Diffusion Weighted Magnetic Resonance Imaging for the Classification of Focal Liver Lesions as Benign or Malignant

Abstract

Background & Aims: To assess the role of diffusion weighted imaging sequence (DWI), routinely used in hepatic magnetic resonance imaging (MRI) for the differentiation of focal liver lesions (FLLs) as benign or malignant.
 Method: 99 FLLs assessed by liver MRI in 80 patients were included in the present study. All lesions were retrospectively analyzed by two experienced radiologists, independent from each other, who were not aware of the previous results obtained by using different imaging techniques. All included FLLs had a final histological diagnosis or a final diagnosis based on consensus reading by two experienced radiologists and follow-up at 6 months. The FLLs signal was qualitatively appreciated on the b-800 sequences and on the apparent diffusion coefficient (ADC) map. The ADC value of each FLL was measured and the ADC ratio between the ADC value of the assessed FLL and that of the surrounding liver parenchyma were calculated.
 Results: The mean ADC value for benign FLLs as assessed by the two independent readers was 1.78 x 10¯³ and 1.72 x 10¯³, respectively. The mean ADC value for malignant FLLs was 0.92 x 10¯³ for the first reader and 0.95 x 10¯³ for the second reader. The mean ADC ratio for benign FLLs was 1.91 and 1.85 for the two readers and for malignant FLLs was 0.91 and 0.94, respectively. Using an ADC value lower than 1.024 x 10¯³ offers a specificity of 100% and a sensitivity of 62.5% for the diagnosis of malignant FLLs. The ADC value is an indicator which is less prone to interobserver variability (correlation of 0.919→1). The ADC ratio has, as the analysis of the ROC curve shows, the best predictive value for differentiation between benign and malignant FLLs. Analysis of the signal intensity on the DWI b-800 image alone is of no significance in differentiating benign from malignant FLLs (p>0.05).
 Conclusions: The ADC value and the ADC ratio assessed on liver DWI are useful diagnostic tools in the differential diagnosis of benign vs. malignant FLLs. Quantitative methods such as calculating the ADC value or ADC ratio have better diagnostic value than the qualitative techniques.

Evaluation of ADCratio on liver MRI diffusion to discriminate benign versus malignant solid liver lesions

“…Magnetic Resonance Imaging (MRI) has superior sensitivity and specificity in diagnosing focal liver lesions when compared to Computer Tomography (CT) and Ultrasound (US) [ 1 ]. Diffusion weighted imaging (DWI) is one of the non-contrast MRI sequences which is playing increasing role in the hepatic MRI interpretation [ 2 , 3 ].…”

The Role of the Diffusion Sequence in Magnetic Resonance Imaging for the Differential Diagnosis between Hepatocellular Carcinoma and Benign Liver Lesions

“…Classically, malignant lesions will demonstrate a restricted diffusion imaging model with high signal intensity on the DWI sequence at higher b-values and low signal intensity on the ADC map [ 19 ].…”

Radiological Methods in Diagnostics of Focal Liver Lesions

“…Проведение КТ рекомендуется пациентам с установленными злокачественными образованиями печени, с хроническими заболеваниями печени, а также для уточнения размеров, количества, расположения и структуры очагов, обнаруженных при УЗИ [9].…”

“…Данные образования будут иметь высокий сигнал на ИКД-картах [30]. Количественная оценка значения ИКД и, тем более, разницы ИКД образования и окружающей паренхимы имеет большую диагностическую ценность, чем качественная оценка интенсивности сигнала на ДВИ c b-800 и ИКД картах [9].…”

“…Согласно ряду публикаций, применение внутривенного контрастирования при УЗИ позволяет добиться большей чувствительности и специфичности, сопоставимой с КТ или с МРТ с контрастным усилением [49][50][51][52][53]. С его помощью удается правильно диагностировать более 80% ООП, а также улучшить визуализацию при выполнении фьюжн-биопсии ОПП [7][8][9][10]. В частности, при использовании эхоконтрасных препаратов второго поколения точность диагностики ГЦР у пациентов с циррозом достигает 89,3% при размерах опухоли менее 2 см и 100% при размерах более 2 см [11].…”