64-Slice CT urography: optimisation of radiation dose

Abstract

CTU cannot be considered a standard examination: the scan parameters need to be adapted to the image quality required for the specific clinical problem.

Use of Nonenhanced Computed Tomography in Predicting Renal Stone Composition

“…Motley G, et al (23) studied the HD of 100 renal stones with 7mm collimation and reported that significant differences were noted between the mean HD of calcium (105 43) and uric acid (50 ± 24) stones (P = 0.006). Shahnani, PS et al (24) stated a strong relationship between the HD and the stone composition in 180 urinary stones from patients seen at Shariati, Kashani and Alzahra CT centers in Iran (CT collimation 6mm) and reported that a relationship between composition of stones and HU (P = 0.001), HD (P <0.0001) were seen , the HD of CO were 49-68 (our result 51-69) , STR stones HD were 20-38 which was similar to our result 23-32, while UA stones show higher HD (23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41) than our result (18)(19)(20)(21)(22)(23)(24)(25), Shahnani, PS et al (25) found no overlap between calcium oxalate and others, except calcium phosphate and their results disagreed with our study about relationship between stones composition and size, were they found positive relation (P value=0.001), these differences may be due to the wider collimation in both studies and involvement of small size stones due to the increase in HU inaccuracies that result from partial volume effect, Predicting the stone composition is very important for the urosurgeon sincemany types of stones resist ESWL while ESWL monotherapy is more likely to be effective against other stones, Nakasato T, ET al report that renal stone less than 815 HU easily treated with monotherapy ESWL than those with a higher HU, Ouzaid I, et al (25) evaluated 50 patients with urinary calculi of 5-22 mm undergoing ESWL, all patients had NCCT at 120 kV and 100 mA , they report that stone-free rate for stones of < 970 HU was 96% vs. 38% for stones of ≥ 970 HU (P< 0.001), in line with that (in our study) these stones which show HU > 900 were the Pure CO and Mixed CO + HXA assumed to be resist to ESWL and another treatment option should be tried, which was the mattered in these 21 stones, ESWL and medical treatment were failed , and all of which treated succ...…”

Bladder Cancer Diagnosis: The Role of CT Urography

“…As CTU is performed for numerous indications, such as abdominal colic pain, urolithiasis, urinary tract obstruction, hydronephrosis, infections, tumors of the urinary tract or of the renal parenchyma, hematuria, iatrogenic injury or trauma, and postoperative follow-up (18), the literature describes a variety of techniques to perform this examination (19, 20). As a consequence, CTU is a method that requires standardization (21) and further studies are needed to achieve this.…”