High-Pitch Computed Tomography of the Lung in Pediatric Patients: An Intraindividual Comparison of Image Quality and Radiation Dose to Conventional 64-MDCT

Abstract

Purpose: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (E_eff).

Materials and Methods: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ± 69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0 – 8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 – no; 1 – moderate; 2 – severe artifacts). E_eff was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables.

Results: The scan time was significantly lower for HPCT compared to MDCT (0.72 ± 0.13 s vs. 3.65 ± 0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100 % vs. 17 % and 31 % vs. 6 %). The total artifact score significantly correlated with the patient's age in MDCT (r = – 0.42; p = 0.01), but not in HPCT (r = – 0.32; p = 0.07). The estimated E_eff was significantly lower in HPCT than in MDCT (1.29 ± 0.31 vs. 1.47 ± 0.37 mSv; p < 0.0001).

Conclusion: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated E_eff was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality.

Key points:

• Fewer artifacts in pediatric lung imaging with HPCT

• Reduced E_eff in HPCT

• HPCT without sedation or breath-hold without loss of image quality

Citation Format:

• Tsiflikas I, Thomas C, Ketelsen D et al. High-Pitch Computed Tomography of the Lung in Pediatric Patients: An Intraindividual Comparison of Image Quality and Radiation Dose to Conventional 64-MDCT. Fortschr Röntgenstr 2014; 186: 585 – 590

Zusammenfassung

Ziel: Ziel der Studie war die Häufigkeit von typischen Artefakten der high-pitch Computertomografie (HPCT) bei low-dose Untersuchungen von Kindern im Vergleich zur MDCT zu evaluieren und die effektive Dosis (D_eff) zu berechnen.

Material und Methoden: 35 Patienten (17 Jungen, 18 Mädchen; Durchschnittsalter 112 ± 69 Monate) wurden in diese retrospektive Studie eingeschlossen. Bei allen Patienten wurden zwei CT-Untersuchungen mit jeweils gleicher Röhrenspannung und -strom im mittleren Zeitabstand von 87 Tagen durchgeführt: entweder zuerst die MDCT gefolgt von der HPCT oder in umgekehrter Reihenfolge. Die Bildqualität wurde durch 2 Radiologen im Konsensus intraindividuell verglichen. Der Gesamtartefaktscore (0 – 8) wurde definiert als Summe der Artefakte durch Bewegung, Atmung sowie Pulsation am Herzen bzw. den pulmonalen Gefäßen (0 – keine; 1 – geringe; 2 – deutliche Artefakte). Die D_eff wurde entsprechend den Europäischen Leitlinien zur Qualitätssicherung in der MDCT berechnet. Zur Auswertung der Unterschiede zwischen den Gruppen wurde die Mann-Whitney U Teststatistik angewandt. Die Korrelation von ordinalen Variabeln wurde mittels der Spearmans Rangkorrelation getestet.

Ergebnisse: Die Scanzeit war für die HPCT im Vergleich zur MDCT signifikant niedriger (0,72 ± 0,13 s vs. 3,65 ± 0,81s; p < 0,0001). In 28 von 35 (80 %) HPCT Untersuchungen traten keine Artefakte auf, wohingegen bei der MDCT bei allen Untersuchungen Artefakte erkennbar waren. Die Häufigkeit von Pulsations- und Atmungsartefakten war in der MDCT höher im Vergleich zur HPCT (100 % vs. 17 % und 31 % vs. 6 %). Der Gesamtartefaktscore korreliert signifikant mit dem Patientenalter für die MDCT (r = –0,42; p = 0,01) aber nicht für die HPCT (r = –0,32; p = 0,07). Die berechnete D_eff war signifikant niedriger für die HPCT (1,29 ± 0,31 mSv vs. 1,47 ± 0,37 mS für die MDCT; p < 0,0001).

Schlussfolgerung: Die HPCT führt zu einer relevanten Reduktion der typischen Bildartefakte in der Lungenbildgebung bei Kindern. Hierbei ist die berechnete effektive Dosis geringer. Darüber hinaus können die Untersuchungen ohne Sedierung und unter freier Atmung ohne Verlust an Bildqualität durchgeführt werden.

