Rational and practical use of imaging in COVID-19 pneumonia.

The severe form of the COVID-19 pandemic caused by the SARS-CoV-2 virus, has largely manifested as a predominant respiratory illness causing severe pneumonia characterized by bilateral, subpleural ground glass haze, progressing to consolidation, and fibrosis on imaging. There is some discrepancy between the governmental guidelines, professional Societies and Radiology and Respiratory Medicine specialists with divided opinions between the use of the chest X-rays and CT scan, and whether the use be screening or diagnostic. So far, the most balanced recommendations have been proposed by the Fleischner Society, which are endorsed by the Radiological Society of Pakistan as well. This writeup describes the approach for a rational use of imaging to the best advantage in the current situation according to local resources, and restricting the spread of infection. The most practical compromise for Pakistan appears to be the use of portable digital radiography equipment, and point-of- care ultrasound; with CT scan reserved for clinical situations not explained by the above two modalities, or demanding disease stratification.

The Significance of Incidental Findings on Computed Tomography of the Chest.

BACKGROUND: Computed tomography (CT) of the chest has replaced lung scans and pulmonary angiography as the criterion standard for the diagnosis of pulmonary embolism (PE). Most of these examinations are negative for PE, but they frequently have incidental findings that may require further evaluation. OBJECTIVE: In order to examine common incidental findings and their possible clinical ramifications and required workup, we reviewed data from relevant studies in which chest CTs were performed and incidental findings discovered. DISCUSSION: The most common incidental findings on chest CT are pulmonary nodules and lymph nodes. Nodules are significantly more commonly found in smokers and are also more likely to be malignant in smokers. The recently updated 2017 Fleischner Society recommendations provide guidance to clinicians in deciding which nodules should be further evaluated. Enlarged lymph nodes similarly represent potential malignancy and most will need further evaluation with positron emission tomography scans or by transbronchial needle aspiration. CONCLUSIONS: Enlarged lymph nodes and pulmonary nodules are both common incidental findings on chest CT. Each represents the potential for malignancy, and under certain conditions requires additional workup and further evaluation. The majority will be benign, even in high-risk populations. However, because of the increasing prevalence of the chest CT and the frequency with which incidental findings will be seen, it is important that the emergency physician be aware of common features and recommended subsequent evaluation.

Pre-Existing Interstitial Lung Abnormalities in Patients with Head and Neck Squamous Cell Carcinoma and Their Follow Up after Therapy.

Interstitial lung abnormalities (ILAs) are incidentally found nondependent parenchymal abnormalities affecting more than 5% of any lung zone and are potentially related to interstitial lung disease and worsening post-treatment outcomes in malignancies and infectious diseases. The aim of this study was to determine the prevalence and type of ILA changes in patients with head and neck squamous cell carcinoma (HNSCC) and their change in the follow-up period. This retrospective single-center study included 113 patients with newly diagnosed HNSCC who underwent lung MSCT prior to treatment. ILAs were reported in 13.3% of patients on pretreatment MSCT. Patients with ILAs were significantly older (median 75 vs. 67 years). ILAs were most prevalent in lower zones (73.3%) (p = 0.0045). The most reported ILA subtype was subpleural non-fibrotic (60%) (p = 0.0354). Reticulations were the most frequently described pattern (93.3%) (p < 0.0001). Progression of ILAs was reported in almost 30% of patients after receiving therapy. Patients with pre-existing ILAs were more likely to develop radiation-induced lung fibrosis after adjuvant radiotherapy (p = 0.0464). In conclusion, ILA's incidence, distribution and presentation were similar to previous research conducted in other special cohorts. Our research suggests a possible association of more frequent radiation pneumonitis with ILA changes in patients with HNSCC, which should be further investigated.

Outcomes of Incidental Lung Nodules With Structured Recommendations and Electronic Tracking.

