Alper ÖZEL, Muzaffer BAŞAK, Özge Yapıcı UĞURLAR, Guzide OZDİL, Önder KIRDAR, ŞÜKRÜ MEHMET ERTÜRK, Fikriye YILMAZ UZUNOGLU, Abdullah SOYDAN MAHMUTOGLU

Fokal renal lezyonlarının benign ve malign ayırımında manyetik rezonans difüzyon tensör görüntülemenin rolü

Amaç: Fokal böbrek lezyonlarının benign, malign ayırımındagörünüşteki difüzyon katsayısı (apparent diffusion coefficient- ADC) ve fraksiyonel anizotropi (Fa) ölçümlerinin diagnostikperformanslarının belirlenmesi.Gereç ve Yöntem: Çalışmamıza, bilgisayarlı tomografi (BT)ve ultrason (US) gibi değişik görüntüleme modaliteleri ile tanıkonulan ve manyetik rezonans diffüzyon tensör görüntülemesi(DTI) yapılmış 21 hastada (9 kadın and 12 erkek ; ortalama yaş54,1 ), 25 fokal renal lezyon dahil edildi. Lezyonlar 6 solid renalhücreli karsinom (RCC), 1 kistik RCC, 1 anjiomyolipom (AML)ve 17 kistik lezyondan ( 16 Bosniak tip I kist, 1 Bosniak tip IIkist) oluşmaktaydı. ADC ve Fa ölçümleri iki radyolog tarafından,konsensusa varılarak yapıldı. Malign ve benign lezyonlara aitADC ve Fa değerleri ANOVA ve Tukey testleri kullanılarakkarşılaştırıldı. ROC analizi kullanıldı; sensitivite ve spesifitehesaplandı.Bulgular: Malign lezyonların ortalama ADC ve Fa değerlerisırasıyla 1.29±0.4 mm2/sn ve 0.34±0.1 ölçüldü. Benign lezyonlarınortalama ADC ve Fa değerleri sırasıyla 2.6±0.7 mm2/sn ve0.19±0.12 ölçüldü. Aralarındaki fark istatistiksel olarak anlamlı idi(P<0.05). Malign lezyonları, benign lezyonlardan ayırmada ADCve Fa ölçümlerinin, Az değerleri sırasıyla 0.95 ve 0.83 bulundu.ADC ve Fa ölçümlerinin sensitivite ve spesifite değerleri sırasıyla100%-83.3% ve 100%-77.8% bulundu.Sonuç: Malign ve benign fokal renal lezyonların ADC ve Faölçümleri değerleri arasında istatistiksel anlamlı farklar mevcuttur.Malign renal lezyonlarda düşük ADC ve yüksek Fa değerleriizlenirken, benign renal lezyonlarda yüksek ADC ve düşük Fadeğerleri izlenir.

Anahtar Kelimeler:

Manyetik rezonans, Difüzyon tensör, Renal lezyon

The role of magnetic resonance diffusion tensor imaging in differentiation of benign from malignant focal renal lesions

Objectives: To determine the diagnostic performance of apparentdiffusion coefficient (ADC) and fractional anisotropy (Fa)measurements in differentiation of malignant from benign focalrenal lesions.Material and Methods: Twenty-one patients (9 women and 12men ; mean age 54,1 years) with 25 focal renal lesions diagnosedby different imaging modalities such as computed tomography(CT) and ultrasound (US) and examined with magnetic resonancediffusion tensor imaging (DTI) were included in the study. Therewere 6 solid renal cell carcinomas (RCC), 1 cystic RCC, 1angiomyolipoma (AML) and 17 cystic lesions ( 16 Bosniak typeI cysts, 1 Bosniak type II cyst). ADC and Fa measurements wereperformed by two radiologists, in consensus. The differences inADC and Fa values of malignant and benign renal lesions werecompared using ANOVA and Tukey tests. A ROC analysis wasapplied; sensitivities and specificities were calculated.Results: The mean ADC and Fa values of malignant lesionswere 1.29±0.4 mm2/sec and 0.34±0.1, respectively. The meanADC and Fa values of benign lesions were 2.6±0.7 mm2/secand 0.19±0.12, respectively. The differences were significant(P<0.05). The Az values for discriminating malignant lesions frombenign ones for ADC and Fa value were 0.95 and 0.83, respectively. The sensitivity-specificity of ADC and Fa were 100%-83.3%, and100%-77.8%, respectively.Conclusion: There are statistically 2l significant differencesbetween ADC and Fa values of malignant and benign focal renallesions. Malignant renal lesions have low ADCs and high Favalues, whereas benign renal lesions have high ADCs and low Favalues.

