CT Perfusion Volume Assessment Of Solitary Osteolytic Bone Lesions In Spine

Objective:Thirty cases of solitary osteolytic bone lesions in spinewith CT perfusion examination, to assess different of BF andBV in the rim and center of the different lesions, thecharacteristic of time density curve (TDC), and the diagnosticvalue of rim-to-center differential blood flow ratio (R_rim-cenBF)and rim-to-center differential blood volume ratio (R_rim-cenBV) indifferential diagnoses of benign from malignant osteolyticlesions of spine.Materials and Methods:During May 2005 to January 2007, 30 patients withsolitary osteolytic bone lesions of spine were examined withCT perfusion imaging at Tianjin Hospital. The lesions involvelumbar spine in 18 cases, thoracic spine in 8 cases, cervical spine in 3 cases and sacrum spine in 1 case. Of the 30 cases20 were examined with X-ray and 10 patients were examined withMR. All the patients were examined with CT plain scan beforeperfusion.CT examination: A SIEMENS multi-slice spiral CT scanner(SOMATOM Sensation) was used in the present study. The scanseries including: plain scan, enhanced scan and perfusion. Thescan parameters of the plain and enhanced scan were as follows:120kv, 200mA, and 3mms lice thickness. And the scan parametersof perfusion scan were as follows: cine acquisition, 80kv,160mh, 512 matrix, 30～35FOV and 5mm slice thickness. Nonioniccontrast agent(Ultravist 300) was injected through the forearm(elbow) vein by an injection pump with 60～70 ml dosage at therate of 3.5ml/sec. AT 5～8sec after the injection starts, theCT perfusion will start. The times of scan were 100sec. Then200 images were acquired.Data were transferred to a workstation. PERFUSION CTsoftware allowed calculation of a variety of perfusion maps.Perfusivon parameters such as BF and BV were obtained on theperiphery and the center of the lesion and calculated R_rim-cenBF and R_rim-cenBV. TDC was calculated with DYNEVA software.Results:The 24 cases were pathologically confirmed by puncture/operation, and 6 cases were confirmed by the other imaginginformation. And they were clinical diagnosed. Twenty casesshowed malignant: metastasis in 16 cases, myeloma 3, andchordoma 1. While 6 cases were benign: giant cell tumor 3,aneurysmal bone cyst 2, neurolemoma 1, and 4 cases with TB ofspine.Twenty-two cases, including 16 of metastasis, 3 ofmyeloma, and 1 chordoma showed high perfusion. The 3 giant celltumor and 2 aneurysmal bone cyst showed moderate or highperfusion. Low perfusion was showed in 1 case of neurolemomaand 4 of TB.BF and BV in the rim were higher than in the center ofmalignant bone tumors and differentiated significantly (P＜0.01). There was no significantly differences between thebenign bone tumors and TB (P＞0.05). BF and BY of benign andmalignant bone tumors were higher than that of TB. R_rim-cenBF andR_rim-cenBV of malignant bone tumors were significantly higher than benign ones and TB. R_rim-cenBF and R_rim-cenBV were no significantlydifferences between the benign bone tumors and TB.TDC curve of malignant tumors rose quickly at thebeginning and kept stabilization when it arrived at peak value.TDC curve of benign tumors rose slowly during the whole period.While in the TB cases, the TDC curve showed a little extent withbetter stabilization and it was only higher than muscle tissue.Conclusions:1. The pattern of vascularity in benign and malignant tumorsof spine is fundamentally different. The BF and BV at therim are significant higher than that in the center ofmalignant bone tumors, while there is no significantlychange in the benign bone tumors and TB. The BF and BV ofboth benign and malignant bone tumors are higher than in TB.2. TDC curve in malignant tumors rise quickly at the beginningand keep stable when it arrives at the peak value. TDC curveof benign tumors rise slowly during the whole period. Whilein the TB cases, the TDC curve showed a little extant withbetter stabilization and it is only higher than muscletissue. 3. The perfusion intensity have been overlap each other in alarge area between the benign and malignant tumors in thisstudy so the high or low intensity could not be used asdifferentiate diagnostic factor. Because the high or low ofthe perfusion intensity only was considered as the vascularextent of osteolytic tumors in spine.4. The R_rim-cenBF and R_rim-cenBV show the different vascularcharacteristic of benign, malignant tumors and TB. They canbe used to differentiate solitary malignant osteolyticlesion from benign ones to malignant in spine.5. All the values of CT perfusion imaging have theirsignificant in differential in benign and malignant tumorsin solitary osteolytic lesion of spine in the clinic.