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Type:
Educational Exhibit
Keywords:
Tissue characterisation, Inflammation, Infection, Contrast agent-intravenous, Ultrasound, MR, CT, Spleen, Abdomen
Authors:
F. Barbiera1, E. Murmura1, L. La Grutta2, M. Scarpulla1, B. Murmura1, G. Maggio3, L. S. Maltese4, M. Accardi1, M. Midiri2; 1Sciacca/IT, 2Palermo/IT, 3Palermo /IT, 4Siena/IT
DOI:
10.1594/ecr2015/C-1945
Findings and procedure details
The radiological aspect of splenic granulomatosis has been defined in literature.
Generally,
US (UltraSonography),
CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) show organomegaly.
At US,
focal granulomas are usually hypoechoic and their diameter is variable.
During CT examination,
small hypodense,
ill-defined lesions with contrast-enhancement may also be encountered.
Usually the granulomas do not enhance more than healthy spleen; however,
their attenuation is higher than that of splenic cysts [8].
In our experience,
splenic nodules became apparent as hypoattenuating lesions.
Contrast-enhanced abdominal CT scan showed hypoattenuating lesions during the arterial and the portal phases,
isoattenuating nodules in the equilibrium phase.
Granulomas has been reported to demonstrate low signal intensity in all MR sequences.
The lesions are most conspicuous on T2-weighted fat-suppressed or early phase contrast-enhanced images.
Sarcoid lesions enhance minimally on delayed images [9].
Old granulomas in histoplasmosis can be calcified,
causing characteristic signal intensity changes with blooming artifacts on MR images.
This appearance is best appreciated on GRE T1-weighted images,
especially those obtained with a long echo time.
At MRI,
in our experience,
the lesions appeared hypointense on T2-weighted images and isointense on T1-weighted images.
After intravenous gadolinium administration,
the nodules were hypointense in the arterial phase,
iso-hypointense in the portal phase and there was a peripheral enhancement during the delayed phase.
This aspect could suspect the presence of secondary splenic lesions to the unidentified primary tumor.
In our experience,
diffusion imaging (DWI) was useful,
because the nodules didn’t show diffusion restriction and this aspect,
similarly to the focal liver lesions, suggested a benign disease: is known indeed the strong diffusion restriction in malignant focal liver lesions.