC=0.712; 95%CI: 0.65-0.78; sensitivity=72.50%; specificity=59.10%), PS (AUC=0.772; 95%CI: 0.71-0.84; sensitivity=65.93%; specificity=82.58%) and MTT (AUC=0.600; 95%CI: 0.52-0.68; sensitivity=52.75%; specificity=78.03%). Finally, the combined diagnostic value of BV and sPLA2-IIa was quite ideal (AUC=0.947; 95%CI: 0.92-0.97; sensitivity=85.70%; specificity=92.70%) for malignant and benign SPNs. CONCLUSIONS: The combined diagnostic value of BV and sPLA2-IIa appeared as a desirable detection method for malignant and benign SPNs.

Incidence of solitary pulmonary nodules in Northeastern France: a population-based study in five regions.

BACKGROUND: The discovery of a solitary pulmonary nodule (SPN) on a chest imaging exam is of major clinical concern. However, the incidence rates of SPNs in a general population have not been estimated. The objective of this study was to provide incidence estimates of SPNs in a general population in 5 northeastern regions of France. METHODS: This population-based study was undertaken in 5 regions of northeastern France in May 2002-March 2003 and May 2004-June 2005. SPNs were identified by chest CT reports collected from all radiology centres in the study area by trained readers using a standardised procedure. All reports for patients at least 18 years old, without a previous history of cancer and showing an SPN between 1 and 3 cm, were included. RESULTS: A total of 11,705 and 20,075 chest CT reports were collected for the 2002-2003 and 2004-2005 periods, respectively. Among them, 154 and 297 reports showing a SPN were included, respectively for each period. The age-standardised incidence rate (IR) was 10.2 per 100,000 person-years (95% confidence interval 8.5-11.9) for 2002-2003 and 12.6 (11.0-14.2) for 2004-2005. From 2002 to 2005, the age-standardised IR evolved for men from 16.4 (13.2-19.6) to 17.7 (15.0-20.4) and for women from 4.9 (3.2-6.6) to 8.2 (6.4-10.0). In multivariate Poisson regression analysis, gender, age, region and period were significantly associated with incidence variation. CONCLUSIONS: This study provides reference incidence rates of SPN in France. Incidence was higher for men than women, increased with age for both gender and with time for women. Trends in smoking prevalence and improvement in radiological equipment may be related to incidence variations.

Development and validation of a nomogram to estimate the pretest probability of cancer in Chinese patients with solid solitary pulmonary nodules: A multi-institutional study.

OBJECTIVES: To develop and validate a nomogram to estimate the pretest probability of malignancy in Chinese patients with solid solitary pulmonary nodule (SPN). MATERIALS AND METHODS: A primary cohort of 1798 patients with pathologically confirmed solid SPNs after surgery was retrospectively studied at five institutions from January 2014 to December 2015. A nomogram based on independent prediction factors of malignant solid SPN was developed. Predictive performance also was evaluated using the calibration curve and the area under the receiver operating characteristic curve (AUC). RESULTS: The mean age of the cohort was 58.9 ± 10.7 years. In univariate and multivariate analysis, age; history of cancer; the log base 10 transformations of serum carcinoembryonic antigen value; nodule diameter; the presence of spiculation, pleural indentation, and calcification remained the predictive factors of malignancy. A nomogram was developed, and the AUC value (0.85; 95%CI, 0.83-0.88) was significantly higher than other three models. The calibration cure showed optimal agreement between the malignant probability as predicted by nomogram and the actual probability. CONCLUSIONS: We developed and validated a nomogram that can estimate the pretest probability of malignant solid SPNs, which can assist clinical physicians to select and interpret the results of subsequent diagnostic tests.

A retrospective validation study of three models to estimate the probability of malignancy in patients with small pulmonary nodules from a tertiary oncology follow-up centre.

AIM: To estimate the probability of malignancy in small pulmonary nodules (PNs) based on clinical and radiological characteristics in a non-screening population that includes patients with a prior history of malignancy using three validated models. MATERIALS AND METHODS: Retrospective data on clinical and radiological characteristics was collected from the medical records of 702 patients (379 men, 323 women; range 19-94 years) with PNs ≤12 mm in diameter at a single centre. The final diagnosis was compared to the probability of malignancy calculated by one of three models (Mayo, VA, and McWilliams). Model accuracy was assessed by receiver operating characteristics (ROC). The models were calibrated by comparing predicted and observed rates of malignancy. RESULTS: The area under the ROC curve (AUC) was highest for the McWilliams model (0.82; 95% confidence interval [CI]: 0.78-0.91) and lowest for the Mayo model (0.58; 95% CI: 0.55-0.59). The VA model had an AUC of (0.62; 95% CI: 0.47-0.64). Performance of the models was significantly lower than that in the published literature. CONCLUSIONS: The accuracy of the three models is lower in a non-screening population with a high prevalence of prior malignancy compared to the papers that describe their development. To the authors' knowledge, this is the largest study to validate predictive models for PNs in a non-screening clinically referred patient population, and has potential implications for the implementation of predictive models.

