Siderotic nodules in the spleen: MR imaging of portal hypertension.

Abstract

The authors retrospectively evaluated magnetic resonance (MR) images obtained at 1.5 T in 233 patients with portal hypertension and 91 subjects without it and pathologic findings in four resected spleens (one normal). Multiple, tiny (3-8 mm in diameter), low-intensity spots in the spleen were observed in 21 of 233 patients. Among the imaging studies performed in these 21 patients, the spots were seen on five of 14 T1-weighted images, 11 of 20 proton density images, and 12 of 20 T2-weighted images obtained with spin-echo techniques and on 14 of 14 fast-scan images obtained with gradient-echo rephasing. MR images in the 91 subjects did not show such lesions. MR images of the three spleens resected from patients with portal hypertension showed the low-intensity spots, which corresponded to siderotic nodules found at pathologic analysis. Despite limited pathologic confirmation, siderotic nodules (so-called Gamna-Gandy nodules) are considered the most likely cause of multiple low-intensity spots in the spleen.

Avaliação ultra-sonográfica de nódulos sideróticos esplênicos em pacientes esquistossomóticos com hipertensão portal

“…These granulomas tend to be larger and more hyperechogenic than siderotic nodules, besides presenting an evident acoustic shadowing, a feature that is not present in the case of non-calcified siderotic nodules (9) , which represented the majority in the present study. Additionally, because of the paramagnetic effect of hemosiderin products, siderotic nodules are clearly visualized on T1-and T2-weighted images as small foci of low-intensity or absent signal and without contrast-enhancement after intravenous gadolinium injection (9,10) .…”

“…Conversely, non-calcified tuberculotic nodules tend to present a variable signal on T1-and T2-weighted images, and most frequently with hyper-intense signal and ring-shaped contrast-enhancement after gadolinium injection (24) . Calcified siderotic nodules may not be distinguishable from different types of calcified granulomas, like those resulting from tuberculosis and histoplasmosis (9) . Amongst the limitations of the present study, it is important to note the restricted number of patients included in the sample, as well as the absence of a control group which would allow the addition of other useful information (for example, specificity, positive and negative predictive values) for determining the US diagnostic accuracy in the detection of these nodules.…”

“…Siderotic nodules, or Gamna-Gandy bodies, were firstly described by Marini, in 1902, but this entity became actually known with the studies developed in 1905 and 1921 by Charles Gandy and Carlo Gamna, giving rise to the eponym (9) . Siderotic nodules consist in small fibrotic nodules impregnated with hemosiderin and, in some cases with calcifications resulting from focal micro-hemorrhages in the splenic parenchyma, generally related to congestive splenomegaly (Figures 3 and 4).…”

“…Gamna-Gandy bodies may be evaluated by different imaging methods (8) , but presently magnetic resonance imaging (MRI)m especially with gradient-echo sequences is considered as the method of choice in the detection of these nodules (9,10) . The US value in the assessment of Gamna-Gandy bodies has been discussed in the literature with controversial results and sensitivity ranging between 12% and 70.6% (10,11) .…”

Small Echogenic Foci in the Ovaries

“…They are due to areas of organized hemorrhage and histologically contain hemosiderin and sometimes also calcification. 15,16 A recent prospective study found that sonography had a sensitivity of 71% for Gamna-Gandy bodies. 17 On sonography, Gamna-Gandy bodies appear as small hyperechoic foci, 17 similar in appearance to the echogenic foci seen in the ovaries.…”