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Ciet P, Serra G, Andrinopoulou ER, Bertolo S, Ros M, Catalano C, Colagrande S, Tiddens HAWM, Morana G. Diffusion weighted imaging in cystic fibrosis disease: beyond morphological imaging. Eur Radiol 2016; 26:3830-3839. [PMID: 26873494 DOI: 10.1007/s00330-016-4248-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/22/2015] [Accepted: 01/25/2016] [Indexed: 12/25/2022]
Abstract
OBJECTIVES To explore the feasibility of diffusion-weighted imaging (DWI) to assess inflammatory lung changes in patients with Cystic Fibrosis (CF) METHODS: CF patients referred for their annual check-up had spirometry, chest-CT and MRI on the same day. MRI was performed in a 1.5 T scanner with BLADE and EPI-DWI sequences (b = 0-600 s/mm2). End-inspiratory and end-expiratory scans were acquired in multi-row scanners. DWI was scored with an established semi-quantitative scoring system. DWI score was correlated to CT sub-scores for bronchiectasis (CF-CTBE), mucus (CF-CTmucus), total score (CF-CTtotal-score), FEV1, and BMI. T-test was used to assess differences between patients with and without DWI-hotspots. RESULTS Thirty-three CF patients were enrolled (mean 21 years, range 6-51, 19 female). 4 % (SD 2.6, range 1.5-12.9) of total CF-CT alterations presented DWI-hotspots. DWI-hotspots coincided with mucus plugging (60 %), consolidation (30 %) and bronchiectasis (10 %). DWItotal-score correlated (all p < 0.0001) positively to CF-CTBE (r = 0.757), CF-CTmucus (r = 0.759) and CF-CTtotal-score (r = 0.79); and negatively to FEV1 (r = 0.688). FEV1 was significantly higher (p < 0.0001) in patients without DWI-hotspots. CONCLUSIONS DWI-hotspots strongly correlated with radiological and clinical parameters of lung disease severity. Future validation studies are needed to establish the exact nature of DWI-hotspots in CF patients. KEY POINTS • DWI hotspots only partly overlapped structural abnormalities on morphological imaging • DWI strongly correlated with radiological and clinical indicators of CF-disease severity • Patients with more DWI hotspots had lower lung function values • Mucus score best predicted the presence of DWI-hotspots with restricted diffusion.
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Affiliation(s)
- Pierluigi Ciet
- Department of Radiology, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Paediatrics, Respiratory Medicine and Allergology, Erasmus Medical Center - Sophia Children's Hospital, P.O. Box 2060, Wytemaweg 80, Rotterdam, 3000 CB, Zuid-Holland, Netherlands.,Department of Radiology, Ca' Foncello - General Hospital, Piazzale Ospedale, 1, 31100, Treviso, Italy
| | - Goffredo Serra
- Department of Radiology, University of Rome "Sapienza", Rome, Italy
| | | | - Silvia Bertolo
- Department of Radiology, Ca' Foncello - General Hospital, Piazzale Ospedale, 1, 31100, Treviso, Italy
| | - Mirco Ros
- Department of Pediatrics, Ca' Foncello Hospital, Treviso, Italy
| | - Carlo Catalano
- Department of Radiology, University of Rome "Sapienza", Rome, Italy
| | - Stefano Colagrande
- Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence - Azienda Ospedaliero-Universitaria Careggi., Largo Brambilla 3, Florence, 50134, Italy
| | - Harm A W M Tiddens
- Department of Radiology, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Paediatrics, Respiratory Medicine and Allergology, Erasmus Medical Center - Sophia Children's Hospital, P.O. Box 2060, Wytemaweg 80, Rotterdam, 3000 CB, Zuid-Holland, Netherlands
| | - Giovanni Morana
- Department of Radiology, Ca' Foncello - General Hospital, Piazzale Ospedale, 1, 31100, Treviso, Italy.
