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Objective: To assess the effect of 2 over-the-counter alkalizing agents on 24 hour urinary parameters. Materials and Methods: Ten healthy volunteers without a history of kidney stones were recruited to complete a baseline 24 hour urinalysis with a 4 day diet inventory. Participants then maintained the same diet on either LithoLyte (20 mEq 2 times per day) or KSPtabs (1 tablet 2 times per day) and submitted another 24 hour urinalysis. The process was repeated with the other supplement. Urinary alkali parameters were compared to baseline, and side effects were elicited with a questionnaire. Results: LithoLyte intake resulted in a non-significant increase in citrate (597-758 mg/day, P =.058, an increase in urine pH (6.46-6.66, P =.028), and a decrease in urine ammonium (41-36 mmol/day, P =.005) compared to baseline. KSPtabs resulted in an increase in citrate (597-797 mg/day, P =.037) and urine pH (6.46-6.86, P =.037), with a non-significant decrease in ammonium (41-34 mmol/day, P =.059). No significant differences were seen comparing urinary analytes between LithoLyte and KSPtabs. With Litholyte, no side effects, mild, moderate, and severe side effects were seen in 50%, 40%, 10%, and 0%, respectively. With KSPtabs, rates were 60%, 20%, 10%, and 10%, respectively. Conclusion: In healthy participants without a history of kidney stones, LithoLyte and KSPtabs are effective over-the-counter alkali supplements, with a similar side effect profile to prescription potassium citrate.

It is documented that Hispanic/Latinx kidney stone formers have inferior health-related quality of life (HRQoL) compared to the general population. We hypothesized that socioeconomic factors drive HRQoL disparities. Specifically, we sought to determine if medical insurance type is associated with HRQoL disparities among Hispanic/Latinx stone formers. This was a prospective cohort observational study of patients with kidney stones across the University of San Diego Health Care System. Patients enrolled from June 2018 to August 2020 completed a validated Wisconsin Stone Quality of Life questionnaire (WISQoL). Patient characteristics and self-reported HRQoL were compared between Hispanic/Latinx and non-Hispanic/Latinx stone formers using MANCOVA and ordinal logistic regression. Matched group comparisons were performed based on age, gender, body mass index, stone symptoms, and insurance type using MACOVA. A total of 270 patients were enrolled (Hispanic/Latinx n = 88; non-Hispanic/Latinx n = 182). Hispanic/Latinx stone formers had higher rates of public insurance at baseline (p p = 0.007)]. However, a matched cohort comparison demonstrated no differences. On multivariate analysis, private insurance increased the likelihood of having higher HRQoL (OR 2.21, p = 0.021), while stone symptoms (OR = 0.06, p p = 0.008) decreased chances of higher HRQoL. Ethnicity was not a significant factor in HRQoL scores on multivariate analysis. Our analysis suggests that differences in HRQoL among Hispanic/Latinx stone formers may be primarily driven by socioeconomic factors as opposed to clinical or racial differences. Specifically, source of insurance appears to have significant effect on HRQoL in this ethnic group.

Kidney stone cultures can be beneficial in identifying bacteria not detected in urine, yet how stone cultures are performed among endourologists, under what conditions, and by what laboratory methods remain largely unknown. Stone cultures are not addressed by current clinical guidelines. A comprehensive REDCap electronic survey sought responses from directed (n = 20) and listserv elicited (n = 108) endourologists specializing in kidney stone disease. Questions included which clinical scenarios prompt a stone culture order, how results influence post-operative antibiotics, and what microbiology lab protocols exist at each institution with respect to processing and resulting stone cultures. Logistic regression statistical analysis determined what factors were associated with performing stone cultures. Of 128 unique responses, 11% identified as female and the mean years of practicing was 16 (range 1-46). A specific 'stone culture' order was available to only 50% (64/128) of those surveyed, while 32% (41/128) reported culturing stone by placing a urine culture order. The duration of antibiotics given for a positive stone culture varied, with 4-7 days (46%) and 8-14 days (21%) the most reported. More years in practice was associated with fewer stone cultures ordered, while higher annual volume of percutaneous nephrolithotomy was associated with ordering more stone cultures (p 0.01). Endourologists have differing practice patterns with respect to ordering stone cultures and utilizing the results to guide post-operative antibiotics. With inconsistent microbiology lab stone culture protocols across multiple institutions, more uniform processing is needed for future studies to assess the clinical benefit of stone cultures and direct future guidelines.

