Whole-body MRI radiomics model to predict relapsed/refractory Hodgkin Lymphoma: A preliminary study.

PURPOSE: A strong prognostic score that enables a stratification of newly diagnosed Hodgkin Lymphoma (HL) to identify patients at high risk of refractory/relapsed disease is still needed. Our aim was to investigate the potential value of a radiomics analysis pipeline from whole-body MRI (WB-MRI) exams for clinical outcome prediction in patients with HL. MATERIALS AND METHODS: Index lesions from baseline WB-MRIs of 40 patients (22 females; mean age 31.7 ± 11.4 years) with newly diagnosed HL treated by ABVD chemotherapy regimen were manually segmented on T1-weighted, STIR, and DWI images for texture analysis feature extraction. A machine learning approach based on the Extra Trees classifier and incorporating clinical variables, 18F-FDG-PET/CT-derived metabolic tumor volume, and WB-MRI radiomics features was tested using cross-validation to predict refractory/relapsed disease. RESULTS: Relapsed disease was observed in 10/40 patients (25%), two of whom died due to progression of disease and graft versus host disease, while eight reached the complete remission. In total, 1403 clinical and radiomics features were extracted, of which 11 clinical variables and 171 radiomics parameters from both original and filtered images were selected. The 3 best performing Extra Trees classifier models obtained an equivalent highest mean accuracy of 0.78 and standard deviation of 0.09, with a mean AUC of 0.82 and standard deviation of 0.08. CONCLUSIONS: Our preliminary results demonstrate that a combined machine learning and texture analysis model to predict refractory/relapsed HL on WB-MRI exams is feasible and may help in the clinical outcome prediction in HL patients.

Dynamic contrast-enhanced (DCE) imaging: state of the art and applications in whole-body imaging.

Dynamic contrast-enhanced (DCE) imaging is a non-invasive technique used for the evaluation of tissue vascularity features through imaging series acquisition after contrast medium administration. Over the years, the study technique and protocols have evolved, seeing a growing application of this method across different imaging modalities for the study of almost all body districts. The main and most consolidated current applications concern MRI imaging for the study of tumors, but an increasing number of studies are evaluating the use of this technique also for inflammatory pathologies and functional studies. Furthermore, the recent advent of artificial intelligence techniques is opening up a vast scenario for the analysis of quantitative information deriving from DCE. The purpose of this article is to provide a comprehensive update on the techniques, protocols, and clinical applications - both established and emerging - of DCE in whole-body imaging.

A regenerative 3D scaffold for inguinal hernia repair. MR imaging and histological cross evidence. Qualitative study.

BACKGROUND: Inguinal hernia is a degenerative disease occurring in a high motile surround. Stopping degeneration and promoting tissue regeneration should be the treatment goal. Groin hernias are conventionally managed with static flat meshes, mostly fixated to the delicate inguinal environment. Far from a regenerative effect, the biologic response of conventional hernia meshes is characterized by a foreign body reaction leading to a stiff/shrunken scar plate, which is often the source of unpleasant complications. Recently, a newly engineered 3D device for inguinal hernia repair - ProFlor-has been developed to produce a regenerative biological response. Unlike conventional hernia meshes, this regenerative 3D hernia scaffold seems to demonstrate suitable features for a pathogenetical and physiological coherent treatment of the disease. The aim of this manuscript is to cross evidence these features through magnetic resonance imaging (MRI) and histology. STUDY DESIGN: The biological response of ProFlor at three defined post-implantation stages has been evaluated through MRI signal intensity and compared to neighbouring muscles and fat. As additional proof, histology of tissue specimens excised at the same post-implantation periods from porcine models during an experimental attempt were also evaluated. RESULTS: MRI of newly ingrown tissue in ProFlor demonstrated similar signal intensity of muscles while fat tissue showed remarkably higher values. These data matched with the histology of ProFlor biopsies excised from pigs. CONCLUSIONS: The motile compliance to groin movements of ProFlor appears to induce a probiotic biologic response comparable to a regenerative scaffold, allowing to physiologically resolve the degenerative source of inguinal hernia disease.

Whole-Body Magnetic Resonance Imaging: Current Role in Patients with Lymphoma.

Imaging of lymphoma is based on the use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) and/or contrast-enhanced CT, but concerns have been raised regarding radiation exposure related to imaging scans in patients with cancer, and its association with increased risk of secondary tumors in patients with lymphoma has been established. To date, lymphoproliferative disorders are among the most common indications to perform whole-body magnetic resonance imaging (MRI). Whole-body MRI is superior to contrast-enhanced CT for staging the disease, also being less dependent on histology if compared to 18F-FDG-PET/CT. As well, it does not require exposure to ionizing radiation and could be used for the surveillance of lymphoma. The current role of whole-body MRI in the diagnostic workup in lymphoma is examined in the present review along with the diagnostic performance in staging, response assessment and surveillance of different lymphoma subtypes.

Imaging side effects and complications of chemotherapy and radiation therapy: a pictorial review from head to toe.