OBJECTIVE: To evaluate the impact of structured recommendations on follow-up completion for incidental lung nodules (ILNs). METHODS: Patients with ILNs before and after implementation of structured Fleischner recommendations and electronic tracking were sampled randomly. The cohorts were compared for imaging follow-up. Multivariable logistic regression was used to assess appropriate follow-up and loss to follow-up, with independent variables including use of structured recommendations or tracking, age, sex, race, ethnicity, setting of the index test (inpatient, outpatient, emergency department), smoking history, and nodule features. RESULTS: In all, 1,301 patients met final inclusion criteria, including 255 patients before and 1,046 patients after structured recommendations or tracking. Baseline differences were found in the pre- and postintervention groups, with smaller ILNs and younger age after implementing structured recommendations. Comparing pre- versus postintervention outcomes, 40.0% (100 of 250) versus 29.5% (309 of 1,046) of patients had no follow-up despite Fleischner indications for imaging (P = .002), and among the remaining patients, 56.6% (82 of 145) versus 75.0% (553 of 737) followed up on time (P < .001). Delayed follow-up was more frequent before intervention. Differences postintervention were mostly accounted for by nodules ≤8 mm in the outpatient setting (P < .001). In multivariable analysis, younger age, White race, outpatient setting, and larger nodule size showed significant association with appropriate follow-up completion (P < .015), but structured recommendations did not. Similar results applied for loss to follow-up. DISCUSSION: Consistent use of structured reporting is likely key to mitigate selection bias when benchmarking rates of appropriate follow-up of ILN. Emergency department patients and inpatients are at high risk of missed or delayed follow-up despite structured recommendations.

Volume Doubling Time of Pulmonary Carcinoid Tumors Measured by Computed Tomography.

INTRODUCTION: Pulmonary carcinoid tumor (PCT) is a rare neuroendocrine lung neoplasm comprising approximately 2% of lung cancer diagnoses. It is classified as either localized low-grade (typical) or intermediate-grade (atypical) subtypes. PCT is known clinically to be a slow-growing cancer, however few studies have established its true growth rate when followed over time by computed tomography (CT). Therefore, we sought to determine the volume doubling time for PCTs as visualized on CT imaging. MATERIALS AND METHODS: We conducted a retrospective analysis of all PCTs treated at our institution between 2006 and 2020. Nodule dimensions were measured using a Picture Archiving and Communication System or retrieved from radiology reports. Volume doubling time was calculated using the Schwartz formula for PCTs followed by successive CT scans during radiographic surveillance. Consistent with Fleischner Society guidelines, tumors were considered to have demonstrated definitive growth by CT only when the interval change in tumor diameter was greater than or equal to 2 mm. RESULTS: The median volume doubling time of 13 typical PCTs was 977 days, or 2.7 years. Five atypical PCTs were followed longitudinally, with a median doubling time of 327 days, or 0.9 years. CONCLUSIONS: Typical pulmonary carcinoid features a remarkably slow growth rate as compared to more common lung cancers. Our analysis of atypical pulmonary carcinoid included too few cases to offer definitive conclusions. It is conceivable that clinicians following current nodule surveillance guidelines may mistake incidentally detected typical carcinoids for benign non-growing lesions when followed for less than 2 years in low-risk patients.

Shades of Gray: Subsolid Nodule Considerations and Management.

Subsolid nodules are common on chest CT imaging and may be either benign or malignant. Their varied features and broad differential diagnoses present management challenges. Although subsolid nodules often represent lung adenocarcinomas, other possibilities are common and influence management. Practice guidelines exist for subsolid nodule management for both incidentally and screening-detected nodules, incorporating patient and nodule characteristics. This review highlights the similarities and differences among these algorithms, with the intent of providing a resource for comparison and aid in choosing management options.

Implementation of a Standardized Template for Reporting of Incidental Pulmonary Nodules: Feasibility, Acceptability, and Outcomes.