Predicting Malignant and Paramalignant Pleural Effusions by Combining Clinical, Radiological and Pleural Fluid Analytical Parameters.

BACKGROUND: The usefulness of clinical, radiological and pleural fluid analytical parameters for diagnosing malignant and paramalignant pleural effusion is not clearly stated. Hence this study aimed to identify possible predictor variables of diagnosing malignancy in pleural effusion of unknown aetiology. METHODS: Clinical, radiological and pleural fluid analytical parameters were obtained from consecutive patients who had suffered pleural effusion of unknown aetiology. They were classified into three groups according to their final diagnosis: malignant, paramalignant and benign pleural effusion. The CHAID (Chi-square automatic interaction detector) methodology was used to estimate the implication of the clinical, radiological and analytical variables in daily practice through decision trees. RESULTS: Of 71 patients, malignant (n = 31), paramalignant (n = 15) and benign (n = 25), smoking habit, dyspnoea, weight loss, radiological characteristics (mass, node, adenopathies and pleural thickening) and pleural fluid analytical parameters (pH and glucose) distinguished malignant and paramalignant pleural effusions (all with a p < 0.05). Decision tree 1 classified 77.8% of malignant and paramalignant pleural effusions in step 2. Decision tree 2 classified 83.3% of malignant pleural effusions in step 2, 73.3% of paramalignant pleural effusions and 91.7% of benign ones. CONCLUSIONS: The data herein suggest that the identified predictor values applied to tree diagrams, which required no extraordinary measures, have a higher rate of correct identification of malignant, paramalignant and benign effusions when compared to techniques available today and proved most useful for usual clinical practice. Future studies are still needed to further improve the classification of patients.

Management of pulmonary nodules in head and neck cancer patients - Our experience and interpretation of the British Thoracic Society Guidelines.

BACKGROUND: and purpose of the study: The frequency of lung nodules in the head and neck cancer population is unknown, currently the only guidance available recommends following local policy. The aim of this study was to determine the incidence of pulmonary nodules in our head and neck cancer group and interpret the recently updated British Thoracic Society (BTS) Lung Nodule Guidelines in a head and neck cancer setting. METHODS: 100 patients were diagnosed with head and neck cancer between July 2013-March 2014, clinico-pathological, demographic and radiological data was extracted from the electronic records. Images with lung findings were re-reviewed by a single consultant radiologist for patients with lung pathology on the initial staging CT report. RESULTS: Twenty patients (20%) had discreet pulmonary findings on CT. Eleven (11%) had lung nodules, 6 (6%) had lesions suspicious for metastasis and 3 (3%) had co-incidental bronchogenic primary cancers. These patients were re-imaged between 6 and 18 months and in 1 patient the previously identified 7 mm nodule had progressed to 16 mm at 1 year. There was no set follow up imaging protocol used. CONCLUSION: The MDT in NHS Lothian has reviewed the BTS guidance and now has a local policy for the management of lung nodules in head and neck cancer patients. Lung Nodules in the head and neck cancer population are common >10%. Higher risk patients with larger nodules should be risk assessed with validated assessment tools. PET-CT has a place in the assessment of lung nodules when risk of malignancy is high.

Recent Trends in the Identification of Incidental Pulmonary Nodules.

RATIONALE: Pulmonary nodules are common incidental findings, but information about their incidence in the era of computed tomography (CT) is lacking. OBJECTIVES: To examine recent trends in pulmonary nodule identification. METHODS: We used electronic health records and natural language processing to identify members of an integrated health system who had nodules measuring 4 to 30 mm. We calculated rates of chest CT imaging, nodule identification, and receipt of a new lung cancer diagnosis within 2 years of nodule identification, and standardized rates by age and sex to estimate the frequency of nodule identification in the U.S. population in 2010. MEASUREMENTS AND MAIN RESULTS: Between 2006 and 2012, more than 200,000 adult members underwent 415,581 chest CT examinations. The annual frequency of chest CT imaging increased from 1.3 to 1.9% for all adult members, whereas the frequency of nodule identification increased from 24 to 31% for all scans performed. The annual rate of chest CT increased from 15.4 to 20.7 per 1,000 person-years, and the rate of nodule identification increased from 3.9 to 6.6 per 1,000 person-years, whereas the rate of a new lung cancer diagnosis remained stable. By extrapolation, more than 4.8 million Americans underwent at least one chest CT scan and 1.57 million had a nodule identified, including 63,000 who received a new lung cancer diagnosis within 2 years. CONCLUSIONS: Incidental pulmonary nodules are an increasingly common consequence of routine medical care, with an incidence that is much greater than recognized previously. More frequent nodule identification has not been accompanied by increases in the diagnosis of cancerous nodules.

