Evaluation of proton density fat fraction (PDFF) obtained from a vendor-neutral MRI sequence and MRQuantif software.

OBJECTIVE: To validate the proton density fat fraction (PDFF) obtained by the MRQuantif software from 2D chemical shift encoded MR (CSE-MR) data in comparison with the histological steatosis data. METHODS: This study, pooling data from 3 prospective studies spread over time between January 2007 and July 2020, analyzed 445 patients who underwent 2D CSE-MR and liver biopsy. MR derived liver iron concentration (MR-LIC) and PDFF was calculated using the MRQuantif software. The histological standard steatosis score (SS) served as reference. In order to get a value more comparable to PDFF, histomorphometry fat fraction (HFF) were centrally determined for 281 patients. Spearman correlation and the Bland and Altman method were used for comparison. RESULTS: Strong correlations were found between PDFF and SS (rs = 0.84, p < 0.001) or HFF (rs = 0.87, p < 0.001). Spearman's coefficients increased to 0.88 (n = 324) and 0.94 (n = 202) when selecting only the patients without liver iron overload. The Bland and Altman analysis between PDFF and HFF found a mean bias of 5.4% ± 5.7 [95% CI 4.7, 6.1]. The mean bias was 4.7% ± 3.7 [95% CI 4.2, 5.3] and 7.1% ± 8.8 [95% CI 5.2, 9.0] for the patients without and with liver iron overload, respectively. CONCLUSION: The PDFF obtained by MRQuantif from a 2D CSE-MR sequence is highly correlated with the steatosis score and very close to the fat fraction estimated by histomorphometry. Liver iron overload reduced the performance of steatosis quantification and joint quantification is recommended. This device-independent method can be particularly useful for multicenter studies. CLINICAL RELEVANCE STATEMENT: The quantification of liver steatosis using a vendor-neutral 2D chemical-shift MR sequence, processed by MRQuantif, is well correlated to steatosis score and histomorphometric fat fraction obtained from biopsy, whatever the magnetic field and the MR device used. KEY POINTS: • The PDFF measured by MRQuantif from 2D CSE-MR sequence data is highly correlated to hepatic steatosis. • Steatosis quantification performance is reduced in case of significant hepatic iron overload. • This vendor-neutral method may allow consistent estimation of PDFF in multicenter studies.

Lack of benefit of routine abdominal CT-scan before bariatric surgery.

BACKGROUND: Scientific societies recommend to seek cancer prior to bariatric surgery. In our tertiary referral center, we aimed to study performance of abdominal CT-scan before bariatric surgery. PATIENTS AND METHODS: We retrospectively included all patients who underwent bariatric surgery and a pre-operative abdominal CT-scan in our academic center, between January 2015 and December 2018. RESULTS: We included 521 patients (417 women and 104 men) with a mean age of 48.0±11.5 years. Mean preoperative body mass index was 44.9±7.0kg/m2. Among the 392 patients with abnormal CT-scan, mean number of anomalies per patient was of 2.2±1.2. Vast majority of anomalies (91.8%) were non-significant. Only 5 (1%) patients needed treatment prior to bariatric surgery. No factor predictive of abnormal CT-scan was found. CONCLUSION: Only few patients had severe anomaly on CT-scan before bariatric surgery. Abdominal CT-scan could not be advocated to seek cancer before bariatric surgery.

Promising clinical performance of pretargeted immuno-PET with anti-CEA bispecific antibody and gallium-68-labelled IMP-288 peptide for imaging colorectal cancer metastases: a pilot study.

