Imaging the urologic patient: the utility of intravenous pyelogram in the CT scan era

Catastrophic complications of urolithiasis in pregnancy

Urolithiasis is the most common non-obstetric complication in pregnancy and has the potential to cause grave consequences resulting in pregnancy loss. We present two such cases. First, a 24-year-old woman, 5 weeks pregnant with a history of urolithiasis presented with right flank pain and fever. She was found to have a right perinephric collection and during the course of her treatment suffered an abortion. The second case was a 25-year-old woman who presented in septic shock. She underwent emergency lower segment caesarean section elsewhere 10 days ago for intrauterine death at 38 weeks of gestation. On evaluation, she was found to have bilateral stone disease with a left subcapsular haematoma. Both the cases were managed conservatively and are planned for definitive management. Thus, women of childbearing age with diagnosed urolithiasis should get themselves evaluated and be free of stone disease before planning a family to prevent increased obstetric complications during pregnancy.

Analysis of Intravenous Urography Findings in a Tertiary Reference Center

Objective

To analyze intravenous urography (IVU) findings in a tertiary reference center.

Materials and Methods

A retrospective, observational study was conducted in a tertiary reference center. The radiology reports of 1,470 patients subjected to IVU in the period from January 2008 to December 2012 were retrieved from the tertiary reference center databases. Patients' demographic characteristics, type of care (inpatient or outpatient), and IVU radiologic findings were reviewed and analyzed.

Results

Of 1470 patients, approximately two-thirds were males. The mean age of the patients was 39.12±14.80 years (range: 2-95). Most of them were inpatients (92.9%; 1365/1470). The IVU findings were abnormal in 68.8% (1012/1470) of patients. Urinary tract calculi were the most frequent type of calculi observed among patients (36.8%; 541/1470), and the kidney was the most frequently affected organ by calculi (66.5%; 541/814). Hydronephrosis was the second most frequent finding, being observed in 29.7% (436/1470) of patients.

Conclusion

The presence urinary tract calculi was the most frequent IVU finding, revealing that urolithiasis could be the main indication for IVU.

Contemporary best practice urolithiasis in pregnancy

Urolithiasis is the most common nonobstetric complication in the gravid patient. The experience can provoke undue stress for the mother, fetus, and management team. The physiologic changes of pregnancy render the physical exam and imaging studies less reliable than in the typical patient. Diagnosis is further complicated by the need for careful selection of imaging modality in order to maximize diagnostic utility and minimize obstetric risk to the mother and ionizing radiation exposure to the fetus. Ultrasound remains the first-line diagnostic imaging modality in this group, but other options are available if results are inconclusive. A trial of conservative management is uniformly recommended. In patients who fail spontaneous stone passage, treatment may be temporizing or definitive. While temporizing treatments have classically been deemed the gold standard, ureteroscopic stone removal is now acknowledged as a safe and highly effective definitive treatment approach. Ultimately, a multidisciplinary, team-based approach involving the patient, her obstetrician, urologist, radiologist, and anesthesiologist is needed to devise a maximally beneficial management plan.

Is a contrast study really necessary prior to ureteroscopy?

This study aimed to evaluate the effect of preoperative imaging techniques on the success and complication rates of ureteroscopy. We performed a retrospective analysis of 736 patients (455 males and 281 females), with a mean age of 45.5±15.2 years (range, 1-88 years), who underwent rigid ureteroscopic procedures for removal of ureteral stones. Patients were divided into 4 groups according to the type of imaging modality used: group I, intravenous urography (n=116); group II, computed tomography (n=381); group III, computed tomography and intravenous urography (n=91), and group IV, ultrasonography and abdominal plain film (n=148). Patients’ demographics, stone size and location, prior shock wave lithotripsy, lithotripsy technique, operation time, success rate, and rate of intraoperative complications were compared among the groups. There were no significant differences in success and complication rates among the groups. The stone-free rate after primary ureteroscopy was 87.1% in group I, 88.2% in group II, 96.7% in group III, and 89.9% in group IV (P=0.093). The overall incidence of intraoperative complications was 11.8%. According to the modified Satava classification system, 6.1% of patients had grade 1, 5.1% had grade 2, and 0.54% had grade 3 complications. Intraoperative complications developed in 12.1% of patients in group I, 12.6% of patients in group II, 7.7% of patients in group III, and 12.2% of patients in group IV (P=0.625). Our findings clearly demonstrate that ureteroscopic treatment of ureteral stones can be safely and effectively performed with no use of contrast study imaging, except in doubtful cases of anatomical abnormalities.

