Performance of a simple robust empiric timing protocol for CT pulmonary angiography

Hsu, Kevin; Levsky, Jeffrey M.; Haramati, Linda B.; Gohari, Arash

doi:10.1016/j.clinimag.2017.09.006

Cited by 10 publications

(8 citation statements)

References 11 publications

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“…Radiation dosimetry data for the present study cohort were not collected. However, institutional dosimetry data for CTPA at our institution, available from 2007 to 2015 (11,12), demonstrated decreased radiation exposure from CTPA from 11 to 5.3 mSv, more recently. The V/Q scan technique was stable during the study period, with an estimated radiation exposure of 2.6 mSv (13).…”

Section: Data Collectionmentioning

confidence: 88%

“…The good diagnostic performance of the V/Q scan in sickle cell disease patients in our practice confers a radiation reduction advantage and obviates the need for iodinated intravenous contrast. Even with aggressive radiation reduction strategies, the radiation exposure for 64-detector row CTPA scanners we-and many other institutions-currently use is double to triple that of V/Q scans (11)(12)(13). When more advanced CT technologies become widespread, this difference may be mitigated and then a further reassessment of risk-benefit recommendations will be necessary.…”

Section: Discussionmentioning

confidence: 99%

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Imaging for Pulmonary Embolism in Sickle Cell Disease: A 17-Year Experience

et al. 2018

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Sickle cell disease, a complex disorder with known pulmonary complications, has the potential to confound the diagnosis of pulmonary embolism. We hypothesized that when the choice of imaging is guided by chest radiographic results, CT pulmonary angiography (CTPA) and ventilation-perfusion (V/Q) scintigraphy have comparable diagnostic performance in sickle cell disease. A retrospective cohort of adults with sickle cell disease who were imaged for suspected pulmonary embolism with either CTPA or V/Q, from 2000 to 2016 at our institution, was established. To reduce radiation exposure, our practice recommends V/Q for stable patients with normal chest radiographs. Results of index pulmonary embolism imaging, 90-d follow-up, and results of chest radiography were recorded. Two hundred forty-five adults with sickle cell disease comprised the cohort. The mean age (±SD) was 33 ± 10.5 y, and 58% (141) were men. Index imaging was V/Q in 62.9% ( = 154) and CTPA in 37.1% ( = 91). Chest radiographs, performed in 96.3% ( = 236), were normal in 72.9% ( = 172). Imaging results for pulmonary embolism were negative in 88.2% ( = 216), positive in 4.1% ( = 10), and indeterminate in 7.8% ( = 19) with no difference between V/Q and CTPA ( = 0.63). Reimaging within 90 d occurred in 9.8% ( = 24), 14.7% (20/136) after initial V/Q, and 5% (4/109) after initial CTPA ( = 0.08). Reimaging revealed a pulmonary embolism diagnosis after negative/indeterminate results in 0.7% (1/149) of V/Qs and 1.2% of (1/86) CTPAs ( = 0.69). Over the 17-y study period, 47% (114/245) underwent repeated imaging, and 11% (27/245) were diagnosed with pulmonary embolism at least once. In sickle cell disease patients with suspected pulmonary embolism, positive imaging rates were low for any given clinical presentation, but 11% of the cohort was diagnosed with pulmonary embolism over the 17-y study period. CTPA and V/Q performed comparably for pulmonary embolism diagnosis when the choice of imaging was guided by results of chest radiography. Hence, V/Q is a reasonable first choice for sickle cell disease patients with normal chest radiographs.

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Section: Data Collectionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Imaging for Pulmonary Embolism in Sickle Cell Disease: A 17-Year Experience

et al. 2018

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“…Moreover, it is difficult to objectively quantify based on relative variance when scanning has been performed by numerous individuals. While enhancement in the pulmonary trunk and aorta may be optimal, if the distal branches are not sufficiently enhanced the scan could still be less than optimal 14 . However, since the mean pulmonary arterial (394 HU) and aortic enhancement (319 HU) were both greater in the bolus track protocol, it is inferred the distal pulmonary artery branches were enhanced in a range between those two vessels 14 …”

Section: Limitationsmentioning

confidence: 99%

“…analysed area's including the ascending and descending aorta however a test bolus protocol unique to their study was used. HSU et al., 14 analysed the main pulmonary artery and descending aorta however they used an empiric timed protocol. In this study, further HU measurements in the distal sections (segmental or subsegmental) of the pulmonary artery vascular tree were not performed, in line with previous research by Goble and Abulkarim 15 and Suckling et al 13 .…”

Section: Introductionmentioning

confidence: 99%

A comparison of bolus track and test bolus computed tomography pulmonary angiography and the implications on pulmonary and aortic vessel enhancement, effective dose and suboptimal scan rate

