Abdominal organ perfusion and inflammation in experimental sepsis: a magnetic resonance imaging study

Abstract

Diffusion-weighted magnetic resonance imaging (DW-MRI) uses water as contrast and enables the study of perfusion in many organs simultaneously in situ. We used DW-MRI in a hypodynamic sepsis model, comparing abdominal organ perfusion with global hemodynamic measurements and inflammation. Sixteen anesthetized piglets were randomized into 3 groups: 2 intervention (sepsis) groups: HighMAP (mean arterial pressure, MAP > 65 mmHg) and LowMAP (MAP between 50 and 60 mmHg), and a Healthy Control group (HC). Sepsis was obtained with endotoxin and the desired MAP maintained with norepinephrine. After 6 h, DW-MRI was performed. Acute inflammation was assessed with IL-6 and TNFα in abdominal organs, ascites, and blood and by histology of intestine (duodenum). Perfusion of abdominal organs was reduced in the LowMAP group compared with the HighMAP group and HC. Liver perfusion was still reduced by 25% in the HighMAP group compared with HC. Intestinal perfusion did not differ significantly between the intervention groups. Cytokine concentrations were generally higher in the LowMAP group but did not correlate with global hemodynamics. However, cytokines correlated with regional perfusion and, for liver and intestine, also with intra-abdominal pressure. Histopathology of intestine worsened with decreasing perfusion. In conclusion, although a low MAP (≤60 mmHg) indicated impeded abdominal perfusion in experimental sepsis, it did not predict inflammation, nor did other global measures of circulation. Decreased abdominal perfusion partially predicted inflammation but intestine, occupying most of the abdomen, and liver were also affected by intra-abdominal pressure. NEW & NOTEWORTHY The study increases the knowledge of abdominal perfusion during sepsis. We used diffusion weighted imaging to assess perfusion simultaneously and noninvasively in different abdominal organs. The technique has not been used in a sepsis model before. Cytokine concentrations were measured in different abdominal organs and vascular beds and related to regional perfusion. Decreased abdominal perfusion, but not global measures of circulation, predicted inflammation. Intestine, occupying most of the abdomen, and liver were also affected by intra-abdominal pressure.

Morphofunctional Alteration of Mesenteric Lymph Nodes in the Inflammation of the Abdominal Cavity

“…One of the most pressing public health problems is inflammation of the abdominal organs because the number of patients, including those with severe forms of this disease, is Biology 2024, 13, 166 2 of 15 constantly increasing. Inflammation in the parietal and visceral layers of the peritoneum is accompanied by severe general health problems in patients [1][2][3].…”

The Use of Diffusion Weighted Imaging and Intravoxel Incoherent Motion to Assess Edema and Perfusion in Abdominal Organs during Endotoxemia

“…However, the potential advantages of the technique's application to these conditions are many. First of all, DW-MRI allows for non-invasive and simultaneous assessment of multiple abdominal organs, while maintaining an intact abdominal environment [12,13]. Secondly, it does not require the injection of an exogen contrast medium, which could alter hemorheology and affect the perfusion measurement [14].…”

“…A paper published by the authors presented preliminary results on the use of DWI in endotemic animals. The presented papers gives a full and more in-depth presentation using a new data set [13].…”