Domenico Albano

Comparison between whole-body MRI with diffusion-weighted imaging and PET/CT in staging newly diagnosed FDG-avid lymphomas.

OBJECTIVES To compare whole body-MRI (WB-MRI) with diffusion-weighted imaging and FDG-PET/CT in staging newly diagnosed FDG-avid lymphomas. METHODS 68 patients (37 males, 31 females; median age 42 years; range 15-86 years) with histologically confirmed lymphoma (37 Classical Hodgkin, 16 Diffuse large B-cell, 10 Follicular, 5 Mantle cell) underwent both MRI and FDG-PET/CT before treatment. Ann Arbor stages obtained with WB-MRI and FDG-PET/CT were compared using Cohens k statistics. Moreover WB-MRI and FDG-PET/CT stages were compared with the pathological stages obtained after the diagnostic iter using also bone marrow and available biopsies if clinically indicated. RESULTS The agreement between WB-MRI and FDG-PET/CT was excellent. WB-MRI stage was equal to those of FDG-PET/CT in 62/68 patients (91.2%). There was an excellent agreement between WB-MRI stage and pathological stage (63/68 patients; 92.6%), and between FDG-PET/CT and pathological stage (64/68 patients; 94.1%). The differences between the stages were more frequent in the patients with Mantle cell lymphoma. CONCLUSIONS WB-MRI can be considered as a promising technique for FDG-avid lymphoma staging.

Whole-body MRI, FDG-PET/CT, and bone marrow biopsy, for the assessment of bone marrow involvement in patients with newly diagnosed lymphoma

To compare whole‐body MRI (WB‐MRI) with diffusion‐weighted imaging (DWI), FDG‐PET/CT, and bone marrow biopsy (BMB), for the evaluation of bone marrow involvement (BMI) in patients with newly diagnosed lymphoma.

18F-FDG PET/CT Follow-up of Rosai-Dorfman Disease.

Rosai-Dorfman disease (RDD) or sinus histiocytosis is a rare histiocytic disorder characterized by massive lymphadenopathy and with extranodal involvement in 25% to 43% of cases. The clinical course of RDD is unpredictable with episodes of exacerbation and remissions that can last many years, and treatment strategies can be different according to organ involvement. We report a case of a 42-year-old woman with extranodal disease followed for almost 10 years from the diagnosis who underwent seven (18)F-FDG PET/CT. PET/CT has proven to be a useful method for the management of this patient, mainly for the staging, follow-up, and evaluation of treatment results.

Pitfalls in whole body MRI with diffusion weighted imaging performed on patients with lymphoma: What radiologists should know

The technological advances in radiological imaging and the relevance of a diagnostic tool that may reduce radiation-induced long-term effects have led to a widespread use of whole body magnetic resonance imaging (WB-MRI) with diffusion weighted imaging for oncologic patients. A lot of studies demonstrated the feasibility and reliability of WB-MRI as an alternative technique for lymphoma staging and response assessment during and after treatment. In this paper, taking advantage of our 2years of experience using WB-MRI for lymphoma, we discuss the main pitfalls and artifacts radiologists should know examining a WB-MRI performed on this typology of patients in order to avoid images misinterpretation.

18F-FDG PET/CT in gastric MALT lymphoma: a bicentric experience

PurposeThe role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma.Materials and methodsSixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics.ResultsThirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage (p=0.010), and Ki67 index (p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index (p=0.047; p=0.012; p=0.042).Conclusions18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio are correlated only with Ki-67 index, and only lesion-to-liver SUVmax ratio was independently associated with Ki-67 score.

18F-FDG PET/CT and extragastric MALT lymphoma: role of Ki-67 score and plasmacytic differentiation

Abstract The detection rate of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in extragastric mucosa associated lymphoid tissue (MALT) lymphoma is under debate and the reason is not clear. Our aim was to investigate the metabolic behavior of extragastric MALT lymphoma and whether the histological features (Ki-67 index and plasmacytic differentiation, PD) might explain it. PET/CT images were analyzed visually and semi-quantitatively and compared with Ki-67 index and PD. Seventy-two patients were included. Twelve of 18 patients with PD showed intense 18F-FDG uptake; on the contrary, 42 of 54 patients without PD had positive 18F-FDG PET/CT. Twenty-six of 27 patients with Ki-67 > 15% had 18F-FDG-avid lesions; 28 of 45 patients with Ki-67 ≤ 15% had positive 18F-FDG PET/CT. 18F-FDG avidity was significantly associated with Ki-67 index (p < .001) and not correlated with PD (p = .352). Maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio and lesion-to-blood pool SUVmax ratio were not correlated with Ki-67 index or PD. 18F-FDG avidity was noted in 75% and is correlated only with Ki-67.

Gadolinium accumulation after contrast-enhanced magnetic resonance imaging: Which implications in patients with Crohn's disease?

