Bone scintigraphy for the diagnosis of an abnormal medial coronoid process in dogs.

Few reports have been published regarding the use of scintigraphy in the diagnosis of elbow joint lameness in dogs. Some authors have speculated about the potential use of bone scintigraphy and its suspected high sensitivity for the early diagnosis of abnormalities of the medial coronoid process (MCP) in dogs. Scintigraphy is used routinely in our institution in dogs presented for thoracic limb lameness and/or suspected of abnormalities of the MCP when radiographic findings were equivocal. Radiographic, scintigraphic, and surgical findings of the elbow joints of 17 dogs with elbow joint lameness were compared with radiographic, scintigraphic, and necropsy findings of the elbow joints of 12 clinically healthy Labrador Retrievers. Quantitative evaluation of scintigraphic images was performed to determine relative radiopharmaceutical uptake in the region of the MCP. Maximum relative uptake of the coronoid process in the normal dogs was taken as a threshold value to classify elbows as positive or negative for an abnormal MCP after all 24 elbows of the 12 healthy dogs were confirmed as being normal at necropsy. All 17 elbows from lame dogs were positive on scintigraphy and confirmed as having chondromalacia, a fissure, or fragmentation of the MCP. Based on our results, bone scintigraphy may be a valuable diagnostic tool for the diagnosis of abnormalities of the MCP in dogs, and particularly in older dogs where clinical and radiographic changes may be ambiguous.

Effect of four sedative and anesthetic protocols on quantitative thyroid scintigraphy in euthyroid cats.

OBJECTIVES: To determine the effect of sedation and anesthesia on thyroid and salivary gland uptake of technetium Tc 99m pertechnetate ((99m)TcO(4)) in euthyroid cats. ANIMALS: 6 euthyroid cats. PROCEDURES: Thyroid scintigraphy was performed by use of a high-resolution low-energy parallel-hole collimator after IV injection of 117 to 133 MBq (3.16 to 3.59 mCi) of (99m)TcO(4)(-). The procedure was performed 4 times on each cat during different sedative and anesthetic protocols in a rotating schedule as follows: propofol, ketamine-midazolam-atropine, ketaminemidazolam, and medetomidine. Regions of interest were drawn around thyroid and salivary glands and counts corrected for background and decay. Percentage of (99m)TcO(4)(-) uptake in salivary and thyroid glands and thyroid-to-salivary gland (99m)TcO(4)(-) uptake ratio were calculated at 20 and 40 minutes. Relative effects of anesthesia and sedation on salivary and thyroid gland (99m)TcO(4)(-) uptake were compared. RESULTS: Significant differences among sedativeanesthetic protocols were found for thyroid gland (99m)TcO(4)(-) uptake, salivary gland (99m)TcO(4)(-) uptake, and thyroid-to-salivary gland (99m)TcO(4)(-) uptake ratio. Thyroid gland (99m)TcO(4)(-) uptake for the ketamine-midazolam protocol at 20 and 40 minutes after (99m)TcO(4)(-) administration was significantly higher than for the propofol protocol. A significant difference in salivary gland(99m) TcO(4)(-) uptake was found between ketamine-midazolam and ketamine-midazolam-atropine protocols at 40 minutes. The thyroid-to-salivary gland (99m)TcO(4)(-) uptake ratio for the ketamine-midazolam protocol was significantly higher at 40 minutes than for propofol or ketamine-midazolam-atropine protocols. CONCLUSIONS AND CLINICAL RELEVANCE: Sedation and anesthesia have a significant effect on thyroid and salivary gland (99m)TcO(4) uptake in euthyroid cats that may interfere with thyroid scintigraphic image interpretation.

Comparison of ultrasonography, computed tomography, and single-photon emission computed tomography for the detection and localization of canine insulinoma.

Accurate preoperative detection, localization, and staging of the primary tumor and metastases are essential for the selection of appropriate candidates for surgery. In dogs with insulinoma, preoperative assessment usually is performed with transabdominal ultrasonography (US). There are no reports on the use of computed tomography (CT) for this purpose. The preoperative use of somatostatin receptor scintigraphy (SRS) recently has been advocated for the identification of insulinoma and gastrinoma in dogs, but its accuracy remains to be established. In this report US, CT, and single-photon emission computed tomography (SPECT) with [111In-DTPA-D-Phe1]-octreotide (a specific form of SRS) were compared for their effectiveness in detecting and localizing primary and metastatic insulinoma in dogs. Findings at surgery or postmortem examination served as control. Of 14 primary insulinomas, 5, 10, and 6 were correctly identified by US, CT, and SPECT, respectively. No lymph node metastases were detected by US or SPECT. CT identified 2 of 5 lymph node metastases but also identified 28 false-positive lesions. Two of 4 livers were found to be positive for metastases by 1 of the imaging techniques. US can be used for the initial evaluation of dogs with hypoglycemia. Although CT identifies most primary tumors, intraoperative inspection and palpation of the pancreas is still superior. SPECT appears as effective as US and CT in detecting insulinomas. Future developments in preoperative imaging techniques might improve current methods of canine insulinoma detection.