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A 66-year-old patient undergoing work-up of microscopic hematuria. An excretory phase 3D reconstruction demonstrates a complete ureteral duplication with completely separate upper and lower ureters (arrows) along their respective course, both of which insert on the bladder. There is incidentally noted concurrent ureteral pseudodiverticulosis (arrowhead)
Source publication
Purpose
The aim of this pictorial essay is to demonstrate several cases where the diagnosis would have been difficult or impossible without the excretory phase image of CT urography.
Methods
A brief discussion of CT urography technique and dose reduction is followed by several cases illustrating the utility of CT urography.
Results
CT urography h...
Citations
... Suboptimal medial orientation of the ablation needle and Following a high-risk percutaneous procedure, radiologists should inspect the ipsilateral collecting system thoroughly for any periureteral free fluid, fluid collection, or collecting system dilation. Although appearance on single arterial or venous phase CT may be nonspecific, a CECT with a delayed excretory phase (CT Urogram) remains the mainstay for diagnosis of ureteral complications, as it can accurately document urinary extravasation or asymmetric contrast holdup [27][28][29][30]. ...
A growing number of treatments for genitourinary diseases can result in various iatrogenic complications. Multimodality imaging in the post-procedural setting is essential for early and accurate diagnosis to limit morbidity and mortality. We review common and uncommon treatment-induced pathologies affecting the genitourinary system via a case-based approach. We illustrate notable complications affecting the kidneys, ureters, bladder, and urethra induced by percutaneous procedures, external beam radiation, immunotherapy, laparoscopic/robotic pelvic surgery, and intravesicular BCG. Finally, we provide guidance on optimal imaging techniques for diagnosis and highlight the role of image-guided interventions for mitigation of complications.
Graphical Abstract
... Overall, CT urography with both nephrographic and excretory phases (the latter is performed 5-20 minutes after contrast administration), emerges as the "gold standard" method for suspected ureteral injuries 58 . In rare instances where the ureter is sutured despite the absence of transection, attempting balloon dilation of the ligated portion may obviate the need for surgery 59,60 . ...
Iatrogenic urinary tract injury constitutes a rare but serious complication of gynecologic surgery, occurring in 0.3% to 1.5% of all procedures. Delayed diagnosis and repair are associated with increased postoperative morbidity, mortality and a long-term negative impact on the quality of life. Intraoperative detection of urinary tract injuries allows for prompt repair, facilitates management and speeds up recovery. Bladder injuries are 3 times more common than ureteral injuries, and usually are recognized and repaired immediately with minimal complications. Undetected ureteral injuries lead to severe postoperative complications such as the formation of genitourinary fistulas, sepsis, renal loss and death. In this review we aim to describe the postoperative clinical manifestations, the diagnostic methods and therapeutic strategies for the management of urinary tract injuries, whether in the acute or delayed setting, in an effort to reduce the potential impact of subsequent complications to both patient and surgeon. Timely and effective repair of urinary tract injuries is critical to improve patient outcome, mitigate litigation risk, and allow an uneventful postoperative recovery in a careful manner.
... The scientific community has diligently worked to optimize different protocols within CTU imaging techniques [13,14]. Unfortunately, there is no consensus on a standard or suitable protocol for clinical indications [15]. CTU commonly involves scanning in 2-6 different phases, both with and without intravenous contrast administration. ...
... Balancing this, however, is the significance of limiting ionizing radiation exposure to patients while ensuring satisfactory CTU image quality. A higher-quality image facilitates early detection and more reliable diagnoses [15]. ...
A Computed Tomography Urography (CTU) scan is a medical imaging test that examines the urinary tract, including the bladder, kidneys, and ureters. It helps diagnose various urinary tract diseases with precision. However, patients undergoing CTU imaging receive a relatively high dose of radiation, which can be a concern. In our research paper, we analyzed the Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) for 203 adult patients who underwent CTU at one of the most important regional centers in Bosnia and Herzegovina that sees a large number of patients. Our study included the distribution of age and sex, the number of phases within one examination, and different clinical indications. We compared our findings with the results available in the scientific literature, particularly the recently published results from 20 European countries. Furthermore, we established the local diagnostic reference levels (LDRLs) that can help set the national diagnostic reference levels (NDRLs). We believe our research is a significant step towards optimizing the protocols used in different hospitals in our country.
