Background Factors indicative of a negative prognosis for appendicular osteosarcoma (OSA) in dogs are visible metastatic disease, location, and size of lesion. In human medicine maximum standard uptake value (SUVmax), as measured on a fluorine18 flourodeoxyglucose positron emission tomography/computed tomography (18F‐FDG PET/CT), is prognostic for survival for several tumor types. Objective Determine if SUVmax is associated with progression‐free interval (PFI) and determination of survival in dogs with appendicular OSA. Animals Sixty‐two dogs with untreated appendicular OSA that had been staged with 18F‐FDG PET/CT. Methods Retrospective analysis of the 18F‐FDG PET/CT was performed. Dogs were excluded from the study if they did not receive definitive intent treatment for their primary OSA and adjuvant chemotherapy with carboplatin, or had visible metastatic disease on initial imaging. A region of interest (ROI) was created around the primary tumor to measure SUVmax. Univariable and multivariable Cox proportional hazards analysis was performed to evaluate for associations between variables including SUVmax and outcome of PFI and overall survival (OS). Results Maximum standard uptake value of the primary tumor was significantly associated with the OS (P = .04) with adjustment for treatment type and monocyte count. The overall median survival time (OST) was 284 days (range, 39‐1293 days) with the OST of dogs having an SUVmax of ≥7.4 of 254 days (range, 98‐428 days) and dogs with an SUVmax of <7.4 of 680 days (range, 108‐811 days, P = .01). Conclusions and Clinical Importance Maximum standard uptake value as measured via 18F‐FDG PET/CT is significantly associated with survival in dogs with appendicular OSA with a high SUVmax being an indicator of a negative prognosis.

Duplex Doppler ultrasound (US) provides a noninvasive method of monitoring cerebral blood flow velocity in newborns. The authors observed the changes in cerebral blood flow velocity in the right middle cerebral artery (RMCA) in 15 neonates during right common carotid artery (RCCA) ligation for extracorporeal membrane oxygenation. Antegrade flow in the RMCA continued uninterrupted in all patients at the moment of ligation. Peak systolic velocity decreased initially and then increased to 70% of baseline levels in the following 3-5 minutes. End diastolic velocity remained relatively unchanged at the time of ligation and rose slightly above baseline during the following 3-5 minutes. This study demonstrates that at the time of RCCA ligation, collateral flow is immediately established in the RMCA distribution and is further augmented within minutes.

Positron emission tomography (PET) imaging utilizing fluorine-18 labeled fluorodeoxyglucose is a relatively new imaging modality in veterinary medicine that is becoming more common for oncological staging and for musculoskeletal imaging. Thus, it is important to identify the normal variations on PET imaging that may be mistaken for pathology. Variation in standardized uptake values (SUVmax) have been anecdotally identified in the spinal cord of dogs undergoing fluorodeoxyglucose (FDG) PET-CT examinations for oncological staging, with notable increase in SUVmax values identified in the region of the cervical and lumbar spinal intumescences. The aim of this retrospective, analytical study was to compare the SUVmax values at four different locations throughout the spinal cord (C3, C5-T1, T13, and L3-S1) of a group of dogs with no evidence of neurologic disease and compare those findings to histologic specimens from dogs euthanized for unrelated disease. SUVmax values were significantly higher at the cervical and lumbar intumescences in comparison to the control regions (P < .0001 and P < .0001, respectively). Neuronal count and spinal cord gray matter area were also significantly greater at the cervical and lumbar intumescences (neuronal count P = .0025 and P = .0001; area P = .0004 and P = .0009, respectively) while overall neuronal density was lower (P = .003 and P = .028, respectively). We presume the increased SUVmax values at the spinal cord intumescences are the result of overall increased neuron count, increased proportion of gray matter, and increased spinal cord gray matter area. These findings will aid in the interpretation of future PET-CT studies and hopefully prevent the misdiagnosis of spinal cord disease in normal canines.

Ten children aged 1 week to 13 years with 12 vascular abnormalities were examined with magnetic resonance imaging (MRI) and other imaging modalities. MRI was the only single non-invasive modality that demonstrated all lesions and their internal structures. The vascular nature of 3 hemangiomas could not be established with MRI alone. No marked differences in MRI appearance was seen in 5 cases with vascular tumors compared with 5 cases with other vascular abnormalities. The status of the blood in the vascular lesions as flowing fast, slow, or not at all was successfully assessed in 9 of the 12 lesions.

We measured the relationship between pulmonary arterial pressure (Ppa), diameter (D), and length of a segment of the main pulmonary artery (MPA) in chronically instrumented conscious dogs breathing spontaneously (CCC). There were no physiologically significant changes in Ppa or D in the CCC dogs postoperatively, and the cross-sectional MPA shape measured by fast computed tomography was nearly circular. These results suggest that the MPA was not distorted by chronic instrumentation. We compared measurements made in the CCC dogs with previous measurements in acutely instrumented anesthetized dogs with open chests (AAO). The elasticity of MPA in the CCC animals was frequency dependent between 1 and 14 Hz and was similar to that in the AAO dogs. Oscillations of D preceded Ppa at cardiac frequencies in the AAO animals, but the D and Ppa oscillations were in phase in the CCC animals. The oscillations of length relative to D were significantly less in the CCC than in the AAO dogs. We conclude that, with limitations, the hemodynamic properties of the MPA can be measured in the CCC subjects. We suggest that the discrepancies between the AAO and CCC dogs can be attributed to differences in extrinsic loading of the MPA.