Kumiko Ishigaki

Triple-phase helical computed tomography in dogs with hepatic masses.

The purpose of this study was to determine the utility of triple-phase helical computed tomography (CT) for differentiating canine hepatic masses. Seventy dogs with hepatic masses underwent triple-phase CT followed by surgical removal of the hepatic masses. Triple-phase helical CT scans for each dog included precontrast, arterial phase, portal venous phase, and delayed phase studies. The removed hepatic masses were histopathologically classified as hepatocellular carcinoma (n = 47), nodular hyperplasia (n = 14), and hepatic metastatic tumors (n = 9) in dogs. Of the 47 hepatocellular carcinomas, the most common CT findings included a heterogeneous pattern with hyper-, iso-, and hypoenhancement in both the arterial and portal venous phases (40/47, 85.1%). Of the 14 nodular hyperplasias, the most common CT findings were a homogeneous pattern with hyper- and isoenhancement in both the portal venous and delayed phases (13/14, 92.9%). Of nine hepatic metastatic tumors, the most common CT findings included a homogeneous hypoenhancement pattern in both the arterial and portal venous phases (8/9, 88.9%). In addition, 5 (55.6%) showed homogeneous hypoenhancement patterns in the delayed phase. Findings from our study indicated that triple-phase CT is a useful tool for preoperative differentiation of hepatocellular carcinoma, nodular hyperplasia, and hepatic metastatic tumors in dogs.

Intraoperative identification of canine hepatocellular carcinoma with indocyanine green fluorescent imaging.

OBJECTIVES To evaluate the feasibility of high-sensitivity near-infrared fluorescence imaging with indocyanine green for intraoperative identification of hepatocellular carcinoma in dogs. METHODS Twelve hepatic nodules were surgically resected from six dogs. In each dog, 0 · 5 mg/kg indocyanine green was intravenously injected for 12 to 18 hours preoperatively. The hepatic nodules were investigated under laparotomy using a near-infrared fluorescence imaging light camera system prior to resection. Resected nodules were histopathologically diagnosed and their fluorescence images were evaluated. RESULTS Of the 12 hepatic nodules, 6 were diagnosed as hepatocellular carcinoma and 6 as nodular hyperplasia. Indocyanine green-fluorescence was observed in four large hepatocellular carcinoma nodules and one case of nodular hyperplasia, whereas it was absent in the remaining nodules. The sensitivity and positive predictive values of indocyanine green fluorescent imaging for hepatocellular carcinoma was 71 · 4 and 80 · 0%, respectively. Complete resection of the hepatic masses was achieved in all dogs. CLINICAL SIGNIFICANCE Near-infrared fluorescence imaging may be feasible for intraoperative mapping of hepatocellular carcinomas in hepatic lobes and may help increase the chance of complete resection of hepatocellular carcinoma in dogs.

Preoperative Differential Diagnosis of Canine Adrenal Tumors Using Triple-Phase Helical Computed Tomography.

OBJECTIVE To characterize the computed tomography (CT) findings for canine adrenal tumors, including cortical adenoma, cortical adenocarcinoma, and pheochromocytoma, and to evaluate the feasibility and usefulness of preoperative triple-phase helical CT for differentiation of tumor types and surgical planning. STUDY DESIGN Retrospective study. ANIMALS Dogs with adrenal tumors (n=36). METHODS All dogs underwent triple-phase helical CT, followed by adrenalectomy and histopathological diagnosis of the resected mass. Precontrast images, arterial, venous, and delayed phase images were obtained. In all cases, morphological characteristics and CT values and calculations, including the percentage enhancement washout ratio, relative percentage washout, enhancement washin, and enhancement washout, were analyzed and compared among the tumor types. RESULTS Of the 36 dogs with adrenal masses, cortical adenocarcinoma was most commonly diagnosed (16 dogs), followed by pheochromocytoma (13 dogs), and cortical adenoma (7 dogs). The precontrast minimum CT value and enhancement washout between venous and delayed phases in the cortical adenoma were significantly higher than those in the cortical adenocarcinoma. The maximum CT values of the precontrast image and arterial and venous phases, the enhancement washin and washouts, percentage enhancement washout ratio, and relative percentage washout in the pheochromocytomas were significantly higher than those in cortical adenocarcinoma. CONCLUSION The differential diagnosis of canine adrenal tumors was feasible based on triple-phase CT findings, including morphological features, CT values, and intratumoral contrast attenuation. Preoperative diagnosis using triple-phase helical CT may be useful for surgical planning in dogs with adrenal tumors.