OBJECTIVE: Incidental pulmonary nodules (IPNs) are common. Up to 70% are not followed up according to current guidelines. Follow-up recommendations are based on the characteristics of the patient and the IPN. However, many IPNs are incompletely characterized in CT reports. Structured radiology reports have been shown to reduce missing information. We sought to improve IPN reporting by assessing the feasibility, acceptability, and effectiveness of a structured dictation template to increase the presence of six key nodule descriptors. METHODS: We performed a mixed methods, pre- and postimplementation assessment. A template was developed with a multidisciplinary group based on Fleischner Society guidelines. A standardized checklist was used to determine the presence of documented descriptors pre- and postimplementation for sequential radiology reports of patients with an IPN present (n = 400 pre-implementation and n = 400 postimplementation) on a CT performed at the Minneapolis Veterans Affairs Health Care System. We conducted qualitative interviews with radiologists (n = 4) and members of the lung nodule tracking team (n = 2) to elicit their experiences of the template implementation process. RESULTS: The proportion of radiology reports including all six elements increased from 12% to 47% (P < .001). Postimplementation, the template was used in 40% of interpretations involving lung nodules, 67% of follow-up scans, and 8% of initial identifications. Response to the template was overall positive. DISCUSSION: Use of a dictation template seems to be effective in increasing compliance with full IPN documentation, streamlining the follow-up process. Low utilization rates of the template for initial nodule identification is a limitation, which may be combated through clearer communication and advances in technology.

Management of Incidental Lung Nodules: Current Strategy and Rationale.

Incidentally detected lung nodules are increasingly common in routine diagnostic computed tomography (CT) imaging. Formal management recommendations for incidental nodules, such as those outlined by the Fleischner Society, must therefore reflect a balance of malignancy risk and the clinical context in which nodules are discovered. Nodule size, attenuation, morphology, and location all influence the likelihood of malignancy and, thus, the necessity and timing of follow-up according to current Fleischner recommendations. As technological advancements in CT imaging continue, there may be greater reliance on advanced computerized analysis of lung nodule features to help determine the risk of clinically significant disease.

Incidental pulmonary nodules in emergent coronary CT angiography for suspected acute coronary syndrome: Impact of revised 2017 Fleischner Society Guidelines.

BACKGROUND: Pulmonary nodules (PN) are frequently detected incidentally during coronary computed tomography angiography (CTA). We evaluated whether the 2017 Fleischner Society guidelines may result in a decrease of follow-up testing of incidental PN as compared to prior guidelines in patients undergoing coronary CTA. METHODS: We conducted a retrospective study of a registry of emergency department patients who underwent coronary CTA for acute coronary syndrome assessment between 2012 and 2017. Based on guidelines, patients <35 years, history of cancer, or prior exams showing stability of PN were excluded. Patients >60 years, history of smoking, irregular/spiculated PN morphology, or PN size >20 mm were classified as high-risk for lung cancer. Radiological findings pertaining to PN were identified (PN size, morphology, quantity) through review of radiology reports. PN follow-up recommendations were established using 2017 Fleischner Society Guidelines and compared with prior guidelines for solid (2005) and subsolid (2013) PN. Data were analyzed with Student's t-test. RESULTS: The registry included 2066 patients (female 45.1%, 52.9 ± 11.0 years), of which 578 (28.0%) reported PN. 438 of those (21.2%) were eligible for guideline-based follow-up evaluation. 205 (4 6.8%) were classified as high-risk for lung cancer. 2017 guidelines reduced the number of individuals requiring follow-up by 64.5%, from 264 (12.8%) to 94 patients (4.5%) when compared to prior guidelines (p < 0.001). The minimum number of follow-up chest CTs decreased by 55.8% from 430 to 190 (p < 0.001). CONCLUSION: Application of the 2017 Fleischner Society Guidelines resulted in a significant decrease of follow-up testing for incidental PN in patients undergoing coronary CTA for suspected acute coronary syndrome.

Addition of the Fleischner Society Guidelines to Chest CT Examination Interpretive Reports Improves Adherence to Recommended Follow-up Care for Incidental Pulmonary Nodules.

