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.

[Impact of partial nephrectomy in a hybrid operating room on the activity of kidney cancer surgery]. / Évaluation de l'utilisation de la salle hybride sur l'activité de chirurgie en cancérologie rénale.

INTRODUCTION: Partial nephrectomy (NP) after embolization of tumor vessels (NPESH) in a hybrid room combines embolization of tumor vessels and enucleation of the tumor under laparoscopy in the same operative time. The purpose of this study was to assess the impact of the use of NPESH in the management of patients treated with surgery for a localized kidney tumor. MATERIAL AND METHODS: Using the uroCCR database, we included all consecutive patients operated in a university hospital for localized kidney tumor. From 2011 to May 2015, patients were treated by Standard Partial Nephrectomy (NPS) Laparoscopic or Open and from May 2015 to May 2019 by NPESH. We evaluated characteristics of patients, tumors, perioperative data and complications. These data were compared by Student and Khi2 tests. RESULTS: 87 NPS were performed during Period 1 and 137 NPS were performed during period 2. The ASA score of patients undergoing NPESH was higher than NPS (P<0.0001). The tumor complexity and median tumor size were similar in the two groups (P=0.852 and P=0.48). The complication rate for NPS and NPESH was 55.2% and 33.6% (P=0.002). There were less severe complications in the NEPSH group (P=0.012). The median length of stay was 8 and 4 days for the NPS and NPESH groups (P<0.0001). Positive surgical margins were 2 (2.3%) and 6 (4.6%) for the NPS and NPESH group (P=0.713). DISCUSSION: NPESH is an efficient technique compared to NPS. It seems to be an interesting alternative to limit renal ischemia, complication rate and length of stay for the management of localized kidney tumors.

Utility of enhanced CT for patients with suspected uncomplicated renal colic and no acute findings on non-enhanced CT.

AIM: To evaluate the utility of contrast-enhanced computed tomography (CECT) for patients with suspected uncomplicated renal colic (URC) and no abnormalities on non-enhanced computed tomography (NECT). MATERIALS AND METHODS: The hospital institutional review board and ethics committee approved this retrospective study with a waiver of informed consent. Between January 2016 and April 2017, all consecutive adult patients who consulted at the adult Emergency Department (ED) with suspected URC and who had undergone both NECT and CECT were included retrospectively. The primary endpoint was prevalence of CECT-only diagnosis without acute findings on NECT. The risk factors for an acute finding were identified by logistic regression analysis. RESULTS: Among 126 patients with suspected URC, 12 were excluded. Among the 76 patients with no acute findings on NECT, CECT led to find acute lesions in 14/76 (18%) cases, but only 2/76 (3%) resulted in a change of management. Predictive factors of abnormal finding on CECT were: low renal clearance and high leukocyte count with OR 0.96 (95% confidence interval [CI]: 0.93-0.99), p=0.0189 and OR 5.79 (95% CI: 1.55-21.64), p=0.0091, respectively. CONCLUSIONS: In most cases, NECT is sufficient for screening patients with suspected URC. If leucocytosis and low renal function are present, stronger consideration may be given to CECT.

Failure of Conservative Treatment of Acute Diverticulitis with Extradigestive Air.

BACKGROUND: Medical management for perforated diverticulitis without abscess or peritonitis (PDwAP) has a success rate of 40-70%. Identifying patients with a risk of medical treatment failure would improve outcomes. The aim of this study was to identify the risk factors for failure of medical treatment in patients admitted with PDwAP. METHODS: This multicenter retrospective observational study included all consecutive patients admitted for PDwAP and not surgically treated over a 7-year period. Peritonitis classified on the Hinchey scale was excluded. Potential clinical, biological and radiological risk factors for medical treatment failure were collected and compared between the group of patient with a failure of medical treatment (F) and the group in which treatment did not fail. Data were collected at referral. RESULTS: Ninety-one patients were included, and 29 had a failure of treatment (31.9%). The median heart rate was different between the two groups (p < 0.001), at approximately 100/min in the F group. A blood level of C-reactive protein (CRP) ≥150 mg/mL was associated with a higher rate of failure (p = 0.021), but it was not confirmed in multivariate analysis. Pneumoperitoneum ≥5 mm and intraperitoneal liquid located in the pouch of Douglas were more likely to be present in the F group (respectively, p = 0.001 and p < 0.001). A multivariate analysis showed independent risk factors as being the highest pneumoperitoneum diameter >5 mm (OR 5.193; p = 0.015) and peritoneal fluid location in the pouch of Douglas (OR 4.103; p = 0.036). CONCLUSION: The severity of sepsis (tachycardia and CRP ≥150 mg/mL) and of imaging signs (pneumoperitoneum ≥5 mm and peritoneal fluid in the pouch of Douglas) were risk factors for medical treatment failure of PDwAP requiring special supervision so as not to lose time in undertaking surgical management.