Newer biologic drugs and immunomodulatory agents, as well as more tolerated and effective radiation therapy schemes, have reduced treatment toxicity in oncology patients. However, although imaging assessment of tumor response is adapting to atypical responses like tumor flare, expected changes and complications of chemo/radiotherapy are still routinely encountered in post-treatment imaging examinations. Radiologists must be aware of old and newer therapeutic options and related side effects or complications to avoid a misinterpretation of imaging findings. Further, advancements in oncology research have increased life expectancy of patients as well as the frequency of long-term therapy-related side effects that once could not be observed. This pictorial will help radiologists tasked to detect therapy-related complications and to differentiate expected changes of normal tissues from tumor relapse.

Whole-body magnetic resonance imaging (WB-MRI) in oncology: an Italian survey.

PURPOSE: To perform a survey among all members of the Italian Society of Medical and Interventional Radiology (SIRM) to assess how whole-body MRI (WB-MRI) is performed in oncologic patients in Italy. METHODS: On March 2019, we administered an online poll to all SIRM members about their use of WB-MRI in 2018 asking 15 questions regarding oncologic indications, imaging protocol, use of contrast media, experience in WB-MRI, duration of scan time and reporting time. RESULTS: Forty-eight members participated to the survey. WB-MRIs/total MRIs ratio was 1%. Lymphoma was the most common indication (17/48, 35%), followed by myeloma and prostate cancer, with these three tumors representing the most common indication in 39/48 of cases (81%). WB-MRI acquisition time and reporting time were 46-60 min in 22/48 centers (46%) and 20-30 min in 19/48 (40%), respectively. WB-MRIs were mostly performed in 1.5T scanners (43/48, 90%), with surface coils (22/48, 46%) being preferred to Q-body (15/48, 31%) and integrated coils (11/48, 23%). Contrast media were injected in 22/48 of the centers (46%), mainly used for breast cancer (13/22, 59%). DWI was the most used sequence (45/48, 94%), mostly with b800 (27/48, 56%), b0 (24/48, 50%) and b1000 (20/48, 42%) values. In about half of cases, radiologists started evaluating WB-MRI non-contrast morphologic sequences, then checking DWI and post-contrast images. CONCLUSION: WB-MRI was mainly performed at 1.5T unit, with lymphoma, myeloma and prostate cancer having been the most common indications. The extreme variability in the choice of imaging protocols and use of contrast agents demonstrates the need of a standardization of WB-MRI application in clinical practice.

Outcome of LR-3 and LR-4 observations without arterial phase hyperenhancement at Gd-EOB-DTPA-enhanced MRI follow-up.

OBJECTIVE: The aim of this study was to retrospectively analyze the outcome of LR-3 and LR-4 without arterial phase hyperenhancement (APHE), and identify which features could predict LR-5 progression on serial Gd-EOB-DTPA-enhanced MRI follow-up. METHODS: Forty-nine cirrhotic patients with 55 LR-3 and 19 LR-4 without APHE were evaluated. Observations were classified as decreased, stable or increased in category at follow-up. Observation size and LI-RADS major and ancillary features were evaluated. RESULTS: Seventeen/fifty-five (31%) LR-3 and 8/19 (42%) LR-4 progressed to LR-5 at follow-up. Baseline LI-RADS major and ancillary features were not significantly different among LR-3 and LR-4. A diameter ≥ 10 mm significantly increased LR-5 progression risk of LR-3 (OR = 6.07; 95% CI: 0.12; 60.28]; P < .001). LR-4 with a diameter ≥ 10 mm more likely become LR-5 at follow-up (OR = 8.95; 95% CI: 0.73; 111.8; P = .083]). CONCLUSION: LR-3 and LR-4 without APHE were often downgraded or remained stable in category on Gd-EOB-DTPA-enhanced MRI follow-up.

CT and MR imaging of cystic renal lesions.

Cystic renal lesions are a common incidental finding on routinely imaging examinations. Although a benign simple cyst is usually easy to recognize, the same is not true for complex and multifocal cystic renal lesions, whose differential diagnosis includes both neoplastic and non-neoplastic conditions. In this review, we will show a series of cases in order to provide tips to identify benign cysts and differentiate them from malignant ones.

Whole-body magnetic resonance imaging (WB-MRI) in lymphoma: State of the art.

The improvements in magnetic resonance imaging (MRI) technology and the concern related to the increased cancer risk in patients with lymphoma, also due to radiation exposure associated with imaging examinations, have led to the introduction of whole-body MRI (WB-MRI) as a radiation-free alternative to standard imaging procedures. WB-MRI seems a less histology-dependent functional imaging test than 18 F-fluorodeoxyglucose-positron emission tomography/CT (18 F-FDG-PET/CT). In patients with FDG-avid lymphomas, such as diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma (HL), 18 F-FDG-PET/CT remains the imaging reference standard for staging, with WB-MRI potentially being a complementary modality that could replace CT, especially in young patients. On the other hand, WB-MRI is a valuable imaging procedure for lymphoma surveillance and in lymphomas with variable/low FDG avidity and nonfollicular indolent lymphomas. The aim of this paper is to discuss the current state of the art of WB-MRI in lymphoma by evaluating its diagnostic performance in different lymphoma subtypes: Hodgkin, aggressive, and indolent lymphomas.