Back to the list
Congress: ECR25
Poster Number: C-22137
Type: Poster: EPOS Radiologist (educational)
Authorblock: I. Yaşar, F. Ozdemir, C. Turan Bektaş, I. T. Rakıcı, H. Özdemir, A. S. Mahmutoglu; Istanbul/TR
Disclosures:
Irem Yaşar: Nothing to disclose
Firat Ozdemir: Nothing to disclose
Ceyda Turan Bektaş: Nothing to disclose
Ibrahim Taşkın Rakıcı: Nothing to disclose
Hanife Özdemir: Nothing to disclose
Abdullah Soydan Mahmutoglu: Nothing to disclose
Keywords: Lung, Respiratory system, CT, Screening, Cancer, Cysts, Neoplasia
Findings and procedure details

To define the Lung-RADS category, the lesions are characterized as either parenchymal nodules, airway nodules, or atypical cystic lesions[1-4]. The Lung-RADS score is then calculated by categorizing these lesions based on size and growth. The LDCT exam is considered Lung RADS 0 if the prior chest exam is absent or being located for comparison, if there are parts of the lungs that cannot be evaluated, or if there are findings suggesting an inflammatory or infectious process.

Fig 1: Fig. 1: Examples of Lung-RADS 0 CT scans. (A) Findings suggesting an infectious process (consolidation and air bronchograms) are seen in the right lung. (B) Upper zones of the lungs are not included in the scan.
In case of inflammatory-infectious processes, a follow-up scan in 1-3 months is required to determine the Lung-RADS score. Lung-RADS 1 includes CT scans that reveal nodules with benign features, such as complete, central, popcorn, or concentric ring calcifications or fat, as well as images that show no nodules at all. Nodule size is defined as the mean of the long and short axes. The threshold for Lung-RADS 3 is ≥6 mm for solid and part-solid nodules and ≥30 mm for non-solid nodules in baseline imaging.
Fig 2: Fig. 2 : Lung-RADS classification of solid nodules.
Fig 3: Fig. 3 : Lung-RADS classification of part solid nodules.
Fig 4: Fig. 4 : Lung-RADS classification of ground glass nodules (GGNs).
Growth is defined as a nodule's size increasing by more than 1.5 mm in one year. Size thresholds for growing nodules are defined for each Lung-RADS category.
Fig 5: Fig. 5: Size thresholds for new or growing nodules for different nodule categories.
Fig 6: Fig. 6: Size growth in a solid nodule. Initial scan (A) shows a category 3 nodule (mean size : 7,1 mm). The nodule is upgraded to category 4B (mean size: 9,7 mm) in the follow-up scan(B).
Endobronchial nodules are referred to as airway nodules in Lung-RADS v2022 and currently classified into category 0, 2, 4A, or 4B[1,4].Airway nodules are sorted based on their localizations, with more distal placements indicating more benignity. 
Fig 7: Fig. 7 : Lung-RADS classification of airway nodules.
Atypical pulmonary cysts are also newly added in the new version of Lung-RADS (2022) and include features such as thick wall (≥2 mm), multilocularity, increased density, and adjacent nodules[4].
Fig 8: Fig. 8 : Lung-RADS classification of atypical pulmonary cysts.
The recommended LDCT screening interval is 12 months for categories 1 and 2 , and 6 months for category 3. Lung-RADS category 4A requires 3-month LDCT, and PET/CT may be added in case of a ≥ 8 mm solid component. Categories 4B and 4X suggest high risk of malignancy; therefore management should include diagnostic chest CT, PET/CT scan (in case of a ≥ 8 mm solid component), and tissue sampling and/or referral for further clinical evaluation.
Fig 9: Fig. 9: Management recommendations according to Lung-RADS categories.
Lung-RADS v2022 classifies slow growing solid or part solid nodules that show growth over multiple exams but do not meet the > 1.5 mm criteria rise in size for any 12-month term as Lung RADS 4B. These nodules might show minimal metabolic activity on PET/CT; hence, biopsy, if achievable, or surgical assessment might be the most suitable management option.
Fig 10: Fig. 10: Slow-growing solid nodule. The patient had a solid nodule with a mean diameter of 11,7 mm (Lung-RADS 4A) in the right lung in her initial screening CT (A). In follow-up CT scans taken 6 months apart (B,C) the nodule showed minimal growth (0,3 mm) . The final score was determined as Lung RADS 4B.
Lung-RADS 4X category constitutes category 3 or 4 nodules with additional imaging features that suggest malignancy, such as lymphadenopathy spiculation or frank metastasis. Incidental lesions detected on the screening CT require an ‘S’ modifier, and an appropriate approach is recommended depending on the findings.[1-4]
Fig 11: Fig. 11: Examples of Lung-RADS S modifiers. (A) Hypodense thyroid nodule seen in the left thyroid lobe, (B) right adrenal mass included in the field of view , and (C) multiple lytic lesions in the bones are visible in the screening scans(red arrows).
      
GALLERY