Comparison of Early Contrast Enhancement Models in Ultrafast Dynamic Contrast-Enhanced Magnetic Resonance Imaging of Prostate Cancer.

Tofts models have failed to produce reliable quantitative markers for prostate cancer. We examined the differences between prostate zones and lesion PI-RADS categories and grade group (GG) using regions of interest drawn in tumor and normal-appearing tissue for a two-compartment uptake (2CU) model (including plasma volume (vp), plasma flow (Fp), permeability surface area product (PS), plasma mean transit time (MTTp), capillary transit time (Tc), extraction fraction (E), and transfer constant (Ktrans)) and exponential (amplitude (A), arrival time (t0), and enhancement rate (α)), sigmoidal (amplitude (A0), center time relative to arrival time (A1 - T0), and slope (A2)), and empirical mathematical models, and time to peak (TTP) parameters fitted to high temporal resolution (1.695 s) DCE-MRI data. In 25 patients with 35 PI-RADS category 3 or higher tumors, we found Fp and α differed between peripheral and transition zones. Parameters Fp, MTTp, Tc, E, α, A1 - T0, and A2 and TTP all showed associations with PI-RADS categories and with GG in the PZ when normal-appearing regions were included in the non-cancer GG. PS and Ktrans were not associated with any PI-RADS category or GG. This pilot study suggests early enhancement parameters derived from ultrafast DCE-MRI may become markers of prostate cancer.

Automated 3D Ultrasound as an Adjunct to Screening Mammography Programs in Dense Breast: Literature Review and Metanalysis.

Purpose: The purpose of this meta-analysis is to investigate the effectiveness of supplementing screening mammography with three-dimensional automated breast ultrasonography (3D ABUS) in improving breast cancer detection rates in asymptomatic women with dense breasts. Materials and Methods: We conducted a thorough review of scientific publications comparing 3D ABUS and mammography. Articles for inclusion were sourced from peer-reviewed journal databases, namely MEDLINE (PubMed) and Scopus, based on an initial screening of their titles and abstracts. To ensure a sufficient sample size for meaningful analysis, only studies evaluating a minimum of 20 patients were retained. Eligibility for evaluation was further limited to articles written in English. Additionally, selected studies were required to have participants aged 18 or above at the time of the study. We analyzed 25 studies published between 2000 and 2021, which included a total of 31,549 women with dense breasts. Among these women, 229 underwent mammography alone, while 347 underwent mammography in combination with 3D ABUS. The average age of the women was 50.86 years (±10 years standard deviation), with a range of 40-56 years. In our efforts to address and reduce bias, we applied a range of statistical analyses. These included assessing study variation through heterogeneity assessment, accounting for potential study variability using a random-effects model, exploring sources of bias via meta-regression analysis, and checking for publication bias through funnel plots and the Egger test. These methods ensured the reliability of our study findings. Results: According to the 25 studies included in this metanalysis, out of the total number of women, 27,495 were diagnosed with breast cancer. Of these, 211 were diagnosed through mammography alone, while an additional 329 women were diagnosed through the combination of full-field digital mammography (FFDSM) and 3D ABUS. This represents an increase of 51.5%. The rate of cancers detected per 1000 women screened was 23.25‱ (95% confidence interval [CI]: 21.20, 25.60; p < 0.001) with mammography alone. In contrast, the addition of 3D ABUS to mammography increased the number of tumors detected to 20.95‱ (95% confidence interval [CI]: 18.50, 23; p < 0.001) per 1000 women screened. Discussion: Even though variability in study results, lack of long-term outcomes, and selection bias may be present, this systematic review and meta-analysis confirms that supplementing mammography with 3D ABUS increases the accuracy of breast cancer detection in women with ACR3 to ACR4 breasts. Our findings suggest that the combination of mammography and 3D ABUS should be considered for screening women with dense breasts. Conclusions: Our research confirms that adding 3D automated breast ultrasound to mammography-only screening in patients with dense breasts (ACR3 and ACR4) significantly (p < 0.05) increases the cancer detection rate.