Introduction and Objective: Guidelines from the American Urological Association (AUA) and American College of Radiology (ACR) recommend that patients with suspected nephrolithiasis undergo low-dose CT of the kidney, ureter, and bladder (LD CT KUB) as opposed to higher dose conventional imaging. We hypothesized that even at institutions with established LD protocols, higher dose imaging is common. Materials and Methods: We identified four academic medical centers where LD CT KUB protocols were implemented to yield an effective dose (EDose) consistent with national guidelines. Fifty consecutive adult patients who underwent CT KUB specifically for the evaluation of nephrolithiasis were retrospectively reviewed at each site. Patient age, sex, body mass index (BMI), imaging location, and EDose (millisieverts [mSv]) were recorded. Results: Two hundred patients with a mean age of 54 years were identified. Forty-six patients (23%) underwent CT KUB with an EDose ≤4 mSv, accounting for 10% to 48% of each institution's cohort. One hundred sixteen patients had a BMI

To evaluate the impact of chronic stone recurrence on an individual's quality of life using the validated Wisconsin Stone Quality of Life (WISQOL) questionnaire. We collected cross-sectional data on patients with kidney stones from 14 institutions in North America. A stone event was defined as renal colic, stone-related procedure or emergency department visit. The regression analyses using general linear models and pairwise comparison determined the impact of the number of stone events on quality of life. The median number of stone events among the 2205 patients who completed the questionnaire was 3 (IQR 1-6). The mean total score was 107.4 ± 28.7 (max 140 points). The number of lifetime stone events was an independent predictor of lower quality of life (p 0.001), specifically, score declined significantly beyond five events. Compared with patients who experienced a single stone event, there was a 0.4, 2.5, and 6.9 point decline in the adjusted mean WISQOL score after 2-5, 6-10, or 10 events, respectively. The cumulative number of lifetime stone events was associated with a lower quality of life when more than five stone events were occurred. These findings underscore the importance of efforts to determine the underlying metabolic etiology of urolithiasis in the recurrent stone former, and the institution of a regimen to place their stone disease in remission.

OBJECTIVE To build the Wisconsin Stone Quality of Life Machine-Learning Algorithm (WISQOL-MLA) to predict urolithiasis patients' health-related quality of life (HRQoL) based on demographic, symptomatic and clinical data collected for the validation of the Wisconsin Stone Quality-of-Life (WISQOL) questionnaire, an HRQoL measurement tool designed specifically for patients with kidney stones. MATERIAL AND METHODS We used data from 3206 stone patients from 16 centres. We used gradient-boosting and deep-learning models to predict HRQoL scores. We also stratified HRQoL scores by quintile. The dataset was split using a standard 70%/10%/20% training/validation/testing ratio. Regression performance was evaluated using Pearson's correlation. Classification was evaluated with an area under the receiver-operating characteristic curve (AUROC). RESULTS Gradient boosting obtained a test correlation of 0.62. Deep learning obtained a correlation of 0.59. Multivariate regression achieved a correlation of 0.44. Quintile stratification of all patients in the WISQOL dataset obtained an average test AUROC of 0.70 for the five classes. The model performed best in identifying the lowest (0.79) and highest quintiles (0.83) of HRQoL. Feature importance analysis showed that the model weighs in clinically relevant factors to estimate HRQoL, such as symptomatic status, body mass index and age. CONCLUSIONS Harnessing the power of the WISQOL questionnaire, our initial results indicate that the WISQOL-MLA can adequately predict a stone patient's HRQoL from readily available clinical information. The algorithm adequately relies on relevant clinical factors to make its HRQoL predictions. Future improvements to the model are needed for direct clinical applications.

Purpose: Metabolic syndrome (MetS) is a cluster of metabolic diseases that is linked to atherosclerotic cardiovascular disease. MetS has also been linked to increased nephrolithiasis. However, limi...

