Diagnostic accuracy of lung subtraction iodine mapping CT for the evaluation of pulmonary perfusion in patients with chronic thromboembolic pulmonary hypertension: Correlation with perfusion SPECT/CT

Tamura, Masashi; Yamada, Yoshitake; Kawakami, Takashi; Kataoka, Masaharu; Iwabuchi, Yu; Sugiura, Hiroaki; Hashimoto, Masahiro; Nakahara, Tsutomu; Okuda, S.; Nakatsuka, Seishi; Sano, Fumiya; Abe, Takayuki; Maekawa, Yuichiro; Fukuda, Keiichi; Jinzaki, Masahiro

doi:10.1016/j.ijcard.2017.05.006

Cited by 50 publications

(49 citation statements)

References 15 publications

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“…We did not investigate smaller perfusion defects (<25 mm), in detail, but most likely they will often not be shown correctly and therefore cannot be detected. As mentioned, subsegmental perfusion defects are in the centimeter range, which explains why they are reported as usually visible in previous studies . Furthermore, since the appropriateness of treating very small subsegmental embolisms is debatable, in cases where these perfusion defects are not depicted, this might not have a deleterious impact on the diagnosis and determination of prognosis of PE .…”

Section: Discussionmentioning

confidence: 73%

“…As mentioned, subsegmental perfusion defects are in the centimeter range, 11 which explains why they are reported as usually visible in previous studies. 1,[18][19][20] Furthermore, since the appropriateness of treating very small subsegmental embolisms is debatable, in cases where these perfusion defects are not depicted, this might not have a deleterious impact on the diagnosis and determination of prognosis of PE. 21,22 The perfusion maps may be less accurate, for structures in the paracardiac, above the diaphragm, and ventral subpleural regions, due to larger movement caused by breathing.…”

Section: Discussionmentioning

confidence: 99%

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Accuracy of registration algorithms in subtraction CT of the lungs: A digital phantom study

et al. 2019

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Purpose The purpose of this study was to assess, using an anthropomorphic digital phantom, the accuracy of algorithms in registering precontrast and contrast‐enhanced computed tomography (CT) chest images for generation of iodine maps of the pulmonary parenchyma via temporal subtraction. Materials and methods The XCAT phantom, with enhanced airway and pulmonary vessel structures, was used to simulate precontrast and contrast‐enhanced chest images at various inspiration levels and added CT simulation for realistic system noise. Differences in diaphragm position were varied between 0 and 20 mm, with the maximum chosen to exceed the 95th percentile found in a dataset of 100 clinical subtraction CTs. In addition, the influence of whole body movement, degree of iodine enhancement, beam hardening artifacts, presence of nodules and perfusion defects in the pulmonary parenchyma, and variation in noise on the registration were also investigated. Registration was performed using three lung registration algorithms — a commercial (algorithm A) and a prototype (algorithm B) version from Canon Medical Systems and an algorithm from the MEVIS Fraunhofer institute (algorithm C). For each algorithm, we calculated the voxel‐by‐voxel difference between the true deformation and the algorithm‐estimated deformation in the lungs. Results The median absolute residual error for all three algorithms was smaller than the voxel size (1.0 × 1.0 × 1.0 mm3) for up to an 8 mm diaphragm difference, which is the average difference in diaphragm levels found clinically, and increased with increasing difference in diaphragm position. At 20 mm diaphragm displacement, the median absolute residual error after registration was 0.85 mm (interquartile range, 0.51–1.47 mm) for algorithm A, 0.82 mm (0.50–1.40 mm) for algorithm B, and 0.91 mm (0.54–1.52 mm) for algorithm C. The largest errors were seen in the paracardiac regions and close to the diaphragm. The impact of all other evaluated conditions on the residual error varied, resulting in an increase in the median residual error lower than 0.1 mm for all algorithms, except in the case of whole body displacements for algorithm B, and with increased noise for algorithm C. Conclusion Motion correction software can compensate for respiratory and cardiac motion with a median residual error below 1 mm, which was smaller than the voxel size, with small differences among the tested registration algorithms for different conditions. Perfusion defects above 50 mm will be visible with the commercially available subtraction CT software, even in poorly registered areas, where the median residual error in that area was 7.7 mm.

