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C-arm rotation as a method for reducing peak skin dose in interventional cardiology.

Pasciak AS, Bourgeois AC, Jones AK - Open Heart (2014)

Bottom Line: Small patients may not benefit from C-arm rotation as a procedural modification.With the exception of rotation to steep craniocaudal angles, rotating the C-arm reduces PSD in IC procedures when used as either a procedural modification or a prophylactic strategy.Tight collimation increases the benefit of C-arm rotation.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Tennessee Medical Center, Knoxville, Tennessee , USA.

ABSTRACT

Purpose: Prolonged interventional cardiology (IC) procedures may result in radiation-induced skin injury, a potentially preventable cause of patient morbidity. Rotating the C-arm during an IC procedure may reduce this risk, although the methods by which the technique can be practically applied remains unexplored. A previous study demonstrated that C-arm rotation often increases peak skin dose (PSD) in interventional radiology procedures. The purpose of this study was to determine whether C-arm rotation reduces the PSD in IC procedures and, if so, under what circumstances.

Materials and methods: Simulations were performed using a numerical ray-tracing algorithm to analyse the effect of C-arm rotation on PSD across a range of patient sizes, C-arm configurations and procedure types. Specific data from modern fluoroscopes and patient dimensions were used as inputs to the simulations.

Results: In many cases, modest C-arm rotation angles completely eliminated overlap between X-ray field sites on the skin. When overlap remained, PSD increases were generally small. One exception was craniocaudal rotation, which tended to increase PSD. C-arm rotation was most effective for large patients and small X-ray field sizes. Small patients may not benefit from C-arm rotation as a procedural modification. The use of a prophylactic method where the C-arm was rotated between small opposing oblique angles was effective in reducing PSD.

Conclusions: With the exception of rotation to steep craniocaudal angles, rotating the C-arm reduces PSD in IC procedures when used as either a procedural modification or a prophylactic strategy. Tight collimation increases the benefit of C-arm rotation.

No MeSH data available.


Related in: MedlinePlus

The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. Vertical bold lines indicating the AAO. The results for each format group represent the X-ray field format and size from the group that required the largest AAO (AAO, angle to avoid overlap; PSD, peak skin dose; CAU, caudal; CRA, cranial; LAO, left anterior oblique; PA, posteroanterior; RAO, right anterior oblique).
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OPENHRT2014000141F2: The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. Vertical bold lines indicating the AAO. The results for each format group represent the X-ray field format and size from the group that required the largest AAO (AAO, angle to avoid overlap; PSD, peak skin dose; CAU, caudal; CRA, cranial; LAO, left anterior oblique; PA, posteroanterior; RAO, right anterior oblique).

Mentions: Depending on patient size and X-ray field size and format, rotation in the LAO direction from 12° to 32° and in the RAO direction from 14° to 40° was necessary to completely avoid overlap with an initial PA projection (figure 2A). In general, RAO rotation required a slightly larger AAO owing to the location of the heart to the left of midline. However, the difference was too small to be clinically meaningful. The use of larger X-ray fields resulted in larger AAO, as did smaller patient size. Less rotation was required to avoid overlap for male patients than for female patients. This finding held true for all patients except very large patients, for which male and female patients were approximately the same size.


C-arm rotation as a method for reducing peak skin dose in interventional cardiology.

Pasciak AS, Bourgeois AC, Jones AK - Open Heart (2014)

The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. Vertical bold lines indicating the AAO. The results for each format group represent the X-ray field format and size from the group that required the largest AAO (AAO, angle to avoid overlap; PSD, peak skin dose; CAU, caudal; CRA, cranial; LAO, left anterior oblique; PA, posteroanterior; RAO, right anterior oblique).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4281570&req=5

OPENHRT2014000141F2: The effect of rotation from a primary PA projection on PSD for female patients: (A) LAO/RAO rotation and (B) CRA/CAU rotation. Vertical bold lines indicating the AAO. The results for each format group represent the X-ray field format and size from the group that required the largest AAO (AAO, angle to avoid overlap; PSD, peak skin dose; CAU, caudal; CRA, cranial; LAO, left anterior oblique; PA, posteroanterior; RAO, right anterior oblique).
Mentions: Depending on patient size and X-ray field size and format, rotation in the LAO direction from 12° to 32° and in the RAO direction from 14° to 40° was necessary to completely avoid overlap with an initial PA projection (figure 2A). In general, RAO rotation required a slightly larger AAO owing to the location of the heart to the left of midline. However, the difference was too small to be clinically meaningful. The use of larger X-ray fields resulted in larger AAO, as did smaller patient size. Less rotation was required to avoid overlap for male patients than for female patients. This finding held true for all patients except very large patients, for which male and female patients were approximately the same size.

Bottom Line: Small patients may not benefit from C-arm rotation as a procedural modification.With the exception of rotation to steep craniocaudal angles, rotating the C-arm reduces PSD in IC procedures when used as either a procedural modification or a prophylactic strategy.Tight collimation increases the benefit of C-arm rotation.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, University of Tennessee Medical Center, Knoxville, Tennessee , USA.

ABSTRACT

Purpose: Prolonged interventional cardiology (IC) procedures may result in radiation-induced skin injury, a potentially preventable cause of patient morbidity. Rotating the C-arm during an IC procedure may reduce this risk, although the methods by which the technique can be practically applied remains unexplored. A previous study demonstrated that C-arm rotation often increases peak skin dose (PSD) in interventional radiology procedures. The purpose of this study was to determine whether C-arm rotation reduces the PSD in IC procedures and, if so, under what circumstances.

Materials and methods: Simulations were performed using a numerical ray-tracing algorithm to analyse the effect of C-arm rotation on PSD across a range of patient sizes, C-arm configurations and procedure types. Specific data from modern fluoroscopes and patient dimensions were used as inputs to the simulations.

Results: In many cases, modest C-arm rotation angles completely eliminated overlap between X-ray field sites on the skin. When overlap remained, PSD increases were generally small. One exception was craniocaudal rotation, which tended to increase PSD. C-arm rotation was most effective for large patients and small X-ray field sizes. Small patients may not benefit from C-arm rotation as a procedural modification. The use of a prophylactic method where the C-arm was rotated between small opposing oblique angles was effective in reducing PSD.

Conclusions: With the exception of rotation to steep craniocaudal angles, rotating the C-arm reduces PSD in IC procedures when used as either a procedural modification or a prophylactic strategy. Tight collimation increases the benefit of C-arm rotation.

No MeSH data available.


Related in: MedlinePlus