... Traditional GFR is measured using radionuclide GFR and estimated GFR (eGFR) from Scr concentration, but these methods are either expensive or time-consuming, and neither reflects the information on the morphology of the kidney lesions [4,5]. Computed tomography urography (CTU) is a frequently used clinical tool to visualize the anatomy of pre-surgical patients and is useful in providing a foundation for surgical planning [2,6]. The advancement of imaging technology has enabled CTU scans to show great potential in simultaneously obtaining both urologic anatomy and GFR [3,7,8]. ...
... With the increasing popularity of DECT equipment and the routine clinical utilization of CTU in clinical practice [6,11], we have demonstrated that DEsCTU possesses the ability to acquire information on renal function. In other words, patients only need a single DEsCTU scan to obtain both anatomical and functional information about the kidneys, maximizing patient benefits and providing more comprehensive information for personalized clinical treatment. ...
Purpose
To explore the feasibility of measuring glomerular filtration rate (GFR) using iodine maps in dual-energy spectral computed tomography urography (DEsCTU) and correlate them with the estimated GFR (eGFR) based on the equation of creatinine-cystatin C.
Materials and methods
One hundred and twenty-eight patients referred for DEsCTU were retrospectively enrolled. The DEsCTU protocol included non-contrast, nephrographic, and excretory phase imaging. The CT-derived GFR was calculated using the above 3-phase iodine maps (CT-GFRiodine) and 120 kVp-like images (CT-GFR120kvp) separately. CT-GFRiodine and CT-GFR120kvp were compared with eGFR using paired t-test, correlation analysis, and Bland–Altman plots. The receiver operating characteristic curves were used to test the renal function diagnostic performance with CT-GFR120kvp and CT-GFRiodine.
Results
The difference between eGFR (89.91 ± 18.45 ml·min⁻¹·1.73 m⁻²) as reference standard and CT-GFRiodine (90.06 ± 20.89 ml·min⁻¹·1.73 m⁻²) was not statistically significant, showing excellent correlation (r = 0.88, P < 0.001) and agreement (± 19.75 ml·min⁻¹·1.73 m⁻², P = 0.866). The correlation between eGFR and CT-GFR120kvp (66.13 ± 19.18 ml·min⁻¹·1.73 m⁻²) was poor (r = 0.36, P < 0.001), and the agreement was poor (± 40.65 ml·min⁻¹·1.73 m⁻², P < 0.001). There were 62 patients with normal renal function and 66 patients with decreased renal function based on eGFR. The CT-GFRiodine had the largest area under the curve (AUC) for distinguishing between normal and decreased renal function (AUC = 0.951).
Conclusion
The GFR can be calculated accurately using iodine maps in DEsCTU. DEsCTU could be a non-invasive and reliable one-stop-shop imaging technique for evaluating both the urinary tract morphology and renal function.
Graphical abstract
... Computed tomography (CT) is employed in various diagnostic applications to detect tumours and guide interventional procedures [1]. CT urography (CTU) refers to a multi-phase CT scan, including postcontrast excretory phase imaging, to examine the urinary tract from the kidneys to the urethra [2,3]. Clinical indications (CIs) for CTU are the investigation of gross hematuria or persistent microhematuria, renal and urothelial masses, obstructive uropathy, strictures, congenital collecting system abnormalities and pre-operative planning in case of complex renal stones or nephron-sparing surgery [3][4][5][6][7]. ...
... However, the CTU examination is not represented by a standardised protocol as observed in the literature [2,[10][11][12][13][14][15][16][17][18]. The technique variation amongst different imaging departments is mainly due to the variations in the CTU protocols, which depend on patient cohorts, CIs, and competent physician preferences. ...
Objective: To establish institutional diagnostic reference levels (IDRLs) based on clinical indications (CIs) for three- and four-phase computed tomography urography (CTU).
Methods: Volumetric computed tomography dose index (CTDIvol), dose-length product (DLP), patients’ demographics, selected CIs like lithiasis, cancer, and other diseases, and protocols’ parameters were retrospectively recorded for 198 CTUs conducted on a Toshiba Aquilion Prime 80 scanner. Patients were categorised based on CIs and number of phases. These groups’ 75th percentiles of CTDIvol and DLP were proposed as IDRLs. The mean, median and IDRLs were compared with previously published values.