Multiparametric MRI-based 5-year Risk Prediction Model for Biochemical Recurrence of Prostate Cancer after Radical Prostatectomy.

Background Current predictive tools to estimate the risk of biochemical recurrence (BCR) after treatment of prostate cancer do not consider multiparametric MRI (mpMRI) information. Purpose To develop a risk prediction tool that considers mpMRI findings to assess the risk of 5-year BCR after radical prostatectomy. Materials and Methods In this retrospective single-center analysis in 1459 patients with prostate cancer who underwent mpMRI before radical prostatectomy (in 2012-2015), the outcome of interest was 5-year BCR (two consecutive prostate-specific antigen [PSA] levels > 0.2 ng/mL [0.2 µg/L]). Patients were randomly divided into training (70%) and test (30%) sets. Kaplan-Meier plots were applied to the training set to estimate survival probabilities. Multivariable Cox regression models were used to test the relationship between BCR and different sets of exploratory variables. The C-index of the final model was calculated for the training and test sets and was compared with European Association of Urology, University of California San Francisco Cancer of the Prostate Risk Assessment, Memorial Sloan-Kettering Cancer Center, and Partin risk tools using the partial likelihood ratio test. Five risk categories were created. Results The median duration of follow-up in the whole cohort was 59 months (IQR, 32-81 months); 376 of 1459 (25.8%) patients had BCR. A multivariable Cox regression model (referred to as PIPEN, and composed of PSA density, International Society of Urological Pathology grade group, Prostate Imaging Reporting and Data System category, European Society of Urogenital Radiology extraprostatic extension score, nodes) fitted to the training data yielded a C-index of 0.74, superior to that of other predictive tools (C-index 0.70 for all models; P ≤ .01) and a median higher C-index on 500 test set replications (C-index, 0.73). Five PIPEN risk categories were identified with 5-year BCR-free survival rates of 92%, 84%, 71%, 56%, and 26% in very low-, low-, intermediate-, high-, and very high-risk patients, respectively (all P < .001). Conclusion A five-item model for predicting the risk of 5-year BCR after radical prostatectomy for prostate cancer was developed and internally verified, and five risk categories were identified. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Aguirre and Ortegón in this issue.

Magnetic Resonance Imaging Evaluation of Bone Metastases Treated with Radiotherapy in Palliative Intent: A Multicenter Prospective Study on Clinical and Instrumental Evaluation Assessment Concordance (MARTE Study).

Metastasis to bone is a common occurrence among epithelial tumors, with a high incidence rate in the Western world. As a result, bone lesions are a significant burden on the healthcare system, with a high morbidity index. These injuries are often symptomatic and can lead to functional limitations, which in turn cause reduced mobility in patients. Additionally, they can lead to secondary complications such as pathological fractures, spinal cord compression, hypercalcemia, or bone marrow suppression. The treatment of bone metastases requires collaboration between multiple healthcare professionals, including oncologists, orthopedists, neurosurgeons, physiatrists, and radiotherapists. The primary objective of this study is to evaluate the correlation between two methods used to assess local control. Specifically, the study aims to determine if a reduction in the volume of bone lesions corresponds to better symptomatic control in the clinical management of patients, and vice versa. To achieve this objective, the study evaluates morphological criteria by comparing pre- and post-radiotherapy treatment imaging using MRI and RECIST 1.1 criteria. MRI without contrast is the preferred diagnostic imaging method, due to its excellent tolerance by patients, the absence of exposure to ionizing radiation, and the avoidance of paramagnetic contrast media side effects. This imaging modality allows for accurate assessment of bone lesions. One of the secondary objectives of this study is to identify potentially useful parameters that can distinguish patients into two classes: "good" and "poor" responders to treatment, as reported by previous studies in the literature. These parameters can be evaluated from the imaging examinations by analyzing morphological changes and radiomic features on different sequences, such as T1, STIR (short tau inversion recovery), and DWI-MRI (diffusion-weighted).

