Abstract:Magnetic resonance imaging analysis of longitudinal relaxation times (T1 values), transverse relaxation times (T2 values), magnetization transfer (MT) rates and apparent water diffusion coefficients (D) was used to authenticate the effect of freezing/thawing in longissimus dorsi pig muscle; these NMR parameters were compared with the gravimetric moisture content values obtained independently by oven drying. A significant increase in the MT rate was observed between fresh and frozen/thawed pork prepared from th… Show more
“…These mechanisms were accompanied by a reduction in T1 [36] and T2 [37] values. Although quantitative MRI of meat has shown that increasing the duration of the freezing period from 2 weeks to a month at − 18 °C does not significantly enhance protein denaturation [38], slight MR signal changes were visible in the current study. The significant superiority in visibility of the PDL in live horses compared to those post-mortem (group A) may be explained by the unavailable blood flow in euthanized horses.Fig.…”
BackgroundThe use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI.ResultsThe CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition.ConclusionsOn comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.
“…These mechanisms were accompanied by a reduction in T1 [36] and T2 [37] values. Although quantitative MRI of meat has shown that increasing the duration of the freezing period from 2 weeks to a month at − 18 °C does not significantly enhance protein denaturation [38], slight MR signal changes were visible in the current study. The significant superiority in visibility of the PDL in live horses compared to those post-mortem (group A) may be explained by the unavailable blood flow in euthanized horses.Fig.…”
BackgroundThe use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI.ResultsThe CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition.ConclusionsOn comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.
“…Although unlikely to have been significant, it is unknown to what extent the differences in duration of freezing contributed to changes in this study. Duration of freezing time from two weeks to two months has been shown to have no effect on protein denaturation in meat and the duration of freezing was deemed not clinically significant in a previous equine cadaver study [ 5 , 23 ].…”
Equine advanced imaging research involving racehorse fetlock pathology commonly uses cadaver limbs and a freeze-thaw process. The presence of short tau inversion recovery (STIR) signal intensity in the distal third metacarpal/metatarsal bone is of particular interest and may be clinically relevant in the diagnosis of horses at risk of fracture. However, little is known about the effect of the freeze-thaw process on the MRI appearance of STIR hyperintensity in these bones. This study compares the low-field MRI appearance of the distal third metacarpal/metatarsal bone from cadaver limbs of Thoroughbreds in race training before and after a freeze-thaw protocol. Blinded and unblinded comparisons were made using objective SNR values and subjective grading. Fifteen cadaver limbs with STIR hyperintensity in the distal third metacarpal/metatarsal bone were included. No overall clinical or statistical significance was detected in STIR signal intensity and distribution after freeze-thaw. Three limbs from one horse had individual changes in STIR hyperintensity that were hypothesized to be attributable to ante-mortem haemodynamic abnormalities caused by anaesthesia. These results indicate that the distribution and intensity of STIR hyperintensity in freeze-thawed cadaver fetlocks can be considered representative of the appearance of pathology in the recently euthanized horse. However, care should be taken with horse selection and handling of the cadaver limbs to ensure reliable appearance of STIR signal after freeze-thaw.
“…In particular, some authors have indicated that MRI permits the study of carcass composition, adipose tissue distribution, connective tissue and muscle fibre type Mitchell, Scholz, Wang, & Song, 2001;Tingle, Pope, Baumgartner, & Sarafis, 1995). MRI can also help to understand the structural changes during processing and storage of meat (Bertram, Whittaker, Shorthose, Andersen, & Karlsson, 2004;Guiheneuf, Parker, Tessier, & Hall, 1997;Guiheneuf, Tessier, Herrod, & Hall, 1996;Renou, Foucat, & Bonny, 2003). Moreover, MRI parameters are also correlated with meat properties such as water content and sensory attributes (Cernadas, Carrion, Rodriguez, Muriel, & Antequera, 2005;Ruiz-Cabrera, Gou, Foucat, Renou, & Daudin, 2004;Shaarani, Nott, & Hall, 2006).…”
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