Vergleichende Messung der Milzfunktion bei Patienten mit chronisch entzündlichen Darmerkrankungen zur Beurteilung einer funktionellen Hypo-/ Asplenie mit Hilfe der Milzszintigraphie mit hitzealterierten, 99mTc-markierten Erythrozyten und der Leber-Milzszintigraphie mit 99mTc-markiertem Zinnkolloid sowie Sonographie und farbkodierter Dopplersonographie

Aim: Ultrasound may be a cheap alternative to scintigraphic determination of splenic function. We directly compared nanocolloid scintigraphy (NS), scintigraphy with heat-altered erythrocytes (ES), and colour-coded Doppler sonography (DS) in patients with chronic inflammatory bowel disease (CIBD). Methods: Clearance rates were determined in ES, spleen/liver ratios (SLR) were measured scintigraphically in ES/NS. In DS, spleen size, echogenicity, and vascular resistance indices (RI) were determined. The results were compared to each other, to the clinical activity scores for IBD, and to the course of the disease. Results: 35 patients were included into the study. Based on the blood erythrocyte clearance serving as standard, patients had a good (19 patients), impaired (5), or missing splenic function (11). There was a good correlation of the clearance to SLR in ES (0.63, p<0.01). The 10 min / 45 min ES clearance showed a high correlation (Spearman-Rho 0.87, p<0.01). The SLR in ES at 2, 5, 10 and 45 min also correlated well with each other (Spearman-Rho > 0.9, p<0.01; SLR > 3.45 normal splenic function, SLR <1.22 indicated hyposplenia). There were no correlations between the results of NS, DS, Howell-Jolly-bodies, or clinical parameters. Only ES and the erythrocyte clearance correlated well. Howell-Jolly-Bodies detected 1 of 11 patients with hyposplenia while false-positive in 4. Conclusion: Ultrasound and colloid scintigraphy show a low correlation with clearance of heat-altered erythrocytes. Only ES shows a good correlation in patients with CIBD. The clearance at 10 min already reliably determines splenic function. SLRs may be determined after 10 minutes and are predictive of normal function if above 3.45 while SLR <1.2 show hyposplenia.