The percentage of image noise for all CTA studies was calculated using a validated equation [16]. European Respiratory Journal Sep 2012, 40 (Suppl 56) P1499; Share This Article: Copy. The current standard of care for members with suspected pulmonary embolism is a spiral CT scan, also called a CTA, CT PA (computed tomography pulmonary angiography), MDCT (multidector CT) or helical CT scan. A region of-interest measurement may be helpful if the attenuation is greater than 78 HU. The objective evaluation classified mean pulmonary arterial opacification as good (≥ 210 HU), acceptable (170–209 HU), or poor (≤ 169 HU), as described in a recent study [15]. The contrast agent is injected into a vein (not an artery as in conventional angiography), usually in the arm. The flow rate was kept constant at 6 mL/s throughout the procedure, and contrast administration was followed by a 50-mL IV saline flush. Computed tomographic (CT) pulmonary angiography has been evaluated with meta-analysis and has demonstrated sensitivities of 53%–100% and specificities of 83%–100% (, 6), wide ranges that are explained in part by technologic improvements over time. Studies analyzing pulmonary CTA of pregnant patients have confirmed that pulmonary arterial opacification is reduced during pregnancy [4, 7, 19, 20] and that transient interruption of the contrast bolus by unopacified blood from the IVC may occur more often in pregnant patients than in the general population [7]. Suspected Pulmonary Embolism: A Management Study . Significance values were set at p ≤ 0.05. The increase in cardiac output was also minimized by using a high concentration of contrast medium and by using bolus tracking, both of which are part of standard practice for CTA of pregnant patients in our institution. • An empiric timing protocol for CT pulmonary angiography had lower radiation exposure compared to a timing bolus protocol. Although bias was limited by blinding readers to the clinical details and the initial pulmonary CTA report, readers were not blinded to the imaging protocol used. Lung volume was quantified employing semi-automated lung software that calculated lung volumes (intellispace -Philips). Evaluation of subjective image quality involved categorizing a study as either adequate or inadequate on the basis of one’s ability to diagnose PE, the adequacy of pulmonary arterial opacification, and the presence or absence of significant motion artifact and image noise. Radiology 245: 577–583. Due to its high sensitivity and specificity [1,2] its wide availability and its potential to assess mediastinal and parenchymal structures for alternate diagnoses, computed tomography pulmonary angiography (CTPA) has become a preferred diagnostic imaging method within the diagnostic algorithm for suspected PE. The flow rate was kept constant at 4 mL/s throughout the procedure. Pulmonary CT Angiography Protocol Adapted to the Hemodynamic Effects of Pregnancy, Transient Interruption of Contrast Material by Unopacified Blood From the Inferior Vena Cava, Original Research. The objective evaluation classified mean pulmonary arterial opacification as good (≥ 210 HU), acceptable (170–209 HU), or poor (≤ 169 HU), as described in a recent study [15]. This effect, known as the “thoracoabdominal pump,” is likely to be prominent in pregnancy because of inherently raised IVC pressures. Conversely, an indeterminate rate of 35.7% was described in a smaller study of 25 patients in which a lower volume of 75 mL of iodinated contrast material and held maximal inspiration were used [7]. The difference in mean gestation between groups A and B (31 vs 29 weeks) was not statistically significant (p = 0.4). In all cases, the clinical and study reinterpretations agreed. There were no reported complications as a result of pulmonary CTA in either group. Criteria to be used for Chest CTA or a CT is requested for Pulmonary Emboli which cannot be approved based on Interqual or Milliman criteria. [Dual-source CT scanners provide high-pitch dual source protocols … To propose a protocol for pulmonary angiography using 64-slice multidetector computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in an unselected patient population, as well as to evaluate vascular enhancement and image quality. Pulmonary embolism (PE) is a common condition with high mortality and morbidity. The mean effective dose per scan was lower in group B (4.8 mSv) than in group A (5.3 mSv) (p = 0.09). The subsequent 20 pregnant patients referred for pulmonary CTA were imaged using a CTA protocol adapted to minimize the hemodynamic effects of pregnancy (Table 1). The potential excessive contribution of unopacified blood from the IVC to the right heart was minimized by adequate coaching from a technologist regarding shallow held inspiration. TABLE 1: Pulmonary CT Angiography Contrast Medium Administration Parameters, Each study was then assessed for the presence or absence of a transient interruption of the contrast bolus by unopacified blood from the IVC. During bolus tracking, the patient was instructed to breathe quietly. Group B consisted of 20 patients, each of whom underwent one pulmonary CTA study. Several study limitations are acknowledged. These data indicate a 143-HU difference in mean opacification between the two groups. There was a strong positive relationship between mean pulmonary arterial attenuation and good subjective image quality (r = 0.55, p = 0.001). Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. There was a strong positive relationship between mean pulmonary arterial attenuation and good subjective image quality (r = 0.55, p = 0.001). The aim of this study was to analyze the dose reduction and image quality achieved by using 80 kV instead of 100 kV in CT pulmonary angiography protocols. Inventive protocols of CT pulmonary angiography (CTPA) avoid artifacts in right pulmonary artery (rPA), improving detectability of pulmonary embolism (PE) Miho Ikura, Hirohiko Ikura, Hisayuki Abe, Seiichiroh Watanabe, Shin Kimoto, Yohko Kawawa. This difference achieved statistical significance (p = 0.03) because three patients in group A had repeat CTA studies. The empiric timing protocol for CT pulmonary angiography yielded good aortic opacification in the majority of patients. These measurements were then combined to calculate mean pulmonary opacification. Arteries are blood vessels that carry blood