“…This In a previous study [2], it was found that the subtraction has a sensitivity of 97.06%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 95.24% by two readers which agreed with our results. Our results were also comparable with another study [16] who found that both subtraction and dynamic techniques showed excellent diagnostic performance with AUC ≥ 0.90 (P < 0.001). With the subtraction has sensitivity 83.3%, specificity 90.9%, PPV 76.9%, and NPV 93.8% compared to 63.9%, 86.9%, 63.9%, and 86.9% respectively for the dynamic technique.…”
Section: Discussionsupporting
confidence: 91%
“…As a conclusion, we found that the subtraction images had higher sensitivity, specificity, PPV, and NPV values compared to the dynamic images and DWI images as found by previous studies [2] and [16]. The readers results to standard of reference agreement…”
Background: Hepatocellular carcinoma is considered to be the fifth most common cancer worldwide. Resection and liver transplantation have a high survival in the correct clinical scenarios; however, locoregional therapy has many advantages over tumor resection like preservation of hepatic parenchyma and overall less morbidity and mortality. Our aim was to present the role of dynamic subtraction MRI technique in the assessment of treatment response of hepatocellular carcinoma to transarterial chemoembolization. Methods: The study consisted of 43 patients with 55 hepatocellular carcinoma lesions who underwent transarterial chemoembolization procedure and followed up by dynamic MRI of the liver with post processing to obtain subtraction images 1-1.5 months after the procedure. If no signs of disease activity, another follow up study was preformed 2-4 months later. Five patients were excluded due to misregistration artifact at the subtraction images. The final cohort is 38 patients having 50 lesions. Precontrast T1, T2, dynamic contrast enhanced, and diffusion-weighted images were acquired. Subtracted dynamic images were created on the workstation. Sequences were assessed by three experienced readers in hepatic imaging. The sensitivity, specificity, positive predictive value, negative predictive value, 95% confidence interval, and overall agreement were calculated for the dynamic and subtracted dynamic images.Results: The subtraction images have sensitivity of 96%, specificity of 100%, PPV of 100%, and NPV of 100% Compared to 96%, 100%, 100%, 96%, and 96%, 100%, 100% 96% for the three readers respectively. On the other hand, the dynamic images has sensitivity of 92%, specificity of 96%, PPV of 95%, and NPV of 92.3% compared to 92%, 96%, 95%, 92.3% and 80%, 68%, 71.4%, and 77.2% for the three readers respectively.Conclusion: Subtraction technique is a useful confirmative tool as it had higher sensitivity, specificity, PPV, and NPV values compared to the dynamic and diffusion images with high level of agreement between the readers and also associated with significantly higher reader confidence levels.
“…This In a previous study [2], it was found that the subtraction has a sensitivity of 97.06%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 95.24% by two readers which agreed with our results. Our results were also comparable with another study [16] who found that both subtraction and dynamic techniques showed excellent diagnostic performance with AUC ≥ 0.90 (P < 0.001). With the subtraction has sensitivity 83.3%, specificity 90.9%, PPV 76.9%, and NPV 93.8% compared to 63.9%, 86.9%, 63.9%, and 86.9% respectively for the dynamic technique.…”
Section: Discussionsupporting
confidence: 91%
“…As a conclusion, we found that the subtraction images had higher sensitivity, specificity, PPV, and NPV values compared to the dynamic images and DWI images as found by previous studies [2] and [16]. The readers results to standard of reference agreement…”
Background: Hepatocellular carcinoma is considered to be the fifth most common cancer worldwide. Resection and liver transplantation have a high survival in the correct clinical scenarios; however, locoregional therapy has many advantages over tumor resection like preservation of hepatic parenchyma and overall less morbidity and mortality. Our aim was to present the role of dynamic subtraction MRI technique in the assessment of treatment response of hepatocellular carcinoma to transarterial chemoembolization. Methods: The study consisted of 43 patients with 55 hepatocellular carcinoma lesions who underwent transarterial chemoembolization procedure and followed up by dynamic MRI of the liver with post processing to obtain subtraction images 1-1.5 months after the procedure. If no signs of disease activity, another follow up study was preformed 2-4 months later. Five patients were excluded due to misregistration artifact at the subtraction images. The final cohort is 38 patients having 50 lesions. Precontrast T1, T2, dynamic contrast enhanced, and diffusion-weighted images were acquired. Subtracted dynamic images were created on the workstation. Sequences were assessed by three experienced readers in hepatic imaging. The sensitivity, specificity, positive predictive value, negative predictive value, 95% confidence interval, and overall agreement were calculated for the dynamic and subtracted dynamic images.Results: The subtraction images have sensitivity of 96%, specificity of 100%, PPV of 100%, and NPV of 100% Compared to 96%, 100%, 100%, 96%, and 96%, 100%, 100% 96% for the three readers respectively. On the other hand, the dynamic images has sensitivity of 92%, specificity of 96%, PPV of 95%, and NPV of 92.3% compared to 92%, 96%, 95%, 92.3% and 80%, 68%, 71.4%, and 77.2% for the three readers respectively.Conclusion: Subtraction technique is a useful confirmative tool as it had higher sensitivity, specificity, PPV, and NPV values compared to the dynamic and diffusion images with high level of agreement between the readers and also associated with significantly higher reader confidence levels.
“…In such cases, subtraction images of unenhanced T1-weighted and arterial-phase images are helpful in detecting arterial-phase hyperenhancement (Fig. 1) (16222324). However, in subtraction imaging, image quality cannot be assured in case of misregistration due to patient-related or technical factors.…”
Diagnosis of hepatocellular carcinoma (HCC) with gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) poses certain unique challenges beyond the scope of current guidelines. The regional heterogeneity of HCC in demographic characteristics, prevalence, surveillance, and socioeconomic status necessitates different treatment approaches, leading to variations in survival outcomes. Considering the medical practices in Korea, the Korean Society of Abdominal Radiology (KSAR) study group for liver diseases has developed expert consensus recommendations for diagnosis of HCC by gadoxetic acid-enhanced MRI with updated perspectives, using a modified Delphi method. During the 39th Scientific Assembly and Annual Meeting of KSAR (2016), consensus was reached on 12 of 16 statements. These recommendations might serve to ensure a more standardized diagnosis of HCC by gadoxetic acid-enhanced MRI.
“…Intrinsic high signal can also be demonstrated in successfully treated HCC [22]. Unenhanced images can be subtracted from arterial-phase gadolinium-enhanced images to assess for arterial enhancement in nodules [23].…”
Section: Mri Techniquementioning
confidence: 99%
“…An ablation zone can demonstrate high signal intensity on pre-contrast T1-weighted images as a result of coagulative necrosis, making evaluation for arterial enhancement difficult in the absence of subtraction imaging. Subtractions should therefore be routinely included within the MRI protocol [22]. Fig.…”
Treatment options for hepatocellular carcinoma have evolved over recent years. Interventional radiologists and surgeons can offer curative treatments for early stage tumours, and locoregional therapies can be provided resulting in longer survival times. Early diagnosis with screening ultrasound is the key. CT and MRI are used to characterize lesions and determine the extent of tumour burden. Imaging techniques are discussed in this article as the correct imaging protocols are essential to optimise successful detection and characterisation. After treatment it is important to establish regular imaging follow up with CT or MRI as local residual disease can be easily treated, and recurrence elsewhere in the liver is common.
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