INTRODUCTION: This pilot study evaluated the imaging performance of pretargeted immunological positron emission tomography (immuno-PET) using an anti-carcinoembryonic antigen (CEA) recombinant bispecific monoclonal antibody (BsMAb), TF2 and the [68Ga]Ga-labelled HSG peptide, IMP288, in patients with metastatic colorectal carcinoma (CRC). PATIENTS AND METHODS: Patients requiring diagnostic workup of CRC metastases or in case of elevated CEA for surveillance were prospectively studied. They had to present with elevated CEA serum titre or positive CEA tumour staining by immunohistochemistry of a previous biopsy or surgical specimen. All patients underwent endoscopic ultrasound (EUS), chest-abdominal-pelvic computed tomography (CT), abdominal magnetic resonance imaging (MRI) and positron emission tomography using [18F]fluorodeoxyglucose (FDG-PET). For immuno-PET, patients received intravenously 120 nmol of TF2 followed 30 h later by 150 MBq of [68Ga]Ga-labelled IMP288, both I.V. The gold standard was histology and imaging after 6-month follow-up. RESULTS: Eleven patients were included. No adverse effects were reported after BsMAb and peptide injections. In a per-patient analysis, immuno-PET was positive in 9/11 patients. On a per-lesion analysis, 12 of 14 lesions were positive with immuno-PET. Median SUVmax, MTV and TLG were 7.65 [3.98-13.94, SD 3.37], 8.63 cm3 [1.98-46.64; SD 14.83] and 37.90 cm3 [8.07-127.5; SD 43.47] respectively for immuno-PET lesions. Based on a per-lesion analysis, the sensitivity, specificity, positive-predictive value and negative-predictive value were, respectively, 82%, 25%, 82% and 25% for the combination of EUS/CT/MRI; 76%, 67%, 87% and 33% for FDG-PET; and 88%, 100%, 100% and 67% for immuno-PET. Immuno-PET had an impact on management in 2 patients. CONCLUSION: This pilot study showed that pretargeted immuno-PET using anti-CEA/anti-IMP288 BsMAb and a [68Ga]Ga-labelled hapten was safe and feasible, with promising diagnostic performance. TRIAL REGISTRATION: ClinicalTrials.gov NCT02587247 Registered 27 October 2015.

Percutaneous CT-guided lung biopsy for the diagnosis of persistent pulmonary consolidation.

PURPOSE: The primary objective of this study was to determine the diagnostic accuracy of percutaneous computed tomography (CT)-guided biopsy of persistent pulmonary consolidations. The secondary objective was to determine the complication rate and identify factors affecting diagnostic yield. MATERIALS AND METHODS: Two radiologists retrospectively reviewed 98 percutaneous CT-guided biopsies performed in 93 patients (60 men, 33 women; mean age, 62±14.0 (SD) years; range: 18-88 years) with persistent pulmonary consolidations. Final diagnoses were based on surgical outcomes or 12 months clinical follow-up findings. Biopsy results were compared to the final diagnosis to estimate diagnostic yield. RESULTS: A final diagnosis was obtained for all patients: 51/93 (54.8%) had malignant lesions, 12/93 (12.9%) specific definite benign lesions (including 9 infections, two pneumoconiosis and one lipoid pneumonia) and 30/93 (32.3%) non-specific benign lesions. CT-guided biopsy had an overall diagnostic yield of 60% (59/98) with a correct diagnosis for 50/51 malignant lesions (diagnostic yield of 98% for malignancy) and for 9/47 benign lesions (diagnostic yield of 19% for benign conditions). Major complications occurred in 4/98 (4%) of lung biopsies (four pneumothoraxes requiring chest tube placement). CONCLUSION: Percutaneous CT-guided biopsy is an alternative to endoscopic or surgical biopsy for the diagnosis of persistent consolidation with a low risk of severe complication.

[Magnetic Resonance Imaging for local preoperative staging in endometrial cancer: Nantes local experience]. / Performances de l'IRM dans le bilan d'extension locale préopératoire des cancers de l'endomètre : l'expérience nantaise.

