H epatocellular carcinoma (HCC) accounts for the majority of primary liver cancers, which are the fourth leading cause of cancer-related deaths worldwide. The burden of HCC is increasing, mainly due to the rising prevalence of obesity and nonalcoholic fatty liver disease (1). Although surveillance programs have been implemented for at-risk patients (eg, patients with cirrhosis) to detect tumors at early stages and to allow for potentially curative treatment, such patients have high recurrence rates and heterogeneous recurrence-free survival (2). Indeed, HCC has strong genomic, molecular, and histologic heterogeneity (3,4). Several histologic subtypes of HCC associated with clinical and molecular features of different prognostic value have been described (5-7), among which the macrotrabecular-massive (MTM) HCC (MTM-HCC) subgroup has been recently identified (7,8). MTM-HCCs have been shown to be associated with poor survival, high serum a-fetoprotein (AFP) level, and histologic features of aggressiveness, including microvascular and macrovascular invasion and satellite nodules (8). This subtype has been newly included in the fifth edition of the World Health Organization Classification of Tumors (9).Identification of the aggressive HCC subtypes during pretherapeutic work-up may have strong prognostic and therapeutic implications (3). In patients with cirrhosis, the diagnosis of HCC may be performed noninvasively using multiphasic CT or dynamic contrast materialenhanced MRI using the Liver Imaging Reporting and Data System (LI-RADS), which provides standardization for HCC imaging acquisition and terminology and allows for accurate stratification of the probability of HCC and overall malignancy (2,10,11). As pathologic diagnosis is thus not systematically required, the identification

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ADC variation observed in CRC metastases following systemic chemotherapy reflects a specific increase in free-molecular diffusion (D), in itself correlated to the degree of metastasis necrosis.

R1 resections were associated with a higher risk of intra-hepatic and surgical margin recurrence but did not negatively impact survival suggesting that in the era of efficient chemotherapy, the risk of an R1 resection should not be considered as a contraindication to surgery.

Whole-body imaging, in particular molecular imaging with fluorine 18 ((18)F)-fluorodeoxyglucose (FDG) positron emission tomography (PET), is essential to management of lymphoma. The assessment of disease extent provided by use of whole-body imaging is mandatory for planning appropriate treatment and determining patient prognosis. Assessment of treatment response allows clinicians to tailor the treatment strategy during therapy if necessary and to document complete remission at the end of treatment. Because of rapid technical developments, such as echo-planar sequences, parallel imaging, multichannel phased-array surface coils, respiratory gating, and moving examination tables, whole-body diffusion-weighted (DW) magnetic resonance (MR) imaging that reflects cell density is now feasible in routine clinical practice. Whole-body DW MR imaging allows anatomic assessment as well as functional and quantitative evaluation of tumor sites by calculation of the apparent diffusion coefficient (ADC). Because of their high cellularity and high nucleus-to-cytoplasm ratio, lymphomatous lesions have low ADC values and appear hypointense on ADC maps. As a result, whole-body DW MR imaging with ADC mapping has become a promising tool for lymphoma staging and treatment response assessment. The authors review their 4 years of experience with 1.5-T and 3-T whole-body DW MR imaging used with (18)F-FDG PET/computed tomography at baseline, interim, and end of treatment in patients with Hodgkin lymphoma and diffuse large B-cell lymphoma and discuss the spectrum of imaging findings and potential pitfalls, limitations, and challenges associated with whole-body DW MR imaging in these patients.

• CEUS is highly specific for the diagnosis of FNH, regardless of lesion size • CEUS shows reduced sensitivity in diagnosing FNH lesions larger than 35 mm • The filling patterns of hepatocellular adenomas are not affected by lesion size.

• Late-arterial iodine concentration is highly related to arterial BF and BV. • Portal iodine concentration mainly reflects tumour blood volume. • Dual-energy CT offers significantly decreased radiation dose compared with perfusion CT.

Both manual and automated multiphase MDCT-based volume measurements were strongly correlated to liver volume (Pearson correlation coefficient, r = 0.87 [p < 0.0001] and 0.90 [p < 0.0001], respectively). Automated multiphase segmentation was significantly more rapid than manual segmentation (mean time, 16 ± 5 [SD] and 86 ± 3 seconds, respectively; p = 0.01). Overall, automated liver volumetry based on multiphase CT acquisitions is feasible and more rapid than manual segmentation.