Results: For the three-phase protocol, the CTDIvol (mGy) and DLP (mGy.cm) were 22.7/992 for the whole group, 23.4/992 for lithiasis, 22.8/1037 for cancer, and 21.2/981 for other diseases. The corresponding CTDIvol (mGy) and DLP (mGy.cm) values for the four-phase protocol were 28.6/1172, 30.6/1203, 27.3/1077, and 28.7/1252, respectively. A significant difference was found in CTDIvol and DLP between the two protocols, among the phases of three-phase (except cancer) and four-phase protocols (except DLP for other diseases), and in DLP between the second and third phases (except for cancer group). The results are comparable or lower than most studies published in the last decade.
Conclusions: The CT technologist must be aware of the critical dose dependence on the scan length and the applied exposure parameters for each phase, according to the patient’s clinical background and the corresponding imaging anatomy, which must have been properly targeted by the competent radiologist. When clinically feasible, restricting the number of phases to three instead of four could remarkably reduce the patient’s radiation dose. CI-based IDRLs will serve as a baseline for comparison with CTU practice in other hospitals and could contribute to national DRL establishment. The awareness and knowledge of dose levels during CTU will prompt optimisation strategies in CT facilities.
... Nowadays, there is no literature reporting data on the preventive strategies for renal, bladder, or urethral IUTIs, nor on preoperative imaging assessment to identify anatomical landmarks or proper trocar positioning [31]. Computed tomography (CT) with excretory phase is the best imaging technique to evaluate the kidneys and the urinary collecting system [38][39][40]. This phase is highly sensitive for the evaluation of urinary tract anatomy and its variations, even in patients with greater risk of IUTI (e.g., locally advanced sigmoid or rectal cancer) [41]. ...
... CT urography with both nephrographic and excretory phases (5-20 min after contrast administration) represents the gold standard technique in case of suspected ureteral injuries [38,146]. Once IUTI is identified, appropriate management depends on the type, location, and grade of the lesion, the time of diagnosis and the patient's condition [119]. ...
Iatrogenic urinary tract injury (IUTI) is a severe complication of emergency digestive surgery. It can lead to increased postoperative morbidity and mortality and have a long-term impact on the quality of life. The reported incidence of IUTIs varies greatly among the studies, ranging from 0.3 to 1.5%. Given the high volume of emergency digestive surgery performed worldwide, there is a need for well-defined and effective strategies to prevent and manage IUTIs. Currently, there is a lack of consensus regarding the prevention, detection, and management of IUTIs in the emergency setting. The present guidelines, promoted by the World Society of Emergency Surgery (WSES), were developed following a systematic review of the literature and an international expert panel discussion. The primary aim of these WSES guidelines is to provide evidence-based recommendations to support clinicians and surgeons in the prevention, detection, and management of IUTIs during emergency digestive surgery. The following key aspects were considered: (1) effectiveness of preventive interventions for IUTIs during emergency digestive surgery; (2) intra-operative detection of IUTIs and appropriate management strategies; (3) postoperative detection of IUTIs and appropriate management strategies and timing; and (4) effectiveness of antibiotic therapy (including type and duration) in case of IUTIs.
... Some studies demonstrated the superiority of the nephrographic phase in the identification of urothelial carcinoma when compared to the excretory phase [14][15][16], whereas the excretory phase has traditionally been considered the most valuable phase for the identification of urothelial carcinomas [14,17,18]. The nephrographic and excretory phases can be set at 100 s and 10-15 min after contrast medium injection, respectively [14]. ...
... Some studies demonstrated the superiority of the nephrographic phase in the identification of urothelial carcinoma when compared to the excretory phase [14][15][16], whereas the excretory phase has traditionally been considered the most valuable phase for the identification of urothelial carcinomas [14,17,18]. ...
Computed Tomography Urography (CTU) is a multiphase CT examination optimized for imaging kidneys, ureters, and bladder, complemented by post-contrast excretory phase imaging. Different protocols are available for contrast administration and image acquisition and timing, with different strengths and limits, mainly related to kidney enhancement, ureters distension and opacification, and radiation exposure. The availability of new reconstruction algorithms, such as iterative and deep-learning-based reconstruction has dramatically improved the image quality and reducing radiation exposure at the same time. Dual-Energy Computed Tomography also has an important role in this type of examination, with the possibility of renal stone characterization, the availability of synthetic unenhanced phases to reduce radiation dose, and the availability of iodine maps for a better interpretation of renal masses. We also describe the new artificial intelligence applications for CTU, focusing on radiomics to predict tumor grading and patients’ outcome for a personalized therapeutic approach. In this narrative review, we provide a comprehensive overview of CTU from the traditional to the newest acquisition techniques and reconstruction algorithms, and the possibility of advanced imaging interpretation to provide an up-to-date guide for radiologists who want to better comprehend this technique.