The Role of Dual-Energy CT for the Assessment of Liver Metastasis Response to Treatment: Above the RECIST 1.1 Criteria.

Imaging assessment of liver lesions is fundamental to predict therapeutic response and improve patient survival rates. Dual-Energy Computed Tomography (DECT) is an increasingly used technique in the oncologic field with many emerging applications. The assessment of iodine concentration within a liver lesion reflects the biological properties of the tumor and provides additional information to radiologists that is normally invisible to the human eye. The possibility to predict tumor aggressiveness and therapeutic response based on quantitative and reproducible parameters obtainable from DECT images could improve clinical decisions and drive oncologists to choose the best therapy according to metastasis biological features. Moreover, in comparison with standard dimensional criteria, DECT provides further data on the cancer microenvironment, especially for patients treated with antiangiogenic-based drugs, in which tumor shrinkage is a late parameter of response. We investigated the predictive role of DECT in the early assessment of liver metastasis response to treatment in comparison with standard dimensional criteria during antiangiogenetic-based therapy.

An overview of the irreversible electroporation for the treatment of liver metastases: When to use it.

Tumour ablation is an established therapy for local treatment of liver metastases and hepatocellular carcinoma. Most commonly two different kind of thermic ablation, radiofrequency ablation and microwave ablation, are used in clinical practice. The aim of both is to induce thermic damage to the malignant cells in order to obtain coagulative necrosis of the neoplastic lesions. Our main concerns about these procedures are the collateral thermic damage to adjacent structures and heat-sink effect. Irreversible electroporation (IRE) is a recently developed, non-thermal ablation procedure which works applying short pulses of direct current that generate an electric field in the lesion area. The electric field increase the transmembrane potential, changing its permeability to ions.Irreversible electroporation does not generate heat, giving the chance to avoid the heat-sink effect and opening the path to a better treatment of all the lesions located in close proximity to big vessels and bile ducts. Electric fields produced by the IRE may affect endothelial cells and cholangiocytes but they spare the collagen matrix, preserving re-epithelization process as well as the function of the damaged structures. Purpose of the authors is to identify the different scenarios where CT-guided percutaneous IRE of the liver should be preferred to other ablative techniques and why.

Ability of Delta Radiomics to Predict a Complete Pathological Response in Patients with Loco-Regional Rectal Cancer Addressed to Neoadjuvant Chemo-Radiation and Surgery.

We performed a pilot study to evaluate the use of MRI delta texture analysis (D-TA) as a methodological item able to predict the frequency of complete pathological responses and, consequently, the outcome of patients with locally advanced rectal cancer addressed to neoadjuvant chemoradiotherapy (C-RT) and subsequently, to radical surgery. In particular, we carried out a retrospective analysis including 100 patients with locally advanced rectal adenocarcinoma who received C-RT and then radical surgery in three different oncological institutions between January 2013 and December 2019. Our experimental design was focused on the evaluation of the gross tumor volume (GTV) at baseline and after C-RT by means of MRI, which was contoured on T2, DWI, and ADC sequences. Multiple texture parameters were extracted by using a LifeX Software, while D-TA was calculated as percentage of variations in the two time points. Both univariate and multivariate analysis (logistic regression) were, therefore, carried out in order to correlate the above-mentioned TA parameters with the frequency of pathological responses in the examined patients' population focusing on the detection of complete pathological response (pCR, with no viable cancer cells: TRG 1) as main statistical endpoint. ROC curves were performed on three different datasets considering that on the 21 patients, only 21% achieved an actual pCR. In our training dataset series, pCR frequency significantly correlated with ADC GLCM-Entropy only, when univariate and binary logistic analysis were performed (AUC for pCR was 0.87). A confirmative binary logistic regression analysis was then repeated in the two remaining validation datasets (AUC for pCR was 0.92 and 0.88, respectively). Overall, these results support the hypothesis that D-TA may have a significant predictive value in detecting the occurrence of pCR in our patient series. If confirmed in prospective and multicenter trials, these results may have a critical role in the selection of patients with locally advanced rectal cancer who may benefit form radical surgery after neoadjuvant chemoradiotherapy.

