Functional statistics based method for the evaluation of the registration of sequences of 3D perfusion MR images

Accurate registration of medical images is a necessary task for several important diagnosis techniques. Nevertheless, it is a difficult challenge due to movement of the patient, deformations, noise in the signal, etc. Besides, evaluation of the quality of the performed registration is also troublesome, specially when no golden pattern (true result) is available and/or when the signal values may have changed between successive images/volumes to be registered.

Mean sets for building 3D probabilistic liver atlas from perfusion MR images

This paper is concerned with liver atlas construction. One of the most important issues in the framework of computational abdominal anatomy is to define an atlas that provides a priori information for common medical task such as registration and segmentation. Unlike other approaches already proposed so far (to our knowledge), in this paper we propose to use the concept of random compact mean set to build probabilistic liver atlases. To accomplish this task a two-tier process was carried out. First a set of 3D images was manually segmented by a physician. We see the different 3D segmented shapes as a realization of a random compact set. Secondly, elements of two known definitions of mean set…

Randomised double-blind clinical trial of intermediate- versus high-dose chloral hydrate for neuroimaging of children.

Orally administered chloral hydrate is the most widely used sedative in children undergoing MRI. We compared intermediate- and high-dose oral chloral hydrate in 97 consecutive children undergoing MRI in a prospective, controlled, double-blind, randomised clinical trial. There were 50 girls and 47 boys, mean weight (+/- SD) 14.7 +/- 6.4 kg, and mean age 38 +/- 31. The children were randomly allocated to receive chloral hydrate syrup either 70 mg/kg (group A, n = 50) or 100 mg/kg (group B, n = 47). These two groups were not significantly different in sex, weight, age, diagnosis or ambulatory medication. The mean initial dose (+/- SEM) was 64 +/- 2 mg/kg for group A and 93 +/- 2 mg/kg for grou…

AKI - human studies

Evaluation of the registration of temporal series of contrast-enhanced perfusion magnetic resonance 3D images of the liver.

The registration of 2D and 3D images is one of the key tasks in medical image processing and analysis. Accurate registration is a crucial preprocessing step for many tasks; consequently, the evaluation of its accuracy becomes necessary. Unfortunately, this is a difficult task, especially when no golden pattern (true result) is available and when the signal values may have changed between successive images to be registered. This is the case this paper deals with: we have a series of 3D images, magnetic resonance images (MRI) of the liver and adjacent areas that have to be registered. They have been taken while a contrast is diffused through the liver tissue, so intensity of each observed poi…

Oral chloral hydrate provides effective and safe sedation in paediatric magnetic resonance imaging.

SUMMARY Sedation is routinely required for successful Magnetic Resonance imaging in infants and children. Five hundred and ninety-six paediatric patients (270 female and 326 male, age (mean±SD) 41±30 months and weight 14.8±6.5 kg) entered an open, non-comparative, prospective study to assess oral chloral hydrate sedation in a large and homogeneous paediatric population undergoing Magnetic Resonance imaging. Chloral hydrate syrup 70 mg/ml was administered 20–40 min prior to the procedure. Effective sedation was reached in 94.1% with a total dose (mean±SEM) of 68±1 mg/kg (range 20–170 mg/kg). Statistical analysis of sedation failures vs. successful examinations after the total dose showed sig…

Probabilistic liver atlas construction

Background Anatomical atlases are 3D volumes or shapes representing an organ or structure of the human body. They contain either the prototypical shape of the object of interest together with other shapes representing its statistical variations (statistical atlas) or a probability map of belonging to the object (probabilistic atlas). Probabilistic atlases are mostly built with simple estimations only involving the data at each spatial location. Results A new method for probabilistic atlas construction that uses a generalized linear model is proposed. This method aims to improve the estimation of the probability to be covered by the liver. Furthermore, all methods to build an atlas involve p…