Stefano Nardacci

Purpose To compare apparent diffusion coefficient (ADC) values in whole-body MRI (WB-MRI) reconstructed from diffusion-weighted imaging (DWI) with three b-values (50–500–1000 s/mm²) compared with two b-values (50–1000 s/mm²). Materials and methods Patients with multiple myeloma who underwent 1.5 T WB-MRI were retrospectively included. Exclusion criteria were severe motion artifacts. Examinations included axial DWI with three b-values (50–500–1000 s/mm²); ADC maps were reconstructed with both three values of b(ADC3b) and two values of b(ADC2b) excluding b500 s/mm². According to MY-RADS guideline, bone lesion with ADC values 700–1400 µm²/sec was considered malignant and regions of interests (ROIs) were placed in bone lesions and healthy bone marrow. Both malignant lesions and healthy bone ADC3b were compared with ADC2b, considering as significant p < 0.05. In case of discordant ROIs on the two ADC maps for malignity/benignity, expert radiologists examined all the WB-MRI sequences to assign a malignant/benign qualitative assessment. Results Fifty-five patients (25 females, 29–83 yo) were retrospectively included; 305 bone lesions and 303 healthy bone segments were assessed. Objective analysis showed different ADC values between bone lesions’ in ADC3b and ADC2b (965.3 ± 216.7 µm²/sec vs 937.2 ± 218.8 µm²/sec, p < 0.0001) and in healthy bone marrow ROIs (588 ± 271.7 vs 573.1 ± 573.1 ± 271.2, p < 0.0001). Despite significant differences, almost all the analyzed ROIs lay in the same range of ADC for bone lesions. 10/305 bone lesions fell into the range of malignity for ADC3b while showing lower values < 700 µm²/sec for ADC2b (ADC3b 715.82 ± 190.9 µm²/sec vs. ADC2b 687.72 ± 185.2 µm²/sec); focal bone lesion with discordant values was then confirmed as lesions, in accordance with ADC3b, by a panel of experts that blind-reviewed the whole sequences of the examinations. Conclusion ADC2b is comparable with ADC3b except for borderline values (650–750 µm²/sec).

Cholangiocarcinoma (CCA) is a malignant biliary system tumor and the second most common primary hepatic neoplasm, following hepatocellular carcinoma. CCA still has an extremely high unfavorable prognosis, regardless of type and location, and complete surgical resection remains the only curative therapeutic option; however, due to the underhanded onset and rapid progression of CCA, most patients present with advanced stages at first diagnosis, with only 30 to 60% of CCA patients eligible for surgery. Recent innovations in medical imaging combined with the use of radiomics and artificial intelligence (AI) can lead to improvements in the early detection, characterization, and pre-treatment staging of these tumors, guiding clinicians to make personalized therapeutic strategies. The aim of this review is to provide an overview of how radiological features of CCA can be analyzed through radiomics and with the help of AI for many different purposes, such as differential diagnosis, the prediction of lymph node metastasis, the defining of prognostic groups, and the prediction of early recurrence. The combination of radiomics with AI has immense potential. Still, its effectiveness in practice is yet to be validated by prospective multicentric studies that would allow for the development of standardized radiomics models.

Background: Neuroendocrine neoplasms (NENs) are slow-growing tumors. Sarcopenia is defined as the loss of muscle mass, strength, and physical performance. First-line NEN therapy is somatostatin analogs, which could be responsible for malabsorption conditions, such as pancreatic exocrine insufficiency (EPI) with underlying sarcopenia. Aim: Evaluate the prevalence of sarcopenia in patients with NENs at diagnosis and during follow-up. Methods: A retrospective single-center study was conducted, including patients with advanced intestinal NENs G1/G2 (excluded pancreatic NENs). CT scans were analyzed at diagnosis and after 6 months of therapy, and the skeletal muscle index was assessed. Results: A total of 30 patients (F:M = 6:24) were enrolled, with the following primary tumor sites: 25 in the ileum, 1 stomach, 2 jejunum, and 2 duodenum. At diagnosis, 20 patients (66.6%) showed sarcopenic SMI values, and 10 patients (33.3%) showed non-sarcopenic SMI values. At follow-up, three more patients developed sarcopenic SMI values. Statistical significance in relation to the presence of sarcopenia was found in the group of patients with carcinoid syndrome (p = 0.0178), EPI (p = 0.0018), and weight loss (p = 0.0001). Conclusion: Sarcopenia was present in 2/3 of the patients with advanced intestinal NENs at the diagnosis and during the follow-up. It is reasonable to consider this condition to improve clinical outcomes.

Magnetic resonance elastography (MRE) is an imaging technique that combines low-frequency mechanical vibrations with magnetic resonance imaging to create visual maps and quantify liver parenchyma stiffness. As in recent years, diffuse liver diseases have become highly prevalent worldwide and could lead to a chronic condition with different stages of fibrosis. There is a strong necessity for a non-invasive, highly accurate, and standardised quantitative assessment to evaluate and manage patients with different stages of fibrosis from diagnosis to follow-up, as the actual reference standard for the diagnosis and staging of liver fibrosis is biopsy, an invasive method with possible peri-procedural complications and sampling errors. MRE could quantitatively evaluate liver stiffness, as it is a rapid and repeatable method with high specificity and sensitivity. MRE is based on the propagation of mechanical shear waves through the liver tissue that are directly proportional to the organ’s stiffness, expressed in kilopascals (kPa). To obtain a valid assessment of the real hepatic stiffness values, it is mandatory to obtain a high-quality examination. To understand the pearls and pitfalls of MRE, in this review, we describe our experience after one year of performing MRE from indications and patient preparation to acquisition, quality control, and image analysis.