Use of Stored Fluoroscopic Images as an Alternative to Spot Images to Reduce Radiation Dose to Children Undergoing Fluoroscopic Studies

Saxena AK, Sodhi KS, Khandelwal N.Department of Radio Diagnosis and Imaging,

Post Graduate Institute of Medical Education and Research, Chandigarh-160012, IndiaPOSTGR

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Fig. 1 : 7 ½ year old female child with history of recurrent episodes of urinary tract infections. SFI shows normal cystogram.

Fig. 2 : 2½ year old male child with history of urinary tract infections. SFI shows normal urethra and absence of VUR.

Fig. 3 : 5 month old child with history of poor urinary stream. SFI features suggestive of posterior urethral valves (PUV).

Fig. 4 : 5 year old male child with history of fulguration of posterior urethral valves. SI (a) and SFI (b) provide similar information about mildly dilated posterior urethra and good anterior urethral stream.

Fig. 5 : 1¼ year old male child with history of urinary tract infection. SI (a) failed while SFI (b) succeeded in documenting urethra. Left vesico-ureteric reflux is seen in both SI & SFI.

Fig. 6 : 5 month old male child who was earlier operated for esophageal atresia and tracheo-esophageal fistula. Lateral (a) and Antero-Posterior (b) views of SFI show short segment esophageal stricture. No SI was taken during this study.

Fig. 7 : 8 month old child with history of failure to thrive. SFI shows f is tu lous c o m m u n i c a t i o n between esophagus and trachea (arrow).

Fig. 8 : 5 year old male child with history of abdomino-perineal pull through with anal stenosis. Patency of distal colon, partial sacral agenesis and absence of recto-urethral fistula is evident on antero-posterior (a) and lateral (b) views of SFI of distal cologram study.

(a) (b)

(a) (b) (a) (b)

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Year MCU Enema Swallow UGI FT NGM RGU DCBE Distal Cologram

Others Total

2003 105 56 52 13 42 40 4 0 19 13 344

2004 311 115 133 23 66 76 10 1 56 33 824

2005 453 144 109 27 61 74 16 0 39 66 989

Total 869 315 294 63 169 190 30 1 114 112 2157

MCU= Micturating Cystourethrogram, UGI= Upper Gastro Intestinal

Study, FT= Follow Through, NGM= Nephrostogram, RGU= Retrograde

Urethrography, DCBE= Double Contrast Barium Enema

Illustrations

Take Home Message :

Radiation Risk

Management Benefits

Use of SFI = ALARA

Background

Objective

What is stored fluoroscopic image (SFI)?

Strategy

Materials & Methods

• Radiation dose during fluoroscopic procedure = Fluoroscopy

time + radiation dose due to spot images (SI)

• To reduce the radiation dose to paediatric patients undergoing

fluoroscopic procedures

• SFI = Permanent recording of last frame of fluoroscopy

• Also called image grab and last image recall

• Does not add to fluoroscopy time or radiation dose

• SFI can be electronically enhanced by post processing

• Replace SI with SFI to achieve decrease in radiation without

compromising diagnostic information

• Period July 2003- Dec. 2005

• Machine: Shimadzu UD150B30 Digitex Pro series

fluoroscopy machine

• Details of procedures:

Observations and Results

• It was possible to replace a large number of SI with SFI without

losing diagnostic information

• Many a times no spot image was required for whole study

• ALARA principle implemented

SFI better than SI

Using SFI: Additional advantages

Lacunae

Conclusions

SFI: Possible future uses

By virtue of being instantaneous, SFI is better

than SI for:

• Documentation of DJ flexure

• Documenting urethra if voiding is intermittent

• Documentation of tracheo esophageal fistula

• Retrograde urethrography

• Reduced scatter radiation dose to medical personnels

• Prolongation of X Ray tube life

• Conservation of electrical energy

• Advantages not quantified

• Reasons:

• This was not a case control study

• Historical data on radiation doses not available

• Radiation dose varies with experience of radiologist, number of

spot images and body weight

• SFI is a good alternative to SI

• Radiation dose can be reduced without compromising diagnostic

information

• In many studies, SI can be completely eliminated

• Use of SFI conforms to ALARA principle

• Low suspicion of abnormal chest X-Ray e.g. bronchiolitis

• Mobile fluoroscopy units for follow up chest X-Rays in intensive

care units

• Localizing radio opaque foreign bodies in abdomen

• Repeat evaluation to exclude artifacts