A guide for effective anatomical vascularization studies: useful ex vivo methods for both CT and MRI imaging before dissection

Abstract

The objective of this study was to develop a simple and useful injection protocol for imaging cadaveric vascularization and dissection. Mixtures of contrast agent and cast product should provide adequate contrast for two types of ex vivo imaging (MRI and CT) and should harden to allow gross dissection of the injected structures. We tested the most popular contrast agents and cast products, and selected the optimal mixture composition based on their availability and ease of use. All mixtures were first tested in vitro to adjust dilution parameters of each contrast agent and to fine-tune MR imaging acquisition sequences. Mixtures were then injected in 24 pig livers and one human pancreas for MR and computed tomography (CT) imaging before anatomical dissection. Colorized latex, gadobutrol and barite mixture met the above objective. Mixtures composed of copper sulfate (CuSO 4 ) gadoxetic acid (for MRI) and iodine (for CT) gave an inhomogeneous signal or extravasation of the contrast agent. Agar did not harden sufficiently for gross dissection but appears useful for CT and magnetic resonance imaging (MRI) studies without dissection. Silicone was very hard to inject but achieved the goals of the study. Resin is particularly difficult to use but could replace latex as an alternative for corrosion instead of dissection. This injection protocol allows CT and MRI images to be obtained of cadaveric vascularization and anatomical casts in the same anatomic specimen. Post-imaging processing software allow easy 3D reconstruction of complex anatomical structures using this technique. Applications are numerous, e.g. surgical training, teaching methods, postmortem anatomic studies, pathologic studies, and forensic diagnoses.

Call for a Multidisciplinary Effort to Map the Lymphatic System with Advanced Medical Imaging Techniques: A Review of the Literature and Suggestions for Future Anatomical Research

“…Even though the smallest of lymphatic vessels may not be suitable for retrograde injection, there is still a wealth of anatomical information to be gained by even visualizing the big‐ to medium‐sized lymphatic vessels in the entire body. On top of that, the contrast agent to achieve this purpose already seems to be readily available (Renard et al , b). As an added bonus, the use of barium sulfate as a contrast agent was even shown to be compatible with micro CT imaging (Blery et al ; Kingston et al ) and the compound is nontoxic (Kingston et al ).…”

A radio‐anatomical correlation study of the cisterna chyli

“…In our study, the injection was performed using green latex mixed with barite and gadobutrol as previously described (Renard et al. ). This made it possible to identify systematically the origin of the TD and CC, when it existed, on high resolution CT and MRI.…”

“…B; Renard et al. ). Because of the fragility of the lymphatic vessels, the injection was performed slowly and carefully with a 5‐mL syringe (BD Medical ® , Le Pont‐de‐Claix, France).…”

“…An injection of green latex mixed with barite at a concentration of 10% and gadobutrol at a concentration of 3 mL/L was performed as reported in the literature ( Fig. 2B; Renard et al 2017). Because of the fragility of the lymphatic vessels, the injection was performed slowly and carefully with a 5-mL syringe (BD Medical â , Le Pont-de-Claix, France).…”

Comparison of CT and MRI in imaging diagnosis of aortic dissection

“…The layer thickness was 7.0 mm, the scanning field of view (FOV) was 300 to 330 mm, the echo time (TE) was 7.5 ms, the repeat time (TR) was 114 ms, left front oblique film parameter settings, slice distance was 2 mm, slice thickness was 5.5 mm, scanning field of view was 300 to 350 mm, and TR/TE was 50ms/12ms. Gadolinium-DTPA (15 mL), a contrast agent, was injected intravenously into the median cubital vein (Bonfanti et al, 2018;Orabi et al, 2018;Renard et al, 2018;Yu, 2018). After the scan was finished, the blood flow in the large blood vessels of the heart was observed using a movie playback software.…”