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

Abstract

Amaç: Fokal böbrek lezyonlarının benign, malign ayırımında

görünüşteki difüzyon katsayısı (apparent diffusion coefficient

- ADC) ve fraksiyonel anizotropi (Fa) ölçümlerinin diagnostik

performanslarının belirlenmesi.

Gereç ve Yöntem: Çalışmamıza, bilgisayarlı tomografi (BT)

ve ultrason (US) gibi değişik görüntüleme modaliteleri ile tanı

konulan ve manyetik rezonans diffüzyon tensör görüntülemesi

(DTI) yapılmış 21 hastada (9 kadın and 12 erkek ; ortalama yaş

54,1 ), 25 fokal renal lezyon dahil edildi. Lezyonlar 6 solid renal

hücreli karsinom (RCC), 1 kistik RCC, 1 anjiomyolipom (AML)

ve 17 kistik lezyondan ( 16 Bosniak tip I kist, 1 Bosniak tip II

kist) oluşmaktaydı. ADC ve Fa ölçümleri iki radyolog tarafından,

konsensusa varılarak yapıldı. Malign ve benign lezyonlara ait

ADC ve Fa değerleri ANOVA ve Tukey testleri kullanılarak

karşılaştırıldı. ROC analizi kullanıldı; sensitivite ve spesifite

hesaplandı.

Bulgular: Malign lezyonların ortalama ADC ve Fa değerleri

sırasıyla 1.29±0.4 mm2/sn ve 0.34±0.1 ölçüldü. Benign lezyonların

ortalama ADC ve Fa değerleri sırasıyla 2.6±0.7 mm2/sn ve

0.19±0.12 ölçüldü. Aralarındaki fark istatistiksel olarak anlamlı idi

(P<0.05). Malign lezyonları, benign lezyonlardan ayırmada ADC

ve Fa ölçümlerinin, Az değerleri sırasıyla 0.95 ve 0.83 bulundu.

ADC ve Fa ölçümlerinin sensitivite ve spesifite değerleri sırasıyla

100%-83.3% ve 100%-77.8% bulundu.

Sonuç: Malign ve benign fokal renal lezyonların ADC ve Fa

ölçümleri değerleri arasında istatistiksel anlamlı farklar mevcuttur.

Malign renal lezyonlarda düşük ADC ve yüksek Fa değerleri

izlenirken, benign renal lezyonlarda yüksek ADC ve düşük Fa

değerleri izlenir.

Keywords

• Manyetik rezonans,Difüzyon tensör,Renal lezyon

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

Abstract

Objectives: To determine the diagnostic performance of apparent

diffusion coefficient (ADC) and fractional anisotropy (Fa)

measurements in differentiation of malignant from benign focal

renal lesions.

Material and Methods: Twenty-one patients (9 women and 12

men ; mean age 54,1 years) with 25 focal renal lesions diagnosed

by different imaging modalities such as computed tomography

(CT) and ultrasound (US) and examined with magnetic resonance

diffusion tensor imaging (DTI) were included in the study. There

were 6 solid renal cell carcinomas (RCC), 1 cystic RCC, 1

angiomyolipoma (AML) and 17 cystic lesions ( 16 Bosniak type

I cysts, 1 Bosniak type II cyst). ADC and Fa measurements were

performed by two radiologists, in consensus. The differences in

ADC and Fa values of malignant and benign renal lesions were

compared using ANOVA and Tukey tests. A ROC analysis was

applied; sensitivities and specificities were calculated.

Results: The mean ADC and Fa values of malignant lesions

were 1.29±0.4 mm2/sec and 0.34±0.1, respectively. The mean

ADC and Fa values of benign lesions were 2.6±0.7 mm2/sec

and 0.19±0.12, respectively. The differences were significant

(P<0.05). The Az values for discriminating malignant lesions from

benign ones for ADC and Fa value were 0.95 and 0.83, respectively. The sensitivity-specificity of ADC and Fa were 100%-83.3%, and

100%-77.8%, respectively.

Conclusion: There are statistically 2l significant differences

between ADC and Fa values of malignant and benign focal renal

lesions. Malignant renal lesions have low ADCs and high Fa

values, whereas benign renal lesions have high ADCs and low Fa

values.

Keywords

• Magnetic resonance,Diffusion tensor,Renal lesion

References

1. 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
2. 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
3. Sugita R, Ito K, Fujita N, Takahashi S. Diffusion-weighted MRI in abdominal oncology: Clinical applications. World J Gastroenterol 2010;16:832-6.
4. 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
5. Le Bihan D, Mangin JF, Poupon C, et al.Diffusion tensor imaging: concepts and applications. J Magn Reson Imaging 2001;13:534–46.
6. 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
7. 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
8. 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

9. 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
10. 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
11. 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
12. 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
13. 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