OBJECTIVES: To determine the diagnostic accuracy of magnetic resonance imaging (MRI) for local preoperative staging in endometrial cancer in our center (Centre Hospitalier Universitaire de Nantes: CHU), since the French National Cancer Institute's surgery recommendations publication in 2010, especially for the prediction of myometrial and cervical stromal invasion. METHODS: Retrospective monocentric study of consecutive women operated of endometrial cancer in gynecology department of CHU de Nantes, who underwent preoperative pelvic MRI in our Radiology department from November 2010 to November 2016. MRI data collected from initial report and compared to surgical histological findings as gold standard. RESULTS: Sixty-four patients were included. Deep myometrial invasion was present in 35 patients in MRI versus 34 patients on postoperative histology (5 false positives, 4 false negatives). Cervical stromal invasion was present in 9 patients in MRI versus 19 patients on postoperative histology (2 false positives, 12 false negatives). The sensitivity and the specificity were respectively 88.23% (95% confidence intervals (CI) [0.71-0.96]) and 83.33% (CI [0.64-0.93]) for the deep myometrial invasion; 36.84% (CI [0.17-0.61]) and 95.55% (CI [0.83-0.99]) for the cervical stromal invasion. CONCLUSION: Our results were comparable to the literature data, with a low sensitivity for the cervical stromal invasion detection, driving us to change our MRI protocol with optional high-resolution T2 sequences perpendicular to the cervical canal if necessary.

Radiographic presentation of musculoskeletal involvement in Werner syndrome (adult progeria).

Werner syndrome (i.e., adult progeria) is a rare autosomal recessive disorder caused by mutations of the WRN gene, which is characterized by the premature appearance of features associated with normal aging and cancer predisposition. Patients with Werner syndrome can present with musculoskeletal complaints, associated with suggestive radiographic features with a potential prognostic or therapeutic impact. This review illustrates the main radiographic features of Werner syndrome, focusing on the musculoskeletal system, such as soft-tissue calcification, muscular atrophy, osteoporosis, foot deformities, osteitis and osteomyelitis, and bone or soft-tissues malignancies. The identification of these features by radiologists can therefore be useful in the clinical screening of Werner syndrome.

Internal rectal prolapse: Definition, assessment and management in 2016.

Internal rectal prolapse (IRP) is a well-recognized pelvic floor disorder mainly seen during defecatory straining. The symptomatic expression of IRP is complex, encompassing fecal continence (56%) and/or evacuation disorders (85%). IRP cannot be characterized easily by clinical examination alone and the emergence of dynamic defecography (especially MRI) has allowed a better comprehension of its pathophysiology and led to the proposition of a severity score (Oxford score) that can guide management. Decision for surgical management should be multidisciplinary, discussed after a complete work-up, and only after medical treatment has failed. Information should be provided to the patient, outlining the goals of treatment, the potential complications and results. Stapled trans-anal rectal resection (STARR) has been considered as the gold standard for IRP treatment. However, inconsistent results (failure observed in up to 20% of cases, and fecal incontinence occurring in up to 25% of patients at one year) have led to a decrease in its indications. Laparoscopic ventral mesh rectopexy has substantial advantages in solving the functional problems due to IRP (efficacy on evacuation and resolution of continence symptoms in 65-92%, and 73-97% of patients, respectively) and is currently considered as the gold standard therapy for IRP once the decision to operate has been made.

Pancreatic carcinoma: Key-points from diagnosis to treatment.

Pancreatic ductal carcinoma is one of the deadliest cancers in the world. The only hope for prolonged survival still remains surgery with complete R0 resection even if most patients will promptly develop metastases and/or local relapses. Due to the silent nature of the disease, fewer than 20% of patients are eligible for a curative-intent resection. As no gain in survival is expected in case of residual tumor, imaging plays a major role for diagnosis and staging to select patients who will undergo surgery. Multidetector-row computed tomography and magnetic resonance imaging are the key stones and radiologists must be aware of imaging protocols, standardized terms and critical points for structured reporting to assess the tumor staging, minimize potential the morbidity associated with surgery and offer patients the best therapeutic strategy.

Peripharyngeal space tumors: Can magnetic resonance and multidetector-row computed tomography help predict location, malignancy and tumor type?