Crohns disease (CD) is a chronic inflammatory condition of the bowel, characterized by an alternation of remission and relapse phases, leading to a progressive intestinal damage with loss of function. Magnetic resonance enterography has been widely used in the past for the evaluation of fistulizing disease, but its use increased over time, being considered helpful in different moments of disease course. Intravenous injection of Gadolinium-based contrast agents has been demonstrated to be crucial to assess mucosal inflammation, transmural involvement, and extraintestinal disease. Recently, Gadolinium accumulation in human tissues has been increasingly reported, although clinical implications of this event are still unclear. In the present paper, we review the main evidence on the topic, focusing on the potential implications for gastroenterological practice.

Gadolinium accumulation after contrast-enhanced magnetic resonance imaging: what rheumatologists should know

Magnetic resonance imaging (MRI) is an imaging modality capable to explore all anatomic areas of the human body, with the great advantage of avoiding ionizing radiation exposure. In the joints,MRI is the modality of choice in the evaluation of cartilage, joint space, and synovium and is excellent in evaluating all periarticular structures. MRI has gained an increased importance in rheumatology, mainly for the possibility of early diagnosis and evaluation of disease activity in patients with seronegative spondyloarthropaties involving the spine [1]. In addition, a baseline evaluation of the hand and wrist in patients with rheumatoid arthritis (RA) is considered useful by many rheumatologists because it can evaluate synovitis, erosions, and bone marrow edema (BME) with a single examination [2]. The European League against Rheumatism (EULAR) recommendations on imaging in RA suggest that MRI can be useful to: confirm the diagnosis of RA by showing synovitis in clinically unaffected joints; predict the severity and progression of RA; and assess residual synovitis in RA patients in clinical remission [3]. The sensitivity in detecting erosions of the RAwrist is higher for MRI than for radiography. As a result, MRI has been accepted by both the Outcome Measures in Rheumatology (OMERACT) [4] and the American College of Rheumatology [5] for the evaluation of structural damage in clinical trials studying novel therapeutic agents in RA and in psoriatic arthritis. BME is a significant predictor of negative prognosis in patients with early, undifferentiated arthritis and in those with established RA [6]. Finally, synovitis can be visualized comparing unenhanced and contrast-enhanced static images but also by dynamic MRI, i.e., following the course of contrast enhancement during the time after injection [7]. All the previous aspects are summarized in a composite score, the rheumatoid arthritis MRI scoring system (RAMRIS), which is used during MRI follow-up of RA patients [8]. In the real world, few patients outside industry-sponsored clinical trials to test the efficacy of new drugs perform a regular follow-up by contrast-enhanced MRI. However, since very often the standards employed in controlled clinical trials are subsequently transferred to everyday clinical practice [9], it is possible that MRI will be more frequently used in RA in the next future. Using static and variable magnetic fields and non-ionizing radiofrequency radiations, MRI has been traditionally regarded as a safe imaging modality in rheumatology, only limited by the presence of absolute contraindications such as the presence of MR-unsafe devices in patient’s body. Contrast agents used in MRI are mainly based on paramagnetic substances, capable to locally change the relaxation times of * Luca Maria Sconfienza io@lucasconfienza.it

Quantification of epicardial adipose tissue in coronary calcium score and CT coronary angiography image data sets: comparison of attenuation values, thickness and volumes

OBJECTIVE The aim of the study was to compare epicardial adipose tissue (EAT) characteristics assessed with coronary calcium score (CS) and CT coronary angiography (CTCA) image data sets. METHODS In 76 patients (mean age 59 ± 13 years) who underwent CS and CTCA owing to suspected coronary artery disease (CAD), EAT was quantified in terms of density (Hounsfield units), thickness and volume. The EAT volume was extracted with a semi-automatic software. RESULTS A moderate correlation was found between EAT density in CS and CTCA image data sets (-100 ± 19 HU vs -70 ± 24 HU; p < 0.05, r = 0.55). The distribution of EAT was not symmetrical with a maximal thickness at the right atrioventricular groove (14.2 ± 5.3 mm in CS, 15.7 ± 5 mm in CTCA; p > 0.05, r = 0.76). The EAT volume resulted as 122 ± 50 cm(3) in CS and 86 ± 40 cm(3) in CTCA (Δ = 30%, p < 0.05, r = 0.92). After adjustment for post-contrast EAT attenuation difference (Δ = 30 HU), the volume was 101 ± 47 cm(3) (Δ = 17%, p < 0.05, r = 0.92). Based on EAT volume median values, no differences were found between groups with smaller and larger volumes in terms of Agatston score and CAD severity. CONCLUSION CS and CTCA image data sets may be equally employed for EAT assessment; however, an underestimation of volume is found with the latter acquisition even after post-contrast attenuation adjustment. ADVANCES IN KNOWLEDGE EAT may be measured by processing either the CS or CTCA image data sets.

Solid bone tumors of the spine: Diagnostic performance of apparent diffusion coefficient measured using diffusion-weighted MRI using histology as a reference standard

To assess the diagnostic performance of mean apparent diffusion coefficient (mADC) in differentiating benign from malignant bone spine tumors, using histology as a reference standard. Conventional magnetic resonance imaging (MRI) sequences have good reliability in evaluating spinal bone tumors, although some features of benign and malignant cancers may overlap, making the differential diagnosis challenging.