The Quantitative Evaluation of Bosniak Category 3 and 4 Cysts on Multiphasic Computed Tomography

Abstract

Objectives: The aim of this study is to evaluate the diagnostic value of mean and net enhancement attenuation values, net enhancement percentage in discrimination of Bosniak category 3 and 4 lesions on multiphasic computed tomography (CT). Materials and Methods: A search was performed through the PACS system using the key word “Bosniak cyst” to identify candidates for the study population. Twenty nine patients with Bosniak category 3 and 4 were enrolled in the study. Enhancement values were measured on precontrast, corticomedullary and nephrogram phases. Net enhancement attenuation value and net enhancement percentage were calculated. The presence of calcification on cyst wall/septa, renal vein thrombosis or lymphadenopathy and mean diameter of these complex cystic lesions were utilized. Results: Bosniak category 4 cysts had a significantly higher mean attenuation value compared with that of Bosniak category 3 cysts on corticomedullary and nephrogram phases (167.2±53.6 HU, 99.8±43 HU; p=0.001, p=0.023; respectively). Significant differences were observed between two pathologies with regard to net enhancement value and net enhancement percentage (p=0.003, p=0.015; respectively). By the use of ROC curve analysis, the cut off value of 131 HU for the mean attenuation value of Bosniak category 4 cyst on corticomedullary phase had the appropriate combination of sensitivity of 82% and specificity of 83% with the area under the cure being 0.848±0.081 (95% CI: 0.68-1). Conclusion: Bosniak category 4 cysts had larger net enhancement value and enhancement percentage. A value of >131 HU on corticomedullary phase can be a predictor value for Bosniak category 4 cysts.

Keywords

• Bosniak Category 3 Cyst
• Bosniak Category 4 Cyst
• Multiphasic Computed Tomography
• Enhancement Value

Bosniak Tip 3 ve Tip 4 Kistlerin Multifazik Bilgisayarlı Tomografi ile Kantitatif Değerlendirilmesi

Abstract

Amaç: Bu çalışmada multifazik bilgisayarlı tomografide (BT) ortalama dansite-net kontrastlanma değerlerinin ve net kontrastlanma yüzdelerinin Bosniak tip 3 ve 4 kistlerin ayırımındaki tanısal değerinin değerlendirilmesi amaçlanmıştır. Gereç ve Yöntem: Hastanemizin Görüntü Arşivleme ve İletişim Sisteminde (PACS) “Bosniak kist” anahtar kelimesi kullanılarak hasta popülasyonunu belirlemek için arama yapıldı. Çalışmaya multifazik BT incelemesi bulunan Bosniak tip 3 ve 4 renal kiste sahip yirmi dokuz hasta dahil edildi. Kontrastsız, kortikomedüller ve nefrogram fazlarında ortalama dansite değerleri ölçüldü. Bu lezyonların net kontrastlanma değerleri ve net kontrastlanma yüzdeleri hesaplandı. Kist duvarı/septada kalsifikasyon varlığı, renal ven trombozu veya lenfadenopati varlığı ve bu kompleks kistik lezyonların ortalama çapı değerlendirildi. Bulgular: Bosniak tip 4 kistler, kortikomedüller ve nefrogram fazlarında Bosniak tip 3 kistlere göre anlamlı derecede daha yüksek ortalama kontrastlanma değerine sahipti (sırasıyla; 167,2±53,6 HU, 99,8±43 HU; p=0,001, p=0,023). Bosniak tip 3-4 lezyonları ayırmada net kontrastlanma değerleri ve yüzdesi açısından anlamlı farklılık saptandı (sırasıyla; p=0,003, p=0,015). ROC eğri analizinde Bosniak tip 4 kistlerin ayrımında kortikomedüller fazda >131 HU kontrastlanma değeri için %82 duyarlılık %83 özgüllük oranları hesaplandı. Bu eşik değer için eğri altında kalan alan 0,848±0,081 (%95 güven aralığı: 0,68-1) olarak bulundu. Sonuç: Bosniak tip 4 kistler, tip 3 kistlere göre daha fazla net kontrastlanma değeri ve net kontrastlanma yüzdesine sahiptirler. Kortikomedüller fazda >131 HU değeri, Bosniak tip 4 kistlerinin tanımlanmasında belirleyici değer olacaktır.

Keywords

• Bosniak Tip 3 Kist
• Bosniak Tip 4 Kist
• Multifazik Bilgisayarlı Tomografi
• Kontrastlanma Değeri

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