Keywords:

Magnetic resonance, Diffusion tensor, Renal lesion,

PDF

___

Le Bihan D, Breton E, Lallemand D, Aubin ML, Vignaud J, Laval-Jeantet M. Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging. Radiology 1988;168:497-505. doi: 10.1148/radiology.168.2.3393671
Bonekamp S, Torbenson MS, Kamel IR. Diffusion-weighted magnetic resonance imaging for the staging of liver fibrosis. J Clin Gastroenterol 2011;45:885-92. doi: 10.1097/ MCG.0b013e318223bd2c
Sugita R, Ito K, Fujita N, Takahashi S. Diffusion-weighted MRI in abdominal oncology: Clinical applications. World J Gastroenterol 2010;16:832-6.
Gurses B, Kabakci N, Kovanlikaya A, et al. Diffusion tensor imaging of the normal prostate at 3 Tesla. Eur Radiol 2008; 18:716–21. doi:10.1007/s00330-007-0795-7
Le Bihan D, Mangin JF, Poupon C, et al.Diffusion tensor imaging: concepts and applications. J Magn Reson Imaging 2001;13:534–46.
Gurses B, Tasdelen N, Yencilek F, et al.Diagnostic utility of DTI in prostate cancer. Eur J Radiol 2011; 79:172–6. doi: 10.1016/j.ejrad.2010.01.009
Kinoshita M, Hashimoto N, Goto T, et al. Fractional anisotropy and tumor cell density of the tumor core show positive correlation in diffusion tensor magnetic resonance imaging of malignant brain tumors. Neuroimage 2008;43:29- 35. doi: 10.1016/j.neuroimage.2008.06.041
Thoeny HC, De Keyzer F, Oyen RH, Peeters RR. Diffusionweighted MR imaging of kidneys in healthy volunteers and patients with parenchymal diseases: initial experience. Radiology. 2005;235:911-7. doi: 10.1148/radiol.2353040554
Cova M, Squillaci E, Stacul F, et al. Diffusion-weighted MRI in the evaluation of renal lesions: preliminary results. Br J Radiol 2004;77:851-7. doi: 10.1259/bjr/26525081
Inci E, Hocaoglu E, Aydin S, Cimilli T. Diffusion-weighted magnetic resonance imaging in evaluation of primary solid and cystic renal masses using the Bosniak classification. Eur J Radiol 2012 ;81:815-20. doi : 10.1016/j.ejrad.2011.02.024
Kim S, Jain M, Harris AB, Lee VS, Babb JS, Sigmund EE, et al. T1 hyperintense renal lesions: characterization with diffusion-weighted MR imaging versus contrast-enhanced MR imaging. Radiology 2009; 251:796-807. doi: 10.1148/ radiol.2513080724
Notohamiprodjo M, Glaser C, Herrmann KA, et al. Diffusion tensor imaging of the kidney with parallel imaging: initial clinical experience. Invest Radiol 2008; 43:677-85. doi: 10.1097/RLI.0b013e31817d14e6
Taouli B, Thakur RK, Mannelli L, et al. Renal lesions: characterization with diffusion-weighted imaging versus contrast-enhanced MR imaging. Radiology. 2009;251:398- 407. doi: 10.1148/radiol.2512080880