Chemotherapy-induced bowel ischemia: diagnostic imaging overview.

Cancer patients need multimodal therapies to treat their disease increasingly. In particular, drug treatment, as chemotherapy, immunotherapy, or various associations between them are commonly used to increase efficacy. However, the use of drugs predisposes a percentage of patients to develop toxicity in multiple organs and systems. Principle chemotherapy drugs mechanism of action is cell replication inhibition, rapidly proliferating cells especially. Immunotherapy is another tumor therapy strategy based on antitumor immunity activation trough agents as CTLA4 inhibitors (ipilimumab) or PD-1/PD-L1 inhibitors as nivolumab. If, on the one hand, all these agents inhibit tumor growth, on the other, they can cause various degrees toxicity in several organs, due to their specific mechanism of action. Particularly interesting are bowel toxicity, which can be clinically heterogeneous (pain, nausea, diarrhea, enterocolitis, pneumocolitis), up to severe consequences, such as ischemia, a rare occurrence. However, this event can occur both in vessels that supply intestine and in submucosa microvessels. We report drug-related intestinal vascular damage main characteristics, showing the radiological aspect of these alterations. Interpretation of imaging in oncologic patients has become progressively more complicated in the context of "target therapy" and thanks to the increasing number and types of therapies provided. Radiologists should know this variety of antiangiogenic treatments and immunotherapy regimens first because they can determine atypical features of tumor response and then also because of their eventual bowel toxicity.

Validation of a standardized CT protocol for the evaluation of varices and porto-systemic shunts in cirrhotic patients.

PURPOSE: The aim of the present study was to propose and validate a standardized CT protocol for evaluating all the types of portosystemic collaterals (P-SC), including gastroesophageal varices and spontaneous portosystemic shunts (SPSS), and to evaluate the prognostic role of portal hypertension CT features for the prediction of the hepatic decompensation risk in cirrhotic patients. METHODS: A retrospective cohort study of 184 advanced chronic liver disease who underwent CT scan between January 2014 and December 2017. Patients with an interval > 6 months between the imaging, elastometric, endoscopic and biochemical evaluation were excluded, as well as patients with previous transjugular intrahepatic portosystemic shunt (TIPS), liver transplantation (LT) or terminal medical conditions. Data on liver disease history, co-morbidities, endoscopic and radiologic findings were collected. The incidence of hepatic decompensation and other events, such as portal vein thrombosis, HCC, TIPS placement, LT, death, and its cause, were also recorded. The procedure was performed at baseline and after the administration of contrast agent using a multiphasic technique and bolus tracking. Two senior radiologists working in different centres and a non-expert radiologist reviewed all CT examinations, to evaluate both intra-observer and inter-observer variability of the CT protocol and to obtain an external validation. The radiological variables were evaluated using both univariate and adjusted multivariate competing risk regression models. RESULTS: Both intra-observer and inter-observer agreement were excellent in detection and measurement of almost all types of P-SC. The presence of SPSS, a spleen diameter > 16 cm, a portal vein diameter > 17 mm and the presence of ascites resulted independent predictors of decompensation-free survival for cirrhotic patients and were incorporated in an easy-to-use score (AUROC = 0.799, p-value = 0.732) which can the risk of decompensation at 5 years, ranking it as low (11.3%), moderate (35.6%) or high (70.8%). CONCLUSIONS: The CT protocol commonly performed during the HCC surveillance program for cirrhotic patients is valid for detecting all types of P-SC. The radiological score identified to predict the decompensation-free survival for cirrhotic patients could be an easy-to-use clinical tool.