Patients presenting with acute renal colic may be at risk of opiate abuse. We sought to analyze prescribing patterns and identify risk factors associated with prolonged opiate use during episodes of acute renal colic. Retrospective study of patients presenting with both a stone confirmed on imaging and an acute pain episode from 6/2017–2/2020. Opiate prescription data was obtained from a statewide prescribing database. Primary outcome was an opiate refill or new opiate prescription prior to resolution of the stone episode (either passage or surgery). Univariate and multivariate linear regression analysis was performed. A total of 271 patients met inclusion criteria. Mean age was 52 years and 48% had a history of nephrolithiasis. 180 (66%) patients filled a new opiate prescription during their acute stone episode. Thirty-eight (14%) patients had an existing opiate prescription within 3 months of their stone episode. Seventy-four (27%) patients refilled an opiate prescription prior to stone passage or surgery. Larger stone size, need for surgery, prolonged time to treatment, existing opiate prescription, new opiate prescription at presentation, and greater initial number of pills prescribed were associated with increased risk of requiring a refill prior to stone resolution. Patients prescribed new opiates for acute nephrolithiasis and those with an existing opioid prescription are likely to require refills before resolution of the stone episode. Larger stones that require surgery (not spontaneous passage) also increase the risk. Timely treatment of these patients and initial treatment with non-narcotics may reduce the risk of prolonged opiate use.

Flexible ureteroscopes are essential devices, and reusable models require meticulous cleaning and sterilization between procedures. Reprocessing is complex, time-consuming, and difficult due to the instrument's small size, fragility, and internal channel. The Food and Drug Administration recently raised concerns about the effectiveness of ureteroscope reprocessing. Due to inadequate reprocessing and maintenance, contaminated and damaged ureteroscopes pose risks to patient safety. This review describes ureteroscope reprocessing methods and summarizes evidence on reprocessing effectiveness and documented outcomes associated with the use of damaged or inadequately cleaned and sterilized ureteroscopes.

Background: Lesch–Nyhan syndrome results from a rare X-linked inborn error of metabolism leading to a total body accumulation of uric acid. Clinical manifestations include self-mutilating behavior, poor muscle control, intellectual disability, gout, and kidney disease. Unfortunately, life expectancy is limited to the second or third decade of life because of symptoms associated with hyperuricemia, particularly renal failure. Patients with this condition frequently necessitate urologic intervention as the buildup of lithogenic substances predispose individuals to the development of kidney and bladder stones. Case Presentation: We present the case of a 23-year-old white man with known Lesch–Nyhan syndrome and recurrent bilateral xanthine stones despite repeated urologic interventions. Conclusion: Therapy for Lesch–Nyhan syndrome consists of reduction of uric acid achieved through allopurinol. However, excess allopurinol dosing can lead to development of xanthine kidney and bladder stones. Thus, the treating clinician must maintain a delicate balance between managing hyperuricemia and avoiding xanthine urolithiasis.

Introduction: Current American Urological Association (AUA) Best Practice Statement recommends antibiotic prophylaxis for cystoscopy with manipulation, including stent removal; although no Level 1b trials explicitly address prophylaxis for stent removal. We sought to determine the efficacy of prophylactic antibiotics to prevent infectious complications after stent removal. Materials and Methods: Following institutional review board approval, patients undergoing removal of ureteral stent placed during stone surgery were recruited from July 2016 to March 2019. Patients were recruited at the time of stent removal and randomized to treatment (single dose 500 mg oral ciprofloxacin) or control group (no antibiotics). Telephone contact was attempted within 14 days of stent removal to assess for urinary tract infection (UTI) symptoms, antibiotic prescriptions, or Emergency Department visits. Primary outcome was UTI within 1 month of stent removal – defined by irritative voiding symptoms, fever or abdominal pain associated with positive urine culture (Ucx) (>100k colony-forming units/mL). Results: Seventy-seven patients were enrolled, with 58 meeting final inclusion criteria for the analysis (33 treatment, 25 controls). No differences were seen with clinical and demographic variables, except a higher body mass index in the treatment group (P = 0.007). Positive Ucx rate before stone surgery (16.7% vs. 11.8%, P = 0.819) and at the time of stent removal (16.0% vs. 11.1%, P = 0.648) was not significantly different in treatment versus control groups, respectively. Primary outcome: No patients in either cohort developed symptomatic culture-diagnosed UTI within 1 month of stent removal. Of patients with documented phone follow-up (treatment n = 29, control n = 22), only one patient (control) reported any positive response on phone survey. Conclusions: We found a low infectious complication rate regardless of antibiotic prophylaxis use during cystoscopic stent removal. The necessity of antibiotics during routine cystoscopic stent removal warrants possible reevaluation of the AUA best practice statement.

