MR signal changes on hepatobiliary imaging after oral ingestion of manganese chloride tetrahydrate: preliminary examination

Manganese-Enhanced Magnetic Resonance Imaging: Overview and Central Nervous System Applications With a Focus on Neurodegeneration

Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and the brief but decorated clinical usage of chelated manganese compound mangafodipir in humans.

Performance survey on a new standardized formula for oral signal suppression in MRCP

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Recently, a new biological standardized product for MRCP became available.

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The product is considered effective as oral signal suppressor in T2-w images.

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Obtained MRCP imagery show a good image quality.

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Patients’ feedback on taste and palatability is very high.

Background

Orally administered substances, which reduce image contamination by overlying gastrointestinal fluid signals, can be used to enhance the quality of MRCP images. Recently, a new standardized formula consisting of biological substances has become available. The objective of this study is to provide a first assessment of achievable MRCP image quality, taste and palatability of this new dedicated agent.

Methods

In January 2015 to May 2015 practicing radiologists in Germany, Austria and Switzerland were asked to evaluate image quality as well as taste and palatability when using the new agent (LumiVision^®; b.e. imaging; Baden-Baden; Germany) in MRCP questionnaire. Both criteria were rated with a 6-point Likert scale ranging from “1” (best) to “6” (worst).

Results

A total 185 of 475 radiologic institutions (39%) submitted feedback on image quality, 187 (39%) on the taste/palatability. Assessments of image quality regarding presence of disturbing gastrointestinal fluid signal resulted in a median of 2. The majority of patients rated the subjective taste as very good (median of 1). No side effects of relevance were recorded.

Conclusion

This large survey shows that the tested product is considered effective by radiologists regarding MRCP image quality. Patients’ feedback on taste and palatability was very positive.

Efficacy of oral contrast agents for upper gastrointestinal signal suppression in MRCP: A systematic review of the literature

Background

Orally administered substances which suppress signals from gastrointestinal fluid can be used to enhance image quality in magnetic resonance cholangiopancreatography (MRCP). In daily practice, the available substances range from commercial products to regular viands such as fruit juices.

Purpose

To provide an overview on the significance of and the substances used as gastrointestinal fluid signal suppressors in MRCP.

Material and Methods

A systematic review of the existing literature was performed to evaluate the efficacy and efficiency of oral T2-signal suppressors in MRCP.

Results

Twenty-five publications on 16 different oral contrast media were identified. The most commonly used substances were ferumoxsil, ferric ammonium citrate, and pineapple juice. Twenty-three out of 25 publications supported the use of oral signal suppressors in MRCP. Advantages of oral signal suppressors include improved visualization of the pancreatobiliary ductal system, increased help with differential diagnoses, and higher detection rates of relevant diagnoses due to a reduction of overlaying signals.

Conclusion

The application of oral substances for gastrointestinal signal suppression in MRCP is recommendable. A variety of substances are used in daily routine with good but varying effectivity and patient tolerance.

[A Low-temperature Manganese Chloride Tetrahydrate Improves the Image Quality of Magnetic Resonance Cholangiopancreatography]

Manganese chloride tetrahydrate (MCT) is one of the oral negative contrast agents which is indispensable for imaging of magnetic resonance cholangiopancreatography (MRCP). In this study, improvement of the image quality of MRCP by using low-temperature MCT is verified. All MR imagings were performed using 1.5 T scanner. The T(1) and T(2) values of the different temperature MCTs were measured in the phantom study. Different concentrations of MCT-doped water (30%, 50%, 70%, and 90%) were measured at several temperature conditions (10°C, 15°C, 23°C, 35°C, and 40°C). As a result, the T(1) and T(2) values became larger with a temperature rise. It was more remarkable in low-concentration MCT. Then, 17 healthy subjects were scanned two times with different temperatures of MCT. The MCT of the normal temperature (23°C) and low temperature (10°C) were taken at consecutive 2 days. The contrast between the stomach and the spleen were significantly higher in 2D half Fourier acquisition single shot turbo spin echo (HASTE) images by use of the low-temperature MCT. The contrast between the common bile duct and the adjacent background were significantly higher in the source images of 3D MRCP by use of the low temperature MCT. In addition, 76% of subjects answered in the questionnaire that the low temperature MCT is easier to drink. The low temperature MCT improves the image quality of MRCP and contributes to performing noninvasive examination.