[Year:2021] [Month:January-March] [Volume:4] [Number:1] [Pages:8] [Pages No:2 - 9]
Aim and objective: Our study's objective is to examine the image quality, radiation dose, and scan time of the split bolus technique in computed tomography (CT) to evaluate urinary tract diseases.
Background: Computed tomography is one of the commonly preferred medical imaging modalities in diagnostic radiology for visualizing several diseases with higher resolution images. However, radiation dose reduction is one of the most crucial causes of a CT examination. Multidetector CT (MDCT) has updated several technical advancements of CT scanner for clinical purposes. The excretory system's radiological investigation is called urography, which is done in conventional radiography in the old days. Urolithiasis is considered a common disease affecting 12% of the global population in their lives.
Materials and methods: In our study, 10 patients underwent a split bolus technique for CT urography (CTU) examination at the Mahatma Gandhi Medical College and Research Institute, Puducherry. Among the 10 patients, 6 patients are adult male, 1 patient is a pediatric male, and 3 patients are adult female. The study was conducted in an MDCT (GE optima 660) scanner. The split bolus technique protocol followed in this study is an initial bolus of 40 mL contrast media given intravenously at 3.5 mL/second flow rate with an interbolus delay of 8–10 minutes to allow the contrast media opacify the ureter and urinary bladder. After 8–10 minutes, the remaining 50 mL of contrast media and 20 mL saline chaser are given, and images were acquired at 25 seconds for the arterial phase and 70 seconds for the venous phase, nephrogenic and excretory images in a single acquisition, which eliminates the need of separate acquisition.
Results: The image quality of the split bolus technique provides comparable results with a single bolus technique for interpretation. The total dose length product (DLP) of the split bolus technique is less than the single bolus technique. So, as a result, the radiation dose is reduced in the split bolus technique. The entire procedure from patient preparation to postprocedure care ranges from 35 to 55 minutes, and the scan time is similar for both the techniques. In our study, various pathologies were also diagnosed, such as, renal cyst was reported in 40% of the patients, and other diseases like hydronephrosis, renal calculus, contracted, a lesion in the kidney, and pyelonephritis were diagnosed in the rest of the patients.
Conclusion: The split bolus technique can be considered for reducing radiation exposure to the patient for the CTU examination. The split bolus technique has some limitations compared to the single bolus technique. Nevertheless, split bolus gives comparable image quality with the less patient dose, making the technique considered for various contrast-enhanced CT investigations.