Pre- and post-treatment computed tomographic findings of a primary intranasal transmissible venereal tumor in a canine patient.

A two-year-old, female intact, cross-breed dog presented with a two-month history of nasal discharge. Computed tomography (CT) demonstrated obliteration of both nasal cavities by soft tissue density, destruction of the nasal and ethmoidal turbinates, and lysis of the frontal and palatine bones and maxilla. Frontal sinuses and maxillary recesses were obscured by soft tissue/fluid density. Histopathological examination of the mass was diagnostic of transmissible venereal tumor. The dog was clinically normal 3 months after treatment initiation with vincristine sulphate and amoxicillin/clavulanate. Six months after the completion of treatment no mass-like lesion was demonstrated in CT sections. Nasal cavities, maxillary recesses and frontal sinuses were filled with air. The reticular turbinate nasal plexus appeared atrophic with focal loss of the nasal turbinates on both sides. The ethmoidal turbinates were well-defined; however, focal loss of turbinates was also seen. Lysis of the frontal and palatine bones were still evident.

Surgical management of recurrent cervical sialoceles in four dogs.

Recurrent cervical sialoceles were diagnosed in four dogs associated with inadequate excision of the sublingual gland. Three dogs were managed by resection of the remnants of the sublingual gland via an oral approach. One dog was managed through a ventral approach as identification of the sublingual gland was not possible with the oral approach. The outcome was favourable in all cases and no relapses were detected after a median follow-up time of 10 months.

Time reversal microwave breast imaging for contrast-enhanced tumor classification.

This paper studies the decomposition of the time reversal operator (DORT, by the French acronym) technique for microwave breast lesion classification. We apply the finitedifference time-domain (FDTD) method to a realistic numerical breast phantom where lesion-like targets are artificially introduced, and obtain the multistatic data matrix (MDM) for a particular antenna array configuration. Then, the singular value decomposition (SVD) of this matrix is derived for different targets, which represent malignant and benign lesions. We show that the singular value spectrum can assist in classifying these targets as malignant or benign, especially in the case where contrast-enhanced agents can be employed to allow the analysis of differential backscatter data.

Contrast-enhanced microwave imaging of breast tumors: a computational study using 3-D realistic numerical phantoms.

The detection of early-stage tumors in the breast by microwave imaging is challenged by both the moderate endogenous dielectric contrast between healthy and malignant glandular tissues and the spatial resolution available from illumination at microwave frequencies. The high endogenous dielectric contrast between adipose and fibroglandular tissue structures increases the difficulty of tumor detection due to the high dynamic range of the contrast function to be imaged and the low level of signal scattered from a tumor relative to the clutter scattered by normal tissue structures. Microwave inverse scattering techniques, used to estimate the complete spatial profile of the dielectric properties within the breast, have the potential to reconstruct both normal and cancerous tissue structures. However, the ill-posedness of the associated inverse problem often limits the frequency of microwave illumination to the UHF band within which early-stage cancers have sub-wavelength dimensions. In this computational study, we examine the reconstruction of small, compact tumors in three-dimensional numerical breast phantoms by a multiple-frequency inverse scattering solution. Computer models are also employed to investigate the use of exogenous contrast agents for enhancing tumor detection. Simulated array measurements are acquired before and after the introduction of the assumed contrast effects for two specific agents currently under consideration for breast imaging: microbubbles and carbon nanotubes. Differential images of the applied contrast demonstrate the potential of the approach for detecting the preferential uptake of contrast agents by malignant tissues.