- Washout Characteristics
-Adenomas washout more rapidly than metastases
-Pheochromocytoma can exhibit high washout levels when hypervascular - Relative Percentage Washout
100 x (Venous HU – Delayed HU)
Venous HU
> 40% ~ adenoma - Absolute Percentage Washout
100 x (Venous HU – Delayed HU)
Venous HU-Precontrast HU
> 60% ~ adenoma - ASIR: Potential Limitations
- Takes longer than standard algorithms to reconstruct CT data by a factor of up to 30%
- Image smoothing may lead to lack of lesion recognition. It is not clear whether this means missed lesions. "The ASIR reconstruction algorithm is a promising technique for providing diagnostic quality CT images at significantly reduced radiation doses."
Innovations in CT Dose Reduction Strategy: Application of the Adaptive Statistical Iterative Reconstruction Algorithm
Silva AC et al.
AJR 2010;194: 191-199
"Currently, increased noise limits the evaluation of thin reconstructed images (<2.5 mm) in abdominal imaging."
Iterative Reconstruction Technique for Reducing Body Radiation Dose at CT: Feasibility Study
Hara AK et al.
AJR 2009; 193:764-771
"Low dose CT with adaptive statistical iterative reconstruction and routine dose CT had identical results for low contrast resolution and nearly identical results for overall image quality. Spatial resolution was better with routine dose CT."
Iterative Reconstruction Technique for Reducing Body Radiation Dose at CT: Feasibility Study
Hara AK et al.
AJR 2009; 193:764-771
"These preliminary results support body CT dose index reductions of 32-65% when adaptive statistical iterative reconstruction is used. Studies with larger statistical samples are needed to confirm these findings."
Iterative Reconstruction Technique for Reducing Body Radiation Dose at CT: Feasibility Study
Hara AK et al.
AJR 2009; 193:764-771
- Three dimensional volume rendered CT successfully displayed the relationship of adrenal masses to adjacent structures and organs before laparoscopic adrenalectomy. Three Dimensional Volume Rendered Helical CT before Laparoscopic Adrenalectomy Hurley ME et al. Radiology 2003; 229:581-586
