We show that even without prior knowledge about materials or spectrum, effective beam hardening correction can be obtained.

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Poppe et al. An Inside Perspective on Magma Intrusion KEYPOINTS -Cutting-edge dynamic wide beam X-ray Computed Tomography and Digital Volume Correlation allows an inside view on the temporal behavior of analog magma intrusion in granular host material in laboratory experiments. -Intrusion-induced 3D displacement and strain can be quantified over time. -Thick cryptodomes form with distributed strain and mixedmode fracturing in weak host materials. -Thin dikes form with localized strain and opening-mode fracturing in strong host materials. -A continuum of cone sheet geometries occurs in between these end-members. Frontiers in Earth Science | www.frontiersin.org

ObjectivesTo assess image quality in abdominal CT at low tube voltage combined with two types of iterative reconstruction (IR) at four reduced contrast agent dose levels.MethodsMinipigs were scanned with standard 320 mg I/mL contrast concentration at 120 kVp, and with reduced formulations of 120, 170, 220 and 270 mg I/mL at 80 kVp with IR. Image quality was assessed by CT value, dose normalized contrast and signal to noise ratio (CNRD and SNRD) in the arterial and venous phases. Qualitative analysis was included by expert reading.ResultsProtocols with 170 mg I/mL or higher showed equal or superior CT values: aorta (278–468 HU versus 314 HU); portal vein (205–273 HU versus 208 HU); liver parenchyma (122–146 HU versus 115 HU). In the aorta, all 170 mg I/mL protocols or higher yielded equal or superior CNRD (15.0–28.0 versus 13.7). In liver parenchyma, all study protocols resulted in higher SNRDs. Radiation dose could be reduced from standard CTDIvol = 7.8 mGy (6.2 mSv) to 7.6 mGy (5.2 mSv) with 170 mg I/mL.ConclusionCombining 80 kVp with IR allows at least a 47 % contrast agent dose reduction and 16 % radiation dose reduction for images of comparable quality.Key Points• There is a balance between image quality, contrast dose and radiation dose.• Iterative reconstruction has a major, positive impact on this balance.• Both contrast dose and radiation dose can be reduced in abdominal CT.• The trade-off can be quantitatively described by a 3D model.• Contrast and radiation dose can be tailored according to specific safety concerns.