{
  "abstract": "Introduction Magnetic resonance imaging (MRI) does not require ionising radiation and is increasingly used for non-invasive dynamic assessment of gastric motility. However, MRI image analysis can be complex and time consuming. We tested the feasibility of using semi-automated MRI spatiotemporal motility mapping (STMM) to quantify gastric motility in patients with and without delayed gastric emptying (GE).Methods Thirty-one patients (87% [27/31] female; mean age 37 years) with chronic upper gastrointestinal symptoms who had undergone both small bowel MRI (with a good coverage of the stomach; 15% mannitol as oral contrast) and GE scintigraphy (scans performed ≤30 days apart) were retrospectively identified from neurogastroenterology clinic records. A STMM tool (Motilent, London) was used to semi-automatically measure gastric luminal diameter changes at 5 mm intervals, producing a motility score as a surrogate of gastric contractility. To validate the STMM score, frame-by-frame analysis of the 20-frame (1 frame/second) MRI images was performed by creating dynamic line plots of the gastric contractility curves (motility maps) [figure 1A&B].The median (Q1;Q3) whole-stomach STMM score (arbitrary units, a.u.) and peak contractile amplitude (% luminal occlusion) in patients with delayed versus normal GE were compared using Mann-Whitney U test.Results There were 18 and 13 patients with delayed and normal GE respectively. The median whole-stomach STMM score was significantly reduced in patients with delayed GE (0.18 a.u. [0.16;0.26]) compared to the normal GE group (0.36 a.u. [0.27;0.5]) (p=0.02) [figure 1C]. Similarly, the median peak contractile amplitude was significantly lower in patients with delayed GE (30% [20;30]) compared to the normal GE cohort (60% [30;60]) (p=0.01).Conclusions MRI can be used to qualitatively and quantitatively assess gastric motility, which may have a place in the diagnostic workup of patients with chronic upper gastrointestinal symptoms. Using GE for correlation, we have demonstrated that semi-automated quantification of gastric motility with STMM is reliable and may have clinical applications. Future work will aim to corroborate these findings in larger prospective studies.Abstract P410 Figure 1Example gastric motility maps derived from magnetic resonance imaging (MRI) demonstrating (A) low (20%) and (B) high (80%) peak contractile amplitude in a patient with delayed versus normal gastric emptying respectively. The different coloured lines denote each of the 20 frames on the MRI cine sequence. (C) Significantly reduced gastric motility (p=0.02) in patients with delayed (n=18) compared with normal (n=13) gastric emptying as quantified by a semi-automated MRI spatiotemporal motility mapping tool (Motilent, London)",
  "authors": [
    {
      "affiliations": [
        "University College London Centre for Medical Imaging, London, United Kingdom"
      ],
      "name": "Asma Fikree"
    },
    {
      "affiliations": [
        "University College London Centre for Medical Imaging, London, United Kingdom"
      ],
      "name": "Jason Mak"
    },
    {
      "affiliations": [
        "Division of Medicine, University College London , London, United Kingdom"
      ],
      "name": "Tianci Hu"
    },
    {
      "affiliations": [
        "University College London Centre for Medical Imaging, London, United Kingdom"
      ],
      "name": "Heather Fitzke"
    },
    {
      "affiliations": [
        "Institute of Nuclear Medicine, University College London Hospital , London, United Kingdom"
      ],
      "name": "Arash Latifoltojar"
    },
    {
      "affiliations": [
        "University College London Centre for Medical Imaging, London, United Kingdom"
      ],
      "name": "Stuart Taylor"
    },
    {
      "affiliations": [
        "Research Department of Targeted Intervention, Division of Surgery & Interventional Science, University College London , London, United Kingdom"
      ],
      "name": "Natalia Zarate-Lopez"
    },
    {
      "affiliations": [
        "Motilent Ltd, London, United Kingdom"
      ],
      "name": "Iyad Naim"
    }
  ],
  "title": "P410 Feasibility of semi-automated MRI spatiotemporal gastric motility mapping – a comparison study in patients with delayed versus normal gastric emptying",
  "uid": "a0b42dc5-d433-5bde-974e-b6f13c76aae6"
}