Water-enema multidetector computed tomography for planning surgery.

PURPOSE: Water-enema multidetector computed tomography (WE-MDCT) is a technique for the localization and preoperative T- and N-stage assessments of colon cancer. It may be a useful tool for planning surgery. The primary aim of this study was to evaluate the diagnostic accuracy of WE-MDCT for T-staging and its ability to locate tumors for laparoscopy planning. The secondary aim was to assess reading reproducibility and diagnostic accuracy for the preoperative determination of N-stage. METHODS: We performed a study to evaluate preoperative WE-MDCT for surgical planning in patients with symptomatic colon adenocarcinomas who underwent surgery between June 2010 and January 2014. A radiologist and a surgeon read the WE-MDCTs separately. Results were compared with colonoscopy and the surgical specimen. RESULTS: Seventy-one patients (42 men (59.1%); mean age 73.1 years (range 45 to 95)) were included. Seventy-six tumors were assessed. The intraclass correlation coefficient (ICC) for location as determined by surgery and that determined by WE-MDCT was 1, and the ICC for location between colonoscopy and WE-MDCT was 0.85 (95% CI 0.75-0.91). For T-stage determination, sensitivity was 96 and 94% and specificity 83 and 88% for readers 1 and 2, respectively. The T-stage assessment allowed for the programing of surgical access and showed good sensitivity and specificity for the assessment of invasion in adjacent organs. CONCLUSION: WE-MDCT is relatively easy to perform, and its results can be read effectively by radiologists and surgeons. WE-MDCT indicated the location of tumors perfectly and permitted a good determination of their T-stage. The technique is thus pertinent for the planning of laparoscopic surgery for colon cancer.

Accuracy of water-enema multidetector computed tomography (WE-MDCT) in colon cancer staging: a prospective study.

PURPOSE: To assess the accuracy of water-enema multidetector computed tomography (WE-MDCT) in extra-rectal colon cancer staging. MATERIALS AND METHODS: Fifty-three patients (mean age 70 years) with extra-rectal colon cancer proven by colonoscopy and biopsy were prospectively evaluated by preoperative WE-MDCT. CT scans were both intraluminal (water enema or WE) and intravenous (iodinated) contrast enhanced (CE). All patients underwent surgery. Tumors were classified with the TNM staging system. Noted CT features were: tumor size and location; tumor form and edges; spread to the pericolic fat or neighboring organs; thickening of retroperitoneal fascia; number, size, and enhancement of the peritumoral lymph nodes. Tumors were classified on CT into 3 T-stage groups: T1/T2, T3, and T4. Lymph nodes were classified by their density after injection [positive over 100 Hounsfield units (HU)]. RESULTS: Tumor localization to the specific colon segment was correct in all the cases. The agreement between WE-MDCT staging and histopathology staging was good (k = 0.64). An irregular and bowl-shaped aspect of the external edges of tumor provided excellent sensitivity for T3/T4 inclusion (Se 97.7%, NPV 85.7%). Thickening of a fascia or the abdominal wall provided good specificity for T4 stage (Sp 88.1%, NPV 94.9%). Enhancement over 100 HU of at least one peritumoral lymph node was the best criterion of N+ staging (Sp 67.7%, NPV 87.5%). CONCLUSION: WE-MDCT permits good staging of colon cancer based on objective features.