Recent studies have demonstrated that quick sequential organ failure assessment criteria may be more accurate than systemic inflammatory response syndrome criteria to predict postoperative sepsis. In this study we evaluated the ability of these 2 criteria to predict septic shock after percutaneous nephrolithotomy.We performed a retrospective multicenter study in 320 patients who underwent percutaneous nephrolithotomy at a total of 8 institutions. The criteria for quick sequential organ failure assessment and systemic inflammatory response syndrome were collected 24 hours postoperatively. The study primary outcome was postoperative septic shock. Secondary outcomes included 30 and 90-day emergency department visits, and the hospital readmission rate.Three of the 320 patients (0.9%) met the criteria for postoperative septic shock. These 3 patients had positive criteria for quick sequential organ failure assessment and systemic inflammatory response syndrome. Of the entire cohort 23 patients (7%) met quick sequential organ failure assessment criteria and 103 (32%) met systemic inflammatory response syndrome criteria. Specificity for postoperative sepsis was significantly higher for quick sequential organ failure assessment than for systemic inflammatory response syndrome (93.3% vs 68.4%, McNemar test p0.001). The positive predictive value was 13% for quick sequential organ failure assessment criteria and 2.9% for systemic inflammatory response syndrome criteria. On multivariate logistic regression systemic inflammatory response syndrome criteria significantly predicted an increased probability of the patient receiving a transfusion (β = 1.234, p0.001). Positive quick sequential organ failure assessment criteria significantly predicted an increased probability of an emergency department visit within 30 days (β = 1.495, p0.05), operative complications (β = 1.811, p0.001) and transfusions (p0.001). The main limitation of the study is that it was retrospective.Quick sequential organ failure assessment criteria were superior to systemic inflammatory response syndrome criteria to predict infectious complications after percutaneous nephrolithotomy.

Postoperative infectious related complications are not uncommon after percutaneous nephrolithotomy. Previously, we noted that 7 days of antibiotics did not decrease sepsis rates compared to just perioperative antibiotics in a low risk percutaneous nephrolithotomy population. This study aimed to compare the same regimens in individuals at moderate to high risk for sepsis undergoing percutaneous nephrolithotomy.Patients were prospectively randomized in this multi-institutional study to either 2 days or 7 days of preoperative antibiotics. Enrolled patients had stones requiring percutaneous nephrolithotomy and had either a positive preoperative urine culture or existing indwelling urinary drainage tube. Primary outcome was difference in sepsis rates between the groups. Secondary outcomes included rate of nonseptic bacteriuria, stone-free rate and length of stay.A total of 123 patients at 7 institutions were analyzed. There was no difference in sepsis rates between groups on univariate analysis. Similarly, there were no differences in nonseptic bacteriuria, stone-free rate and length of stay. On multivariate analysis, 2 days of antibiotics increased the risk of sepsis compared to 7 days of antibiotics (OR 3.1, 95% CI 1.1-8.9, p=0.031). Patients receiving antibiotics for 2 days had higher rates of staghorn calculus than the 7-day group (58% vs 32%, p=0.006) but post hoc subanalysis did not demonstrate increased sepsis in the staghorn only group.Giving 7 days of preoperative antibiotics vs 2 days decreases the risk of sepsis in moderate to high risk percutaneous nephrolithotomy patients. Future guidelines should consider infectious risk stratification for percutaneous nephrolithotomy antibiotic recommendations.