Imaging for Urinary Stones: Update in 2015

CONTEXT

Imaging is essential for the diagnosis and the clinical decision-making process of patients with urinary stones.

OBJECTIVE

To assess the benefits and limitations of various imaging techniques by specifically focusing on different phases of stone patients' management.

EVIDENCE ACQUISITION

PubMed and Web of Science databases were used to identify studies published in the last 10 yr on this argument. Search terms included 'urolithiasis', nephrolithiasis', or 'urinary stones' in combination (AND) with the terms 'imaging', 'computer tomography', 'ultrasonography', 'intravenous pyelogram', or 'radiation exposure'. Study selection was based on an independent peer-review process of all the authors after the structured data search.

EVIDENCE SYNTHESIS

Noncontrast-enhanced computer tomography (CT) provides the highest value of diagnostic accuracy for urinary stones. Stone composition can be specifically assessed through the use of dual-energy CT. When information about the anatomy of the renal collecting system is required or alternative pathologies are suspected, CT with contrast injection is recommended. Low-dose protocols allowed a drastic reduction of the effective dose administered to the patient, thus limiting the biological risk due to ionising radiations. Other strategies to contain the radiation exposure include the dual-split bolus dual energy CT and the adaptive statistical image reconstruction. Abdomen ultrasound may be a valid alternative as an initial approach since it does not change the outcome of patients compared with CT, and should be the imaging of choice in children and pregnant women.

CONCLUSIONS

Noncontrast-enhanced CT is the most accurate imaging technique to identify urinary stones. Abdomen ultrasound seems to be a valid alternative in the initial evaluation of urinary colic. New low-dose protocols and strategies have been developed to contain radiation exposure, which is a major issue especially in specific circumstances.

PATIENT SUMMARY

Noncontrast-enhanced computer tomography has been increasingly used for the diagnosis and management of urinary stones. Low-dose protocols as well as alternative imaging should be considered by clinicians in specific circumstances to minimise radiation exposure.

False-Positive Cystoscopic Diagnosis of Ureteral Obstruction After Hysterectomy Due to a Nonfunctional Kidney

BACKGROUND

An estimated 0.2% of the population may have a unilateral nonfunctional kidney. This pre-existing condition may lead to the mistaken presumption that a ureteral injury has occurred when performing cystoscopy after hysterectomy.

CASES

Two cases are presented in which cystoscopy to confirm ureteral patency after hysterectomy was performed in patients with pre-existing unknown nonfunctional kidneys. These false-positive findings resulted in additional operative time, additional cost, and unnecessary surgical exploration.

CONCLUSION

Cystoscopy to confirm ureteral patency after hysterectomy may lead to an incorrect presumption of a ureteral injury in patients with a pre-existing nonfunctional kidney.

Accuracy of Unenhanced Computerized Tomography Interpretation by Urologists in Patients with Acute Flank Pain

<b><i>Purpose:</i></b> The aim was to compare the findings of non-contrast computerized tomography (NCCT) evaluated by urology specialists with the findings of experienced radiologists, who are accepted as a standard reference for patients who present with acute flank pain. <b><i>Materials and Methods:</i></b> Five hundred patients evaluated with NCCT were included in the study. The NCCT images of these patients were evaluated by both radiologists and urology specialists in terms of the presence of calculus, size of calculus, the location of calculus, the presence of hydronephrosis, and pathologies other than calculus, and the results were compared. <b><i>Results:</i></b> The evaluations of urology specialists and standard reference radiology specialists are consistent with each other in terms of the presence of calculus (kappa [&#954;]: 0.904), categorical stone size (&#954;: 0.81), the location of calculus (&#954;: 0.88), and hydronephrosis (&#954;: 0.94). However, the evaluations of urology specialists in detecting pathologies other than calculus, which may cause acute flank pain or accompany renal colic, were found to be inadequate (&#954;: 0.37). The false-negative rate of detecting pathologies outside of the urinary system by the urology specialists is calculated as 0.86. <b><i>Conclusion:</i></b> Although the urology specialists can evaluate the findings related to calculus sufficiently with NCCT, they may not discover pathologies outside of the urinary system.