U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Atoll sign

MedGen UID:
1711199
•Concept ID:
C5397975
•
Sign or Symptom
Synonyms: Atoll sign, pulmonary; Reverse halo sign; Reversed halo sign
 
HPO: HP:0032983

Definition

CT finding of central ground-glass opacity surrounded by denser consolidation of crescentic shape (forming more than three-fourths of a circle) or complete ring of at least 2 mm in thickness. A rare sign, it was initially reported to be specific for cryptogenic organizing pneumonia, but was subsequently described in patients with paracoccidioidomycosis. [from HPO]

Recent clinical studies

Etiology

Hepatocellular Adenoma Subtypes Based on 2017 Classification System: Exploratory Study of Gadoxetate Disodium-Enhanced MRI Features With Proposal of a Diagnostic Algorithm.
Tse JR, Felker ER, Cao JJ, Naini BV, Liang T, Lu DSK, Raman SS
AJR Am J Roentgenol 2023 Apr;220(4):539-550. Epub 2022 Sep 28 doi: 10.2214/AJR.22.28233. PMID: 36169546
Comparison of chest CT findings in outpatient and hospitalized COVID-19 RT-PCR positive patients of Shiraz.
Zarei F, Moezi P, Jahromi MG, Zeinali-Rafsanjani B
J Med Imaging Radiat Sci 2022 Mar;53(1):107-112. Epub 2021 Nov 9 doi: 10.1016/j.jmir.2021.10.009. PMID: 34836832Free PMC Article
New MRI features improve subtype classification of hepatocellular adenoma.
Bise S, Frulio N, Hocquelet A, Alberti N, Blanc JF, Laurent C, Laumonier H, Balabaud C, Bioulac-Sage P, Trillaud H
Eur Radiol 2019 May;29(5):2436-2447. Epub 2018 Dec 6 doi: 10.1007/s00330-018-5784-5. PMID: 30523457
Cryptogenic organizing pneumonia.
Cottin V, Cordier JF
Semin Respir Crit Care Med 2012 Oct;33(5):462-75. Epub 2012 Sep 21 doi: 10.1055/s-0032-1325157. PMID: 23001801
Hepatocellular adenomas: correlation of MR imaging findings with pathologic subtype classification.
van Aalten SM, Thomeer MG, Terkivatan T, Dwarkasing RS, Verheij J, de Man RA, Ijzermans JN
Radiology 2011 Oct;261(1):172-81. Epub 2011 Aug 26 doi: 10.1148/radiol.11110023. PMID: 21875850

Diagnosis

I saw the "atoll sign" - and now I need a tropical vacation.
Williams JM, Hurst P, Rajiah PS
Clin Imaging 2023 Sep;101:156-160. Epub 2023 Jun 4 doi: 10.1016/j.clinimag.2023.05.017. PMID: 37369143
Classics in abdominal imaging: the atoll sign.
Bisig AM, Ayoob AR, Owen JW
Abdom Radiol (NY) 2019 Apr;44(4):1621-1622. doi: 10.1007/s00261-018-1821-8. PMID: 30465102
Liver atoll sign: Inflammatory hepatocellular adenoma.
Xiang H, Han J, Ridley WE, Ridley LJ
J Med Imaging Radiat Oncol 2018 Oct;62 Suppl 1:89. doi: 10.1111/1754-9485.36_12784. PMID: 30309147
Liver atoll sign: Nodular regenerative hyperplasia.
Xiang H, Han J, Ridley WE, Ridley LJ
J Med Imaging Radiat Oncol 2018 Oct;62 Suppl 1:84. doi: 10.1111/1754-9485.32_12784. PMID: 30309113
Cryptogenic organizing pneumonia.
Cottin V, Cordier JF
Semin Respir Crit Care Med 2012 Oct;33(5):462-75. Epub 2012 Sep 21 doi: 10.1055/s-0032-1325157. PMID: 23001801

Therapy

Cryptogenic organizing pneumonia.
Cottin V, Cordier JF
Semin Respir Crit Care Med 2012 Oct;33(5):462-75. Epub 2012 Sep 21 doi: 10.1055/s-0032-1325157. PMID: 23001801

Clinical prediction guides

Hepatocellular Adenoma Subtypes Based on 2017 Classification System: Exploratory Study of Gadoxetate Disodium-Enhanced MRI Features With Proposal of a Diagnostic Algorithm.
Tse JR, Felker ER, Cao JJ, Naini BV, Liang T, Lu DSK, Raman SS
AJR Am J Roentgenol 2023 Apr;220(4):539-550. Epub 2022 Sep 28 doi: 10.2214/AJR.22.28233. PMID: 36169546
New MRI features improve subtype classification of hepatocellular adenoma.
Bise S, Frulio N, Hocquelet A, Alberti N, Blanc JF, Laurent C, Laumonier H, Balabaud C, Bioulac-Sage P, Trillaud H
Eur Radiol 2019 May;29(5):2436-2447. Epub 2018 Dec 6 doi: 10.1007/s00330-018-5784-5. PMID: 30523457

Supplemental Content

Table of contents

    Clinical resources

    Consumer resources

    Reviews

    Related information

    • PMC Articles
      Related information in PubMed Central Links
    • PubMed
      Related literature resources in PubMed

    Recent activity

    Clear Turn Off Turn On

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...