Could Spectral CT Have a Potential Benefit in Coronavirus Disease (COVID-19)?

OBJECTIVE. The purpose of this study is to evaluate the potential benefit of spectral imaging, notably electron density imaging, in patients with suspected or confirmed coronavirus disease (COVID-19), by retrospectively reviewing the cases of four patients who each underwent two chest CT scans for confirmed COVID-19. CONCLUSION. The use of spectral CT with electron density imaging could improve the assessment of lung lesion extent in patients with early-stage COVID-19.

Liver biopsy for diagnosis of presumed benign hepatocellular lesions lacking magnetic resonance imaging diagnostic features of focal nodular hyperplasia.

BACKGROUND & AIMS: The contribution of liver biopsy for the diagnosis of presumed benign hepatocellular lesions lacking the diagnostic features of focal nodular hyperplasia (FNH) on magnetic resonance imaging (MRI) is unknown. We evaluated liver biopsy and MRI performances in this setting. METHODS: Magnetic resonance imaging and slides of liver biopsies performed for a presumed benign hepatocellular lesion (2006-2013) without the typical features of FNH on MRI were blindly reviewed (n = 45). Eighteen lesions were surgically removed and also analyzed. The final diagnosis was the diagnosis established after surgery or on the biopsy in the absence of surgery. RESULTS: The final diagnosis was FNH (n = 19), hepatocellular adenoma (HCA, n = 15), hepatocellular carcinoma (n = 3) and indefinite (n = 4). Four lesions corresponded to non hepatocellular lesions. FNH, HNF1A mutated and inflammatory HCA were diagnosed accurately on the biopsy in 95%, 67% and 100% of the cases respectively. Diagnostic performance of liver biopsy for HNF1A mutated HCA was lower because of the lack of non-tumoral tissue. Diagnosis based on morphological analysis was certain and correct in 27 cases. Immunostaining allowed a definite diagnosis in 12 additionnal cases. Radiological diagnosis was in agreement with the histological diagnosis in 75.6% of the cases, with a very high sensitivity (97%) and specificity (100%) for the diagnosis of HNF1A mutated HCA. CONCLUSIONS: Liver biopsy has a good diagnostic performance particularly for FNH and inflammatory HCA, and sampling of non-lesional tissue is highly recommended. A biopsy does not seem necessary if H-HCA is diagnosed on MRI.

Is computed tomography volumetric assessment of the liver reliable in patients with cirrhosis?

OBJECTIVES: The estimation of liver volume (LV) has been widely studied in normal liver, the density of which is considered to be equivalent to 1 kg/l. In cirrhosis, volumetric evaluation and its correlation to liver mass remain unclear. The aim of this study was to evaluate the accuracy of computed tomography (CT) scanning to assess LV in patients with cirrhosis. METHODS: Liver volume was evaluated by CT (CTLV) and correlated to the explanted liver weight (LW) in 49 patients. Liver density (LD) and its association with clinical features were analysed. Commonly used formulae for estimating LV were also evaluated. The real density of cirrhotic liver was prospectively measured in explant specimens. RESULTS: Wide variations between CTLV (in ml) and LW (in g) were found (range: 3-748). Cirrhotic livers in patients with hepatitis B virus infection presented significantly increased LD (P = 0.001) with lower CTLV (P = 0.005). Liver volume as measured by CT was also decreased in patients with Model for End-stage Liver Disease scores of >15 (P = 0.023). Formulae estimating LV correlated poorly with CTLV and LW. The density of cirrhotic liver measured prospectively in 15 patients was 1.1 kg/l. CONCLUSIONS: In cirrhotic liver, LV assessed by CT did not correspond to real LW. Liver density changed according to the aetiology and severity of liver disease. Commonly used formulae did not accurately assess LV.

Prediction of evolution toward brain death upon admission to ICU in comatose patients with spontaneous intracerebral hemorrhage using simple signs.

The aim of the study was to identify the predictors of brain death (BD) upon admission to the intensive care unit (ICU) of comatose patients with spontaneous intracerebral hemorrhage (ICH). Patients admitted in our ICU from 2002 to 2010 for spontaneous ICH and placed under mechanical ventilation were retrospectively analyzed. Of the 72 patients, 49% evolved to BD, 39% died after withdrawal of life support, and 12% were discharged alive. The most discriminating characteristics to predict BD were included in two models; Model 1 contained ≥3 abolished brainstem responses [adjusted odds ratios (OR) = 8.4 (2.4, 29.1)] and the swirl sign on the baseline CT-scan [adjusted OR = 5.0 (1.6, 15.9)] and Model 2 addressed the abolition of corneal reflexes [unilateral/bilateral: adjusted OR = 4.2 (0.9, 20.1)/8.8 (2.4, 32.3)] and the swirl sign on the baseline CT-scan [adjusted OR = 6.2 (1.9, 20.0)]. Two scores predicting BD were created (sensitivity: 0.89 and 0.88, specificity: 0.68 and 0.65). Risk of evolution toward BD was classified as low (corneal reflexes present and no swirl sign), high (≥1 corneal reflexes abolished and swirl sign), and intermediate. Simple signs at ICU admission can predict BD in comatose patients with ICH and could increase the potential for organ donation.