Planned caesarean in the interventional radiology cath lab to enable immediate uterine artery embolization for the conservative treatment of placenta accreta.

AIM: To evaluate the feasibility and efficacy of routine uterine artery embolization (UAE) immediately after planned caesareans performed in the cath lab for conservative treatment of placenta accreta. MATERIALS AND METHODS: A retrospective study included all patients who had a planned caesarean in the cath lab for conservative treatment of placenta accreta at Angers University Hospital, which is a tertiary care centre, from April 2001 to September 2010. Twelve patients underwent UAE immediately after caesarean with the placenta left partially or totally in situ. The success rate of embolization, blood loss, and complications were reported. RESULTS: Diagnosis of abnormal placentation was confirmed by caesarean findings in 14 cases. Four patients had a percreta form with bladder invasion. In seven cases blood loss was insignificant and UAE was prophylactic; no secondary haemorrhage was observed in this group. Postpartum haemorrhage occurred in five cases: control of immediate postpartum bleeding by embolization was successful in three and failed in two leading to hysterectomy. In one case uterine necrosis occurred 6 weeks after embolization, requiring a hysterectomy. Delayed complications resulted in hysterectomy and partial bladder resection 3 months after delivery for one of the patients with placenta percreta. CONCLUSION: UAE immediately after a caesarean performed in the cath lab is a feasible therapeutic option for conservative treatment of placenta accreta. Advantages include reducing stress and risks associated with transferring women with potentially unstable haemodynamics.

Surgical management of adhesive small bowel obstruction: Is it still mandatory to wait? - An update.

Small bowel obstruction syndromes (SBO) represent one of the main causes of emergency admission for surgical abdominal pain. The 2018 Bologna Guidelines (Ten Broek et al. 2018) recommend non-operative management at the outset if there are no signs of severity; surgery is proposed after 72h for the 20-30% of patients who fail medical management. However, these recommendations were based on old studies published at a time when laparoscopic surgery was not commonplace and when diagnostic capabilities (particularly for establishing etiology) were less developed than they are today. Additionally, the advent and development of laparoscopy and enhanced rehabilitation after surgery have led to a decrease in surgical morbidity. These guidelines are therefore now debated and several recent publications have encouraged urgent or semi-urgent surgical management for patients presenting for SBO in order to reduce morbidity, mortality, duration of hospitalization and costs, and to improve the feasibility of therapeutic laparoscopy. Prompt surgical management could also reduce the risk of recurrent small bowel obstructions. This model for early surgical management probably cannot be applied to all patients. It therefore seems important to select those patients at risk for failure of medical treatment and to identify those in whom the probability of successful laparoscopy is high. New radiological tools should allow better selection in the future. At the present time, the indications for early surgery "within 24h" should be emphasized.

Distribution of abdominal adipose tissue as a predictor of hepatic steatosis assessed by MRI.

AIM: To evaluate the relationship between the distribution of visceral and subcutaneous adipose tissue and hepatic steatosis assessed using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One T1-weighted, in-/out-of-phase, single-section sequence at the L3/L4 level and one multi-echo gradient MRI (MGRE) sequence were performed on 65 patients [19 females and 46 males; age 57+/-9.5 years; body mass index (BMI) 31+/-5.1kg/m(2)]. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) surfaces, and hepatic steatosis were automatically calculated using in-house software. Weight, height, BMI, waist circumference, hip circumference, and waist:hip ratio were recorded. The probability of having a steatosis greater than 10% on MRI was evaluated by receiver operating characteristic (ROC) curves. RESULTS: The anthropometric parameter best correlated to hepatic steatosis was the waist-to-hip ratio (r=0.301). VAT and proportion of VAT were correlated to liver fat content (r=0.307 and r=0.249, respectively). No significant correlations were found for BMI, hip circumference, and SAT. The area under the receiver operating characteristics (AUROCs) for the relationship between liver steatosis and BMI, waist circumference, waist:hip ratio, VAT surface, and proportion of VAT, were respectively 0.52, 0.63, 0.71, 0.73 and 0.75. CONCLUSION: Adipose tissue distribution is more relevant than total fat mass when assessing the possibility of liver steatosis in overweight patients.