PURPOSE: The goal of this study was to assess the performances of magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) in determining tumor location, suggesting the specific diagnosis of tumors involving the peripharyngeal space and identifying findings suggestive for malignancy using histopathological findings as standard of reference. MATERIAL AND METHODS: The MDCT and MRI examinations of 99 patients with a total of 102 tumors located in the retropharyngeal, carotid and parapharyngeal spaces were retrospectively reviewed. MDCT and MRI examinations were independently analyzed for tumor location and specific histological type of tumor. Finally, benign or malignant criteria were evaluated. Agreement between imaging features and final histopathological diagnosis that served as the standard of reference was assessed with the Kappa statistic. RESULTS: Regarding tumor location almost perfect agreement was obtained between imaging findings and histopathological findings (kappa=0.86 and 0.92 for MDCT and MRI, respectively). Agreement between the results of imaging and histopathological findings regarding malignancy was substantial for MDCT (Kappa=0.73), MRI (Kappa=0.65). A definite histopathological diagnosis was suggested on the basis of imaging findings for 84 tumors and in agreement with the final histopathological diagnosis in 77/84 tumors (92%). CONCLUSION: MDCT and MRI provide accurate information to localize and characterize peripharyngeal tumors. These two examinations provide complementary data to identify imaging criteria that suggest malignancy.

Medico-economic study of the management of hepatocellular carcinoma by chemo-embolization.

PURPOSE: This study has two aims. The first is to compare conventional lipiodol chemo-embolization (Trans Arterial Chemo-Embolization - TACE) to one using pre-loaded particles (Trans Arterial Chemo-Embolisation-Drug Eluted Bead - TACE-DEB) using a cost minimization study. The second is to define the fundable nature of TACE-DEB and the conditions under which it is cost-effective. MATERIALS AND METHODS: Retrospective study of patients treated by chemo-embolization (n=31: TACE; n=32: TACE-DEB) during the year 2010. The cost minimization study was conducted from the hospital perspective. Direct medical costs were calculated and compared using the readjusted ENCC (National Studies of Costs by Common Methodology) method. The affordability of the two techniques and definition of a cost-effective hypothesis (break-even point) were also established. RESULTS: All DRGs combined, lengths of stay (TACE: 4.90 ± 3.36; TACE-DEB: 5.03 ± 3.36) does not change significantly. An average upper mean cost for TACE-DEB is described (TACE: 2869.05 €; TACE-DEB: 3960.10 €). The affordability calculations in the study show that, overall, TACE-DEB can be funded regardless of DRG. A ratio of 1.3 procedures using the conventional (TACE) method would enable TACE-DEB procedures to be funded. CONCLUSION: This medico-economic analysis demonstrates that the TACE-DEB procedure is fundable.

A solid pancreatic mass: tumour or inflammation?

The prognosis for pancreatic cancer is poor, and early diagnosis is essential for surgical management. By comparison with its classic form, the presence of acute or chronic inflammatory signs will hinder its detection and delay its diagnosis. The atypical forms of acute pancreatitis need to be known in order to detect patients who require additional morphological investigations to search for an underlying tumour. In contrast, pseudotumoral forms of inflammation (chronic pancreatitis, cystic dystrophy in heterotopic pancreas, autoimmune pancreatitis) may simulate a cancer, and make up 5-10% of the surgical procedures for suspected cancer. Faced with these pseudotumoral masses, interpretation relies on various differentiating signs and advances in imaging.

Lymphomas: Basic points that radiologists should know.

Lymphomas affect the lymphoid system and may be expressed in a variety of ways and behave in different fashions. The polymorphism of their expression, depending on the organ involved, their variable aggressiveness and their relative rarity compared with primary or secondary diseases sometimes makes it difficult to diagnose them from imaging. Knowledge of predisposing factors and radiological signs should help suggest this diagnosis and thus lead to biopsy samples being taken to confirm it.

FDG-PET in the evaluation of myeloma in 2012.

