Role of Dual-Energy Computed Tomography in Characterization of Ureteric Calculi and Urinary Obstruction

Abstract

The present study was carried out to assess the accuracy of dual-energy computed tomography (DECT) in the morphological and chemical characterization of ureteric calculi along with the prediction of the grade of urinary obstruction. Methods This was a prospective observational study that included 100 cases with ultrasonography (USG)-diagnosed ureteric calculi that underwent surgery or had spontaneous expulsion of ureteric calculi. At enrolment, DECT was performed for an in vivo evaluation of volume, chemical composition, and grade of obstruction by subjective assessment of the perinephric edema. After surgical intervention, in vitro evaluation of volume was done by fluid displacement followed by infrared spectroscopy (IRS) for chemical composition. DECT findings were compared with the biochemical analysis and degree of obstruction was validated against excretory CT urograms. Sensitivity, specificity, and the positive predictive and negative predictive values of DECT were assessed. Results No significant difference was observed between the mean volume of stones by fluid displacement (65.1±77.61 mm 3) and DECT assessment (66.09±81.78 mm 3). IRS revealed the composition of stones as hydroxyapatite, uric acid, cysteine, oxalic acid, and mixed type in 48, 23, 15, five, and nine cases. The sensitivity and specificity of DECT for hydroxyapatite, uric acid, cysteine, oxalic acid, and mixed types were 89.6% and 88.5%, 82.6% and 97.5%, 86.7% and 96.5%, 80% and 98.9%, and 88.9% and 98.9%, respectively. On CT urography, a total of 35 had a high-grade and 65 had a low-grade obstruction, whereas DECT revealed high-and low-grade obstructions in 42 and 58 cases. The sensitivity and specificity of DECT for a high-grade obstruction were 94.3% and 86.2%. Conclusions The findings of the study showed that DECT provides comprehensive information regarding the morphological, chemical, and anatomical characterization of ureteric stones.

Dual-energy Computed Tomography (DECT) Scan for Determination of Renal Stone Composition: A Phantom Study

“…For stones which are a mixture of several stone types, the results of DECT were completely inaccurate. Overall, the present results are consistent with the findings of previous research (13)(14)(15). In conclusion, based on the results of this brief research, for an accurate detection of all pure and mixed renal stones, further analytical methods are needed.…”

“…Dual-energy CT (DECT) scanning, which is known as one of the most promising developments in radiology, is used for determining the components of different materials or material identification (9). Several studies have reported the clinical benefits of DECT in the identification of renal stone types (10)(11)(12)(13)(14)(15)(16).…”

The value of dual-energy computed tomography (DECT) in the diagnosis of urinary calculi: a systematic review and meta-analysis of retrospective studies

“…Thus, the detection sensitivity of urinary calculi with lengths <three mm was high ( Spek et al, 2016 ). A previous study found that most ureteral stones with lengths of less than three mm can be excreted by themselves, although even if the length of the stone is less than three mm, it can cause pain and microscopic hematuria ( Singh et al, 2020 ).…”

Dual-Energy Computed Tomography for the Diagnosis of Urethral Foreign Body: A Case Study

“…The ability of DECT to differentiate various materials has been applied in the components analysis of urinary stones in the field of urology, with a reported diagnostic accuracy of over 80% [9]. We anticipate that DECT will become widely applicable in various cases in the future.…”