CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSISEISENBERG

1. 40Intra-Articular Masses on
Magnetic Resonance Imaging

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig B 40-1 Lipoma arborescens. (A) Sagittal
proton density-weighted image shows a
lobulated mass in the suprapatellar bursa (arrow)
with signal intensity equivalent to that of fat. (B)
A fat-saturation sequence shows loss of signal of
the synovial proliferation (arrow) surrounded by a
large joint effusion extending into the popliteal
bursa (*).48

4. • Fig B 40-2 Synovial osteochondromatosis. (A)
Coronal proton density-weighted image
demonstrates an intermediate-signal-intensity
mass (*) in the radioulnar joint. (B) Coronal T2-
weighted image shows that the mass (*) is
hyperintense. On both MR images, note the
multiple low-signal-intensity areas (arrowhead)
representing regions of calcification that were
evident on plain radiographs.48

5. • Fig B 40-3 Synovial osteochondromatosis. Sagittal
proton density-weighted image demonstrates
calcified nodules as masses of low signal intensity
(arrow) in the deep infrapatellar bursa.48

6. • Fig B 40-4 Diffuse PVNS. Sagittal proton density-weighted image
shows lobulated, mass-like synovial proliferation with characteristic
low signal intensity. Note the tibial articular erosions.48

7. • Fig B 40-5 Focal PVNS. Sagittal proton density-
weighted image shows a low-signal-intensity
mass (arrow) in the anterior joint space.48

8. • Fig B 40-6 Rheumatoid arthritis. A sagittal T1-
weighted image shows a low-signal-intensity
lesion (*) in the talus, with low-signal-intensity
pannus (arrows) in the joint space.48

9. • Fig B 40-7 Tuberculous arthritis. (A) Coronal T1-weighted image of
the right shoulder demonstrates an erosion of the humeral head
(arrowhead) and a distended joint space with proliferative
synovium (arrow). Note the adjacent large mass (*). (B) On a T1-
weighted contrast study with fat saturation, the mass (*) appears as
a fluid-filled collection with an enhancing periphery rather than a
solid tumor. Note the enhancement of the synovium within the
joint (arrow) and the marginal erosion (arrowhead). The
combination of a destructive inflammatory arthritis decompressing
into the adjacent subdeltoid bursa to form a cold abscess is typical
of tuberculous arthritis.48

10. • Fig B 40-8 Coccidiodomycosis. (A) Coronal T1-
weighted image demonstrates a joint effusion
and marginal erosions of the proximal tibia
with preservation of the joint spaces. (B) Axial
proton density-weighted image with fat
saturation demonstrates multiple rice bodies
(arrow) within a joint effusion.48

11. • Fig B 40-9 Gout. Sagittal STIR image
demonstrates low signal intensity of the gouty
tophus (*). There is erosion with an
overhanging edge at the distal head of the
first metatarsal and preservation of the joint
space.48

12. • Fig B 40-10 Klippel-Trenaunay-Weber syndrome. An axial T2-
weighted image demonstrates a joint effusion (*) and an
intermediate-signal-intensity AVM in the suprapatellar bursa with a
prominent serpentine signal void (arrow) from a large feeding
artery. Note the large, dilated superficial veins (arrowheads).48

13. • Fig B 40-11 Synovial hemangioma. Sagittal proton
density-weighted image with fat saturation
demonstrates a mass in the suprapatellar bursa that
invades the musculature anteriorly (arrow). The
markedly high signal of the mass reflects pooling of
blood within the vascular spaces of this synovial
hemangioma.48

14. • Fig B 40-12 Synovial hemangioma. (A) Axial T1-
weighted image shows an intermediate-signal-
intensity lesion in the suprapatellar pouch
(arrow) containing areas of high signal intensity.
(B) Corresponding fat-suppressed T2-weighted
image shows a characteristic circular-linear
pattern (arrow) that probably represents fibrous
septa or vascular channels traversing the lesion.49

15. • Fig B 40-13 Synovial sarcoma. Sagittal contrast T1-
weighted image with fat saturation demonstrates
enhancement of a mass (arrow) in the anterior joint
space of the knee. Note the foci of low signal intensity,
which persisted on all pulse sequences, consistent with
areas of calcification.48

16. • Fig B 40-14 Synovial chondrosarcoma. (A) Axial
T1-weighted image demonstrates a large,
lobulated, low-signal-intensity mass (*)
distending the knee joint space, with erosions
and invasion of the femoral condyles (arrows). (B)
Axial T2-weighted image obtained more distally
demonstrates high signal intensity (*) within the
mass.48

17. • Fig B 40-15 Cyclops lesion. Sagittal T2-weighted image
following anterior cruciate ligament reconstruction
demonstrates a mass anteriorly in the joint space of
the knee. Note the characteristic low signal intensity of
this fibrous mass (arrow).48