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MRI characteristics of cysts and "cyst-like" lesions in and around the knee: what the radiologist needs to know.

Perdikakis E, Skiadas V - Insights Imaging (2013)

Bottom Line: A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee.In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended.However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, 412 General Military Hospital-212 Mobile Army Surgical Hospital, Terma Lefkou Pyrgou, Xanthi, 67100, Greece, perdikakis_ev@yahoo.gr.

ABSTRACT

Objectives and methods: A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee. These lesions comprise a diverse group of entities from benign cysts to complications of underlying diseases. In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended. However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures.

Results: This article includes a comprehensive pictorial essay of the characteristic MRI features of common and uncommon benign cysts and "cyst-like" lesions in and around the knee joint.

Discussion: For accurate assessment of the "cystic structure", a radiologist should be able to identify typical MRI patterns that contribute in establishing the correct diagnosis and thus guiding specific therapy and avoiding unwarranted interventional procedures such as biopsy or arthroscopy.

Teaching points: • Cystic lesions are common in knee MRI and the commonest, the Baker's cyst, has an incidence of 38 %. • Synovial cysts, meniscal cysts, normal knee bursae and recesses have characteristic MR appearances. • Miscellaneous "cyst-like" lesions may require a more dedicated MR protocol for a correct diagnosis.

No MeSH data available.


Related in: MedlinePlus

Intrameniscal cysts. The coronal (a) fat saturated proton density weighted image shows a small cystic fluid collection inside the anterior horn of the lateral meniscus (white arrow) communicating with a horizontal meniscal tear (black arrow). The sagittal (b), (c) fat saturated proton density weighted images in two different patients show intrameniscal cysts of the anterior horn of the lateral meniscus (in b) and of the posterior horn of the medial meniscus (in c)
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Fig9: Intrameniscal cysts. The coronal (a) fat saturated proton density weighted image shows a small cystic fluid collection inside the anterior horn of the lateral meniscus (white arrow) communicating with a horizontal meniscal tear (black arrow). The sagittal (b), (c) fat saturated proton density weighted images in two different patients show intrameniscal cysts of the anterior horn of the lateral meniscus (in b) and of the posterior horn of the medial meniscus (in c)

Mentions: Meniscal cysts are divided into intrameniscal and parameniscal cysts [23–27]. An intrameniscal cyst is a focal collection of fluid located within the meniscus. A parameniscal cyst is a focal joint fluid collection located adjacent to a meniscus. Both types of cysts are associated with a meniscal tear [23–28]. Direct communication with the meniscal tear may or may not be demonstrated on MR images. Meniscal cysts are typically demonstrated in all pulse sequences as well-defined cystic masses with fluid signal intensity [23–28]. Occasionally they may demonstrate isointensity to skeletal muscles on T1-weighted images, due to haemorrhage or high protein content. In addition, low signal intensity on T2-weighted images may be secondary to water resorption by parameniscal tissues with residual desiccated cyst contents or due to haemosiderin deposition. Most parameniscal cysts are lobulated and internally septated and may rarely cause adjacent bone erosion [23–28]. The commonest medial parameniscal cyst is that adjacent to the posterior horn of the meniscus, since tears there are far more common. The commonest location for a lateral paremeniscal cyst is adjacent to the anterior horn or the body of the lateral meniscus. Since the lateral meniscus is not tightly bound to the joint capsule, parameniscal cysts originating from the anterior horn and body of lateral meniscus may penetrate the lateral supporting structures and extend even deep to the iliotibial tract (Figs. 9, 10 and 11).Fig. 9


MRI characteristics of cysts and "cyst-like" lesions in and around the knee: what the radiologist needs to know.

Perdikakis E, Skiadas V - Insights Imaging (2013)

Intrameniscal cysts. The coronal (a) fat saturated proton density weighted image shows a small cystic fluid collection inside the anterior horn of the lateral meniscus (white arrow) communicating with a horizontal meniscal tear (black arrow). The sagittal (b), (c) fat saturated proton density weighted images in two different patients show intrameniscal cysts of the anterior horn of the lateral meniscus (in b) and of the posterior horn of the medial meniscus (in c)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig9: Intrameniscal cysts. The coronal (a) fat saturated proton density weighted image shows a small cystic fluid collection inside the anterior horn of the lateral meniscus (white arrow) communicating with a horizontal meniscal tear (black arrow). The sagittal (b), (c) fat saturated proton density weighted images in two different patients show intrameniscal cysts of the anterior horn of the lateral meniscus (in b) and of the posterior horn of the medial meniscus (in c)
Mentions: Meniscal cysts are divided into intrameniscal and parameniscal cysts [23–27]. An intrameniscal cyst is a focal collection of fluid located within the meniscus. A parameniscal cyst is a focal joint fluid collection located adjacent to a meniscus. Both types of cysts are associated with a meniscal tear [23–28]. Direct communication with the meniscal tear may or may not be demonstrated on MR images. Meniscal cysts are typically demonstrated in all pulse sequences as well-defined cystic masses with fluid signal intensity [23–28]. Occasionally they may demonstrate isointensity to skeletal muscles on T1-weighted images, due to haemorrhage or high protein content. In addition, low signal intensity on T2-weighted images may be secondary to water resorption by parameniscal tissues with residual desiccated cyst contents or due to haemosiderin deposition. Most parameniscal cysts are lobulated and internally septated and may rarely cause adjacent bone erosion [23–28]. The commonest medial parameniscal cyst is that adjacent to the posterior horn of the meniscus, since tears there are far more common. The commonest location for a lateral paremeniscal cyst is adjacent to the anterior horn or the body of the lateral meniscus. Since the lateral meniscus is not tightly bound to the joint capsule, parameniscal cysts originating from the anterior horn and body of lateral meniscus may penetrate the lateral supporting structures and extend even deep to the iliotibial tract (Figs. 9, 10 and 11).Fig. 9

Bottom Line: A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee.In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended.However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, 412 General Military Hospital-212 Mobile Army Surgical Hospital, Terma Lefkou Pyrgou, Xanthi, 67100, Greece, perdikakis_ev@yahoo.gr.

ABSTRACT

Objectives and methods: A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee. These lesions comprise a diverse group of entities from benign cysts to complications of underlying diseases. In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended. However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures.

Results: This article includes a comprehensive pictorial essay of the characteristic MRI features of common and uncommon benign cysts and "cyst-like" lesions in and around the knee joint.

Discussion: For accurate assessment of the "cystic structure", a radiologist should be able to identify typical MRI patterns that contribute in establishing the correct diagnosis and thus guiding specific therapy and avoiding unwarranted interventional procedures such as biopsy or arthroscopy.

Teaching points: • Cystic lesions are common in knee MRI and the commonest, the Baker's cyst, has an incidence of 38 %. • Synovial cysts, meniscal cysts, normal knee bursae and recesses have characteristic MR appearances. • Miscellaneous "cyst-like" lesions may require a more dedicated MR protocol for a correct diagnosis.

No MeSH data available.


Related in: MedlinePlus