Renal access in percutaneous nephrolithotomy (PCNL) may be obtained via a pre-existing nephrostomy tube (NT) tract; however, emergent NTs are not always ideal for subsequent surgery. We sought to determine the rate of NT tract usability and assess factors related to the usability of emergently placed NTs.A retrospective review was performed of UC San Diego subjects undergoing percutaneous renal surgery between January 2016 and October 2018. Demographics and peri-operative variables were collected. The primary outcome was the usability of NT tract for dilation and instrumentation. "Usable" indicated a tract in which PCNL could be completed; "unusable" indicated lack of dilation and the requirement of additional tract(s) for PCNL.35 PCNL cases had previous emergently placed NT which were indwelling at time of percutaneous surgery. 51% of these NT tracts (18/35) were deemed usable and dilated for PCNL. No significant difference was seen between usable and unusable NT groups for number of dilated tracts during PCNL (p=0.13), or either the location of indwelling NT (p=0.96) or renal stones (p=0.95). In the usable NT tract cohort PCNL access was via the lower pole 56% of the time, where as when previous NT tracts were deemed unusable, a separate upper-pole access was obtained intra-operatively 53% of the time (p0.01).Pre-existing, emergent NTs served a ssufficient PCNL access tracts in over half of recorded cases. Contrary to recently published reports, the utility of pre-existing NTs appears to vary among health systems. Other variables, including the desired location of PCNL appear to directly influence the like lihood of NT tract usability.El acceso renal en la nefrolitotomía percutánea puede obtenerse a través de una nefrostomía pre-existente, aunque las nefrostomías urgentes no siempre son ideales para la posterior cirugía. Nosotros intentamos determinar la tasa de uso del tracto de nefrostomía y los factores de acceso relacionados con el uso de la nefrostomía urgente.MÉTODOS: Una revisión retrospectiva se realizó en UC San Diego de los pacientes que habían recibido cirugía renal percutánea entre enero 2016 y octubre 2018. Las variables demográficas y perioperatorias fueron recolectadas. El objetivo primario fue el uso del trayecto de nefrostomía después de dilatación e instrumentación.¨Usable” indicó un trayecto en el que la nefrolitotomía percutánea se completo. “No usable” indicó falta de dilatación y el requerimiento de un nuevo trayecto para la cirugía percutánea.35 casos de nefrolitotomía percutánea tenían nefrostomías urgentes previamente y presentes al empezar la cirugía. 51% de estos trayectos (18/35) fueron usados y dilatados para la nefrolitotomía percutánea. No hubo diferencias significativas entre los trayectos usables y no usables en el numero de trayectos dilatados durante la cirugía percutánea (p=0,13), ni en la localización de la sonda de nefrostomía (p=0,96) o las litiasis renales (p=0,95). En el grupo de pacientes con nefrostomía usable, en el 56% la nefrostomía accedía por el polo inferior. Cuando el trayecto de nefrostomía se considero no usable, un nuevo acceso intraoperatorio por el polo superior fue obtenido en el 53% de lo scasos (p0,01).El trayecto de nefrostomía pre-existente fue suficiente para el acceso percutáneo en la mitad de los casos. Contrario a lo publicado recientemente, la utilidad de la nefrostomía pre-existente parece variar según el Sistema sanitario. Otras variables, incluyendo la localización deseada para la nefrostomía influencia el uso del trayecto.

Acute epididymo-orchitis is an inflammatory process caused by bacterial infection. Emphysematous epididymitis is an extremely rare manifestation characterized by gas within the epididymal tissues. We report a case of emphysematous epididymitis following hydrocelectomy in a patient with a history of spinal cord injury and chronic bacteriuria. The diagnosis was made by clinical and laboratory data with imaging demonstrating foci of gas within the epididymal structures. We hypothesize that intermittent catheterization may have contributed to bacterial translocation into the adjacent cord structures and development of infection. High level of suspicion leading to early diagnosis, aggressive antibiotics and adequate debridement are required.

Introduction and Objectives: The goal of this study is to evaluate the outcomes in a cohort of patients who underwent minimally invasive percutaneous nephrolithotomy (MIP) at a single institution f...

Renal colic is a common cause of pain; however, there have been few reports of treating this pain with regional anesthesia. We report on a 49-year-old man presenting with severe left flank pain resulting from a 4-mm stone in the left ureter. The pain was minimally responsive to intravenous opioids. Left-sided paravertebral blocks were performed at T7 and T9 with 10 mL bupivacaine 0.5% with epinephrine 2.5 µg/mL to each paravertebral space. The pain resolved over the following 30 minutes, and the patient was discharged home. No further pain was experienced before and while subsequently passing the stone.

