title: Effect of diagnostic cone-beam computed tomography protocols on image quality, patient dose, and lesion detection.
abstract: OBJECTIVE
  To evaluate the effect of cone-beam computed tomography (CBCT) image acquisition protocols on image quality, lesion detection, delineation, and patient dose.
  
  
  METHODS
  100-patients and a CTDI phantom combined with an electron density phantom were examined using four different CBCT-image acquisition protocols during image-guided transarterial chemoembolization (TACE). Protocol-1 (time: 6s, tube rotation: 360°), protocol-2 (5s, 300°), protocol-3 (4s, 240°) and protocol-4 (3s, 180°) were used. The protocols were first investigated using a phantom. The protocols that were found to be clinically appropriate in terms of image quality and radiation dose were then assessed on patients. A higher radiation dose and/or a poor image quality were inappropriate for the patient imaging. Patient dose (patient-entrance dose and dose-area product), image quality (Hounsfield Unit, noise, signal-to-noise ratio and contrast-to-noise ratio), and lesion delineation (tumor-liver contrast) were assessed and compared using appropriate statistical tests. Lesion detectability, sensitivity, and predictive values were estimated for CBCT-image data using pre-treatment patient magnetic resonance imaging.
  
  
  RESULTS
  The estimated patient dose showed no statistical significance (p>0.05) between protocols-2 and -3; the assessed image quality between these protocols manifested insignificant difference (p>0.05). Two other phantom protocols were not considered for patient imaging due to significantly higher dose (protocols-1) and poor image quality (protocol-4). Lesion delineation and detection were insignificant (p>0.05) between protocols-2 and -3. Lesion sensitivities generated were 81-89% (protocol-2) and 81-85% (protocol-3) for different lesion types.
  
  
  CONCLUSIONS
  Data acquisition using protocols-2 and -3 provided good image quality, lesion detection and delineation with acceptable patient dose during CBCT-imaging mainly due to similar frame numbers acquired.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. Electronic address: jijopaul1980@gmail.com.
authors.forename: Jijo
authors.initials: J
authors.lastname: Paul
authors.affiliation: Division of Applied Mathematics and Statistics, Dougherty System, 31705 Albany, GA, United States. Electronic address: sajinichacko2011@gmail.com.
authors.forename: Annamma
authors.initials: A
authors.lastname: Chacko
authors.affiliation: Department of Biomedical Instrumentation, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Rome, Italy. Electronic address: p.saccomandi@unicampus.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Saccomandi
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. Electronic address: T.Vogl@em-uni-frankfurt.de.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany; Department of Diagnostic and Interventional Radiology, University Hospital, Cairo University, Cairo, Egypt. Electronic address: nour.410@hotmail.com.
authors.forename: Nour-Eldin A
authors.initials: NA
authors.lastname: Nour-Eldin
mesh_terms: D000368:Aged; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011786:Quality Control; D011829:Radiation Dosage; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Cone-beam computed tomography; Image acquisition protocols; Image quality; Lesion delineation; Lesion detection; Patient dose