Mediastinal lymph nodes and pulmonary nodules in children: MDCT findings in a cohort of healthy subjects.

OBJECTIVE: Existing data are very limited on incidentally detected pulmonary nodules or mediastinal lymph nodes in healthy children who undergo chest MDCT. We aimed to evaluate the prevalence, distribution, and average dimensions of these occasional findings in a cohort of otherwise healthy patients. MATERIALS AND METHODS: Two radiologists reviewed in consensus the scans of patients referred for chest MDCT during the preoperative workup for pectus carinatum or pectus excavatum treatments. Exclusion criteria included the presence of any documented malignancy (by date of MDCT or during the 2 years after the examination), history of recent infections, or trauma. Patients' records were assessed after 2 years for the development of any malignancy. RESULTS: A total of 99 individuals (63 boys, 36 girls; mean age, 13.5 years; range, 4-18 years) who fulfilled the study criteria were evaluated. The presence of at least one pulmonary nodule was observed in 75% of the patients, with a mean diameter of 2.8 mm. Of a total number of 225 pulmonary nodules, only 24 (10.7%) were calcified. Mediastinal lymph nodes were also identified in 81% of the cases, with a maximum diameter of 7 mm (smallest axis). CONCLUSION: The presence of pulmonary nodules or mediastinal lymph nodes on the basis of preoperative chest MDCT scans in healthy children is frequent. Given that 95% of the nodules and 100% of the lymph nodes measured less than 6 mm and 7 mm, respectively, we conclude that incidental findings under these limits are very unlikely to be pathologic.

The role of ¹8F-FDG uptake features in the differential diagnosis of solitary pulmonary lesions with PET/CT.

BACKGROUND: The aim of this study is to evaluate the value of (18)F-FDG uptake features in the diagnosis of solitary pulmonary lesions. METHODS: One hundred thirty-nine patients with solitary pulmonary lesions were divided into full uptake, circular uptake, multi-focus uptake, mild uptake, and no-uptake groups according to the uptake features of (18)F-FDG in solitary pulmonary lesions. The incidence of benign and malignant lesions and the false-positive and false-negative rates in each group were analyzed. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the method using (18)F-FDG uptake features combined with maximum standard uptake value (SUVmax) (SUV method) in the differential diagnosis of solitary pulmonary lesions were evaluated. RESULTS: There were 89 malignant and 50 benign lesions. (1) The malignant incidence of the full uptake group was 84.0% (63/75), and there were significant differences when compared with the other groups except the circular uptake group (16/23) (all P = 0.0001). The benign incidence of the multi-focus and no-uptake groups was 83.3% (10/12) and 82.4% (14/17), respectively, and there were significant differences when compared with the full uptake and the circular uptake groups, respectively (all P < 0.05). The benign incidence of the mild uptake group was 58.3% (7/12), and there were no significant differences when compared with the others except the full uptake group (all P > 0.05). No statistical significance was found between either two of the no-uptake, mild uptake, and multi-focus uptake groups (all P > 0.05). (2) In cases with SUVmax ≥2.5, the false-positive rate in the multi-focus uptake group was 83.3% (10/12), which was significantly higher than in the full uptake (12/75) or circular uptake group (7/23) (all P < 0.05). In cases with SUVmax <2.5, the false-negative rates in the mild and no-uptake groups were 41.7 and 17.6% (P = 0.218). (3) The sensitivity, specificity, accuracy, PPV, and NPV of the method using (18)F-FDG uptake features combined with SUVmax and the single SUV method were 88.7%/91.0%, 62.0%/42.0%, 79.1%/73.4%, 80.6%/73.6%, and 75.6%/72.4%, respectively. CONCLUSIONS: The method using uptake features of (18)F-FDG combined with SUVmax can improve the diagnostic specificity and accuracy of solitary pulmonary lesions. The multi-focus uptake feature maybe a benign sign, which still needs more researches to confirm.

Prevalence and variables associated with solitary pulmonary nodules in a routine clinic-based population: a cross-sectional study.

