Comparison of two volumetric techniques for estimating liver volume using magnetic resonance imaging

Abstract

Purpose:To compare the conventional technique of manual planimetry with the point counting technique for estimating liver volume from magnetic resonance imaging (MRI) data. Materials and Methods:This study comprised abdominal MR examinations of 38 consecutive patients. Evaluation of the images showed that liver size appeared normal in 27 patients and increased in 11. Liver volume was estimated using the techniques of planimetry and point counting. Both techniques were used in combination with the Cavalieri method of modern design stereology. A systematic slice sampling procedure was performed to estimate liver volumes using both volumetric techniques. The point counting technique was optimized by altering the point spacing of the grid. The agreement between the two techniques was found. Measurement repeatability of both volumetric techniques was also evaluated.Results: Both techniques allowed the same degree of optimization through the procedure of systematic section sampling. The application of a point spacing of 2.5 cm reduced the time measurement by a factor of 3.5 in relation with the time needed with planimetry. An excellent agreement was observed between the two volumetric techniques with mean differences (ϮSD) of 2.4 Ϯ 41.6 cm 3 and 8.5 Ϯ 49.8 cm 3 for the patients presenting normal and increased liver sizes, respectively. Both techniques were highly reproducible. Conclusion:The point counting technique could be considered a more efficient approach than planimetry for estimating liver volume from MRI, due to its speed and simplicity.

Morphometry of Hepatic Neoplasms and Altered Foci in the Mummichog, Fundulus heteroclitus

“…Early efforts using stereology to estimate histological lesion volumes (Pitot et al, 1980;Xu et al, 1990;Hanigan et al, 1993) provided an innovative approach to estimate lesion extent. However, more recent efforts by Eustis et al (1994) and Mazonakis et al (2002), using renal histopathology and hepatic MRI, respectively, show that observations from multiple 380 STINE ET AL.…”

Stereological Evaluation of Brain Magnetic Resonance Images of Schizophrenic Patients

“…A is the measured area of the sections using planimetry and the others are constants. This formula allows the researcher to evaluate the area changes and the measured cut surface areas in the consecutive section series (Mazonakis et al, 2002).…”

The Effect of Slice Thickness on the Assessment of Bone Defect Volumes by the Cavalieri Principle Using Cone Beam Computed Tomography

“…The average of the three scores was used for calculation. The sum of the areas was used to estimate the volume using the following formula, which has been described in previous reports [7][8][9]:…”

“…Due to this principle, volume of an arbitrarily shaped object can be estimated in an unbiased manner from the product of the distance between planes and the sum of areas on systematic random sections through the object [5]. Since systems such as CT, MRI, and ultrasonography section imaging can obtain entire sets of two-dimensional slices through objects which are parallel to each other and separated by a known distance, they are used in the estimation of the volume of an object utilizing this method [6][7][8][9].…”