Relapse of Crohn's disease following ileal pouch-anal anastomosis: MDCT and MR features.

OBJECTIVE: The purpose of our study is to use MDCT and MR imaging to describe the normal ileal pouch and to identify features of Crohn's disease (CD) relapse in patients after ileal pouch-anal anastomosis (IPAA). CONCLUSIONS: After total colectomy followed by IPAA, features, optimally evaluated with pelvic MRI, such as fistulas, abscesses, pouch inflammation, and stenoses, indicate CD relapse. Although uncommon, radiologists should be aware that these imaging features strongly favor this diagnosis.

Femoral venous catheter: a misleading cause of gas in the liver.

OBJECTIVES: The presence of a femoral venous catheter could be associated with gas presence in the hepatic veins. This entity should be recognized to avoid a misdiagnosis of gas presence in the portal veins or in the biliary tract. Objectives are to assess: 1) the incidence of gas presence in the hepatic veins in intensive care unit patients explored by abdominal computed tomography scan; 2) the rate of gas presence in the liver in intensive care unit patients with a catheter inserted in the femoral vein; and 3) the specific imaging features. DESIGN: A retrospective study in a medical intensive care unit in a teaching hospital in France. MEASUREMENTS: All consecutive abdominal computed tomography scans performed in intensive care unit patients between 2008 and 2010 were retrospectively reviewed independently by an intensivist and a radiologist. Presence of gas in the liver was noticed and its location was specified using multiplanar reconstruction. MAIN RESULTS: We analyzed 235 computed tomography scans (performed in 207 patients). Gas was identified in the liver on 10.2% of computed tomography scans. Gas was located in the hepatic veins in 12 cases (50%), in the biliary tract in ten cases (41.7%), and in the portal veins in two cases (8.3%). All patients with gas in the hepatic veins had a femoral venous catheter. Characteristics of gas location within the hepatic veins on computed tomography scan axial views were not different from those of gas located in the biliary tract or in the portal venous system. Gas was present in the hepatic veins in 12 of 83 (14.5%) of the computed tomography scans with a femoral venous catheter and was associated with gas presence in other vessels of the inferior vena cava system in five of 12 (41.7%) cases. CONCLUSIONS: Gas located in the hepatic veins related to femoral venous catheter is a frequent cause of gas in the liver in intensive care unit patients. This imaging feature could be misleading. Multiplanar reconstruction should be performed to differentiate this aspect from those of gas in the biliary tract or in the portal venous system.

CT and MRI features of ileostomies.

OBJECTIVE: The purpose of this article is to describe CT and MRI features of normal anatomy, variants, and pathologic conditions of different ileostomies. CONCLUSION: Multiplanar imaging techniques are useful to identify the complications related to stoma construction and preexisting disease. Understanding the indications for ileostomy construction, surgical techniques, and postoperative anatomy is important for differentiating normal and abnormal imaging features.

[Imaging of acute pancreatitis]. / Imagerie de la pancréatite aiguë.

The radiological management of acute pancreatitis is well codified. The positive diagnosis of acute pancreatitis is based on clinical and biological signs. However, imaging helps for in diagnosing severity and complications. The etiological diagnosis should strive to detect gallstones by an abdominal ultrasound to be performed within 24 hours of onset of symptoms. The severity is assessed at 48-72 hours per scanner after contrast media injection, according to the classification CTSI. It is important to avoid the two following pitfalls: realising the scanner too early, which could be falsely reassuring because necrosis of the pancreatic parenchyma appears at least 48 to 72 hours after onset of clinical signs, and dispense with ultrasound at 24 hours, because the gallstones are visible only in 50% of the scanner. Imaging helps to manage some complications of acute pancreatitis: in case of infectious complications, remember to perform a needle aspiration or percutaneous drainage of fluid collections; in case of haemorrhage from rupture of a false aneurysm, the treatment of choice is embolization for hemostasis under radiological guidance.

Transcatheter arterial chemoembolization for liver metastases in patients with adrenocortical carcinoma.

