double line sign

Osteonecrosis

• Avascular necrosis of the knee - Ganzer Fall bei Radiopaedia

Gaillard F, Avascular necrosis of the knee. Case study, Radiopaedia.org (Accessed on 08 Dec 2022) https://doi.org/10.53347/rID-2583 • CC by-nc-sa 3.0 (modified)

Osteochondral

defect • Avascular necrosis of the knee - Ganzer Fall bei Radiopaedia

Gaillard, F. Avascular necrosis of the knee. Case study, Radiopaedia.org. (accessed on 24 Oct 2022) https://doi.org/10.53347/rID-2583 • CC by-nc-sa 3.0 (modified)

Systemic

lupus erythematosus • Medullary bone infarct - lupus on corticosteroids - Ganzer Fall bei Radiopaedia

Skalski, M. Medullary bone infarct - lupus on corticosteroids. Case study, Radiopaedia.org. (accessed on 22 Oct 2022) https://doi.org/10.53347/rID-26931 • CC by-nc-sa 3.0 (modified)

Osteonecrosis

• Avascular necrosis of humerus - Ganzer Fall bei Radiopaedia

Babu V, Avascular necrosis of humerus. Case study, Radiopaedia.org (Accessed on 08 Dec 2022) https://doi.org/10.53347/rID-58924 • CC by-nc-sa 3.0 (modified)

Double line

sign • Bone infarcts - Ganzer Fall bei Radiopaedia

Farouk A, Bone infarcts. Case study, Radiopaedia.org (Accessed on 23 Jan 2023) https://doi.org/10.53347/rID-47896 • CC by-nc-sa 3.0 (modified)

Subchondral

insufficiency fractures, subchondral insufficiency fractures with osteonecrosis, and other apparently spontaneous subchondral bone lesions of the knee—pathogenesis and diagnosis at imaging. Double line rim in MRI. a In the illustrated case, on T2-weighted image, high signal intensity lines project behind the low signal intensity lines at the anterior aspect of the osteonecrotic areas (arrowhead), but also behind the lines with low signal at the posterior part of the osteonecrotic areas (arrows). This shifted position of the lines in the same direction in front and behind the necrotic areas is consistent with a chemical shift artifact. b On fat-suppressed T2-weighted image, the low signal component of the cellular rim has the same signal as the suppressed fat, and therefore a double rim line cannot be seen

insightsimaging.springeropen.com • CC-by-4.0

Hier werden Begriffe / Krankheitsbilder genannt, die ähnlich sind oder klingen, aber nicht das Gleiche sind.

nicht verwechseln mit: Doppelrandzeichen Hirnabszess

Radiopaedia • CC-by-nc-sa 3.0 • de

The double line sign is a pathognomonic MRI finding seen at the periphery of a region of osteonecrosis (avascular necrosis, bone infarct), representing the border between the viable and non-viable bone . It is best seen on T2 and T2 FS sequences and consists of two serpentine lines: an inner bright line representing reparative granulation tissue and an outer dark line representing adjacent sclerotic bone. The outer line is always continuous, while the inner line can be discontinuous or absent . This sign is reported in up to 80-85% of cases .

It should not be confused with the rim sign demarcating an osteochondral fragment with surrounding fluid (indicating that it is potentially unstable).

Practical points

The chemical shift artifact on non-fat-suppressed sequences can decrease the visibility of the double line sign, by either obscuring it or making it far more pronounced .

double line sign

Practical points

See also

Siehe auch:

und weiter: