ABSTRACT
BACKGROUND: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. METHODS: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. RESULTS: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). CONCLUSION: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas.
ABSTRACT
A technique for Thallium-201 imaging after two separate injections of the tracer, which took less than I hour, was performed to evaluate if this technique could be used clinically as a noninvasive screening test of angina pectoris. 29 patients who complained of chest pain were included in this study: 18 patients were proven to have coronary artery disease by coronary angiography and 11 patients had normal coronary arteries. With the patient supine at rest, 1.0 mCi of Thallium was injected intravenously and imaging was performed in the anterior and 50degrees left anterior oblique projections for a preset time according to Okada's protocol. Immediately after acquisition of the rest images, without moving the camera head, an infusion of dipyridamole was done at the rate of 0.14 mg/Kg/min for 4 minutes. Two minutes after stopping the infusion, 1.0 mCi of Thallium was injected intravenously and 50degrees left anterior oblique and anterior projection images were acquired. Images of the same projection were realigned using computer image registration approach (PDP-11/34 computer of DEC company). The rest image was then subtracted from the realigned dipyridamole image to produce an image representing perfusion during dipyridamole induced hyperemia (subtraction image). The results were as follows; 1) All of the subtraction images were of adequate quality for interpretation. 2) 16 cases in 18 patients of angina pectoris and 1 case in 11 normal control showed perfusion defects, so the over all sensitivity and specificity of the subtraction versus rest Thallium image technique for diagnosis of angina pectoris were 89% and 91%, respectively. 3) All patients (8 cases) whose left ventriculography revealed abnormality of regional wall motion showed perfusion defects in corresponding segments. But qualitative analysis of Thallium image could not predict if the patient whose Thallium image revealed perfusion defect has abnormality of regional wall motion. 4) segmental analysis was performed to know the association between the site of coronary artery stenosis and the perfusion defects in Thallium scan, which revealed the sensitivities for detecting stenosis of LCX, LAD & RCA were 50-60% in range and the range of specificities were 89-92%. 5) Adverse effects of dipyridamole were headache (2 cases) and chest pain (4 cases) but aminophylline was not needed in any case. In conclusion, split dose Thallium dipyridamole scan can be used as a noninvasive screening test of angina pectoris reducing the total duration of imaging to less than one hour. Futher applications of this technique may include the assessment of myocardial perfusion before and immediately after coronary angioplasty and coronary artery bypass graft and the evaluation of the impact of pharmacotheraphy on regional myocardial perfusion.