Endorectal Ultrasound and Magnetic Resonance Imaging for Rectal Cancer Staging: A Modern Multimodality Approach.

Preoperative staging represents a crucial point for the management, type of surgery, and candidacy for neoadjuvant therapy in patient with rectal cancer. The most recent clinical guidelines in oncology recommend an accurate preoperative evaluation in order to address early and advanced tumors to different therapeutic options. In particular, potential pitfalls may occur in the assessment of T3 tumors, which represents the most common stage at diagnosis. The depth of tumor invasion is known to be an important prognostic factor in rectal carcinoma; as a consequence, the T3 imaging classification has a substantial importance for treatment strategy and patient survival. However, the differentiation between tumor invasion of perirectal fat and mesorectal desmoplastic reactions remains a main goal for radiologists. Magnetic resonance imaging (MRI) is actually considered as the best imaging modality for rectal cancer staging. Although the endorectal ultrasound (ERUS) is the preferred staging method for early tumors, it could also be useful in identifying perirectal fat invasion. Moreover, the addiction of diffusion weighted imaging (DWI) improves the diagnostic performance of MRI in rectal cancer staging by adding functional information about rectal tumor and adjacent mesorectal tissues. This study investigated the diagnostic performance of conventional MRI alone, in combination with the DWI technique and ERUS in order to assess the best diagnostic imaging combination for rectal cancer staging.

Preoperative computed tomography assessment for a deep inferior epigastric perforator (DIEP) flap: a new easy technique from the Bologna experience.

BACKGROUND: Deep inferior epigastric perforator (DIEP) flap reconstruction is the gold standard reconstructive technique for women undergoing breast cancer surgery. A preoperative computed tomography angiography (CTA)-dedicated protocol and 3D reconstructions are mandatory for correct surgical planning. PURPOSE: To evaluate the diagnostic performance of a new preoperative CTA protocol and a new reconstruction method in the assessment of DIEP technique. MATERIAL AND METHODS: A total of 263 women (median age 49 years, age range 26-73 years) underwent preoperative CTA examination before DIEP flap breast reconstruction. A CTA-dedicated protocol followed by 3D-reconstructions were performed. Identification, branching pattern, and caliber at origin were assessed for each perforator. Intraoperative findings were the standard of reference. The sensitivity, positive predictive value, and diagnostic accuracy of the preoperative CTA protocol were calculated. RESULTS: In 255/263 (97%) patients, the dominant perforators assessed by CTA resulted adequate for surgical reconstruction. In 260/263 (99%) cases, the imaging localization of the dominant perforators corresponded with those seen intraoperatively (mean errors ≤1 cm). The preoperative CTA imaging sensitivity, positive predictive value, and diagnostic accuracy in determining the localization of perforators were 99% (95% CI 98-100), 100% and 99% (95% CI 98-100), respectively. No statistically significant differences were found between the CTA findings and the surgical findings for the assessment of branching pattern and caliber of the dominant perforators (P < 0.001). CONCLUSION: The present protocol has demonstrated high accuracy in the CTA imaging assessment of the perforators before DIEP flap reconstruction with high reproducibility between CT and surgical findings.

Chest CT Computerized Aided Quantification of PNEUMONIA Lesions in COVID-19 Infection: A Comparison among Three Commercial Software.

