Blood perfusion in osteomyelitis studied with [15O]water PET in a juvenile porcine model

Lars Jødal,Aage K O Alstrup,Ole L Nielsen,Søren B Hansen,Pia Afzelius

doi:10.1186/s13550-016-0251-2

Abstract

BackgroundOsteomyelitis is a serious disease which can be difficult to treat despite properly instituted antibiotic therapy. This appears to be related at least partly to degraded vascularisation in the osteomyelitic (OM) lesions. Studies of perfusion in OM bones are, however, few and not quantitative. Quantitative assessment of perfusion could aid in the selection of therapy. A non-invasive, quantitative way to study perfusion is dynamic [15O]water positron emission tomography (PET). We aim to demonstrate that the method can be used for measuring perfusion in OM lesions and hypothesize that perfusion will be less elevated in OM lesions than in soft tissue (ST) infection. The study comprised 11 juvenile pigs with haematogenous osteomyelitis induced by injection of Staphylococcus aureus into the right femoral artery 1 week before scanning (in one pig, 2 weeks). The pigs were dynamically PET scanned with [15O]water to quantify blood perfusion. OM lesions (N = 17) in long bones were studied, using the left limb as reference. ST lesions (N = 8) were studied similarly.ResultsPerfusion was quantitatively determined. Perfusion was elevated by a factor 1.5 in OM lesions and by a factor 6 in ST lesions.ConclusionsBlood perfusion was successfully determined in pathological subacute OM lesions; average perfusion was increased compared to that in a healthy bone, but as hypothesized, the increase was less than in ST lesions, indicating that the infected bone has less perfusion reserve than the infected soft tissue.

Highlights

Osteomyelitis is a serious disease which can be difficult to treat despite properly instituted antibiotic therapy
Wannfors and Gazelius [7] applied laser Doppler flowmetry (LDF) directly to the jaw bones affected by chronic osteomyelitis, finding bone blood flow to be decreased in patients with low clinical activity of the disease, while being increased in patients with high clinical activity of the disease; blood flow was found to be increased in the initial subacute lesions
Perfusion in femoral medullar canal and thigh muscle This comparison was made in all 11 pigs, in order to compare the right and left hind limb in uninfected locations

Summary

Introduction

Osteomyelitis is a serious disease which can be difficult to treat despite properly instituted antibiotic therapy. This appears to be related at least partly to degraded vascularisation in the osteomyelitic (OM) lesions. Studies of perfusion in OM bones are, few and not quantitative. A non-invasive, quantitative way to study perfusion is dynamic [15O]water positron emission tomography (PET). Studies of blood perfusion in OM lesions are, scarce, Colour Doppler ultrasound has been used to measure blood flow in osteomyelitis [4, 5]; both of these studies were on children with recent symptoms (2–15 days in one study, 2–10 days in the other), and both found elevated blood flow within or around the involved periosteum. Müller et al [8] combined contrastenhanced ultrasound with static [18F]NaF positron

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