A not so solitary fibrous tumor of the liver.

Solitary fibrous tumor (SFT) is a rare neoplasm. Liver parenchyma is a rare location of SFT and, in this case, it usually follows a benign course. We report here the case of a 54-year-old man who presented a large SFT tumor of the right hepatic lobe. The tumor was surgically resected. Local recurrence occurred 6 years later as a 15 cm diameter liver tumor. Histological examination of the resected lesion showed features of an aggressive form of SFT. Two years later, the patient presented with complaints of neck pain and ensuing examinations revealed a tumor of the cranial base. A new surgical resection was performed and histological examination confirmed a metastasis of the SFT. Few weeks later, the patient presented an irreducible psoitis due to an iliac bone metastasis. He died within 1 month.

Radiation-induced cholangitis with hepatocellular carcinoma.

There are no reports of hepatocellular carcinoma complicating postradiotherapy cholangitis. We report the case of a 45-year-old patient who had undergone upper abdominal radiotherapy for Hodgkin's disease, 21 years before, which was complicated years later by cholangitis with stricture of the common bile duct. Biliodigestive anastomosic surgery was scheduled due to recurrent angiocholitis, and hepatocellular carcinoma was discovered. The patient died from carcinoma some months later.

[Cystic and cavitary lesions of the lung: imaging characteristics and differential diagnosis]. / Kystes et cavités du poumon: description sémiologique et approche étiologique.

Gas containing lesions of the lung can be differentiated into cystic and cavitary lesions based on their imaging characteristics, which is helpful for differential diagnosis. The imaging features include number, size, thickness and smoothness of the walls, content, lesion distribution and occasional associated lesions. Some imaging features have characteristic diagnostic implications: mural nodule and meniscus sign. Cysts are characterized by thin and regular walls, less than 2 mm in thickness. The differential diagnosis includes: histiocytosis X, lymphangioleiomyomatosis, cystic metastases, septic emboli, pulmonary sequestration. Emphysema, honeycombing and cystic bronchiectases should also be considered. Cavitary lesion have thicker walls. The most frequent etiologies include abscess, cavitary tumors, mycobacterial infections and fungal infections.

Liver fibrosis staging with contrast-enhanced ultrasonography: prospective multicenter study compared with METAVIR scoring.

We prospectively assessed contrast-enhanced sonography for evaluating the degree of liver fibrosis as diagnosed via biopsy in 99 patients. The transit time of microbubbles between the portal and hepatic veins was calculated from the difference between the arrival time of the microbubbles in each vein. Liver biopsy was obtained for each patient within 6 months of the contrast-enhanced sonography. Histological fibrosis was categorized into two classes: (1) no or moderate fibrosis (F0, F1, and F2 according to the METAVIR staging) or (2) severe fibrosis (F3 and F4). At a cutoff of 13 s for the transit time, the diagnosis of severe fibrosis was made with a specificity of 78.57%, a sensitivity of 78.95%, a positive predictive value of 78.33%, a negative predictive value of 83.33%, and a performance accuracy of 78.79%. Therefore, contrast-enhanced ultrasound can help with differentiation between moderate and severe fibrosis.

[Recurrent acute pancreatitis revealing a hydatid cyst of the pancreas]. / Pancréatite aiguë récidivante révélant un kyste hydatique du pancréas.

The authors report a case of hydatid cyst of the pancreas in a 29-year-old man. Biology and computed tomography contributed to the preoperative diagnosis. The intervention consisted in a left pancreatectomy with spleen ablation. In the light of this case and the literature review, the authors discuss diagnostic issues raised by hydatid cyst of the pancreas.

[Postoperative imaging of the cardia and stomach]. / Imagerie post-opératoire du cardia et de l'estomac.

In addition to treatment of complications from peptic ulcer disease, gastroesophageal reflux and gastric cancer, bariatric surgical procedures have increased over the recent years. Complications after gastric surgery are imaged with upper gastrointestinal contrast studies and CT. This imaging is not always easy and it is important for radiologists to know the different types of surgical techniques and to be familiar with normal postoperative anatomical and pathological findings.

