absent bow tie sign
A radiologic sign consisting of the loss of the normal bow tie appearance of the menisci on parasagittal MRI, which is diagnosed when less than 2
sagittal T1 weighted images demonstrate a normal body of meniscus (bow tie), or when 2 or more consecutive sagittal images lack a normal meniscal body segment. Absent bow tie is suggestive of meniscal injury, and
usually indicates a bucket handle tear of the meniscus, where the displaced fragment corresponds to the “handle” of the bucket.
Background Normally, the medial and lateral menisci* (of the knee) appear as low signal bowtie-shaped structures between the femoral condyles and tibial plateaux†.
As the normal meniscus laterally measures 9mm–12mm in width, the bow tie appearance should be seen on several adjacent slices (2 to 3 images if imaged with 3mm thick slices and 1mm skips).
*The correct plural of meninscus, not meniscuses, as some authors have written it. †The correct plural of plateau–because it is originally a French word; that said, only the Brits use plateaux; in American, Canadian, Australian, and New Zealand English, plateaus is the norm.
Am J Roentgenol. 1998 Jan;170(1):57-61
Radiology 2000; 215:263-265.