Kernaussagen:

• HPCT führt zu einer Reduzierung von Artefakten in der Lungenbildgebung bei Kindern

• Reduzierte D_eff für die HPCT

• HPCT unter freier Atmung und ohne Sedierung ohne Verlust an Bildqualität

Key words

thorax - CT - artifacts

• References

• 1 Nievelstein RA, van Dam IM, van der Molen AJ. Multidetector CT in children: current concepts and dose reduction strategies. Pediatr Radiol 2010; 40: 1324-1344
• 2 Rogalla P, Stover B, Scheer I et al. Low-dose spiral CT: applicability to paediatric chest imaging. Pediatr Radiol 1999; 29: 565-569
• 3 Singh S, Kalra MK, Moore MA et al. Dose reduction and compliance with pediatric CT protocols adapted to patient size, clinical indication, and number of prior studies. Radiology 2009; 252: 200-208
• 4 Sury M, Bullock I, Rabar S et al. Sedation for diagnostic and therapeutic procedures in children and young people: summary of NICE guidance. BMJ 2010; 341: c6819
• 5 Flohr TG, Leng S, Yu L et al. Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: image reconstruction and assessment of image quality. Med Phys 2009; 36: 5641-5653
• 6 Hausleiter J, Bischoff B, Hein F et al. Feasibility of dual-source cardiac CT angiography with high-pitch scan protocols. J Cardiovasc Comput Tomogr 2009; 3: 236-242
• 7 Leschka S, Stolzmann P, Desbiolles L et al. Diagnostic accuracy of high-pitch dual-source CT for the assessment of coronary stenoses: first experience. Eur Radiol 2009; 19 (12) 2896-2903
• 8 Alkadhi H, Stolzmann P, Desbiolles L et al. Low-dose, 128-slice, dual-source CT coronary angiography: accuracy and radiation dose of the high-pitch and the step-and-shoot mode. Heart 2010; 96: 933-938
• 9 Lell M, Hinkmann F, Anders K et al. High-pitch electrocardiogram-triggered computed tomography of the chest: initial results. Invest Radiol 2009; 44: 728-733
• 10 Lell MM, May M, Deak P et al. High-Pitch Spiral Computed Tomography: Effect on Image Quality and Radiation Dose in Pediatric Chest Computed Tomography. Invest Radiol 2010;
• 11 Bongartz GSJG, Jurik AG, Leonardi M et al. European Guidelines on Quality Criteria for Multislice Computed Tomography. In: Commission E. ed. FIGM-CT2000-20078-CT-TIP Luxembourg: 2004
• 12 Pauls S, Aschoff AJ, Wahl J et al. Multi-detector row CT: is prospective electrocardiographic triggering improving the detection of small pulmonary tumors?. Acad Radiol 2005; 12: 614-619
• 13 Fuchs J, Seitz G, Ellerkamp V et al. Analysis of sternotomy as treatment option for the resection of bilateral pulmonary metastases in pediatric solid tumors. Surg Oncol 2008; 17: 323-330
• 14 Grundy PE, Green DM, Dirks AC et al. Clinical significance of pulmonary nodules detected by CT and Not CXR in patients treated for favorable histology Wilms tumor on national Wilms tumor studies-4 and -5: A report from the Children's Oncology Group. Pediatr Blood Cancer 2012;
• 15 Warmann SW, Furtwangler R, Blumenstock G et al. Tumor biology influences the prognosis of nephroblastoma patients with primary pulmonary metastases: results from SIOP 93-01/GPOH and SIOP 2001/GPOH. Annals of surgery 2011; 254: 155-162
• 16 Kroft LJ, Roelofs JJ, Geleijns J. Scan time and patient dose for thoracic imaging in neonates and small children using axial volumetric 320-detector row CT compared to helical 64-, 32-, and 16- detector row CT acquisitions. Pediatr Radiol 2010; 40: 294-300
• 17 Vanderby SA, Babyn PS, Carter MW et al. Effect of anesthesia and sedation on pediatric MR imaging patient flow. Radiology 2010; 256: 229-237
• 18 Ing C, DiMaggio C, Whitehouse A et al. Long-term differences in language and cognitive function after childhood exposure to anesthesia. Pediatrics 2012; 130: e476-e485
• 19 DiMaggio C, Sun LS, Ing C et al. Pediatric anesthesia and neurodevelopmental impairments: a Bayesian meta-analysis. Journal of neurosurgical anesthesiology 2012; 24: 376-381
• 20 Sargent MA, McEachern AM, Jamieson DH et al. Atelectasis on pediatric chest CT: comparison of sedation techniques. Pediatr Radiol 1999; 29: 509-513
• 21 Newman B, Krane EJ, Gawande R et al. Chest CT in children: anesthesia and atelectasis. Pediatr Radiol 2013;
• 22 Co SJ, Mayo J, Liang T et al. Iterative reconstructed ultra high pitch CT pulmonary angiography with cardiac bowtie-shaped filter in the acute setting: effect on dose and image quality. Eur J Radiol 2013; 82: 1571-1576