meniscus sign

crescent sign

1. in radiography of the lung, a crescent of gas near the top of a mass lesion, signifying cavitation with a space above the debris; seen in aspergilloma, hydatidoma;
2. in computed tomography, a high attenuating layer of new blood in an aneurysm; indicates a ruptured abdominal aortic aneurysm;
3. in diagnostic ultrasound, a sonolucent crescentic layer in a tumor mass, typically necrosis in stromal tumors of the small bowel;
4. in diagnostic ultrasound, a hyperechoic crescent, representing the entering limb of an intussusception; also known as crescent-in-a-doughnut;
5. in osteoradiology, a subcortical lucent crescent in the femoral head, signifying osteonecrosis.
Synonym(s): meniscus sign
Colon A radiolucency typically seen in a barium enema of a child with intussusception, which consists of a rounded apex of the intussusceptum protruding into the column of contrast material
Lung Air meniscus sign

meniscus sign

Air crescent sign Radiology A semilunar radiolucency peripheral to a pulmonary mass described as typical of echinococcal infection/hydatid cyst disease; most common cause in the US for the MS is a fungus 'ball', usually due to Aspergillus fumigatus; it may be seen in lung abscesses, tumors, hematomas, granulomatous infections and Rasmussen's aneurysm.

cres·cent sign

(kres'ĕnt sīn)
1. radiography In the lung, a crescent of gas near the top of a mass lesion, signifying cavitation with a space above the debris; seen in aspergilloma, hydatidoma.
2. computed tomography A high attenuating layer of new blood in an aneurysm; indicates a ruptured abdominal aortic aneurysm
3. diagnostic ultrasound A sonolucent crescentic layer in a tumor mass, typically necrosis in stromal tumors of the small bowel.
4. diagnostic ultrasound A hyperechoic crescent, representing the entering limb of an intussusception; also known as crescent-in-a-doughnut.
5. osteoradiology A subcortical lucent crescent in the femoral head, signifying osteonecrosis
Synonym(s): meniscus sign.
References in periodicals archive ?
On sagittal views, a dislocated meniscus was seen on the anterior segment of the lateral meniscus, depicting the flipped meniscus sign (Figure 1(b)) [3].
However, if a flipped meniscus sign of the lateral meniscus is detected on MRI in a knee joint without a history of trauma or locking symptoms, PSLM should be considered.
Kiernan, "The flipped meniscus sign," Skeletal Radiology, vol.
FIGURE 1: MRI PD axial and sagittal images showing bucket handle tear of medial meniscus with flipped meniscus sign (Arrow).
FIGURE 2: MRI PD sagittal and axial images showing bucket handle tear of medial meniscus with flipped meniscus sign (Arrow) and double PCL sign (Arrow).
FIGURE 6: MRI PD axial and sagittal images showing radial tear of medial meniscus with ghost meniscus sign (Arrow).
5) Contrast enema confirming an intussusception may also show a meniscus sign.
These tears may also result in the flipped meniscus sign, double delta sign, or double anterior horn sign, in which the displaced meniscal segment of the posterior horn is located anterior to, on top of, or posterior to the anterior horn.