Treatment of a unicameral bone cyst in a dog using a customized titanium device.

A 4-year-old Shih-Tzu, referred for an enlarged left carpus, was diagnosed with a unicameral bone cyst. A customized titanium device was inserted into cystic lesion and fixed by titanium screws. Sufficient strength of the affected bone with the device inserted to maintain limb function was established after resection of contents of cystic lesion. There was no deterioration of the lesion of bone cyst, and acceptable function of the affected limb with no clinical signs of lameness was maintained during 36 months follow-up. The results of this study demonstrated that bone cyst curettage and use of a customized titanium device could provide an effective alternative treatment of huge lesion of unicameral bone cysts with the intent of preventing pathologic fractures.

Surgical resection of twenty-three cases of brain meningioma.

The aim of this study was to report the effectiveness of MRI scanning during brain meningioma resection surgery in the canine and feline. The subjects were 23 cases from 2006 to 2008 in canines and feline diagnosed with meningioma. All were between 8 and 16 years of ages. There were 12 males and 11 females. An appropriate craniotomy was performed for each case according to the initial MRI taken to diagnose meningioma prior to the surgery. Once the dura mater was exposed, an MRI biopsy needle was placed in the tumor as a guide. The first MRI sequence during the surgery was performed with this needle to confirm the location of the tumor. This MRI image was also processed and displayed by multi planar reconstruction to reveal the tumor extent in three dimensions. A Sonopet was applied to the middle of the tumor to destroy the inner part and release pressure from the entire tumor. Creating some space between the brain tissue and tumor, we treated blood vessels and carefully resected them. This procedure was repeated until complete removal of the tumor was confirmed by MRI. Sixteen of the 23 cases survived for more than 2 years postoperatively. The other seven died due to other disorders within 2 years. Our method with MRI navigation during the surgery improved our surgical performance and contributed to a prolonged survival time for the patients. In order to perform multiple MRI procedures smoothly during the surgery, it is necessary to have skillful assistants.

Contrast agent Gd-EOB-DTPA (EOB·Primovist®) for low-field magnetic resonance imaging of canine focal liver lesions.

Contrast-enhanced magnetic resonance (MR) imaging with a new liver-specific contrast agent gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA; EOB·Primovist®) was studied in 14 normal beagles and 9 dogs with focal liver lesions. Gd-EOB-DTPA accumulates in normally functioning hepatocytes 20 min after injection. As with Gd-DTPA, it is also possible to perform a dynamic multiphasic examination of the liver with Gd-EOB-DTPA, including an arterial phase and a portal venous phase. First, a reliable protocol was developed and the appropriate timings for the dynamic study and the parenchymal phase in normal dogs using Gd-EOB-DTPA were determined. Second, the patterns of these images were evaluated in patient dogs with hepatic masses. The optimal time of arterial imaging was from 15 s after injection, and the optimal time for portal venous imaging was from 40 s after injection. Meanwhile, the optimal time to observe changes during the hepatobiliary phase was from 20 min after injection. In patient dogs, 11 lesions were diagnosed as malignant tumors; all were hypointense to the surrounding normal liver parenchyma during the hepatobiliary phase. Even with a low-field MR imaging unit, the sequences afforded images adequate to visualize the liver parenchyma and to detect tumors within an appropriate scan time. Contrast-enhanced MR imaging with Gd-EOB-DTPA provides good demarcation on low-field MR imaging for diagnosing canine focal liver lesions.