Murphy,

White

2023

J of Medical Radiation Sci

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IntroductionBolus track and test bolus are the most commonly used contrast timing protocols to undertake computed tomography pulmonary angiography (CTPA). The aim of this study was to compare test bolus and bolus track contrast enhancement protocols in terms of enhancement of the pulmonary vessels and aorta, radiation dose and suboptimal scan rate to determine the optimal technique for CTPA.MethodsA total of 200 CTPA examinations (100 using each protocol) performed between January and February 2021 were assessed retrospectively. All scans were performed on a 2x128 Dual Source Siemens Drive Scanner. CT attenuation was measured in Hounsfield Units (HU), with measurements taken from the main pulmonary trunk, right pulmonary artery and left pulmonary artery, ascending and descending aorta. The mean effective dose was calculated from the dose‐length product (DLP). The suboptimal scan rate was calculated as the percentage of examinations below 210HU.ResultsThe average HU of the pulmonary arteries was 358 HU ± SD 129.2 in the test bolus group and increased to 394 HU ± SD 133.9 in the bolus track group with a P value of ≤0.05. The average HU of the aorta was 235 HU ± SD 82.8 in the test bolus group and increased to 319 HU ± SD 91.8 in the bolus track group with a P value of <0.001. Although not statistically significant, the mean effective dose was reduced by 4.2% for the bolus track protocol (2.4 mSv vs. 2.5 mSv, P > 0.05). Fewer suboptimal scans were performed with the bolus track protocol (5 scans <210HU Bolus Track vs. 9 scans <210HU Test Bolus).ConclusionThe bolus track protocol results in increased enhancement of the pulmonary arteries and aorta, with the added benefits of a lower suboptimal scan rate and lower effective dose.

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“…As CTPA focuses on pulmonary arteries, additional scans are needed to rule out aortic, parenchymal or mediastinal disease, increasing radiation exposure, and its potential risks [6,7]. In this regard, various methods of protocol optimization and dose reduction have been proposed, including the use of a lower tube voltage [8], lower iodine concentration and/or quantity [9,10], iterative and filtered back projection reconstruction techniques [11], and the optimization of contrast material injection [12][13][14]. However, the radiation burden may still be problematic, especially in oncology patients for whom the association between cancer and the development of PE is well known [15,16].…”

Section: Introductionmentioning

confidence: 99%

Identification of pulmonary embolism: diagnostic accuracy of venous-phase dual-energy CT in comparison to pulmonary arteries CT angiography

et al. 2020

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Objectives To evaluate the diagnostic accuracy of venous-phase dual-energy computed tomography (VP-DECT) in the identification of PE compared with standard CT pulmonary angiography (CTPA). Methods This prospective IRB-approved study included 61 consecutive oncology patients (35 females, 26 males, mean age 66.91 years) examined by CTPA and VP-DECT. DECT data were post-processed on a SyngoVia workstation to obtain monoenergetic images (MEI+). The diagnosis of PE was based on the presence of any vascular perfusion defects. DECT images were evaluated independently by two radiologists (8 and 16 years of experience). A consensus reading of CTPA images (two senior radiologists, 18 and 24 years of experience) represented the reference for diagnosis. The diagnostic accuracy values of VP-DECT on a per-patient and per-lobe basis were assessed. Interobserver agreement was calculated using k-statistics. A value of p < 0.05 was considered statistically significant. Results Thirty of 61 patients (49.18%) were diagnosed with PE by CTPA, with 57/366 lobes being involved (15.57%). The sensitivity and specificity of the per-patient analysis of VP-DECT images were 90.0% (27/30) and 100% (31/31) respectively, for both readers. As concerns the per-lobe analysis, the sensitivity ranged from 100% for the right lower lobe to 50% for the left upper lobe for reader 1, and from 100% for the left upper lobe to 69.23% for the lingula for reader 2. The interobserver agreement ranged from 0.8671 (patients' analysis) to 0.6419 (lobes' analysis). Conclusion VP-DECT could be considered an accurate imaging tool for diagnosing PE in a selected, high-prevalence population, compared with CTPA. Key Points • With regard to the patients' analysis, venous-phase DECT sensitivity and specificity in diagnosing pulmonary embolism were 90% and 100%, respectively, for both readers.• With regard to the lobes' analysis, the sensitivity ranged from 100 to 50%, for reader 1, and from 100 to 69.23%, for reader 2, respectively. • The sensitivity and specificity of lung perfusion maps obtained from venous DECT were 73.33% and 67.74% as concerns the patients' analysis and 71.92% and 75.72% as regards the lobes' analysis, respectively.

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Performance of a simple robust empiric timing protocol for CT pulmonary angiography

Cited by 10 publications

References 11 publications

Imaging for Pulmonary Embolism in Sickle Cell Disease: A 17-Year Experience

Imaging for Pulmonary Embolism in Sickle Cell Disease: A 17-Year Experience

A comparison of bolus track and test bolus computed tomography pulmonary angiography and the implications on pulmonary and aortic vessel enhancement, effective dose and suboptimal scan rate

Identification of pulmonary embolism: diagnostic accuracy of venous-phase dual-energy CT in comparison to pulmonary arteries CT angiography

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