Intramammary Findings on CT of the Chest - a Review of Normal Anatomy and Possible Findings

A pictorial review of scrotal and penile pathology on computed tomography

Computed tomography (CT) may show a variety of scrotal and penile pathologic finding, but is usually not used as a first-line imaging due to its limited soft tissue contrast. Nonetheless, there are three main scenarios for imaging of the scrotum and penis with CT. Pathologies may be found incidentally in patients undergoing abdominal and pelvic CT scanning for different reasons. In emergency settings, CT is frequently performed, and the recognition of scrotal and penile pathologies by the reporting radiologist is crucial to ensure optimal patient treatment and outcome. If MRI scanning cannot be performed due to contraindications or is unavailable in resource, limited CT may be used for the further characterization of scrotal and penile pathology found on ultrasound. This pictorial review wants to familiarize general and emergency radiologists with the anatomy and possible pathological findings of the scrotum and penis on CT.

Missed and Detected Incidental Breast Cancers on Contrast Enhanced Chest CT: Detection Rates and CT Features

This study investigated the rate at which radiologists miss or detect incidental breast cancers on chest CT and to compare the CT features between the two groups. This retrospective study evaluated chest CT examinations and medical records of patients who registered with the diagnosis code of "breast cancer" between January 2016 and December 2020, and who had undergone contrast enhanced chest CT 3-18 months before registration, during which they were unaware of any breast lesions. This study found that out of 84 patients, incidental breast cancer lesions were missed in 54 (64.3%) and detected in 30 (53.7%). The initial treatment was delayed in the missed breast lesions group (p = 0.004). Breast lesions of smaller sizes (<9.0 mm, p = 0.01), or with lower enhancement ratios (<1.4, p = 0.009), were more likely to be missed. When three radiologists re-read the CTs with more attention to breast area, they detected breast cancers with higher accuracies (90.1%, 87.9%, and 81.3%). In summary, this study revealed that radiologists miss 64.3% of incidental breast cancers on chest CT, especially those of sub-centimeter sizes and weak enhancements.

Breast Implants on Computed Tomography—A Pictorial Review of Normal and Pathologic Findings

Breast augmentation with implants is frequently performed. Therefore breast implants can be seen quite frequently on computed tomography (CT) of the body. This offers the possibility to detect incidental pathology and help to improve patient outcome. Basic knowledge about imaging findings of breast implants on CT is therefore needed for radiologists reporting body CT. CT may also be used for further workup of breast implants if magnetic resonance imaging (MRI) is contraindicated or not available. The purpose of this pictorial review is to give a brief overview of normal and pathologic findings of breast implants on CT.

Frequency and spectrum of incidental findings when using chest CT as a primary triage tool for COVID-19

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Of the 232 participants triaged with chest CT for COVID-19, 126 (54 %) showed one or more incidental findings (IF).

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53 Participants (23 %) showed a potentially significant IF.

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A potentially significant IF requires further diagnostic or clinical work up.

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The most common potentially significant IFs were coronary artery calcifications, suspicious breast- and pulmonary nodules.

Purpose

To determine the prevalence and spectrum of incidental findings (IFs) identified in patients undergoing chest CT as a primary triage tool for COVID-19.

Methods

In this study 232 patients were triaged in our COVID-19 Screening Unit by means of a chest CT (March 25–April 23, 2020). Original radiology reports were evaluated retrospectively for the description of IFs, which were defined as any finding in the report not related to the purpose of the scan. Documented IFs were categorized according to clinical relevance into minor and potentially significant IFs and according to anatomical location into pulmonary, mediastinal, cardiovascular, breast, upper abdominal and skeletal categories. IFs were reported as frequencies and percentages; descriptive statistics were used.

Results

In total 197 IFs were detected in 126 patients (54 % of the participants). Patients with IFs were on average older (54.0 years old, SD 16.6) than patients without IFs (44.8 years old, SD 14.6, P < 0.05). In total 60 potentially significant IFs were detected in 53 patients (23 % of the participants). Most often reported were coronary artery calcifications (n = 23, 38 % of total potentially significant IFs/ 10 % of the total study population), suspicious breast nodules (n = 7, 12 % of total potentially significant IFs/ 3% of the total study population) and pulmonary nodules (n = 7, 12 % of total potentially significant IFs/ 3% of the total study population).

Conclusion

A considerable number of IFs were detected by using chest CT as a primary triage tool for COVID-19, of which a substantial percentage (23 %) is potentially clinically relevant.

Incidental Breast Findings on Computed Tomography and MR Imaging

Computed tomography (CT) and magnetic resonance (MR) imaging may demonstrate a wide variety of incidental findings in the breast, including primary breast carcinoma, the second most common cancer in women. It important to recognize the spectrum of pathologic conditions in order to properly assess the need for further workup. Some findings may be diagnosed as benign on the basis of CT/ MR imaging and clinical history alone, whereas others will require evaluation with dedicated breast imaging and possibly biopsy. This article serves to guide radiologists' management of the wide spectrum of incidental breast findings encountered on cross-sectional imaging.

Extrapulmonary neoplasms in lung cancer screening

A significant reduction in lung cancer specific mortality rate was demonstrated by the National Lung Screening Trial (NLST) in participants who had annual low-dose computed tomography (LDCT) screening. In addition to early detection of lung cancer, lung cancer screening (LCS) provides an opportunity to detect cardiovascular disease, pulmonary disease (such as chronic obstructive pulmonary disease and interstitial lung disease), and extrapulmonary neoplasms, such as thyroid, breast, kidney, liver, esophageal, pancreatic and mediastinal tumors. Considering the fact that 22.3% of the certified deaths in the computed tomography (CT) arm of the NLST trial were due to extrapulmonary malignancies, compared to 22.9% of deaths from lung cancer, it is possible that early diagnosis and treatment of clinically significant incidental findings may further decrease morbidity and mortality in screening participants. In this article we review prevalence, clinical relevance and management of incidentally detected extrapulmonary malignancies.