Somatom emotion duo

Comprehensive cryosurgery was performed on all 55 patients. Obvious intrahepatic masses were cryoablated as previously reported.^30,31 (link) Percutaneous cryoablation was performed under double-row helical computed tomography (Somatom Emotion Duo; Siemens, Munich, Germany) or color ultrasound (ALOKA SSD-5500SA; Aloka, Tokyo, Japan) guidance. All cryosurgery was performed by Dr. Lizhi Niu and assistants (Haibo Li and Feng Mu). Each procedure comprised one to 3 freeze/thaw cycles accomplished using an argon gas-based cryosurgical unit (Endocare, Irvine, CA, USA).^30,31 (link) Depending on the location of the metastasis, probes were inserted percutaneously under ultrasound or CT guidance; 2 or 5 mm probes or, rarely, 10 mm probes (Cryo-42; Endocare, Irvine, CA, USA) were used according to the size of the tumor. Two or more probes were used simultaneously for large lesions. Individual tumors were frozen sequentially on a tumor-by-tumor basis. The duration of freezing depended on the formation of an “ice-ball” visible on ultrasonography as a hypoechogenic area > 1 cm larger than the diameter of the lesion. Thawing was achieved by input of helium for a period of time equal to the freezing time before the next freezing process was begun.

Under general anesthesia, all dogs underwent CT and MRI. For head and cervical spine (to the level of the caudal C3 vertebra) CT images, we used a helical dual‐slice CT scanner (Somatom Emotion Duo, Siemens AG, Forcheim, Germany), with a bone algorithm and a slice thickness of 1 mm (feed/rotation, 2 mm; reconstruction increment, 0.5 mm; 110 kV). We positioned the dogs so that the base of the skull was aligned perpendicular to the ventral vertebral canal in the cranial cervical spine.
For MR images, we used a 0.2 Tesla MR scanner (Esaote S.p.A, Genova, Italy) and positioned all dogs in sternal recumbency with the base of the skull aligned perpendicular to the ventral vertebral canal at the first 2 cervical vertebrae. In dogs without CM/SM‐related clinical signs, MRI consisted of sagittal T1‐ and T2‐weighted sequences of the brain and cervical spine (with slice thickness ranging from 3.5 to 4.5 mm), T1‐ and T2‐weighted transverse sequences of the brain, and T1‐weighted transverse sequences of the spinal cord between C1 and C4/5. Transverse slices were adjusted to center the syrinx, if visible. Dogs with CM/SM‐related clinical signs underwent a similar protocol with the addition of T2‐weighted transverse images throughout the entire cervical spine.