The imaging appearances of calyceal diverticula complicated by uroliathasis

Abstract

The presence of diverticula arising from the calyceal system is a relatively uncommon urological problem, occurring with an incidence of 2.1-4.5 per 1000 intravenous urogram (IVU) examinations. While the incidence of calyceal diverticula is low, the frequency of stone formation within them is high. We describe the aetiology and clinical presentation and describe the role of imaging with ultrasound, intravenous and retrograde pyelography and CT in diagnosis and planning treatment. We also describe the potential of fluid-sensitive magnetic resonance imaging techniques as a radiation-free alternative to the use of more conventional modalities, such as intravenous urography and retrograde pyelography, in delineating the anatomy of calyceal diverticula before surgical and radiological intervention especially in young patients and pregnant women.

CT Urography for Diagnosis of Upper Urinary Tract Urothelial Carcinoma: Are Both Nephrographic and Excretory Phases Necessary?

“…Nephrographic phase CT has several advantages over split-bolus CTU: shorter examina-tion time, better evaluation of solid organs, and ability to potentially reveal significant urinary tract stones without unenhanced CT. On the other hand, excretory phase CT can reveal abnormalities of the urinary tract that may cause hematuria such as papillary necrosis, renal tubular ectasia, and calyceal diverticulum [27][28][29]. Future studies are needed to compare the diagnostic performance of the nephrographic phase, excretory phase, and combination of the two phases for identifying the cause of hematuria other than upper tract urothelial carcinoma.…”

Interobserver Reliability and Reproducibility of S.T.O.N.E. Nephrolithometry for Renal Calculi

“…Hence, this scoring can be made more challenging by the presence of compound calices and numerous variations in caliceal configuration between kidneys and across upper, mid, and lower zones of the same kidney. 2,12 As such, users with different levels of expertise and background knowledge in urinary system CT imaging may score involvement of two compound calices (each composed of two smaller calices) as either a ''1'' (1-2 calyces assuming each compound calix as a solitary calix) or higher (if each smaller calix is assumed to be a solitary calix). Depending on whether or not the caliceal involvement is adjacent and contiguous, this may lead to further upscoring of stones as staghorn calculi.…”

Metabolic evaluation

“…In our opinion, every stone former should have at least once a CT urography to reflect the anatomy of the urinary tract and to reveal even small or subtle collecting system abnormalities [45]. Nephrocalcinosis and anatomical anomalies favouring stones like medullary sponge kidney, calyceal diverticula and horseshoe kidney can be differentiated with this examination [46][47][48][49].…”