Renal Cell Carcinoma Metastatic to the Liver: Early Response Assessment after Intraarterial Therapy Using 3D Quantitative Tumor Enhancement Analysis

AbstractPURPOSELiver metastases from renal cell carcinoma (RCC) are not uncommon in the course of disease. However, data about tumor response to intraarterial therapy (IAT) are scarce. This study assessed whether changes of enhancing tumor volume using quantitative European Association for the Study of the Liver (qEASL) on magnetic resonance imaging (MRI) and computed tomography (CT) can evaluate tumor response and predict overall survival (OS) early after therapy.METHODS AND MATERIALSFourteen patients with liver metastatic RCC treated with IAT (transarterial chemoembolization: n= 9 and yttrium-90: n= 5) were retrospectively included. All patients underwent contrast-enhanced imaging (MRI: n= 10 and CT: n= 4) 3 to 4 weeks pre- and posttreatment. Response to treatment was evaluated on the arterial phase using Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization, modified RECIST, EASL, tumor volume, and qEASL. Paired t test was used to compare measurements pre- and post-IAT. Patients were stratified into responders (≥65% decrease in qEASL) and nonresponders (<65% decrease in qEASL). OS was evaluated using Kaplan-Meier curves with log-rank test and the Cox proportional hazard model.RESULTSMean qEASL (cm3) decreased from 93.5 to 67.2 cm3 (P= .004) and mean qEASL (%) from 63.1% to 35.6% (P= .001). No significant changes were observed using other response criteria. qEASL was the only significant predictor of OS when used to stratify patients into responders and nonresponders with median OS of 31.9 versus 11.1 months (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.97; P= .042) for qEASL (cm3) and 29.9 versus 10.2 months (HR, 0.09; 95% CI, 0.01-0.74; P= .025) for qEASL (%).CONCLUSIONThree-dimensional (3D) quantitative tumor analysis is a reliable predictor of OS when assessing treatment response after IAT in patients with RCC metastatic to the liver. qEASL outperforms conventional non-3D methods and can be used as a surrogate marker for OS early after therapy

Vaskuläre Ursachen eines klinisch unklaren akuten Abdomens

Das klinisch akute Abdomen wird selten durch vaskuläre Pathologien verursacht. Letztere lassen sich einerseits in Blutungen oder Ischämien, andererseits in arterielle oder venöse Prozesse unterteilen, wobei bei akutem Abdomen venöse Blutungen naturgemäß eine untergeordnete Rolle spielen. Die häufigste Ursache für ein ischämisch bedingtes akutes Abdomen ist eine akute Mesenterialischämie durch Verschluss der A. mesenterica superior, gefolgt von Thrombosen der V. portae, der V. mesenterica superior sowie der Lebervenen und der suprahepatischen V. cava. Als Blutungsquelle bei einem blutungsbedingten akuten Abdomen kommen prinzipiell alle arteriellen Strukturen des Abdomens in Frage, besonders aber Aortenrupturen und Blutungen aus Ästen der A. mesenterica superior. Empfehlung für die Praxis Aufgrund der hohen Mortalität vaskulärer Pathologien als Ursache des akuten Abdomens ist eine rasche Diagnostik essenziell. Die Computertomographie (CT) ist dank der guten Verfügbarkeit und der hohen Geschwindigkeit Methode der 1. Wahl. Um die verschiedenen vaskulären Pathologien mit hoher Sensitivität und Spezifität differenzieren zu können, ist die Verwendung eines triphasischen CT-Untersuchungsprotokolls bei der Abklärung des akuten Abdomens essenziell. Die intraarterielle Angiographie hat im Bereich der Diagnostik ausgedient, spielt aber im Bereich der Therapie eine zunehmende Rolle.Clinical Issue Vascular abnormalities are a rare cause of an acute abdomen. They include arterial bleeding and ischemia, the latter being either in the arterial or venous system. The most common cause of an acute ischemic abdomen is acute mesenteric ischemia caused by a thromboembolic occlusion of the superior mesenteric artery, followed by thrombotic occlusion of the portal vein, the mesenteric vein as well as the hepatic veins and the suprahepatic part of the inferior vena cava. In the case of an acute abdomen due to internal bleeding, all abdominal arteries can be the source but most common are ruptures of aortic aneurysms and inflammatory-driven bleeding from the superior mesenteric artery. Practical recommendations Due to the high mortality, vascular causes should be diagnosed as soon as possible. For this purpose, computed tomography (CT) has evolved into the preferred tool due to its high availability and speed. To differentiate various vascular causes of an acute abdomen, it is important to incorporate a CT protocol without contrast media as well as contrast-enhanced series in arterial and venous phases. Conventional angiography has been replaced by CT for the diagnosis of vascular pathologies causing an acute abdomen; however, it plays an increasing role in the treatment of these pathologies.(VLID)365983

Low-dose high-pitch CT angiography of the supraaortic arteries using sinogram-affirmed iterative reconstruction.