PURPOSE: To compare different commercial software in the quantification of Pneumonia Lesions in COVID-19 infection and to stratify the patients based on the disease severity using on chest computed tomography (CT) images. MATERIALS AND METHODS: We retrospectively examined 162 patients with confirmed COVID-19 infection by reverse transcriptase-polymerase chain reaction (RT-PCR) test. All cases were evaluated separately by radiologists (visually) and by using three computer software programs: (1) Thoracic VCAR software, GE Healthcare, United States; (2) Myrian, Intrasense, France; (3) InferRead, InferVision Europe, Wiesbaden, Germany. The degree of lesions was visually scored by the radiologist using a score on 5 levels (none, mild, moderate, severe, and critic). The parameters obtained using the computer tools included healthy residual lung parenchyma, ground-glass opacity area, and consolidation volume. Intraclass coefficient (ICC), Spearman correlation analysis, and non-parametric tests were performed. RESULTS: Thoracic VCAR software was not able to perform volumes segmentation in 26/162 (16.0%) cases, Myrian software in 12/162 (7.4%) patients while InferRead software in 61/162 (37.7%) patients. A great variability (ICC ranged for 0.17 to 0.51) was detected among the quantitative measurements of the residual healthy lung parenchyma volume, GGO, and consolidations volumes calculated by different computer tools. The overall radiological severity score was moderately correlated with the residual healthy lung parenchyma volume obtained by ThoracicVCAR or Myrian software, with the GGO area obtained by the ThoracicVCAR tool and with consolidation volume obtained by Myrian software. Quantified volumes by InferRead software had a low correlation with the overall radiological severity score. CONCLUSIONS: Computer-aided pneumonia quantification could be an easy and feasible way to stratify COVID-19 cases according to severity; however, a great variability among quantitative measurements provided by computer tools should be considered.

Impact of coronavirus disease 2019 (COVID-19) emergency on Italian radiologists: a national survey.

OBJECTIVES: To perform an online survey aimed at evaluating the impact of COVID-19 on Italian radiology departments. METHODS: We launched a survey composed of 25 questions about how COVID-19 has changed the safety and organization of daily activity in Italian radiology units. RESULTS: A total of 2136/10,564 (20.2%) radiologists of the Italian Society of Medical and Interventional Radiology participated. Two-thirds performed at least one diagnostic/interventional procedure on COVID-19 patients. The 88.1% reported a reduction in the elective imaging volumes, with US, mammography, and MRI having shown the greater decrease (41.1%, 23.9%, and 21.1%, respectively). In 69.6% of cases, institutions had trouble getting personal protective equipment (PPE), especially public hospitals and southern institutions. Less than 30% of participants were subjected to RT-PCR swab test, although 81.5% believed that it should be done on all health workers and 70% suggested it as the most important measure to improve safety at work. Slightly more than half of participants declared to work safely and felt to be adequately protected by their institutions. Up to 20% of northern participants were redeployed to clinical services. The first imaging examination performed by admitted COVID-19 patients was chest radiography in 76.3% of cases. Almost half of participants reported that less than 30% of health workers were infected in their radiology department, with higher rates in northern regions and public institutions. CONCLUSIONS: This snapshot of the current situation in Italian radiology departments could be used to harmonize the organization of working activity in order to safely and effectively face this pandemic. KEY POINTS: • More than two-thirds of institutions had trouble getting PPE for health workers, with public hospitals and southern institutions that presented more procurement problems • A substantial drop of imaging volumes was observed in the vast majority of Italian radiology departments, mostly due to the decrease of ultrasound, mammography, and MRI, especially in private practice were working activity was stopped in 13.3% of institutions • RT-PCR swab to health workers was reported as the most suggested measure by Italian radiologists to improve safety at work, as more than 80% of them believed that it should be performed to all health workers, although less than 30% were subjected to this test.

Gastric Cancer Staging: Is It Time for Magnetic Resonance Imaging?

