Mehmet OĞUZMAN, Cüneyt ÇALIŞIR, Ulukan İNAN

YUMUŞAK DOKU KİTLELERİNDE DİFÜZYON AĞIRLIKLI GÖRÜNTÜLEME: GÖRÜNÜR DİFÜZYON KATSAYISI ÖLÇÜMÜ MALİGN LEZYONLARI BENİGNLERDEN AYIRABİLİR Mİ ?

AMAÇ: Yumuşak doku tümörlerinin değerlendirilmesinde di-füzyon ağırlıklı görüntüleme (DAG) yöntemi ile elde olunan gö-rünür difüzyon katsayısı (apparent diffusion coefficient, ADC) haritalamasının benign ve malign lezyonların ayrımında etkinli-ğini değerlendirmek ve bu lezyonların ayrımında kullanılabile-cek niceliksel ADC eşik değeri oluşturmak.GEREÇ VE YÖNTEM: Bu retrospektif çalışmaya yumuşak doku kitleleri nedeniyle DAG yapılan ve histopatolojik sonuçları mevcut olan toplam 34 hasta dahil edildi. Patolojik sonuçlarına göre hastalar benign ve malign lezyonlara sahip olarak katego-rize edildi. Ölçümler serbest el ilgi bölgesi tekniği kullanılarak yapıldı. Değerlendirilen parametrelerde herhangi bir fark olup olmadığı araştırıldı (boyut, yaş, cinsiyet, minimum, ortalama ve maksimum ADC değerleri). DAG’de değerlendirilen parametre-ler için kesim değeri Alıcı işlem karakteristikleri (ROC), Receiver Operating Characteristic) analizi ile belirlendi. BULGULAR: Minimum ADC değeri ortalaması benign yumuşak doku kitlelerinde 1,28x10-³mm²/s, malign yumuşak doku kit-lelerinde 1,00x10-³mm²/s ölçüldü. Minimum ADC değerleri iki grup arasında istatistiksel olarak anlamlı farklılık göstermekte-dir (p=0,007). Minimum ADC için ≤1,01x10-³mm²/s eşik değerini kullanarak %78,95 duyarlılık ve %73,33 özgüllük ile yumuşak doku kitlelerini karakterize edilmesini sağladık. Ortalama ve maksimum ADC değerleri iki grup arasında istatistiksel olarak anlamlı farklılığa sahip değildir (sırasıyla p=0,319; 0,960). SONUÇ: DAG yumuşak doku kitlelerin değerlendirilmesinde benign ve malign ayrımında etkili bir yöntemdir ve minimum ADC hesaplamasında ≤1,01x10-³mm²/s eşik değerinin kullanımı klinik yararlılığı artıracaktır.

Anahtar Kelimeler:

Difüzyon ağırlıklı MRG, Manyetik rezo-nans görüntüleme, Yumuşak doku neoplazileri

DIFFUSION WEIGHTED IMAGING OF SOFT TISSUE MASSES: CAN APPARENT DIFFUSION COEFFICIENT MEASUREMENT DIFFERENTIATE BETWEEN MALIGNANT AND BENIGN LESIONS ?

OBJECTIVE: To investigate the efficacy of apparent diffusion coefficient (ADC) mapping obtained using the diffusion-weighted imaging (DWI) method in the differentiation of benign and malignant lesions of soft tissue tumors and to establish a quantitative cut-off value for ADC to be used in the differentiation of these lesions. MATERIAL AND METHODS: This retrospective study included a total of 34 patients who underwent DWI due to soft tissue masses and had available histopathological results. According to the pathological results; patients were categorized as having benign and malignant lesions. Measurements were performed using the free hand-drawn region of interest technique. It was investigated whether there was any difference in the evaluated parameters (size, age, gender, and minimum, mean and maximum ADC values). The cut-off value for the parameters evaluated in DWI was determined by the Receiver Operating Characteristic (ROC) analysis. RESULTS: The mean minimum ADC value was 1,28×10-³mm²/s in benign soft tissue masses and 1,00×10-³mm²/s in malignant soft tissue masses. Minimum ADC values differ statistically between the two groups. (p=0,007). A cut-off value of ≤1,01×10-³mm²/s for the minimum ADC allowed for the characterization of soft tissue masses at 78,95% sensitivity and 73,33% specificity. However, the mean and maximum ADC values were not statistically significantly different between the two groups. (p=0,319 and 0,960, respectively). CONCLUSIONS: DWI is an effective method in the evaluation of soft tissue masses in the differentiation of benign and malignant, and taking the cut-off value as ≤1,01×10-³mm²/s in the calculation of minimum ADC will increase the clinical usefulness.

Keywords:

Diffusion-weighted MRI, Magnetic resonance Imaging, Soft tissue neoplasms.,

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