Initial experience with magnetic resonance fluoroscopy in the evaluation of oesophageal motility disorders. Comparison with manometry and barium fluoroscopy

Abstract

The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results.

Magnetic resonance-fluoroscopy as long-term follow-up examination in patients with narrow gastric tube reconstruction after radical esophagectomy

“…Since now, different MR-fluoroscopy techniques have been introduced for the evaluation of esophageal functionality: in their paper [25], Barkhausen et al first discussed the characteristics of TrueFISP sequences for the dynamic visualization of pharynx and upper esophagus, while other authors lately proposed T1-weighted Fast Field Echo/Turbo Field Echo [16], Turbo-FLASH [17], and Dynamic Gradient-Echo sequences for the MR-fluoroscopy imaging of esophageal functionality. For the study of patients with NGT reconstruction of the esophagus, we chose to adopt T1-weighted Turbo-FLASH sequences basing on the encouraging results reported in the evaluation of esophageal functionality in subjects with motility disorders [17]; since a just compromise between temporal and spatial resolution (highest possible frame rate with sufficient spatial definition) is the most critical factor to perform proper MR-fluoroscopy imaging, our primary objective was to set low values of repetition time (TR = 600 ms), Flip Angle (FA = 88) and, consequentially, of sequence TA (50 s), maintaining at the same time an adequate matrix (125 Â 256). Several different mixtures have been proposed as oral contrast agent for MR-fluoroscopy, ranging from ferric-ammonium solutions [16], to semolina pudding [25], yoghurt [17], or water mixed with Gadolinium: the yoghurt/ Gadolinium mixture we used was an optimal solution providing excellent signal intensity with barium-like physical properties, and improving patient comfort with good compliance during examination.…”

“…For the study of patients with NGT reconstruction of the esophagus, we chose to adopt T1-weighted Turbo-FLASH sequences basing on the encouraging results reported in the evaluation of esophageal functionality in subjects with motility disorders [17]; since a just compromise between temporal and spatial resolution (highest possible frame rate with sufficient spatial definition) is the most critical factor to perform proper MR-fluoroscopy imaging, our primary objective was to set low values of repetition time (TR = 600 ms), Flip Angle (FA = 88) and, consequentially, of sequence TA (50 s), maintaining at the same time an adequate matrix (125 Â 256). Several different mixtures have been proposed as oral contrast agent for MR-fluoroscopy, ranging from ferric-ammonium solutions [16], to semolina pudding [25], yoghurt [17], or water mixed with Gadolinium: the yoghurt/ Gadolinium mixture we used was an optimal solution providing excellent signal intensity with barium-like physical properties, and improving patient comfort with good compliance during examination. The combination of all these factors allowed real-time imaging of NGT functionality and morphology: the peculiar post-surgery changes occurring in patient with NGT reconstruction of the esophagus were correctly evaluated in all cases, yielding sufficient information to assign each patient to the corresponding score group.…”

“…Outside scan room, the ability of each patient to swallow a small amount of water in prone and supine position was tested to detect eventual aspiration, avoiding dangerous circumstances inside the magnet bore [17]. We used as oral contrast agent a mixture of semi-fluid yoghurt and Gd-DTPA 0.5 M, 1:100 (Multihance, Bracco SpA, Milano, Italy) [17]. All subjects were strictly instructed to swallow the contrast agent, during the exam, in a single act.…”

“…In order to obtain proper evaluation of post-surgery leaks, strictures, or functional abnormality in patients with esophageal reconstruction, the imaging examination of choice is actually represented by conventional videofluoroscopy [15]. The constant technological progress in the field of magnetic resonance (MR) imaging, in addition to an increasing interest in developing new radiation-free modalities to obtain realtime evaluation of physiological processes, have recently disclosed the possibility to perform MR-fluoroscopic imaging of the esophageal functionality: at present, the employment and evolution of this interesting technique is limited to a few feasibility [16] and preliminary clinical studies mainly based on the evaluation of esophageal motility disorders [17] but, to our knowledge, current literature completely lacks any evidence on post-surgery patients. The aim of our work was to assess the value of MR-fluoroscopy as potential long-term follow-up modality for the evaluation of functionality and morphology of the NGT in subjects who underwent radical esophagectomy.…”

Functional Magnetic Resonance in the Evaluation of Oesophageal Motility Disorders

“…The main limitation of SDV is the use of ionizing radiation while the magnetic resonance imaging (MRI) technique offers the same information of radiology in absence of radiation [8]. …”