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Demol B, Viard R, Reynaert N. Monte Carlo calculation based on hydrogen composition of the tissue for MV photon radiotherapy. J Appl Clin Med Phys 2015; 16:117–130. [PMID: 26699320 PMCID: PMC5690166 DOI: 10.1120/jacmp.v16i5.5586] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/14/2015] [Accepted: 04/09/2015] [Indexed: 12/04/2022] Open
Abstract
The purpose of this study was to demonstrate that Monte Carlo treatment planning systems require tissue characterization (density and composition) as a function of CT number. A discrete set of tissue classes with a specific composition is introduced. In the current work we demonstrate that, for megavoltage photon radiotherapy, only the hydrogen content of the different tissues is of interest. This conclusion might have an impact on MRI‐based dose calculations and on MVCT calibration using tissue substitutes. A stoichiometric calibration was performed, grouping tissues with similar atomic composition into 15 dosimetrically equivalent subsets. To demonstrate the importance of hydrogen, a new scheme was derived, with correct hydrogen content, complemented by oxygen (all elements differing from hydrogen are replaced by oxygen). Mass attenuation coefficients and mass stopping powers for this scheme were calculated and compared to the original scheme. Twenty‐five CyberKnife treatment plans were recalculated by an in‐house developed Monte Carlo system using tissue density and hydrogen content derived from the CT images. The results were compared to Monte Carlo simulations using the original stoichiometric calibration. Between 300 keV and 3 MeV, the relative difference of mass attenuation coefficients is under 1% within all subsets. Between 10 keV and 20 MeV, the relative difference of mass stopping powers goes up to 5% in hard bone and remains below 2% for all other tissue subsets. Dose‐volume histograms (DVHs) of the treatment plans present no visual difference between the two schemes. Relative differences of dose indexes D98,D95,D50,D05,D02, and Dmean were analyzed and a distribution centered around zero and of standard deviation below 2% (3σ) was established. On the other hand, once the hydrogen content is slightly modified, important dose differences are obtained. Monte Carlo dose planning in the field of megavoltage photon radiotherapy is fully achievable using only hydrogen content of tissues, a conclusion that might impact MRI dose calculation, but can also help selecting the optimal tissue substitutes when calibrating MVCT devices. PACS numbers: 87.55.D‐, 87.55.dk, 87.55.K‐, 87.57.Q‐
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Sheikh K, Coxson HO, Parraga G. This
is what
COPD
looks like. Respirology 2015; 21:224-36. [DOI: 10.1111/resp.12611] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 06/22/2015] [Accepted: 06/24/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Khadija Sheikh
- Robarts Research Institute London Canada
- Department of Medical BiophysicsThe University of Western Ontario London Canada
| | - Harvey O Coxson
- UBC Centre for Heart Lung InnovationSt. Paul's Hospital Vancouver Canada
- Department of RadiologyUniversity of British Columbia Vancouver Canada
| | - Grace Parraga
- Robarts Research Institute London Canada
- Department of Medical BiophysicsThe University of Western Ontario London Canada
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Ohno Y, Koyama H, Yoshikawa T, Seki S, Takenaka D, Yui M, Lu A, Miyazaki M, Sugimura K. Pulmonary high-resolution ultrashort TE MR imaging: Comparison with thin-section standard- and low-dose computed tomography for the assessment of pulmonary parenchyma diseases. J Magn Reson Imaging 2015. [PMID: 26223818 DOI: 10.1002/jmri.25008] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND To determine the accuracy of pulmonary MR imaging with ultrashort echo time (UTE) for lung and mediastinum assessments using computed tomography (CT) as the reference standard, for various pulmonary parenchyma diseases. METHODS Eight-five consecutive patients (46 males: mean age, 69 years and 39 females: mean age, 69 years) with various pulmonary parenchyma diseases were examined with chest standard- and low-dose CTs and pulmonary MR imaging with UTE. This was followed by visual assessment using a 5-point system of the presence of nodules or masses, ground-glass opacity, micronodules, nodules, patchy shadow or consolidation, emphysema or bullae, bronchiectasis, reticular opacity, and honeycomb and traction bronchiectasis. Presence of aneurysms, pleural or pericardial effusions, pleural thickening or tumor, and lymph adenopathy was also evaluated using a 5-point system. To compare the capability of the methods for lung parenchyma and mediastinum evaluation, intermethod agreement was evaluated by means of kappa statistics and χ2 test. Receiver operating characteristic analyses were used to compare diagnostic performance of all methods. RESULTS Intermethod agreements between pulmonary MR imaging and standard-dose and low-dose CT were significant and either substantial or almost perfect (0.67 ≤ κ ≤ 0.98; P < 0.0001). Areas under the curve for emphysema or bullae, bronchiectasis or traction bronchiectasis and reticular opacity on standard-dose CT were significantly larger than those on low-dose CT (emphysema or bullae: P = 0.0002; reticular opacity: P < 0.0001) and pulmonary MR imaging (emphysema or bullae: P < 0.0001; bronchiectasis: P = 0.008; reticular opacity: P < 0.0001). CONCLUSION Pulmonary MR imaging with UTE is useful for lung and mediastinum assessment and evaluation of radiological findings for patients with various pulmonary parenchyma diseases.
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Affiliation(s)
- Yoshiharu Ohno
- Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.,Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Hisanobu Koyama
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Takeshi Yoshikawa
- Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.,Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Shinichiro Seki
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Daisuke Takenaka
- Department of Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Masao Yui
- Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Aiming Lu
- Toshiba Medical Research Institute USA, Vernon Hills, Illinois, USA
| | - Mitsue Miyazaki
- Toshiba Medical Research Institute USA, Vernon Hills, Illinois, USA
| | - Kazuro Sugimura
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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Abstract
Lung diseases cause significant morbidity and mortality and lead to high healthcare utilization. However, few lung disease-specific biomarkers are available to accurately monitor disease activity for the purposes of clinical management or drug development. Advances in cross-modal imaging technologies, such as combined positron emission tomography (PET) and magnetic resonance (MR) imaging scanners and PET or single-photon emission computed tomography (SPECT) combined with computed tomography (CT), may aid in the development of noninvasive, molecular-based biomarkers for lung disease. However, the lungs pose particular challenges in obtaining accurate quantification of imaging data due to the low density of the organ and breathing motion. This review covers the basic physics underlying PET, SPECT, CT, and MR lung imaging and presents technical considerations for multimodal imaging with regard to PET and SPECT quantification. It also includes a brief review of the current and potential clinical applications for these hybrid imaging technologies.
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Affiliation(s)
- Delphine L Chen
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA. Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Campus Box 8225, 510 S. Kingshighway Blvd, St. Louis, MO 63110, USA
| | - Paul E Kinahan
- Department of Radiology and Bioengineering and Physics, University of Washington Medical Center, Seattle, WA, USA
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