OBJECTIVE: To determine the prevalence of solitary pulmonary nodules (SPNs) in chest radiology studies and patient's features associated with malignancy in a non-high-risk clinical population. METHODS: Patients ≥35 years were referred for thoracic imaging in two hospitals (2010-2011). Eight radiologists determined the presence and characteristics of SPN. Selected variables were collected from radiological register and medical records. Observer agreement in the diagnosis of SPN was assessed. RESULTS: 25,529 patients were included: 23,102 (90.5%) underwent chest radiograph and 2,497 (9.5%) a CT. The prevalence of SPN was 2.1% (95% CI 1.9 - 2.3) in radiographs and 17.0% (95% CI 15.5 - 18.5) in CT. In patients undergoing chest radiograph, detection of SPN with an irregular border was more frequent among smokers. In patients who had a CT, larger SPNs appeared to be associated with 60 years of age or over, diagnosis of a respiratory illness, or male gender. In addition, an irregular border was also more common among men. CONCLUSIONS: The prevalence of SPNs detected by both radiograph and CT was lower than that shown in screening studies. Patient characteristics such as age, sex, respiratory disease, or smoking habit were associated with nodule characteristics that are known to be related with malignancy. KEY POINTS: There is a lower SPN prevalence in the clinical population than in screening studies. SPN prevalence is associated with some patient characteristics: sex, age, imaging test. Nodule characteristics related to malignancy were associated with some patient characteristics.

Positron emission tomography in the evaluation of pulmonary nodules among patients living in a coccidioidal endemic region.

BACKGROUND: Within a coccidioidal endemic region, pulmonary nodules due to coccidioidomycosis are common. Uptake of (18)fluorodeoxyglucose ((18)FDG) by positron emission tomography with computed axial tomography (PET/CT) has been used to assess whether pulmonary nodules are malignant but inflammatory lesions can be positive. The purpose of this study was to compare by PET/CT the (18)FDG uptake in pulmonary nodules likely due to coccidioidomycosis to that of nodules shown to be malignant among patients living in a coccidioidal endemic region. METHODS: We retrospectively reviewed patients who underwent a PET/CT at the Southern Arizona Veterans Affairs Health Care System between January 2008 and March 2012 who were subsequently found on biopsy to have pulmonary nodules that were coccidioidal or granulomatous or were due to malignancy. RESULTS: Among 245 diagnostic biopsies where the subject had a previous PET/CT, 15 (6.1 %) were either coccidioidal (n = 12) or granulomatous without an identified organism (n = 3). The median maximum standard unit of uptake (SUV(max)) on PET/CT of coccidioidal or granulomatous lesions was 2.0 compared to 9.8 for malignant lesions (P < 0.001). The maximum diameter of the coccidioidal or granulomatous nodules was 2.1 cm compared to 3.0 cm for the malignant lesions (P = 0.009). On multivariable analysis, an elevated SUV(max) was the only distinguishing feature between the malignant and the granulomatous lesions (OR 1.28, 95 % CI 1.05-1.55; P = 0.013). CONCLUSIONS: Coccidioidal pulmonary nodules take up significantly less (18)FDG than those due to malignancies, but there is considerable overlap between granulomatous and malignant lesions at lower SUV(max).

Incidental findings on cardiac computed tomography in incident hemodialysis patients: the predictors of arrhythmic and cardiovascular events in end-stage renal disease (PACE) study.

BACKGROUND: This is the first study that has examined non-cardiac incidental findings in research cardiac computed tomography (CT) of hemodialysis patients and their relationship with patient characteristics. METHODS: We performed a cross-sectional analysis in the Predictors of Arrhythmic and Cardiovascular Events in End-Stage Renal Disease (PACE) study, a prospective cohort study on incident hemodialysis patients. Non-cardiac structures in the cardiac CT scan were reviewed and evaluated. The type and frequencies of non-cardiac incidental CT findings were summarized. Univariate and multivariate logistic regression were performed to analyze the associations between gender, older age, obesity, history of cardiovascular disease (CVD), smoking status, history of chronic pulmonary disease and history of cancer with presence of any incidental CT findings and, separately, pulmonary nodules. RESULTS: Among the 260 participants, a total of 229 non-cardiac incidental findings were observed in 145 participants (55.8% of all participants). Of these findings, pulmonary nodules were the most common incidental finding (24.2% of all findings), and 41.3% of them requiring further follow-up imaging per radiology recommendation. Vascular and gastrointestinal findings occurred in 11.8% and 15.3% of participants, respectively. Participants 65 years or older had a higher odds of any incidental findings (Odds Ratio (OR) =2.55; 95% Confidence Intervals (CI) 1.30, 4.99) and pulmonary nodules (OR=4.80; 95% CI 2.51, 9.18). Prior history of CVD was independently and significantly associated with any incidental findings (OR=2.00; 95% CI 1.19, 3.40); but not with the presence of pulmonary nodules. CONCLUSIONS: We demonstrate that the prevalence of incidental findings by cardiac CT scanning is extremely high among patients on hemodialysis. Further investigations to follow-up on the high occurrence of incidental findings during our research study and potentially clinical studies raises important practical, ethical and medico-legal issues that need to be carefully considered in research projects using imaging studies.