Ruling out Cystic Fibrosis (CF) in a Pediatric Patient – Examination in 0.56 Seconds

SOMATOM Definition Flash Scanning

*Sedat Alibek, MD; *Michael Lell, MD; **Gundula Staatz, MD |  2009-10-05

* Institute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
** Section Pediatric Radiology, Institute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
Andreas Blaha; Business Unit CT, Siemens Healthcare, Forchheim, Germany



This 10-year-old patient has a known allergic asthma disease. Due to recurrent dyspnea conventional chest x-ray imaging was performed. Findings were described as acute and chronic inflammatory changes of the lung tissue. Due to clinical symptoms consistent with those of cystic fibrosis, a standard sweat test was performed (It measuring the concentration of salt in a person’s sweat) indicating elevated values. Conventional chest x-ray examinations did not show clear signs of infiltrations but a rule-out was also not possible.
The patient was referred to the pediatric hospital at the University of Erlangen. Radiologists decided not to do further x-ray exams, but an ultra-low-dose CT scan was ordered for diagnostic information with maximum patient safety.



With the sub-second, 1mSv scan, all kinds of acute and chronic pulmonary tissue changes such as inflammatory changes as well as specific findings of cystic fibrosis such as bronchiectasis, mucoid impactions and necrotic changes could be ruled out. The fast scan time of only 0.56 seconds did not require any sedation of the young patient, who was cooperative.
After this CT scan the patient could be discharged and no further work-up or follow-up was necessary.



The high resolution, non-contrast-enhanced CT examination was performed utilizing only 1 mSv of effective dose. The scan reliably excluded specific findings indicative of cystic fibrosis, thereby indicating a prolonged life expectancy for the patient.

Examination Protocol

Scanner SOMATOM Definition Flash
Scan area Thorax Flash Scan
Scan length 225 mm
Scan direction Cranio-Caudal
Scan time 0.56 s
Tube voltage 100/100 KV
Tube current 32 mAs
Dose modulation CARE Dose 4D
DLP 39
Dose mSv 1.01 mSv
Rotation time 0.28 s
Pitch 3.0
Slice collimation 128x0.6 mm
Slice width 0.75 mm
Spatial Resolution 0.33 mm
Reconstruction increment 0.7
Reconstruction kernel B26

The information presented in this case study is for illustration only and is not intended to be relied upon by the reader for instruction as to the practice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not intended by Siemens Medical Systems to be used for any purpose in that regard.

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole responsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The source for the technical data is the corresponding data sheets. Results may vary.