Qi Jing,  Eutsler Eric,  Siegel Marilyn

Final Pr. ID: Poster #: EDU-068

Dual-energy CT (DECT) refers to the acquisition of CT datasets at two different energy spectra, which allows differentiation and classification of tissues. The purpose of this this poster is to describe post-processing algorithms and clinical applications of DECT in children on a dual-source CT system. Read More

Authors:  Qi Jing , Eutsler Eric , Siegel Marilyn

Keywords:  Dual energy CT, Pediatric Radiology, Clinical application

Haq Adeel,  Siegel Marilyn,  Awali Mohamed

Final Pr. ID: Poster #: EDU-096

Dual energy CT with material-specific reconstructions including iodine, pulmonary blood volume, and lung vessel images can improve assessment of vascular and associated parenchymal abnormalities.
An understanding of material-specific reconstruction algorithms, clinical applications and potential pitfalls can help in accurate interpretation of dual energy CT examinations.

Purpose of this exhibit is to review:

Basic principles of dual energy CT material-specific reconstructions
● Iodine maps
● Pulmonary blood volume (PBV) images
● Lung vessel images

Specific applications and benefits of material-specific reconstructions in cardiothoracic imaging
● Pulmonary embolism: Vessel and PBV images can improve detection of embolus and infarction
● Congenital cyanotic heart disease: Material-specific reconstructions can have a role in assessing pulmonary artery flow/lung perfusion and adequacy of reconstruction surgery
● Arteriovenous malformations: Material-specific images can increase conspicuity of small malformations and can be used to evaluate the success of embolization
● Pulmonary hypertension: Material-specific images are useful to detect subtle decreases in parenchymal perfusion and pulmonary blood flow
● Airway diseases: Reconstructions can provide information on the downhill effect of bronchial obstruction.

Potential pitfalls and artifacts in interpreting material specific reconstructions
● Beam-hardening artifacts
● Diaphragmatic motion
● Cardiac motion

Radiation Dose: Similar or less than single-energy CT Read More

Authors:  Haq Adeel , Siegel Marilyn , Awali Mohamed

Keywords:  Dual Energy CT, Iodine mapping, Pulmonary Blood Volume

Hornsby Richard,  Brady Samuel,  Mccarville Beth,  Nett Elizabeth,  Rupcich Franco,  Blancq Terry,  Artz Nathan

Final Pr. ID: Poster #: EDU-054

This educational exhibit will review 1) challenges of CT imaging near metal, 2) current acquisition and reconstruction methods for reducing metallic artifacts, and 3) our initial experience using a GE Revolution CT system for Dual-energy scanning combined with metal artifact reduction (MAR) image reconstruction. Artifacts caused by metallic implants have limited clinical diagnoses for decades using single-energy CT (single kVp, polyenergetic beam) with standard image reconstruction. Low-energy photons in the beam are absorbed by metal, leaving only high-energy photons passing through (ie. beam hardening). Beam hardening due to metal, along with photon starvation and scatter, result in dark shading and bright/dark streaking, as well as lower signal-to-noise levels. Dual-energy CT (DECT) has demonstrated promise for beam hardening reduction because it enables reconstruction of a monoenergetic image, similar in theory to acquiring data with a monoenergetic beam. Recent developments in CT data reconstruction have also achieved better image quality near metal by mitigating shading and streaking artifacts. On our Revolution CT, MAR reconstruction is available solely in dual-energy mode. For our patients with metallic prostheses, we perform DECT and review monoenergetic images with and without MAR. MAR images typically show markedly reduced artifacts from metal and thereby improved image quality. Fig 1 displays 70 keV monoenergetic images both with and without MAR for a patient with a pacemaker. Streaking artifacts arising from the pacemaker were apparent throughout anatomy without MAR, while significantly reduced streaking and improved visualization of the aortic bifurcation is observed in the MAR reconstructed image. Images from a patient with pedicle screws and metallic rods in the spine are shown in Fig 2. Although present, shading and streaking was noticeably reduced with MAR allowing better visibility of the paraspinal soft-tissue structures and the main portal vein. On occasion, however, MAR yielded more severe artifacts for certain slices, such as in the thigh for a patient with a metallic femoral rod just above a total knee replacement (Fig 3). In summary, recent technical advancements incorporated into the Revolution CT system have improved image quality for many of our patients with metallic implants. Predicting a priori when MAR will be worse is not yet possible, so viewing monoenergetic images with and without MAR is recommended. Read More

Authors:  Hornsby Richard , Brady Samuel , Mccarville Beth , Nett Elizabeth , Rupcich Franco , Blancq Terry , Artz Nathan

Keywords:  metal artifact reduction, Dual-energy CT

Siegel Marilyn,  Ramirez Giraldo Juan Carlos

Final Pr. ID: Paper #: 037

To develop diagnostic reference ranges (DRRs) for pediatric contrast-enhanced dual-energy CT (DECT) examinations as a function of patient size and radiation output of the CT scanner with comparison to conventional single energy CT (SECT). Read More

Authors:  Siegel Marilyn , Ramirez Giraldo Juan Carlos

Keywords:  Dual-Energy CT, Chest CT, Dose Reduction

Alizadeh Houman,  Siegel Marilyn,  Ramirez Giraldo Juan Carlos

Final Pr. ID: Poster #: EDU-075

Dual-energy computed tomography (DECT) decomposition software has expanded the scope of CT post-processing. It is an efficient method in pediatric thoracic imaging to define both vascular and parenchymal abnormalities. Read More

Authors:  Alizadeh Houman , Siegel Marilyn , Ramirez Giraldo Juan Carlos

Keywords:  Dual Energy CT, chest, pediatric

Alizadeh Houman,  Siegel Marilyn,  Cullinane Mike

Final Pr. ID: Paper #: 146

Mediastinal tumors comprise a range of congenital, neoplastic and inflammatory tumors. While many benign and malignant lesions can be differentiated by CT appearance and attenuation values, many cannot be reliably separated. The purpose of this paper is to evaluate the feasibility of dual-energy computed tomography (DECT) in differentiating a spectrum of mediastinal tumors in children Read More

Authors:  Alizadeh Houman , Siegel Marilyn , Cullinane Mike

Keywords:  Dual Energy CT, Mediastinal Tumors, children