. Author manuscript; available in PMC: 2017 Jan 1.

Published in final edited form as: J Nucl Med. 2015 Oct 15;57(1):70–77. doi: 10.2967/jnumed.115.161646

TABLE 2.

Description of various diagnostic criteria used for data analysis

PARAMETER	Pre-contrast T2, DWI, T1	Post-contrast T1 + gadolinium chelate	¹⁸FDG PET
MORPHOLOGY
Solid	Restricted diffusion	Tumor enhancement	Increased visual avidity for¹⁸FDG^*
Cystic	Hyperintense on T2 and DWI (T2-shine through)	No contrast enhancement	No central ¹⁸FDG avidity; exception: single paraspinal
Homogenous	Uniform T2 and DWI signal	Uniform contrast enhancement	N/A
Heterogeneous	Varying T2 and DWI signal	Varying contrast enhancement	N/A
Presence of necrosis(y/n), areas of decreased/absent contrast enhancement within lesion	Heterogenous/hyperintense on T2 and DWI (T2-shine through)	Decreased or absent areas of contrast enhancement	No ¹⁸FDG avidity and fluid noted present on CT or MRI
Tumor margins	Well-defined = distinct; Ill-defined = indistinct tumor boundary		N/A since all margins on PETare ill defined

TUMOR EXTENT
Infiltration of adjacent organs (y/n)	Tumor/areas of visualized ¹⁸FDG avidity extends beyond organ of origin and infiltrates adjacent structures
Extension across midline(y/n)	Tumor/¹⁸FDG avidity extends beyond contralateral margin of the contralateral vertebral body
Encasement of vessels (y/n)	Tumor/¹⁸FDG avidity surrounding vessel more than 270°. For ¹⁸FDG PET, MRI or CT was used for anatomic correlation
Tumor thrombosis (y/n)	Enlarged vein with altered signal on T2 and DWI	Enlarged vein with focal area of intraluminal enhancement	Focal linear ¹⁸FDG uptake within a vein that was either enlarged or in contiguity solid tumoral tissue

METASTASES
Solid organ (liver, spleen, kidney and pancreas) (y/n)	Hyperintense on T2 and DWI	Lesions with Gd-enhancement and washout on delayed scans	Obvious ¹⁸FDG avidity beyond background visually within the organ^*
Bone (y/n)	Hyperintense on T2 and DWI	Tumor enhancement	Visual ¹⁸FDG avidity either diffusely or focally within lesion^*
Lymph node (y/n)	Short axis >1cm with loss of normal kidney bean shape		Visual ¹⁸FDG avidity within the lymph node despite size^*

FINAL DIAGNOSIS	Most appropriate diagnosis based on imaging features

If equivocal, than an ROI was placed within the lesion of concern, mean SUVmax taken and compared to mediastinal blood pool or hepatic background. If the mean SUVmax was greater than 2.5, this was considered concerning for tumoral involvement or metastatic disease.