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Öğe Dynamic contrast enhanced MRI in the differential diagnosis of soft tissue tumors(Elsevier Sci Ireland Ltd, 2005) Tuncbilek, N; Karakas, HM; Okten, OOPurpose: The value of the dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) in differentiating benign and malignant soft tissue tumors was investigated. Materials and methods: Turbo FLASH DCE-MRI was performed on 22 subjects (2-74 years) with soft tissue tumors. Enhancement in the first min (E-max/1), second min (E-max/2) and maximum peak enhancement (E-max), and steepest slope were calculated. Discriminant analyses were performed to reveal parametric differences of benign and malignant lesions. Results: Diagnosis of benign (N = 10) tumors were hemangioma (n = 3), neurogenic tumor (n 3) lipoma (n = 2), giant cell tumor (n = 1) and desmoid (n = 1), whereas malignant lesions (N = 12) were classified as liposarcoma (n 5), malignant fibrous histiocytoma (n = 5) and synovial sarcoma (n = 2). For malignant lesions E-max/1 was 65-198%, E-max/2 was 65-145%, E-max was 78-198%, and steepest slope was 1.45-4.06. For benign lesions these values were 4-98%, 5-105%, 7-125% and 0.67-2.57, respectively. To determine the relation between the variables analysed, Pearson correlation coefficients were calculated. E-max was found to be highly correlated with other variables (rxy > 0.86, P < 0.0001). Consequently, this variable was excluded from the discriminant analysis. In order to determine discrimination of malignant and benign tumors using E-max/1, E-max/2, and steepest slope of the enhancement curve logistic regression was applied to the above mentioned data. When combined these parameters had a 95.5% of overall accuracy in classifying benign and malignant lesions (P = 0.004). Conclusion: DCE-MRI parameters that thought to be the surrogate markers of tumoral microcirculation and tissue perfusion provides a specific preoperative diagnosis. Dynamic imaging parameters are therefore advocated for monitoring the effect of chemotherapy in soft tissue tumors. (c) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Dynamic magnetic resonance imaging in determining histopathological prognostic factors of invasive breast cancers(Elsevier Ireland Ltd, 2005) Tuncbilek, N; Karakas, HM; Okten, OOObjective: To evaluate the relation between morphological features and enhancement parameters in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging with histopathological prognostic factors. Materials and methods: Fifty-five patients with surgicopathological diagnosis of breast carcinoma were evaluated with 1.0 T MR scanner as a part of their preoperative diagnostic work-up. Dynamic studies were performed in axial plane using 3D fast low angle shot (FLASH) sequence. Time intensity curves (TICs) were obtained from the regions showing maximal enhancement in subtraction images. The correlations between enhancement parameters and histopathological findings were analyzed using stepwise multiple regression analysis, Student's t-test, chi(2)-tests and Pearson's moment correlation coefficient. Results: Significant correlations were found between the presence of lymph node metastasis and tumor size (P < 0.05) and edge characteristics (P < 0.05). A highly significant correlation was found between histopathological grades and qualitative enhancement patterns (r = 0.403, P < 0.01). Statistically significant differences were found between the groups with and without lymph node metastasis regarding enhancement in the first minute (P < 0.01) and TIC slope (P < 0.05). A significant difference was found between the histopathological grades I and III regarding all quantitative enhancement parameters, whereas no difference was found between the grades I-II, and II-III. Conclusion: DCE-MR imaging helps to predict prognostic factors of breast cancer by revealing morphological features and enhancement parameters of the primary tumor. Additional morphological factors further improve our ability to predict lymphatic metastasis. (C) 2003 Elsevier Ireland Ltd. All rights reserved.Öğe Dynamic MRI in indirect estimation of microvessel density, histologic grade, and prognosis in colorectal adenocarcinomas(Springer-Verlag, 2004) Tuncbilek, N; Karakas, HM; Altaner, SThe relations of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters to microvessel density (MVD), histologic grade, and presence of metastasis were evaluated to establish new prognostic indicators in colorectal cancer (CRC). Fast-low angle shot DCE-MRI parameters (time-intensity curves, TICs; maximal relative enhancement within the first minute, E-max/1; maximal relative enhancement of the entire study, E-max; steepest slope of the contrast enhancement curve; and time to peak enhancement) of 21 CRCs (seven Duke stage B, 12 Duke stage C, and two Duke stage D) were retrospectively evaluated and correlated with corresponding postoperative MVD measurements, histologic grades, and presence of metastasis at 2 years. TICs were classified as type A in nine (43%), type B in seven (33%), and type C in five cases (24%). There was a significant difference between TIC types with regard to MVD (p < 0.05-0.001). Time to peak enhancement, steepest slope of TIC, and E-max/1 were strongly correlated with MVD (r = -0.765, p < 0.01; r = 0.681, p < 0.01; r = 0.634, p < 0.01; respectively). MVD, steepest slope of the enhancement curve, E-max/1, and E-max strongly correlated with histologic grade (r = 0.475, p < 0.05; r = 0.683, p < 0.01; r = 0.687, p < 0.01; r = 0.791, p < 0.01; respectively). There was a significant difference between groups of patients with and without metastasis with regard to histologic grade (p < 0.05) and two of the DCE-MRI parameters (p < 0.005 for E-max/1 and p < 0.05 for time to peak enhancement). Discriminant analysis correctly predicted the metastatic occurrence at 2 years in 90.5% of cases using E-max/1 (p < 0.001). Histologic grade resulted in lower rates of discrimination (66.7%; p < 0.05). DCE-MRI parameters may help in the prediction of MVD and histologic grade in CRC and may be used to predict therapeutic outcome.Öğe Imaging of granulomatous mastitis: assessment of three cases(Churchill Livingstone, 2004) Tuncbilek, N; Karakas, HM; Okten, OOGranulomatous mastitis is a benign, inflammatory breast disease of unknown aetiology, which can mimic breast carcinoma in its clinical manifestations. Imaging features of three cases of granulomatous mastitis mimicking breast carcinoma on both clinical and radiographic examination are presented, with special emphasis on the role of dynamic contrast-enhanced-magnetic resonance mammography in the differential diagnosis. (C) 2004 Elsevier Ltd. All rights reserved.Öğe MRI in multiple myeloma with orbital and dural invasion(Sage Publications Ltd, 2005) Tuncbilek, N; Karakas, HM; Okten, OO; Vural, OThe case of a 42-year-old woman with aleukemic Bence Jones-type multiple myeloma who developed ocular abnormalities is described. Extramedullary plasmocytomas, either as solitary lesions or as manifestations of multiple myeloma, rarely involve the orbit and dural structures. Early detection of such lesions indicates an aggressive clinical course. In this paper we describe the magnetic resonance imaging findings of ocular and dural myelomatous involvement.