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Section: Discussionmentioning

confidence: 73%

Section: Discussionmentioning

confidence: 99%

Accuracy of registration algorithms in subtraction CT of the lungs: A digital phantom study

et al. 2019

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“…Nowadays, Lung Perfused Blood Volume using dual-energy CT or Lung Subtraction Iodine Mapping CT using the subtraction technique are being used for evaluating lung perfusion in CTEPH patients. 6,7 However, these techniques have the limitation that they cannot completely separate pulmonary and systemic arterial perfusion of the lung, which can lead to overestimation of lung perfusion. 6 Thus, it is now necessary to evaluate lung perfusion by 99m Tc-MAA Single Photon Emission Computed Tomography (SPECT) or SPECT/CT, which evaluates pulmonary arterial perfusion alone.…”

Section: Discussionmentioning

confidence: 99%

Successful depiction of systemic collateral supply to pulmonary artery in CTEPH using time‐resolved 4D CT angiography: a case report

et al. 2020

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A 49-year-old man with CTEPH (pre-procedural mean pulmonary artery pressure: 36 mmHg) underwent balloon pulmonary angioplasty. Chronic total occlusion of the left inferior pulmonary artery trunk was observed. To evaluate the collateral vessels of the chronic total occlusion, 4D-CTA was performed. The examination was performed using a 256-row detector CT system using the test bolus tracking method. 4D-CTA showed the bronchial artery-to-left inferior pulmonary artery collateral supply, which was confirmed by a selective bronchial artery angiography. The patient’s symptoms improved with balloon pulmonary angioplasty of the other stenotic lesions. 4D-CTA can noninvasively evaluate the anatomy and hemodynamics of multiple systemic collaterals simultaneously. This technique can support interventions in systemic artery-to-pulmonary artery collaterals, such as embolization, and could be helpful in challenging balloon pulmonary angioplasty interventions for chronic total occlusion to identify vessel structures distal to the chronic total occlusion and collateral channels for a retrograde approach.

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“…Since it is software-based, it is signi cantly less expensive and potentially more available than costly DECT equipment. Nevertheless, being a novel approach, concerns regarding potential bias resulting from subtraction of non-contrast images from contrast-enhanced images need to be addressed, and greater experience and better knowledge of typical pitfalls is needed to improve the diagnostic accuracy (20)(21)(22). Fifth, some of the iodine maps were uninterpretable.…”

Section: Discussionmentioning

confidence: 99%

COVID-19: What Can Iodine Maps From Perfusion CT Teach Us? A Prospective Cohort Study.

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et al. 2020

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Background: Subtraction CT angiography (sCTA) is a technique used to evaluate pulmonary perfusion based on iodine distribution maps. The aim of this study is to assess lung perfusion changes with sCTA seen in patients with COVID-19 pneumonia and correlate them with clinical outcomes.Material and Methods: A prospective cohort study was carried out with 45 RT-PCR-confirmed COVID-19 patients that required hospitalization at three different hospitals, between April and May 2020. In all cases, a basic clinical and demographic profile was obtained. Lung perfusion was assessed using sCTA. Evaluated imaging features included: Pattern predominance of injured lung parenchyma in both lungs (ground-glass opacities, consolidation and mixed pattern) and anatomical extension; predominant type of perfusion abnormality (increased perfusion or hypoperfusion), perfusion abnormality distribution (focal or diffuse), extension of perfusion abnormalities (mild, moderate and severe involvement); presence of vascular dilatation and vascular tortuosity. All participants were followed-up until hospital discharge searching for the development of any of the study endpoints. These endpoints included intensive-care unit (ICU) admission, initiation of invasive mechanical ventilation (IMV) and death.Results: Forty-one patients (55.2 +/- 16.5 years, 22 men) with RT-PCR-confirmed SARS-CoV-2 infection and an interpretable iodine map were included. Patients with perfusion anomalies on sCTA in morphologically normal lung parenchyma showed lower Pa/Fi values (294 ± 111.3 vs. 397 ± 37.7, p=0.035), and higher D-dimer levels (1156 ± 1018 vs. 378 ± 60.2, p<0.01). The main common patterns seen in lung CT scans were ground-glass opacities, mixed pattern with predominant ground-glass opacities and mixed pattern with predominant consolidation in 56.1%, 24.4% and 19.5% respectively. Perfusion abnormalities were common (36 patients, 87.8%), mainly hypoperfusion in areas of apparently healthy lung. Patients with severe hypoperfusion in areas of apparently healthy lung parenchyma had an increased probability of being admitted to ICU and to initiate IMV (HR of 11.9 (95%CI 1.55-91.9) and HR 7.8 (95%CI 1.05-61.1), respectively). Conclusion: Perfusion abnormalities evidenced in iodine maps obtained by sCTA are associated with increased admission to ICU and initiation of IMV in COVID-19 patients.

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Diagnostic accuracy of lung subtraction iodine mapping CT for the evaluation of pulmonary perfusion in patients with chronic thromboembolic pulmonary hypertension: Correlation with perfusion SPECT/CT

Cited by 50 publications

References 15 publications

Accuracy of registration algorithms in subtraction CT of the lungs: A digital phantom study

Accuracy of registration algorithms in subtraction CT of the lungs: A digital phantom study

Successful depiction of systemic collateral supply to pulmonary artery in CTEPH using time‐resolved 4D CT angiography: a case report

COVID-19: What Can Iodine Maps From Perfusion CT Teach Us? A Prospective Cohort Study.

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