[Real-time contrast-enhanced ultrasound in the evaluation of focal liver lesions: diagnostic efficacy and economical issues from a French multicentric study]. / Echographie de contraste temps réel dans la prise en charge diagnostique des lésions nodulaires hépatiques: évaluation des performances diagnostiques et de l'impact économique sur une étude multicentrique française.

The recent introduction of high-end ultrasound equipment combined with recent contrast agents provides marked improvements in the characterization of focal liver lesions as previously reported by monocentric studies. The aim of the present study was to evaluate the diagnostic performance of Contrast-Enhanced Ultrasonography (CEUS) using SonoVue as well as its medico-economic value for characterization of focal liver lesions. These nodules were not characterized on previous CT or conventional sonography. This prospective multicentric study conducted in 15 French centres found diagnostic performances similar to those reported for CT and MRI, with a concordance rate of 84.5%, sensitivity greater than 80% and specificity greater than 90% for all types of lesions. Higher acceptance was found for CEUS compared to other imaging modalities. Economical assessment based on examination reimbursment and contrast agent cost showed a lower cost for contrast ultrasound versus CT and MRI. This French multicentric study confirmed the high diagnostic value of CEUS for focal liver lesion characterization and demonstrated a lower economical impact compared to other imaging modalities such as CT and MRI.

Diagnosis of focal liver lesions from ultrasound using deep learning.

PURPOSE: The purpose of this study was to create an algorithm that simultaneously detects and characterizes (benign vs. malignant) focal liver lesion (FLL) using deep learning. MATERIALS AND METHODS: We trained our algorithm on a dataset proposed during a data challenge organized at the 2018 Journées Francophones de Radiologie. The dataset was composed of 367 two-dimensional ultrasound images from 367 individual livers, captured at various institutions. The algorithm was guided using an attention mechanism with annotations made by a radiologist. The algorithm was then tested on a new data set from 177 patients. RESULTS: The models reached mean ROC-AUC scores of 0.935 for FLL detection and 0.916 for FLL characterization over three shuffled three-fold cross-validations performed with the training data. On the new dataset of 177 patients, our models reached a weighted mean ROC-AUC scores of 0.891 for seven different tasks. CONCLUSION: This study that uses a supervised-attention mechanism focused on FLL detection and characterization from liver ultrasound images. This method could prove to be highly relevant for medical imaging once validated on a larger independent cohort.

Distribution of adipose tissue: quantification and relationship with hepatic steatosis and vascular profiles of type 2 diabetic patients with metabolic syndrome.

AIM: As the distribution of fat is increasingly related to cardiovascular events, we examined whether or not abdominal-fat quantification using magnetic resonance imaging (MRI) software is reliable, and whether or not it is related to clinical markers of fat distribution as well as to metabolic and vascular status. METHODS: We recorded the anthropometric measurements of 34 obese type 2 diabetic patients with metabolic syndrome. The patients were enrolled to evaluate their abdominal (visceral and subcutaneous) adipose tissue by single-slice L3-L4 MRI. Manual and automated analyses were compared. The relationships between anthropometric measurements, biological markers and intima-media thickness of the common carotid artery were also assessed. RESULTS: We validated the automated software to quantify abdominal-fat deposition with MRI compared with manual measurements (r2=0.95). The waist-to-hip-circumference ratio (WHR) was the only clinical parameter that correlated with the proportion and quantity of visceral and subcutaneous abdominal-adipose tissue evaluated by MRI (r=0.60). In addition, fat repartition as evaluated by WHR was related to hepatic steatosis parameters (ferritin and ALAT) and to intima-media thickness, whereas simple waist circumference was not a determinant in these obese patients. We also showed that the adiponectin-to-leptin ratio was related to adipose tissue distribution. CONCLUSION: Distribution of abdominal fat, as evaluated by MRI, can be reflected by clinical determination of the WHR. Differences in regional accumulations of abdominal fat may be specifically related to variations in the risks of steatosis and vascular rigidity among obese type 2 diabetic patients.