Outpatient percutaneous nephrolithotomy (PCNL) has been described for highly selected patients. We sought to assess the safety and feasibility of outpatient PCNL in a tertiary referral stone center without strict patient selection criteria.We reviewed all PCNLs performed at our institution from September 2015 to October 2016. Of the 97 eligible cases, 60 patients underwent planned outpatient PCNL. Primary outcome was complication rate, and secondary outcome determined predictor variables of inpatient admission.Thirty-seven inpatient and 60 planned outpatient (one bilateral) PCNLs were performed with 65% and 44% American Society of Anesthesiologists (ASA) score ≥3, respectively. The 30-day overall complication rate for the inpatient and planned outpatient groups was 27% and 20%, respectively (p = 0.43) [70% and 92% Clavien grades I-II]. Emergency department presentation within 30 days was 19% and 18% (p = 0.94), and unplanned hospital readmission rate was 3% and 10% (p = 0.05). The 37 inpatient PCNL patients had larger total stone burden than outpatient cases (40.7 vs 25.8 mm, p = 0.0014); more often required two or more punctures into the kidney during the procedure (73% vs 45%, p = 0.025); and more often had supracostal access (20% vs 7%, p = 0.05). For the outpatient PCNL cohort, 72% patients were discharged same day, 28% were observed overnight for refractory symptoms or social reasons. Outpatient cohort radiographic stone-free rate by CT (no stones) was 67%.Outpatient PCNL has been safely and effectively performed within our institution in moderate-sized stones almost regardless of comorbidity status. We suggest that this approach is a potential algorithmic change in centers with sufficient case volume.

Background To compare head to head two end-engaging nitinol stone retrieval devices available to urologists, in terms of durability, versatility and efficacy. Methods For durability testing, 30 NGage and Dakota baskets were cycled 20 times between grasping and releasing synthetic stone models and evaluated for damage or device failure. For versatility and efficacy testing, baskets were assessed in their ability to capture and release stone models from 1 to 11 mm. Each stone was raised above the capture site and the basket was opened to passively release the stone. If the stone did not release, the basket handle was shaken and the OpenSure feature employed if needed. Manual release was used as a last resort. Results Durability—the Cook NGage demonstrated a statistically significant increased rate of visible device breakdown (P=0.0046) in 8 of 30 (26.7%) devices vs. 0 of 30 Dakota devices, with mean damage at 13.5 cycles. Versatility and efficacy—both 8 mm baskets successfully captured stones from 1–8 mm. The Dakota more effectively released 7–8 mm stones (P

Patients presenting with acute renal colic may be at risk of opiate abuse. We sought to analyze prescribing patterns and identify risk factors associated with prolonged opiate use during episodes of acute renal colic.Retrospective study of patients presenting with both a stone confirmed on imaging and an acute pain episode from 6/2017-2/2020. Opiate prescription data was obtained from a statewide prescribing database. Primary outcome was an opiate refill or new opiate prescription prior to resolution of the stone episode (either passage or surgery). Univariate and multivariate linear regression analysis was performed.A total of 271 patients met inclusion criteria. Mean age was 52 years and 48% had a history of nephrolithiasis. 180 (66%) patients filled a new opiate prescription during their acute stone episode. Thirty-eight (14%) patients had an existing opiate prescription within 3 months of their stone episode. Seventy-four (27%) patients refilled an opiate prescription prior to stone passage or surgery. Larger stone size, need for surgery, prolonged time to treatment, existing opiate prescription, new opiate prescription at presentation, and greater initial number of pills prescribed were associated with increased risk of requiring a refill prior to stone resolution.Patients prescribed new opiates for acute nephrolithiasis and those with an existing opioid prescription are likely to require refills before resolution of the stone episode. Larger stones that require surgery (not spontaneous passage) also increase the risk. Timely treatment of these patients and initial treatment with non-narcotics may reduce the risk of prolonged opiate use.

Purpose: Kidney stone patients routinely have CT scans during diagnostic work-up before being referred to a tertiary center. How often these patients exceed the recommended dose limits for occupational radiation exposure of >100 mSv for 5 years and >50 mSv in a single year from CT alone remains unknown. This study aimed to quantify radiation doses from CTs received by stone patients before their evaluation at a tertiary care stone clinic. Methods: From November 2015 to March 2017, consecutive new patients enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU™) had the dose-length product of every available CT abdomen/pelvis within 5 years of their initial visit recorded, allowing for an effective dose (EDose) calculation. Multivariate logistic regression analysis identified factors associated with exceeding recommended dose limits. Models were created to test radiation reducing effects of low-dose and phase-reduction CT protocols. Results: Of 343 noncontrast CTs performed, only 29 (8%) were low-dose CTs (calculated EDose 20 mSv and >50 mSv/year, respectively. Increased body mass index, number of scans, and multiphase scans were associated with exceeding exposure thresholds (p 50%. Conclusions: Stone patients referred to a tertiary stone center may receive excessive radiation from CT scans alone. Unnecessary phases and underutilization of low-dose CT protocols continue to take place. Enacting new approaches to CT protocols may spare stone patients from exceeding recommended dose limits.