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01-01-2016 | Chest

Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking

Authors: Tetsuro Araki, Mizuki Nishino, Wei Gao, Josée Dupuis, Gary M. Hunninghake, Takamichi Murakami, George R. Washko, George T. O’Connor, Hiroto Hatabu

Published in: European Radiology | Issue 1/2016

Abstract

Objective

To investigate CT appearance and size of the thymus in association with participant characteristics.

Materials and methods

2540 supposedly healthy participants (mean age 58.9 years, 51 % female) were evaluated for the CT appearance of thymic glands with four-point scores (according to the ratio of fat and soft tissue), size and morphology. These were correlated with participants’ age, sex, BMI and smoking history.

Results

Of 2540 participants, 1869 (74 %) showed complete fatty replacement of the thymus (Score 0), 463 (18 %) predominantly fatty attenuation (Score 1), 172 (7 %) half fatty and half soft-tissue attenuation (Score 2) and 36 (1 %) solid thymic gland with predominantly soft-tissue attenuation (Score 3). Female participants showed less fatty degeneration of the thymus with higher thymic scores within age 40–69 years (P < 0.001). Participants with lower thymic scores showed higher BMI (P < 0.001) and were more likely to be former smokers (P < 0.001) with higher pack-years (P = 0.04).

Conclusions

Visual assessment with four-point thymic scores revealed a sex difference in the fatty degeneration of the thymus with age. Women show significantly higher thymic scores, suggesting less fat content of the thymus, during age 40–69 years. Cigarette smoking and high BMI are associated with advanced fatty replacement of the thymus.

Key Points

• 74 % of participants (mean age 58.9 years) demonstrated complete fatty thymus.

• Women show less fatty thymus compared to men at ages 40–69 years.

• Smoking and high BMI are associated with advanced fatty degeneration in thymus.

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Title: Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking
Authors: Tetsuro Araki
Mizuki Nishino
Wei Gao
Josée Dupuis
Gary M. Hunninghake
Takamichi Murakami
George R. Washko
George T. O’Connor
Hiroto Hatabu
Publication date: 01-01-2016
Publisher: Springer Berlin Heidelberg
Published in: European Radiology / Issue 1/2016
Print ISSN: 0938-7994
Electronic ISSN: 1432-1084
DOI: https://doi.org/10.1007/s00330-015-3796-y

At a glance: The STEP trials

Springer Medicine

Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking

Abstract

Objective

Materials and methods

Results

Conclusions

Key Points

At a glance: The STEP trials

Springer Medicine

Abstract

Objective

Materials and methods

Results

Conclusions

Key Points

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