Multiple myeloma (MM) is a malignant haematological disease characterised by clonal proliferation of malignant plasma cells in the bone marrow. MM is expressed by diffuse infiltration of the bone marrow, focal bone lesions and extra-medullary lesions. Conventional staging follows the Salmon and Durie classification, which was recently revised (Salmon and Durie plus) to include MRI and FDG-PET examinations. FDG-PET is being evaluated for initial staging and therapeutic monitoring and its place still needs to be validated, particularly in comparison with MRI of the pelvis and spine, the reference examination for diagnosis, which is systematically combined with X-rays of the skeleton. Certain recent data in the literature suggest that FDG-PET provides better staging of the disease at the time of diagnosis than MRI, and that the examination has considerable prognostic value when it normalises after the initial courses of chemotherapy and at the end of treatment. As for the evaluation of lymphomas, the interpretation criteria should be standardised.

Staging and monitoring in the treatment of lymphomas.

Lymphoma staging systematically includes a CT scan of the cervical, thoracic and abdominopelvic regions. PET is indicated in diffuse large B cell lymphomas (DLBCL) and Hodgkin's disease. Evaluation of the response to treatment is based on Cheson's 1999 morphological criteria, which have been replaced by the 2007 IWC criteria, which combine morphological and metabolic responses. CT and FDG-PET are complementary in characterizing residual masses: if negative, a PET scan indicates the absence of residual disease, if positive; it directs a CT-guided biopsy to obtain the histological evidence. Monitoring clinical features and laboratory values is primordial following treatment. Imaging is performed as a second intention for investigating a relapse, if necessary associated with a PET scan. Multimodal imaging implies multidisciplinary consultation between haematologists, imaging specialists and histopathologists.

FDG-PET in Follicular Lymphoma Management.

18-Fluoro-deoxyglucose positron emission tomography/computerised tomography (FDG PET/CT) is commonly used in the management of patients with lymphomas and is recommended for both initial staging and response assessment after treatment in patients with diffuse large B-cell lymphoma and Hodgkin lymphoma. Despite the FDG avidity of follicular lymphoma (FL), FDG PET/CT is not yet applied in standard clinical practice for patients with FL. However, FDG PET/CT is more accurate than conventional imaging for initial staging, often prompting significant management change, and allows noninvasive characterization to guide assessment of high-grade transformation. For restaging, FDG PET/CT assists in distinguishing between scar tissue and viable tumors in residual masses and a positive PET after induction treatment would seem to predict a shorter progression-free survival.

Central pancreatectomy: comparison of results according to the type of anastomosis.

INTRODUCTION: The mild pancreatic tumors are more and more treated by central pancreatectomy (CP) in alternative with the widened pancreatectomies. Indeed, their morbidity is lesser but they are however burdened by a rate of important postoperative fistulas. The purpose of our study is to compare pancreatico-jejunal anastomosis and pancreatico-gastric anastomosis. METHODS: This work was realized in a bicentric retrospective way. Twenty-five CP were included and classified according to two groups according to the pancreatic anastomosis (group 1 for pancreatico-jejunal anastomosis and group 2 for the pancreatico-gastric anastomosis). CP was realized according to a protocol standardized in both centers and the complications were classified according to the classification of Clavien and Dindo and the fistulas according to the classification of Bassi. RESULTS: Both groups were comparable. The duration operating and the blood losses were equivalent in both groups. There was a significant difference (P=0,014) as regards the rate of fistula. The pancreatico-gastric anastomosis complicated more often of a low-grade fistula. However, in both groups, the treatment was mainly medical. Our results were comparable with those found in the literature and confirmed the advantages of the CP with regard to the cephalic duodeno-pancreatectomy (DPC) or to the distal pancreatectomy (DP). However, in the literature, a meta-analysis did not report difference between both types of anastomosis but this one concerned only the DPC. CONCLUSIONS: This work showed a less important incidence of low-grade fistula after pancreatico-jejunal anastomosis in the fall of a PM. This result should be confirmed by a later study on a more important sample of PM.