Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Spectrophotometry: Introduction01:16

Spectrophotometry: Introduction

Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material.
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation01:26

Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation

Inductively coupled plasma (ICP) is the common plasma source used in atomic emission spectroscopy (AES), a technique that detects and analyzes various elements in a sample. This method is often called inductively coupled plasma atomic emission spectroscopy (ICP-AES).
There are three main types of inductively coupled plasma atomic emission spectroscopy  (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used.
UV–Vis Spectrometers01:14

UV–Vis Spectrometers

The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell. Samples for...
IR Spectrometers01:25

IR Spectrometers

There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
Atomic Emission Spectroscopy: Instrumentation01:22

Atomic Emission Spectroscopy: Instrumentation

The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers.  Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
Scanning Electron Microscopy01:07

Scanning Electron Microscopy

A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Clinical benefits and current challenges of photon-counting detector CT in vascular imaging.

Radiology advances·2026
Same author

Hallucination at low radiation dose: Evaluation of two deep-learning reconstruction methods in high-resolution chest CT.

Proceedings of SPIE--the International Society for Optical Engineering·2026
Same author

Accuracy and precision of automated kidney stone detection on CT.

Abdominal radiology (New York)·2026
Same author

The Uncoupling of CT Dose and Noise.

Radiology·2026
Same author

A framework for quantifying and leveraging uncertainty in pre-trained CT denoising model.

IEEE transactions on bio-medical engineering·2026
Same author

Mitigating CT number variability between scanners, tube potentials, and patient sizes using spectral CT virtual monoenergetic imaging.

Physics in medicine and biology·2026

Related Experiment Video

Updated: Jun 3, 2026

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering
07:55

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Published on: April 17, 2018

CT scanner x-ray spectrum estimation from transmission measurements.

Xinhui Duan1, Jia Wang, Lifeng Yu

  • 1Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905, USA.

Medical Physics
|April 2, 2011
PubMed
Summary

Accurately estimating X-ray spectra from CT scanners using transmission data and the expectation maximization (EM) method is crucial for dose calculations and material decomposition. This robust technique validates well against simulations and phantom experiments.

More Related Videos

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples
10:12

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

Published on: June 19, 2018

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

Related Experiment Videos

Last Updated: Jun 3, 2026

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering
07:55

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering

Published on: April 17, 2018

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples
10:12

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

Published on: June 19, 2018

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

Area of Science:

  • Medical Physics
  • Diagnostic Imaging
  • Radiological Sciences

Background:

  • Accurate X-ray spectral information is vital for diagnostic CT applications like Monte Carlo dose calculations and dual-energy material decomposition.
  • Direct measurement of X-ray spectra from CT scanners is challenging due to high photon flux.
  • Indirect spectrum estimation from transmission measurements offers a viable alternative.

Purpose of the Study:

  • To evaluate the expectation maximization (EM) method for indirect X-ray spectrum estimation from transmission measurements in a commercial CT scanner.
  • To assess the accuracy and robustness of the EM method for CT X-ray spectrum determination.

Main Methods:

  • Transmission measurements were performed using polycarbonate and aluminum step-wedges on a commercial CT scanner.
  • The expectation maximization (EM) method was applied to transmission data to estimate X-ray spectra.
  • Estimated spectra were compared with manufacturer-simulated spectra and verified using a water phantom experiment.

Main Results:

  • X-ray spectra for 80, 100, 120, and 140 kVp were successfully estimated from a dual-source CT scanner.
  • Estimated and simulated spectra showed excellent agreement, with mean energy differences under 1 keV.
  • Verification experiments demonstrated excellent agreement between measured and calculated transmission values using estimated spectra.

Conclusions:

  • Spectrum estimation using transmission data and the EM method is a quantitatively accurate and robust technique for CT systems.
  • This validated method can significantly benefit research and applications requiring precise CT X-ray spectral knowledge.