away from the heart. Pulmonary angiography is an invasive procedure and due to its costs and potential risks is usually reserved for patients in whom more information or certainty of the diagnosis of PE are necessary. CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients, Original Research. Three of 11 CTA studies judged to have transient interruption of the contrast bolus in group A were considered of diagnostic quality at the time of image acquisition and by subjective image quality evaluation, but the mean pulmonary arterial enhancement was classified as poor in two and as adequate in one of these studies. Pulmonary embolism ppt resmigs. In pregnant patients with suspected PE, a pulmonary CTA protocol optimized for use in pregnancy that includes a high flow rate, a high volume, and high concentration of contrast medium and shallow held inspiration significantly increases the rate of diagnostic adequacy and pulmonary arterial opacification and decreases the incidence of transient interruption of the contrast bolus by unopacified blood from the IVC. The PE Graduated D-dimer (PEGeD) Study . Vessel opacification was provided by IV injection of 75 mL of iopamidol (Niopam 370, Bracco) via the antecubital vein. The reviewers were blinded to the clinical information or the initial radiologic interpretation. A Combination of Normal-Dose Corticomedullary Phase With Low-Dose Unenhanced and Excretory Phases, Review. There was a strong positive relationship between mean pulmonary arterial attenuation and good objective image quality (r = 0.67, p = 0.001). The mean effective dose per patient was also lower in group B (4.8 mSv) than in group A (5.6 mSv). Although this protocol optimized for imaging pregnant patients significantly improved pulmonary CTA image quality, two of the 20 patients in group B had nondiagnostic studies. Intrathoracic pressure decreases on deep inspiration and the thoracoabdominal gradient becomes more pronounced, resulting in increased venous return to the right heart. The specific feature of this protocol is to place the region of interest (ROI) (bolus detection) in the superior vena cava. Forty-eight pulmonary CTA examinations were performed of 45 pregnant patients (age range, 17–41 years; mean age, 31 years; gestation range, 18–39 weeks; mean gestation, 30 weeks) with suspected PE. cerebral angiography – to check the blood vessels in and around the brain ; pulmonary angiography – to check the blood vessels supplying the lungs ; renal angiography – to check the blood vessels supplying the kidneys ; Occasionally, angiography may be done using scans instead of X-rays. KIVC values range from 0 to 1.0; a high KIVC (> 0.8) indicates a larger contribution from the IVC to the right heart relative to the SVC and suggests the presence of transient interruption of the contrast bolus by unopacified blood from the IVC, whereas healthy control subjects have average KIVC values of approximately 0.5 [17]. For example, in a recent study of 43 pregnant patients, investigators reported a 19% rate of indeterminate CTA studies using 100–120 mL of contrast medium and held maximal inspiration, with slow breathing used as a trouble-shooting maneuver [20]. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. • Wittram C, Maher MM, Halpern E, Shepard JO. To propose a protocol for pulmonary angiography using 64-slice multidetector computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in an unselected patient population, as well as to evaluate vascular enhancement and image quality. Pulmonary embolism (PE) is a common condition with high mortality and morbidity. Radiology 2005; 237: 329-337. Fig. As a result, these patients had a higher cumulative dose than those in group B; none of the group B patients underwent repeat CTA studies. Intrathoracic pressure decreases on deep inspiration and the thoracoabdominal gradient becomes more pronounced, resulting in increased venous return to the right heart. The pulmonary vasculature may be evaluated with various invasive and noninvasive methods. Imaging of Pulmonary Embolism Gamal Agmy. In group A, eight patients had nondiagnostic pulmonary CTA studies. 1), attenuation measurements were made in the area of decreased attenuation and in the proximal and distal areas of higher attenuation, as described in the literature [17, 18]. Subjective image quality was also significantly better in group B. Eighteen of 20 CTA studies (90%) in group B were classified as adequate, indicating good pulmonary arterial enhancement and no significant noise or motion artifact, compared with 18 of 28 studies (64%) in group A (p = 0.03). Radiology 2005; 237: 329-337. Role of CT Pulmonary Angiography. Methods: Other larger studies do not describe the breathing instructions used [6, 15] and report indeterminate rates of 17% and 5.6% using 100–125 mL and 80–95 mL of contrast material, respectively. The pulmonary vasculature may be evaluated with various invasive and noninvasive methods. The mean pulmonary attenuation was also higher in group B than in group A: 321 ± 148 HU compared with 178 ± 67 HU (p = 0.0001). To compare intravenous contrast material (CM) injection protocols for dual-energy CT pulmonary angiography (CTPA) in patients with suspected acute pulmonary embolism with regard to image quality and pulmonary perfused blood volume (PBV) values. 2). 1,2 Since the 1990s, CT pulmonary angiography (CTPA) has become the method of choice for imaging in suspected PE. Subjective image quality was also significantly better in group B. Eighteen of 20 CTA studies (90%) in group B were classified as adequate, indicating good pulmonary arterial enhancement and no significant noise or motion artifact, compared with 18 of 28 studies (64%) in group A (p = 0.03). The purpose of this study was to evaluate the feasibility, image quality (image quality) and radiation dose of a 70-kVp simultaneous acquisition dual-source CT pulmonary angiography (CTPA) protocol with 40 ml of contrast medium (CM) and to compare the image quality and radiation dose to a high-pitch spiral acquisition CTPA protocol with automated tube potential selection (ATPS). Ct angio ppt drksp. Copyright © 2013-2020, American Roentgen Ray Society, ARRS, All Rights Reserved. Lemon and Banana signs Sameer Dikshit. The flow rate was kept constant at 4 mL/s throughout the procedure. 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