Search Results
You are looking at 1 - 2 of 2 items for :
- Author or Editor: Milan Milovancev x
- Diagnostic Imaging x
- Refine by Access: All Content x
Abstract
OBJECTIVE To assess dimensions and attenuation of sternal lymph nodes (SLNs) observed by means of CT in healthy dogs.
ANIMALS 12 healthy adult research dogs.
PROCEDURES Precontrast and postcontrast enhanced CT of the thorax was performed on each dog. Objective and subjective contrast-enhanced CT measurements were obtained.
RESULTS By use of CT, 2 SLNs were identified in 10 of the 12 dogs and 1 SLN was identified in 2. Median SLN length, height, and width were 8.5 mm (range, 4 to 22 mm), 6.0 mm (range, 3 to 10 mm), and 5.0 mm (range, 3 to 10 mm), respectively. Median SLN length-to-T4 ratio, height-to-T4 ratio, and width-to-T4 ratio were 0.64 (range, 0.24 to 1.22), 0.37 (range, 0.25 to 0.53), and 0.29 (range, 0.19 to 0.67), respectively. Median SLN volume was 123 mm3 (range, 38 to 484 mm3). Median height-to-length ratio, width-to-length ratio, and height-to-width ratio were 0.57 (range, 0.27 to 1.75), 0.51 (range, 0.31 to 1.25), and 1.27 (range, 0.50 to 2.50), respectively. All SLNs had homogenous contrast enhancement with median precontrast and postcontrast attenuation values of 18.3 Hounsfield units (HU; range, 4.4 to 36.9 HU) and 41.3 HU (range, 24.0 to 77.4 HU), respectively. All SLNs had a visible hilus, which was fat attenuating in 8 dogs and hypoattenuating in 4 dogs.
CONCLUSIONS AND CLINICAL RELEVANCE CT imaging characteristics described in this study may provide a reference for dimensions and appearance of SLNs of healthy dogs and serve as a basis for comparison with results for diseased dogs.
Abstract
Objective—To construct and optimize a fiducial marker suitable for both CT and MRI.
Sample—Fiducial markers containing serial dilutions of iopamidol mixed with water.
Procedures—IV tubing sets were infused with serial dilutions (0% to 100%; increments of 10%) of iopamidol. Tubing ends were sealed; additional seals were added to create an equilateral triangle. A reference point was created by placing a crimp in 1 side. Markers were fixed to a gelatin soft tissue–attenuating phantom and evaluated by use of CT and MRI. For CT, simple linear regression analysis was used to assess the relationship between the percentage of marker contrast medium and quantitative variables, including marker attenuation, attenuation changes in the phantom, and beam-hardening artifact length. A subjective grading scheme for artifact creation on CT images and marker visibility on MRI images was used. Measurements were obtained by investigators who were unaware of the contents of each marker.
Results—Percentage of contrast medium in each marker was strongly correlated with marker attenuation (r 2 = 0.96), artifact length (r 2 = 0.765), and mean attenuation changes within the phantom (r 2 = 0.826) for CT. Subjective CT scores indicated that concentrations of contrast medium > 50% resulted in excessive artifacts. Markers with concentrations of iopamidol > 50% had poor subjective MRI visibility scores. No artifacts were seen on MRI.
Conclusions and Clinical Relevance—A marker containing a 10% solution of iodinated contrast medium mixed with water provided ideal contrast for both CT and MRI.
