Seong Jong Yun, Presenter: Nothing to Disclose

Wook Jin, Abstract Co-Author: Nothing to Disclose

Gou Young Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Yong Koo Park MD, PhD, Abstract Co-Author: Nothing to Disclose

Woo Jin Yang, Abstract Co-Author: Nothing to Disclose

Kyung Jin Lee MD, Abstract Co-Author: Nothing to Disclose

Ji Su Kim, Abstract Co-Author: Nothing to Disclose

Sohee Yoon MD, Abstract Co-Author: Nothing to Disclose

So Young Park, Abstract Co-Author: Nothing to Disclose

Jung Eun Lee, Abstract Co-Author: Nothing to Disclose

Ji Seon Park MD, PhD, Abstract Co-Author: Nothing to Disclose

Kyung Nam Ryu MD, PhD, Abstract Co-Author: Nothing to Disclose

During evaluation of the knee MR images, we can often observe increased signal intensity (SI) in the posterior portion of the proximal patellar tendon (PT) on T1-weighted images (T1WI), which shows no signal suppression on fat-suppressed sequences. Therefore, we correlated the MR findings with the histologic findings in 5 cadavers to investigate the cause of signal change, and also retrospectively evaluated SI of the PTs in 84 patients.

MR imaging was performed in 5 cadavers followed by gross histologic correlation. To compare SI of the PTs, 84 patients (31 men, 53 women) without trauma history and anterior knee pain were included in this study. Length and thickness of increased SI portion in the proximal PT on T1WI were recorded and we divided these 84 patients into 3 groups as follows; between 20 and 39 years old (group 1, n = 21), between 40 and 59 years old (group 2, n = 37), and above 60 years old (group 3, n = 26). Demographic characteristics, length, and thickness of the PTs of the 84 patients were also recorded and compared in the 3 groups.

Histologic specimens of 5 cadavers showed the fat, vessels, and connective tissue invaginating into the posterior portion of the proximal PT, corresponding to signal change of the tendon on MR imaging. Linear increased SI of proximal PT was seen in all of 84 patients (100%) on T1WI. There were no differences in length and thickness of increased SI portion among the 3 groups (p > 0.05). No differences in demographic characteristics, length, and thickness of the PTs were also found among the 3 groups (p > 0.05).

On T1WI and fluid-sensitive MR images, a normal PT can present linear increased SI without any disease process, which results from invaginating intratendinous fat, vessels, and connective tissue. It was not related to the age, sex, and size of the PT. Therefore, this might be a normal finding without clinical significance.

The linear increased SI of proximal PT on T1WI and fluid-sensitive MR images is not a pathologic or degenerative condition, but a common normal finding.

Yun, S, Jin, W, Kim, G, Park, Y, Yang, W, Lee, K, Kim, J, Yoon, S, Park, S, Lee, J, Park, J, Ryu, K, Increased Signal Intensity at the Proximal Patellar Tendon: MR Imaging-Histologic Correlation in Five Cadavers and MR Imaging Studies of 84 Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045542.html