Dellschaft Neele, Murray Kathryn, Ren Yi, Marciani Luca, Gowland Penny, Spiller Robin, Hoad Caroline
Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
NIHR Nottingham Biomedical Research Centre (BRC), Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK.
Neurogastroenterol Motil. 2025 Apr;37(4):e14999. doi: 10.1111/nmo.14999. Epub 2025 Jan 10.
The human colon receives 2 L of fluid daily. Small changes in the efficacy of absorption can lead to altered stool consistency with diarrhea or constipation. Drugs and formulations can also alter colonic water, which can be assessed using the magnetic resonance imaging (MRI) longitudinal relaxation time constant, T1. We explore the use of regional T1 assessment in evaluating disorders of colonic function.
Individual participant data analysis of data from 12 studies from a single center of patients with constipation, irritable bowel syndrome with diarrhea (IBS-D), and healthy volunteers (HV). T1 was quantified by measuring the signal from the tissue at different times after a pulse which inverts the magnetization.
When diarrhea was induced by a macrogol laxative T1 in the ascending colon, T1AC was negatively correlated with stool bacterial content, r = 0.78, p < 0.001. T1AC was increased by another laxative, rhubarb. Patients with IBS-D had elevated fasting T1AC (0.78 ± 0.28 s, N = 67) compared to HV (0.62 ± 0.21 s, N = 92) while those with constipation lay within the normal range (HV 10-90th centiles 0.33-0.91 s). Fasting T1AC in IBS-D was reduced by mesalazine treatment. T1 in the descending colon was consistently lower than T1AC, with a bigger reduction in patients with constipation than HV. Pre-feeding dietary fiber (bran, nopal, and psyllium) was associated with fasting T1AC at or above the normal 90th centile.
T1 is an MRI parameter which could be used to monitor effectiveness of novel agents designed to alter colonic water content and stool consistency.
人类结肠每天接收2升液体。吸收效率的微小变化会导致粪便稠度改变，出现腹泻或便秘。药物和制剂也会改变结肠内的水分，这可以通过磁共振成像（MRI）纵向弛豫时间常数T1进行评估。我们探讨使用区域T1评估来评价结肠功能紊乱。
对来自单一中心的12项研究的数据进行个体参与者数据分析，这些研究涉及便秘患者、腹泻型肠易激综合征（IBS-D）患者和健康志愿者（HV）。通过测量在使磁化反转的脉冲后不同时间的组织信号来量化T1。
当用聚乙二醇泻药诱导腹泻时，升结肠的T1（T1AC）与粪便细菌含量呈负相关，r = 0.78，p < 0.001。另一种泻药大黄可使T1AC升高。与HV（0.62±0.21秒，N = 92）相比，IBS-D患者的空腹T1AC升高（0.78±0.28秒，N = 67），而便秘患者的T1AC在正常范围内（HV第10-90百分位数为0.33-0.91秒）。美沙拉嗪治疗可降低IBS-D患者的空腹T1AC。降结肠的T1始终低于T1AC，便秘患者的降低幅度比HV更大。预喂膳食纤维（麸皮、仙人掌和车前子壳）与空腹T1AC处于或高于正常第90百分位数相关。
T1是一种MRI参数，可用于监测旨在改变结肠水分含量和粪便稠度的新型药物的疗效。