Gastric cancer (GC) is a common cancer worldwide. Its incidence and mortality vary depending on geographic area, with the highest rates in Asian countries, particularly in China, Japan, and South Korea. Accurate imaging staging has become crucial for the application of various treatment strategies, especially for curative treatments in early stages. Unfortunately, most GCs are still diagnosed at an advanced stage, with the peritoneum (61-80%), distant lymph nodes (44-50%), and liver (26-38%) as the most common metastatic locations. Metastatic disease is limited to the peritoneum in 58% of cases; in nonperitoneal distant metastases, the most involved GC metastasization site is the liver (82%). The eighth edition of the tumor-node-metastasis staging system is the most commonly used system for determining GC prognosis. Endoscopic ultrasonography, computed tomography, and 18-fluorideoxyglucose positron emission tomography are historically the most accurate imaging techniques for GC staging. However, studies have recently shown renewed interest in magnetic resonance imaging (MRI) as a useful tool in GC staging, especially for distant metastasis assessment. The technical improvement of diffusion-weighted imaging and the increasing use of hepatobiliary contrast agents have been shown to increase the diagnostic performance of MRI, particularly for detecting peritoneal and liver metastasis. However, no principal oncological guidelines have included the use of MRI as a first-line technique for distant metastasis evaluation during the GC staging process, such as the National Comprehensive Cancer Network Guidelines. This review analyzed the role of the principal imaging techniques in GC diagnosis and staging, focusing on the potential role of MRI, especially for assessing peritoneal and liver metastases.

Ablation for hepatocellular carcinoma: beyond the standard indications.

Hepatocellular carcinoma (HCC), the most common primary liver neoplasia, represents the fifth most common malignant disease in men. Percutaneous ablation treatment is recommended among the treatments suggested for HCC patients in the very early/early stage. In the last decade, very important results in terms of survival benefits have been obtained with local ablative therapies, also outside the standard indications, thanks to many technical innovations. In particular, important results of ablation as a safe and effective technique have been obtained in the treatment of intermediate- or advanced-stage patients with HCC, and in the treatment of unfavourable tumour locations. Moreover, awareness is growing regarding the necessity of overcoming the rigidity of traditional guidelines in the treatment of HCC due to the complexity of patients with HCC, focusing on Precision Medicine. In this context, it is important to know the standard and non-standard indications of ablation in the treatment of HCC in order to offer the best therapeutic option tailored for each patient. The aim of this study was to analyse the possible clinical applications of ablative therapies for HCC patients, beyond the traditional indications recommended in the most widespread clinical practice guidelines for the management of HCC.

Imaging of Colorectal Liver Metastases: New Developments and Pending Issues.

Computed tomography (CT), magnetic resonance imaging (MRI), and 18-fluorideoxyglucose positron emission tomography (18FDG-PET) are historically the most accurate imaging techniques for diagnosing liver metastases. Recently, the combination of diffusion-weighted imaging and hepatospecific contrast media, such as gadoxetic acid in MRI, have been demonstrated to have the highest diagnostic accuracy, sensitivity, and specificity for detecting liver metastases. Various recent meta-analyses have confirmed the diagnostic superiority of this combination (diffusion-weighted imaging and gadoxetic acid-enhanced MRI), especially in terms of per lesion sensitivity, as compared with CT and 18FDG-PET, even for smaller lesions (≤1 cm). However, none of the oncological guidelines have suggested the use of MRI as a first-line technique for liver metastasis detection during the staging process of oncological patients. This review analyzes the history of the principal imaging techniques for the diagnosis of liver metastases, in particular of colorectal liver metastases, focusing on the most accurate method (diffusion-weighted imaging combined with gadoxetic acid-enhanced MRI), possible reasons for the lack of its diffusion in the guidelines, and possible future scenarios.

Apparent diffusion coefficient magnetic resonance imaging (ADC-MRI) in the axillary breast cancer lymph node metastasis detection: a narrative review.