RATIONALE AND OBJECTIVES: The study aimed to determine whether the addition of the Fleischner Society guidelines to chest computed tomography (CT) reports identifying incidental pulmonary nodules affects follow-up care. PATIENTS AND METHODS: Beginning in 2008, a template containing the Fleischner Society guidelines was added at the interpreting radiologist's discretion to chest CT reports describing incidental solid pulmonary nodules at our institution. The records of all medical centers in Olmsted county were used to capture the complete medical history of local patients >35 years old diagnosed with a pulmonary nodule from April 1, 2008 to October 1, 2011. Patients with a history of cancer or previously diagnosed nodule, or who died before follow-up, were excluded. Patients were categorized according to whether they did ("template group") or did not ("control group") have the template added. Nodule size and smoking history were used to determine recommended follow-up care. Differences in follow-up were compared between groups using Pearson's chi-square test. RESULTS: A total of 510 patients (276 in the template group, 234 in the control group) were included in the study. Only 198 patients (39%) received their recommended follow-up care. Template group patients were significantly more likely to receive recommended follow-up care compared to control group patients (45% vs 31%, P = .0014). Most patients whose management did not adhere to Fleischner Society guidelines did not receive a recommended follow-up chest CT (210 out of 312, 67%). CONCLUSIONS: The addition of the Fleischner Society guidelines to chest CT reports significantly increases the likelihood of receiving recommended follow-up care for patients with incidental pulmonary nodules. Additional education is needed to improve appropriate guideline utilization by radiologists and adherence by ordering providers.

"Rounding" the Size of Pulmonary Nodules: Impact of Rounding Methods on Nodule Management, as Defined by the 2017 Fleischner Society Guidelines.

RATIONALE AND OBJECTIVES: The objective of this study was to quantify the impact of different rounding methods on size measurements of pulmonary nodules and to determine the number of nodules that change management categories as a result of rounding. MATERIALS AND METHODS: For this retrospective institutional review board-approved study, we included 503 incidental pulmonary nodules (308 solid and 195 subsolid) from a data repository. Long and short axes were measured. Average diameters were calculated using four different rounding methods (method 1: no rounding; method 2: rounding only the average diameter to the closest millimeter; method 3: rounding only short and long axes; and method 4: rounding short and long axes and the average diameter to the closest millimeter). Nodules were classified for each rounding method according to the 2017 Fleischner Society guideline management categories. Measurements were compared among the four rounding methods using analysis of variance. RESULTS: Without rounding, the average nodule diameter was 15.67 ± 5.97 mm. This increased between 0.03 and 0.29 mm using rounding methods 2-4 (range: P < 0.001-0.017). The nodule size was more frequently rounded up (range: 52.1%-77.5%) than rounded down (range: 17.7%-42.5%) using rounding methods 2-4, as compared to no rounding. In the 308 solid nodules, up to 2.9% of the nodules changed management category, whereas none of the 195 subsolid nodules changed category. CONCLUSIONS: Rounding methods have a small absolute but statically significant effect on nodule size, impacting management category in less than 3% of the nodules. This suggests that, in clinical practice, any rounding method can be used for determining nodule size without substantially biasing individual nodules toward given management categories.

Follow-up of Incidental Pulmonary Nodules and the Radiology Report.