OBJECTIVE: To prospectively evaluate image quality and radiation dose using a low-dose computed tomography angiography protocol and iterative image reconstruction for high-pitch dual-source CT-angiography (DSCTA) of the supraaortic arteries. MATERIAL AND METHODS: DSCTA was performed in 42 patients, using either 120 kVp tube voltage, 120 mAS tube current, 2.4 pitch and filtered back projection, or 100 kVp tube voltage, 100 mAs tube current, 3.2 pitch, and sinogram affirmed iterative reconstruction. Measurements of vessel attenuation, of the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were performed to objectively evaluate image quality. Two readers evaluated subjective image quality and image noise, using a four-point scale. Effective dose was used to compare the differences in radiation dose. RESULTS: Low-dose protocol application showed significantly higher vessel opacification (p = 0.013), and non-significantly higher CNR and SNR values. There was no difference in the subjective image quality and image noise reading between the protocols. Effective dose was significantly lower using the low-dose protocol (1.29 ± 0.21 mSv vs. 2.92 ± 0.72 mSv; p < 0.001). CONCLUSION: The combined use of reduced tube voltage, reduced tube current, and iterative reconstruction reduces radiation dose by 55.4% in high-pitch DSCTA of the supraaortic arteries without impairment of image quality

Feasibility of a Modified Cone-Beam CT Rotation Trajectory to Improve Liver Periphery Visualization during Transarterial Chemoembolization

PURPOSE: To compare liver coverage and tumor detectability by using preprocedural magnetic resonance (MR) images as a reference, as well as radiation exposure of cone-beam computed tomography (CT) with different rotational trajectories. MATERIALS AND METHODS: Fifteen patients (nine men and six women; mean age ± standard deviation, 65 years ± 5) with primary or secondary liver cancer were retrospectively included in this institutional review board–approved study. A modified cone-beam CT protocol was used in which the C-arm rotates from +55° to −185° (open arc cone-beam CT) instead of −120° to +120° (closed arc cone-beam CT). Each patient underwent two sessions of transarterial chemoembolization between February 2013 and March 2014 with closed arc and open arc cone-beam CT (during the first and second transarterial chemoembolization sessions, respectively, as part of the institutional transarterial chemoembolization protocol). For each cone-beam CT examination, liver volume and tumor detectability were assessed by using MR images as the reference. Radiation exposure was compared by means of a phantom study. For statistical analysis, paired t tests and a Wilcoxon signed rank test were performed. RESULTS: Mean liver volume imaged was 1695 cm(3) ± 542 and 1857 cm(3) ± 571 at closed arc and open arc cone-beam CT, respectively. The coverage of open arc cone-beam CT was significantly higher compared with closed arc cone-beam CT (97% vs 86% of the MR imaging liver volume, P = .002). In eight patients (53%), tumors were partially or completely outside the closed arc cone-beam CT field of view. All tumors were within the open arc cone-beam CT field of view. The open arc cone-beam CT radiation exposure by means of weighted CT index was slightly lower compared with that of closed arc cone-beam CT (−5.1%). CONCLUSION: Open arc cone-beam CT allowed for a significantly improved intraprocedural depiction of peripheral hepatic tumors while achieving a slight radiation exposure reduction. (©) RSNA, 2015 Online supplemental material is available for this article

Complement Factor C5a Is Increased in Blood of Patients with Abdominal Aortic Aneurysm and Has Prognostic Potential for Aneurysm Growth

In this observational case-control study, circulating levels of complement factors C3a and C5a and leukotriene B4 (LTB4) were analysed in abdominal aortic aneurysm (AAA) patients regarding their association with diagnosis and prognosis. Serum C5a was significantly raised in AAA patients compared to healthy controls—median 84.5 ng/ml (IQR = 37.5 ng/ml) vs. 67.7 ng/ml (IQR = 26.2 ng/ml), p = 0.007—but was not elevated in patients with athero-occlusive disease. Serum C5a levels correlated significantly with the increase in maximum AAA diameter over the following 6 months (r = 0.319, p = 0.021). The median growth in the lowest quartile of C5a ( 101 ng/ml): 1.0 mm/6 months (IQR = 0.8 mm) vs. 2.0 mm/6 months (IQR = 1.5 mm), p = 0.014. A log-linear mixed model predicted AAA expansion based on current diameter and C5a level. To our knowledge, this is the first study linking complement activation, in particular C5a serum level, with AAA progression. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12265-020-10086-5

Radiologic-pathologic analysis of quantitative 3D tumour enhancement on contrast-enhanced MR imaging: a study of ROI placement

ObjectivesTo investigate the influence of region-of-interest (ROI) placement on 3D tumour enhancement [Quantitative European Association for the Study of the Liver (qEASL)] in hepatocellular carcinoma (HCC) patients treated with transcatheter arterial chemoembolization (TACE).MethodsPhase 1: 40 HCC patients had nine ROIs placed by one reader using systematic techniques (3 ipsilateral to the lesion, 3 contralateral to the lesion, and 3 dispersed throughout the liver) and qEASL variance was measured. Intra-class correlations were computed. Phase 2: 15 HCC patients with histosegmentation were selected. Six ROIs were systematically placed by AC (3 ROIs ipsilateral and 3 ROIs contralateral to the lesion). Three ROIs were placed by 2 radiologists. qEASL values were compared to histopathology by Pearson's correlation, linear regression, and median difference.ResultsPhase 1: The dispersed method (abandoned in phase 2) had low consistency and high variance. Phase 2: qEASL correlated strongly with pathology in systematic methods [Pearson's correlation coefficient = 0.886 (ipsilateral) and 0.727 (contralateral)] and in clinical methods (0.625 and 0.879). However, ipsilateral placement matched best with pathology (median difference: 5.4 %; correlation: 0.89; regression CI: [0.904, 0.1409]).ConclusionsqEASL is a robust method with comparable values among tested placements. Ipsilateral placement showed high consistency and better pathological correlation.Key pointsIpsilateral and contralateral ROI placement produces high consistency and low variance. Both ROI placement methods produce qEASL values that correlate well with histopathology. Ipsilateral ROI placement produces best correlation to pathology along with high consistency