Determination of Porto-Azygos Shunt Anatomy in Dogs by Computed Tomography Angiography

OBJECTIVE To describe the morphology of porto-azygos shunts in a large series of dogs using computed tomography (CT) angiography. STUDY DESIGN Retrospective study. ANIMALS Dogs (n=36) with porto-azygos shunts. METHODS CT angiography was performed in dogs subsequently proven to have a porto-azygos shunt. The origin and insertion of the shunts were assessed on native images. The diameter of the porto-azygos shunt and the portal vein, cranial and caudal to the shunt origin, were measured. The porto-azygos shunt anatomy was studied on three-dimensional images. RESULTS All porto-azygos shunts originated either in the left gastric vein (33 left gastro-azygos shunts) or the right gastric vein (3 right gastro-azygos shunts). Two left gastro-azygos shunts had concurrent caval-azygos continuation and 2 right gastro-azygos shunts had a caudal splenic loop. All shunts crossed the diaphragm through the esophageal hiatus. The majority of porto-azygos shunts (32) followed a straight pathway after traversing the diaphragm, although 4 shunts followed a tortuous route. All shunts terminated in the thoracic part of the azygos vein, perpendicular to the aorta. The shunt diameter at insertion was only 3 mm on average. The insertion site was consistently the narrowest part of the shunt. CONCLUSION CT angiography was well suited to provide anatomic details of porto-azygos shunts and comprehensively documented that all porto-azygos shunts had a thoracic terminus, after crossing the diaphragm through the esophageal hiatus. Different shunt types existed with minor variations.

Endoscopic photodynamic therapy using talaporfin sodium for recurrent intranasal carcinomas after radiotherapy in three dogs

Radiation is the treatment of choice for canine nasal tumours but, in almost all cases, there is local recurrence associated with poor prognosis. This report describes the effect of endoscopic photodynamic therapy using talaporfin sodium for canine intranasal carcinoma recurring after radiation therapy. Rhinoscopic photodynamic therapy was administered after radiation therapy in three dogs with recurrent intranasal carcinoma. Two to 24 illuminations of a 665-nm diode laser were performed two hours after intravenous bolus injection of 5·0 mg/kg of talaporfin sodium. Photodynamic therapy induced almost complete remission and prolonged survival time in all cases suggesting that it might be a useful treatment for intranasal carcinomas that recur after radiation.

Triple-phase helical computed tomography in dogs with solid splenic masses

We investigated the utility of triple-phase helical computed tomography (CT) in differentiating between benign and malignant splenic masses in dogs. Forty-two dogs with primary splenic masses underwent triple-phase helical CT scanning (before administration of contrast, and in the arterial phase, portal venous phase, and delayed phase) prior to splenectomy. Tissue specimens were sent for pathological diagnosis; these included hematomas (n=14), nodular hyperplasias (n=12), hemangiosarcomas (n=11), and undifferentiated sarcomas (n=5). The CT findings were compared with the histological findings. Nodular hyperplasia significantly displayed a homogeneous normal enhancement pattern in all phases. Hemangiosarcoma displayed 2 significant contrast-enhancement patterns, including a homogeneous pattern of poor enhancement in all phases, and a heterogeneous remarkable enhancement pattern in the arterial and portal venous phases. Hematoma and undifferentiated sarcoma displayed a heterogeneous normal enhancement pattern in all phases. The contrast-enhanced volumetric ratios of hematoma tended to be greater than those of undifferentiated sarcoma. Our study demonstrated that the characteristic findings on triple-phase helical CT could be useful for the preoperative differentiation of hematoma, nodular hyperplasia, hemangiosarcoma, and undifferentiated sarcoma in dogs. Triple-phase helical CT may be a useful diagnostic tool in dogs with splenic masses.

Contrast-enhanced ultrasonographic findings of hepatic arterioportal fistulas in a dog

FIG 1 . The images of the tortuous vessels (*) at 6 seconds (A) and 30 minutes (B) after injection in contrast-enhanced ultrasonographic examination. The arrow is a pointer of an ultrasound system, so it does not indicate a certain structure in the image

Gene Expression of Growth Factors and Growth Factor Receptors for Potential Targeted Therapy of Canine Hepatocellular Carcinoma

ABSTRACT The purpose of this study was to evaluate the gene expression of growth factors and growth factor receptors of primary hepatic masses, including hepatocellular carcinoma (HCC) and nodular hyperplasia (NH), in dogs. Quantitative real-time reverse transcriptase-polymerase chain reaction was performed to measure the expression of 18 genes in 18 HCCs, 10 NHs, 11 surrounding non-cancerous liver tissues and 4 healthy control liver tissues. Platelet-derived growth factor-B (PDGF-B), transforming growth factor-α, epidermal growth factor receptor, epidermal growth factor and hepatocyte growth factor were found to be differentially expressed in HCC compared with NH and the surrounding non-cancerous and healthy control liver tissues. PDGF-B is suggested to have the potential to become a valuable ancillary target for the treatment of canine HCC.