PMC3742063_01
A fat-suppressed, PD-w image in the coronal plane of the left knee shows a longitudinal tear in the body of medial meniscus (long arrow) and the displaced meniscal fragment within the intercondylar notch (short arrow). In addition, osteoarthritic changes with minimal subcortical cyst formations and reactive bone marrow edema are noted in the medial tibial plateau (open arrow)
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PMC3742063_01_10.1177_2047981613477401-fig1.jpg
ARR477401F1
The imaging findings included a flap tear of the medial meniscus with a displaced meniscal fragment in the medial intercondylar notch (Fig. 1). In addition, osteoarthritis was noted in the medial joint compartment with marked attenuation of the articular cartilage, reactive subcortical bone marrow edema in the medial tibial plateau, and minimal subcortical cystic changes (Fig. 1).
(a) A T2*-w sagittal image in the left knee represents foci of iron deposits within the supra patellae pouch right above the superior pole of the patellae (short arrow) and also in contact with the patellae cartilage at the upper pole (long arrow), as well as within the Hoffa's fat pad in contact with the patellae cartilage in its inferior pole (open arrow) and in the cartilage surface over the trochlea (doted arrow). (b) A fat-suppressed PD-w image in the sagittal plane in the left knee shows foci of iron deposition along the surface of the cartilage over the lateral trochlea (short arrow). We note the drop of signal in the area of iron deposits, which is less prominent in comparison with the corresponding T2*-w image
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PMC3742063_01_10.1177_2047981613477401-fig2.jpg
ARR477401F2
Foci of iron deposits were identified macroscopically within the supra-patellar pouch right above the superior pole of the patellae and also in contact with the patellae cartilage at the upper pole, as well as within the Hoffa's fat pad in contact with the patellae cartilage in its inferior pole and in the cartilage surface over the trochlea (Fig. 2a). However, iron deposits were less conspicuous on the T1-w and PD-w sequences, with particular signal loss on gradient echo (Fig. 2B).
This image represents four corresponding axial images from different pulse sequences of the left knee. (a) is a T2*-w image, (b) is an ultra short time echo (UTE) image, (c) was obtained with susceptibility weighted imaging (SWI), and (d) represents PD-w imaging with a turbo spin echo sequence. In (a), we note a large area of iron deposit in contact with the patellae and trochlea groove cartilage presented as a low signal intensity focus (arrow). In (b) and (c) we highlight a further exaggeration of the signal loss in the area of iron deposits on the UTE and SWI sequences, respectively (arrows). In (d) we note less conspicuous signal loss of the iron deposit area in the PD-w sequence (arrow)
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PMC3742063_01_10.1177_2047981613477401-fig3.jpg
ARR477401F3
During the above study we also noticed further exaggeration of the signal loss on the SWI and UTE sequences (Fig. 3).
A T2*-w sagittal image of the right knee obtained with a gradient recalled echo (GRE) pulse sequence. Iron deposits are noted in contact with the inferior pole of the patellae cartilage (short arrow), as well as in contact with the anterior cartilage surface of the lateral femoral condyle (long arrow)
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PMC3742063_01_10.1177_2047981613477401-fig4.jpg
ARR477401F4
Iron deposits were also noted in the right knee (Fig. 4).