PURPOSE: Incidental pulmonary nodules that require follow-up are often noted on chest CT. Evidence-based guidelines regarding appropriate follow-up have been published, but the rate of adherence to guideline recommendations is unknown. Furthermore, it is unknown whether the radiology report affects the nodule follow-up rate. METHODS: A review of 1,000 CT pulmonary angiographic studies ordered in the emergency department was performed to determine the presence of an incidental pulmonary nodule. Fleischner Society guidelines were applied to ascertain if follow-up was recommended. Radiology reports were classified on the basis of whether nodules were listed in the findings section only, were noted in the impression section, or had explicit recommendations for follow-up. Whether the rate of nodule follow-up was affected by the radiology report was determined according to these 3 groups. RESULTS: Incidental pulmonary nodules that required follow-up were noted on 9.9% (95% confidence interval, 8%-12%) of CT pulmonary angiographic studies. Follow-up for nodules was poor overall (29% [28 of 96]; 95% confidence interval, 20%-38%) and decreased significantly when the nodules were mentioned in the findings section only (0% [0 of 12]). Specific instructions to follow up nodules in radiology reports still resulted in a low follow-up rate of 29% (19 of 65; 95% confidence interval, 18%-40%). CONCLUSIONS: Incidental pulmonary nodules detected on CT pulmonary angiography are common and are frequently not followed up appropriately. Although the inclusion of a pulmonary nodule in the impression section of a radiology report is helpful, it does not ensure follow-up. Better systems for appropriate identification and follow-up of incidental findings are needed.

Natural history of incidental pulmonary nodules in children.

RATIONALE: As there are no evidence based guidelines for the diagnosis and/or management of pulmonary nodules in children, there is an over reliance on the adult based algorithms when dealing with pulmonary nodules in children. We present our experience of pediatric patients evaluated for incidentally found pulmonary nodules. METHODS: Retrospective chart review of patients diagnosed with a pulmonary nodule and evaluated at Goryeb Children's Hospital between January 2000 and December 2012. PRIMARY OUTCOME: change in the size of the pulmonary nodule between the initial and follow-up imaging. RESULTS: Thirty six patients with pulmonary nodule (21 male/15 female; Median [range] age 15 [5-20] years.) were included in the study. Chest CT was obtained for respiratory symptoms and/or abnormal chest radiograph in 19 (52%). Nine pulmonary nodules (25%) were identified on abdominal CT obtained for abdominal symptoms. A total of 46 nodules were identified in 36 patients. Nine of the pulmonary nodules (9 patients) were ≤4 mm in size, 37 of the pulmonary nodules (27 patients) were >4 mm in size. Twenty-two of the 27 (81%) patients with nodule size >4 mm had follow-up CT: 14 nodules (54%) remained unchanged in size, 5 nodules (19%) decreased in size, and 7 nodules (27%) were not detected. CONCLUSION: Our review of 36 patients with pulmonary nodules shows no obvious growth of the nodules over the study period, suggesting low risk of malignancy. Routine follow-up chest computer tomography using ACCP/Fleischner Society guidelines may not apply in children without known malignancy.

Follow-up of incidental pulmonary nodules and the radiology report.

PURPOSE: Incidental pulmonary nodules that require follow-up are often noted on chest CT. Evidence-based guidelines regarding appropriate follow-up have been published, but the rate of adherence to guideline recommendations is unknown. Furthermore, it is unknown whether the radiology report affects the nodule follow-up rate. METHODS: A review of 1,000 CT pulmonary angiographic studies ordered in the emergency department was performed to determine the presence of an incidental pulmonary nodule. Fleischner Society guidelines were applied to ascertain if follow-up was recommended. Radiology reports were classified on the basis of whether nodules were listed in the findings section only, were noted in the impression section, or had explicit recommendations for follow-up. Whether the rate of nodule follow-up was affected by the radiology report was determined according to these 3 groups. RESULTS: Incidental pulmonary nodules that required follow-up were noted on 9.9% (95% confidence interval, 8%-12%) of CT pulmonary angiographic studies. Follow-up for nodules was poor overall (29% [28 of 96]; 95% confidence interval, 20%-38%) and decreased significantly when the nodules were mentioned in the findings section only (0% [0 of 12]). Specific instructions to follow up nodules in radiology reports still resulted in a low follow-up rate of 29% (19 of 65; 95% confidence interval, 18%-40%). CONCLUSIONS: Incidental pulmonary nodules detected on CT pulmonary angiography are common and are frequently not followed up appropriately. Although the inclusion of a pulmonary nodule in the impression section of a radiology report is helpful, it does not ensure follow-up. Better systems for appropriate identification and follow-up of incidental findings are needed.