PURPOSE: To retrospectively evaluate the effectiveness, tolerance, and predictors of response to transcatheter arterial chemoembolization for treatment of liver metastases from adrenocortical carcinoma. MATERIALS AND METHODS: Twenty-nine patients with progressive liver metastases from adrenocortical carcinoma were treated with transcatheter arterial chemoembolization. Rate and duration of tumor response were defined according to Response Evaluation Criteria In Solid Tumors. The size of liver metastases, percentage of liver involvement, and Lipiodol uptake were studied as potential predictive factors of response. Time to liver and metastatic lesion progression were considered as endpoints. RESULTS: Three months after transcatheter arterial chemoembolization, a liver morphologic response was observed in six of 29 patients (21%), stabilization in 18 (62%), and progression in five (17%). According to per-lesion analysis (n = 103), a morphologic response was observed in 23 lesions (22%), stabilization in 67 (65%), and progression in 13 (13%). Higher response rates were observed in cases in which the diameter of the target metastasis was 3 cm or smaller (P = .002) and in cases of high Lipiodol uptake (> 50%; P < .0001). On per-patient and per-lesion bases, progression rates were 32% and 55% at 6 months and 23% and 38% at 12 months. The median time to progression was 9 months and median survival was 11 months after the first procedure. CONCLUSIONS: Transcatheter arterial chemoembolization should be considered as part of the therapeutic arsenal to treat liver metastases from adrenocortical carcinoma. The size of liver metastases and the percentage of Lipiodol uptake may help identify patients likely to benefit most from transcatheter arterial chemoembolization.

Uterine fibroid vascularization and clinical relevance to uterine fibroid embolization.

Embolization has become a first-line treatment for symptomatic uterine fibroid tumors. Selective catheterization and embolization of both uterine arteries, which are the predominant source of blood flow to fibroid tumors in most cases, is the cornerstone of treatment. Although embolization for treatment of uterine fibroid tumors is widely accepted, great familiarity with the normal and variant pelvic arterial anatomy is needed to ensure the safety and success of the procedure. The uterine artery classically arises as a first or second branch of the anterior division of the internal iliac artery and is usually dilated in the presence of a uterine fibroid tumor. Angiography is used for comprehensive pretreatment assessment of the pelvic arterial anatomy; for noninvasive evaluation, Doppler ultrasonography, contrast material-enhanced magnetic resonance (MR) imaging, and MR angiography also may be used. After the uterine artery is identified, selective catheterization should be performed distal to its cervicovaginal branch. For targeted embolization of the perifibroid arterial plexus, injection of particles with diameters larger than 500 mum is generally recommended. Excessive embolization may injure normal myometrium, ovaries, or fallopian tubes and lead to uterine necrosis or infection or to ovarian failure. Incomplete treatment or additional blood supply to the tumor (eg, via an ovarian artery) may result in clinical failure. The common postembolization angiographic end point is occlusion of the uterine arterial branches to the fibroid tumor while antegrade flow is maintained in the main uterine artery.

Solid-pseudopapillary tumor of the pancreas: MR imaging findings in 21 patients.

PURPOSE: Solid-pseudopapillary tumor (SPT) of the pancreas is a rare, low-grade malignancy, which mostly occurs in adolescent and young adult females. The goal of this study was to retrospectively analyze the magnetic resonance (MR) imaging presentation of SPT of the pancreas. METHODS: We retrospectively reviewed the preoperative MR imaging examinations and the medical, surgical and histopathological records of 21 patients who underwent surgery for SPT of the pancreas. MR imaging included T1-weighted, T2-weighted, and gadolinium chelate-enhanced MR imaging. In addition, 10 patients had diffusion-weighted (DW) MR imaging. MR examinations were retrospectively reviewed for location, size, morphological features and signal intensity of the tumors. RESULTS: Nineteen women and 2 men (median age, 23 years; range, 14-59) were included. Seven patients (7/21; 33%) presented with abdominal symptoms. The median largest tumor diameter was 53mm (range, 32-141 mm). SPTs were located in the pancreatic head, body, and tail in 9 (9/21; 43%), 5 (5/21; 24%) and 7 (7/21, 33%) patients, respectively. All patients (21/21; 100%) had a single SPT. SPTs were more frequently oval (12/21; 57%), predominantly solid (12/21; 57%), fully encapsulated (16/21; 76%), larger than 30 mm (21/21; 100%), hypointense on T1-weighted MR images (21/21, 100%), hyperintense on T2-weighted MR images (21/21; 100%) and with an enhancing capsule after gadolinium-chelate administration (21/21; 100%). CONCLUSIONS: There is trend of appearance for SPT of the pancreas on MR imaging but that variations may be observed in a number of cases. SPT uniformly presents as a single, well-demarcated and encapsulated pancreatic mass.

MR features of inflammatory hepatic adenoma.

Hepatocellular adenomas are a group of benign tumors forming three molecular pathological subgroups. Inflammatory hepatic adenomas have typical MR findings, which help for diagnosis: hypersignal on T2W sequences, hyperintense peripheral signal band, strong arterial enhancement, with persistent enhancement in delayed phase.