ABSTRACT
Objective To explore the imaging features of solitary fibrous tumor (SFT)in the head and neck.Methods The CT and MR findings of 10 patients with SFT in the head and neck confirmed by hsitopathology were analyzed retrospectively.All patients underwent CT (including contrast-enhanced dual-phase CT),and MR imaging was obtained in 2 patients.Results All 10 lesions were found as solitary masses ranging in maximum diameter from 20 to 1 1 5 mm (average 35.5 mm),with the location in the orbit (2 cases),nasal cavity and nasal sinuses (4 cases),parotid gland (1 case),supraclavicular region (1 case),subcutaneous tissue of the maxillofacial (1 case)and occipital region (1 case).The lesions showed elliptic shape in 7 cases and lobulated configuration in 3 cases.The majority (8/10 )of lesions demonstrated well-defined margin.The lesions on CT imaging were isodensity or low density, homogeneous density in 4 cases and inhomogeneous density in 6 cases,cystic changes in 2 cases,calcification in 1 case.9 lesions showed strongly homogeneous (n=3)or inhomogeneous (n=6)enhancement,1 lesion showed mildly homogeneous enhancement on contrast-enhanced CT imaging.On dual-phase enhanced CT,8 patients exhibited a rapidly enhancing and slow washout pattern,1 patient exhibited a rapidly enhancing and rapid washout pattern,and 1 patient exhibited delayed enhancement.The lesions showed homogeneous isointense relative to gray matter on T1 WI in 1 patient,mixed isointense and hypointense in 1 patient.On T2 WI,the lesion showed isointense signal in 1 patient,and heterogeneous mixed isointense and hyperintense signal in another.2 lesions demonstrated markedly homogeneous and inhomogeneous enhancement respectively.Conclusion Solitary fibrous tumors shall be considered in cases of inhomogeneous hypervascular tumors in the head and neck.Compared with the gray matter,isointense or mildly hyperintense signal on T2 WI, marked enhancement on contrast-enhanced CT,and a rapidly enhancing and slow washout pattern on dual-phase enhanced CT may be valuable imaging features of SFT.
ABSTRACT
<p><b>OBJECTIVE</b>To in vivo dynamically observe the time-effect characteristic of local stimulating effect on acupoints after micro-invasion embedding, which could provide references for the interval period of micro-invasion embedding.</p><p><b>METHODS</b>With magnetic resonance imaging (MRI) technique, the local T2WI fat-suppression images and T2 Mapping 8-echo sequence images were collected at multiple time points from 8 healthy subjects who received embedding at left Sanyinjiao (SP 6).After the 8-echo sequence images were transformed into T2 Mapping images by using software FuncTool, the T2 average value of embedding area was measured, and the changes of local signal strength of T2WI fat-suppression images and T2 average value along with time after embedding at left Sanyinjiao (SP 6)were analyzed.</p><p><b>RESULTS</b>Compared before embedding, the signal strength of local T2WI fat-suppression images and the T2 average value began to increase 8 h after being embedded(<0.01); the signal strength of T2WI fat-suppression images and the T2 average value were significantly increased 3 d and 7 d after being embedded(all<0.01);the signal strength of local T2WI fat-suppression images and the T2 average value 14 d after being embedded were lower than those at previous 2 time points, but higher than those before embedding(both<0.01); 21 d, 28 d and 35 d after embedding, the signal strength of local T2WI fat-suppression images and the T2 average value were similar to those before treatment (all>0.05).</p><p><b>CONCLUSIONS</b>After micro-invasion embedding at Sanyinjiao (SP 6), the stimulation effect period on acupoint is approximately 21 days.When applying micro-invasion embedding under similar condition at acupoints which has similar structure as Sanyinjiao (SP 6), the interval period of embedding could consider 21 days as a reference.</p>