Oesophageal transit time evaluated by a biomagnetic method

Abstract

The aim of this work was to determine the oesophageal transit time (OTT) of a bolus using the biomagnetic technique and compare the results to those obtained by means of scintigraphy. For the biomagnetic evaluation, a test meal (yoghurt) uniformly labelled with 5 g of powder ferrite was swallowed in a single gulp by 19 normal volunteers in the upright position. One sensor (first order gradiometer) was placed at the furcula and a second one at the xiphoid process to detect the passage of the test meal and the magnetic signal output was recorded in a computer. The OTT was determined by plotting the voltage signal against time. The scintigraphic technique was used in the same volunteers: the test meal was labelled with less than 350 MBq of 99mTc-phytate and swallowed in the same way. The bolus transit was recorded at 4 frames s(-1) (100-120 frames acquisition) and the OTT was determined by drawing two regions of interest in the same areas as the sensors. The results were determined by plotting counts against time. The averages for OTTs were 3.8 +/- 0.8 s for the scintigraphic technique and 4.6 +/- 0.9 s for the biomagnetic technique. Although scintigraphic OTT was significantly shorter than magnetic OTT, there was a significant correlation between them. We conclude that the biomagnetic study may be used to evaluate OTT.

Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

“…Using the biomagnetic technique, we demonstrated that ETT is affected by anatomical position, with a significantly larger transit time when subjects adopted an upright position. These results concur with previous reports [1] , including studies in which a biosusceptometer magnetometer was used [27] . Previously, researchers reported that ETT in healthy individuals was approximately 4-8 s for solid and semisolid meals, and 1-2 s for liquid meals [11,28,29] .…”

“…Additionally, because of its low cost and non-invasiveness, this technique could be implemented in small clinical areas and hospitals. Although this technique has already been validated [27] , further studies are needed to compare biomagnetism with the most innovative and sophisticated techniques commonly used for esophageal evaluation in order to identify its sensitivity and reproducibility.…”

“…These studies have the advantage of being non-invasive, comfortable for the patient, and do not use ionizing radiation. Daghastanli et al [27] in 1998 reported an ETT study carried out with a biosusceptometer and a magnetic tracer, where they used 5 g of manganese (Mn) and ferrite power. In their study, they also measured the ETT using the scintigraphy technique and found that the ETT was 4.6 ± 0.9 s when biomagnetic technique was used, in comparison to a time of 3.8 ± 0.8 s as measured by the scintigraphy technique.…”

Study of the magnetic content movement present in the large intestine

“…Gamma-scintigraphy also imposes radiation exposure, and depends on the availability of expensive equipment [1,2]. As the importance of the knowledge on gastrointestinal motility is increasingly recognized, simple, easy to perform, harmless and inexpensive methods are required, and some biomagnetic techniques represent a promising alternative [3][4][5]. The colon exhibits complex motor patterns with variations of frequency and amplitude yielding compaction and movement of its contents along its extension.…”

Pharyngeal Clearance and Pharyngeal Transit Time Determined by a Biomagnetic Method in Normal Humans

“…The biomagnetic method is noninvasive, causes no discomfort to the patient, does not use radiation, and has already been used to study motility functions associated with gastric emptying [11], orocecal transit time [12], gastric contractions [13], esophageal transit time [14], segmental transit time [15,16], and mixing of food in the stomach [17]. The electrical activity of the gastrointestinal tract has also been studied by measuring the magnetic ®elds produced by the depolarization currents of the stomach [18,19] and the gut [20].…”