title: Diagnosing Lung Nodules on Oncologic MR/PET Imaging: Comparison of Fast T1-Weighted Sequences and Influence of Image Acquisition in Inspiration and Expiration Breath-Hold.
abstract: First, to investigate the diagnostic performance of fast T1-weighted sequences for lung nodule evaluation in oncologic magnetic resonance (MR)/positron emission tomography (PET). Second, to evaluate the influence of image acquisition in inspiration and expiration breath-hold on diagnostic performance.
  
  
  
  The study was approved by the local Institutional Review Board. PET/CT and MR/PET of 44 cancer patients were evaluated by 2 readers. PET/CT included lung computed tomography (CT) scans in inspiration and expiration (CTin, CTex). MR/PET included Dixon sequence for attenuation correction and fast T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences (volume interpolated breath-hold examination acquired in inspiration [VIBEin], volume interpolated breath-hold examination acquired in expiration [VIBEex]). Diagnostic performance was analyzed for lesion-, lobe-, and size-dependence. Diagnostic confidence was evaluated (4-point Likert-scale; 1 = high). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed.
  
  
  
  Seventy-six pulmonary lesions were evaluated. Lesion-based detection rates were: CTex, 77.6%; VIBEin, 53.3%; VIBEex, 51.3%; and Dixon, 22.4%. Lobe-based detection rates were: CTex, 89.6%; VIBEin, 58.3%; VIBEex, 60.4%; and Dixon, 31.3%. In contrast to CT, inspiration versus expiration did not alter diagnostic performance in VIBE sequences. Diagnostic confidence was best for VIBEin and CTex and decreased in VIBEex and Dixon (1.2 ± 0.6; 1.2 ± 0.7; 1.5 ± 0.9; 1.7 ± 1.1, respectively). The JAFROC figure-of-merit of Dixon was significantly lower. All patients with malignant lesions were identified by CTex, VIBEin, and VIBEex, while 3 patients were false-negative in Dixon.
  
  
  
  Fast T1-weighted VIBE sequences allow for identification of patients with malignant pulmonary lesions. The Dixon sequence is not recommended for lung nodule evaluation in oncologic MR/PET patients. In contrast to CT, inspiration versus expiratory breath-hold in VIBE sequences was less crucial for lung nodule evaluation but was important for diagnostic confidence.
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Nina F
authors: NF
authors: Schwenzer
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Ferdinand
authors: F
authors: Seith
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Sergios
authors: S
authors: Gatidis
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.; Department of Diagnostic and Interventional Neuroradiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Cornelia
authors: C
authors: Brendle
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Holger
authors: H
authors: Schmidt
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Christina A
authors: CA
authors: Pfannenberg
authors: Department of Nuclear Medicine, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Christian
authors: C
authors: laFougère
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Konstantin
authors: K
authors: Nikolaou
authors: Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076, Germany.
authors: Christina
authors: C
authors: Schraml
mesh_terms: D000368:Aged; D062485:Breath Holding; D045853:Exhalation; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography / Q000379:methods
keywords: Expiration; Inspiration; Lung; MR/PET; PET/MR; PET/MRI; Pulmonary nodule