Using the differences in energy attenuation of soft tissue at 80 kVp and 140 kVp, this technique can allow reconstruction of virtual noncontrast CT images as well as significantly reduce metal artifact in the assessment of metal implants, improving the diagnostic value of imaging in the surrounding soft tissues [49,50]. It has also shown application in the assessment of marrow edema [51,52] and has been investigated in the distinction of marrow edema from intramedullary tumor invasion [53]. Furthermore, spectral CT is emerging as a useful tool for distinguishing benign from malignant soft tissue masses [54]. CT Area of Interest Without and With IV Contrast Dual-phase CT without and with IV contrast as the next imaging study for the evaluation of a soft tissue mass may be appropriate when MRI is contraindicated. Although single-phase CT with IV contrast is considered most appropriate in this clinical scenario given the advent of virtual noncontrast reconstruction with modern dual-source CT scanners [31], a traditional CT without and with IV contrast can be helpful for characterization of mineralization in an anatomically complex area. CT Area of Interest Without IV Contrast The literature does not support the use of a single-phase CT without IV contrast as the next imaging study for the evaluation of a soft tissue mass when MRI is contraindicated. However, single-phase CT with IV contrast is a useful technique for the evaluation of patients who cannot undergo MRI and is the modality of choice in this scenario [29]. In the evaluation of suspected tumors, contrast imaging is especially useful in distinguishing vascularized from potentially necrotic regions of the tumor. With modern CT technology, calcification can usually be distinguished from vascular enhancement. Therefore, CT without IV contrast is usually not beneficial.
Soft Tissue Masses. Using the differences in energy attenuation of soft tissue at 80 kVp and 140 kVp, this technique can allow reconstruction of virtual noncontrast CT images as well as significantly reduce metal artifact in the assessment of metal implants, improving the diagnostic value of imaging in the surrounding soft tissues [49,50]. It has also shown application in the assessment of marrow edema [51,52] and has been investigated in the distinction of marrow edema from intramedullary tumor invasion [53]. Furthermore, spectral CT is emerging as a useful tool for distinguishing benign from malignant soft tissue masses [54]. CT Area of Interest Without and With IV Contrast Dual-phase CT without and with IV contrast as the next imaging study for the evaluation of a soft tissue mass may be appropriate when MRI is contraindicated. Although single-phase CT with IV contrast is considered most appropriate in this clinical scenario given the advent of virtual noncontrast reconstruction with modern dual-source CT scanners [31], a traditional CT without and with IV contrast can be helpful for characterization of mineralization in an anatomically complex area. CT Area of Interest Without IV Contrast The literature does not support the use of a single-phase CT without IV contrast as the next imaging study for the evaluation of a soft tissue mass when MRI is contraindicated. However, single-phase CT with IV contrast is a useful technique for the evaluation of patients who cannot undergo MRI and is the modality of choice in this scenario [29]. In the evaluation of suspected tumors, contrast imaging is especially useful in distinguishing vascularized from potentially necrotic regions of the tumor. With modern CT technology, calcification can usually be distinguished from vascular enhancement. Therefore, CT without IV contrast is usually not beneficial.