The presence of axillary lymph nodes metastases in breast cancer is the most significant prognostic factor, with a great impact on morbidity, disease-related survival and management of oncological therapies; for this reason, adequate imaging evaluation is strictly necessary. Physical examination is not enough sensitive to assess breast cancer nodal status; axillary ultrasonography (US) is commonly used to detect suspected or occult nodal metastasis, providing exclusively morphological evaluation, with low sensitivity and positive predictive value. Currently, sentinel lymph node biopsy (SLNB) and/or axillary dissection are the milestone for the diagnostic assessment of axillary lymph node metastases, although its related morbidity. The impact of magnetic resonance imaging (MRI) in the detection of nodal metastases has been widely investigated, as it continues to represent the most promising imaging modality in the breast cancer management. In particular, diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values represent additional reliable non-contrast sequences, able to improve the diagnostic accuracy of breast cancer MRI evaluation. Several studies largely demonstrated the usefulness of implementing DWI/ADC MRI in the characterization of breast lesions. Herein, in the light of our clinical experience, we perform a review of the literature regarding the diagnostic performance and accuracy of ADC value as potential pre-operative tool to define metastatic involvement of nodal structures in breast cancer patients. For the purpose of this review, PubMed, Web of Science, and SCOPUS electronic databases were searched with different combinations of "axillary lymph node", "breast cancer", "MRI/ADC", "breast MRI" keywords. All original articles, reviews and metanalyses were included.

Pathobiological and Radiological Approach For Hepatocellular Carcinoma Subclassification.

Many advances have been made in the imaging diagnosis and in the histopathological evaluation of HCC. However, the classic imaging and histopathological features of HCC are still inadequate to define patient's prognosis. We aimed to find the link between new proposed morphovascular patterns of hepatocellular carcinoma (HCC) and magnetic resonance imaging (MRI) features to identify pre-operatory markers of biologically aggressive HCC. Thirty-nine liver nodules in 22 patients were consecutively identified. Histopathological analysis and immunohistochemistry for CD34 and Nestin were performed to identify the four different HCC morphovascular patterns. MRI was performed using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid. Three out of four morphovascular HCC patterns showed peculiar MRI features: in particular Pattern D (solid aggressive HCCs with CD34+/Nestin+ new-formed arteries) were isointense on T1-WI in 83% of cases and hyperintense on T2-WI in 50%. Five histologically-diagnosed HCC were diagnosed as non-malignant nodules on MRI due to their early vascularization and low aggressiveness (Pattern A). The comparison between histology and MRI confirms that a subclassification of HCC is possible in a pre-operatory setting. MRI seems to reinforce once more the identity of the different morphovascular HCC patterns and the possibility to pre-operatively identify HCCs with features of biological aggressiveness.

Delayed enhancement in differential diagnosis of salivary gland neoplasm.

BACKGROUND: Multi-phasic Computed Tomography (CT) evaluation allows to study the enhancement features of parotid gland masses. The aim of our study was to evaluate the role of delayed enhancement in the characterization of different histologic types of parotid tumours. METHODS: Forty-eight patients (22 male and 26 female) with at least one parotid gland tumor, were included in our study. Multi-phase CT images were obtained before and 30, 120 s and 8 minutes after intravenous contrast injection. The images were evaluated by two radiologists for lesion enhancement degree. A quantitative assessment was performed using a region of interest on each lesion and density changes between different phases were compared. The tumoral enhancement ratio was calculated between the 8 minutes delayed and the early (30 s) phase. The pathological diagnosis was confirmed in all patients after surgery. RESULTS: All patients had unilateral lesion for a total of 48 lesions. Twenty-eight were pleomorphic adenomas, 15 Warthin's tumours and 5 carcinomas. All Warthin tumours showed a rapid contrast enhancement at the early phase (30 sec) followed by a progressive wash-out during the delayed scans. Most of pleomorphic adenomas (89.2%) showed the highest density at the 8-minutes delayed phase. Malignant tumours showed slower contrast enhancement and 3 out of 5 (60%) showed a marked decrease at the 8 minutes delayed phase while the remaining 2 (40%), did not show any density reduction. The tumoral enhancement ratio was significantly different between Warthin tumours and pleomorphic adenomas and between Warthin's and malignant tumours. CONCLUSIONS: Multi-phasic CT examination with 8 minutes delayed acquisition has shown to be useful in parotid gland lesion differentiation.