... Despite its widespread use, optimizing CTU technique is a challenge, and there is no consensus regarding a standard protocol [6]. The most common CTU technique acquires three separate phases or CT acquisitions at the following timepoints: An unenhanced phase prior to contrast media injection; a nephrographic phase acquired 80-120 s after intravenous (IV) injection of contrast media; and an excretory phase, acquired several minutes after contrast media injection, during which contrast media is excreted by the kidneys and opacifies the upper urinary tracts [6]. ...
... Despite its widespread use, optimizing CTU technique is a challenge, and there is no consensus regarding a standard protocol [6]. The most common CTU technique acquires three separate phases or CT acquisitions at the following timepoints: An unenhanced phase prior to contrast media injection; a nephrographic phase acquired 80-120 s after intravenous (IV) injection of contrast media; and an excretory phase, acquired several minutes after contrast media injection, during which contrast media is excreted by the kidneys and opacifies the upper urinary tracts [6]. In this technique, the entire contrast media volume is injected as a single bolus; the advantage is that all of the contrast bolus contributes to the nephrographic and excretory phases, at the expense of three separate CT acquisitions, which results in higher ionizing radiation dose to the patient [6,7]. ...
... The most common CTU technique acquires three separate phases or CT acquisitions at the following timepoints: An unenhanced phase prior to contrast media injection; a nephrographic phase acquired 80-120 s after intravenous (IV) injection of contrast media; and an excretory phase, acquired several minutes after contrast media injection, during which contrast media is excreted by the kidneys and opacifies the upper urinary tracts [6]. In this technique, the entire contrast media volume is injected as a single bolus; the advantage is that all of the contrast bolus contributes to the nephrographic and excretory phases, at the expense of three separate CT acquisitions, which results in higher ionizing radiation dose to the patient [6,7]. The second most common CTU technique is the split-bolus technique, where the nephrographic and excretory phases are acquired at the same time, in order to eliminate CT acquisition, and thereby, reduce the radiation dose by approximately one-third. ...
The purpose of this study was to compare the scan time, image quality and radiation dose of CT urograms (CTU) using a split vs. single bolus contrast media injection technique. A total of 241 consecutive CTUs performed between August 2019-February 2020 were retrospectively reviewed. There were three study groups: Group 1, <50 years old, 50/80 cc split-bolus administered at 0 and 700 s post initiation of injection, with combined nephrographic and excretory phases; group 2, ≥50 years old, same split-bolus protocol; and group 3, ≥50 years old, 130 cc single bolus injection, with nephrographic and excretory phases acquired at 100 s and 460 s post injection initiation. The recorded data elements were scan time, number of excretory phases, imaging quality based on opacification of the urinary collecting system (<50%, 50–75%, 75–100%), and dose-length product (DLP). Associations between group and categorical variables were assessed (Chi-square); mean scan time and DLP were compared (one-way ANOVA). Following analysis, proportionally fewer CTUs required a repeat excretory phase in group 3 (32/112, 28.6%) than in groups 1 (25/48, 52.1%) and 2 (37/80, 46.3%) (p = 0.006). Mean scan time was significantly lower in group 3 (678 s) than in groups 1 (1046 s) and 2 (978 s) (p < 0.0001). There was no association between groups and image quality (p = 0.13). DLP was higher in group 3 (1422 ± 837 mGy·cm) than in groups 1 (1041 ± 531 mGy·cm) and 2 (1137 ± 646 mGy·cm) (p = 0.003). In conclusion, single bolus CTU resulted in significantly fewer repeat phases and faster scan time at the expense of a slightly higher radiation dose.
... The differential diagnosis between pyeloureteritis cystica and multifocal UTUC may be difficult. Nevertheless, the latter is usually characterized by presence of fewer and more inhomogeneous lesions [7,12,29,30]. ...
Urothelial carcinoma (UC) is the fourth most frequent tumor in Western countries and upper tract urothelial carcinoma (UTUC), affecting pyelocaliceal cavities and ureter, accounts for 5–10% of all UCs. Computed tomography urography (CTU) is now considered the imaging modality of choice for diagnosis and staging of UTUC, guiding disease management. Although its specificity is very high, both benign and malignant diseases could mimic UTUCs and therefore have to be well-known to avoid misdiagnosis. We describe CTU findings of upper urinary tract carcinoma, features that influence disease management, and possible differential diagnosis.
Traumatic injuries are the leading cause of death in Americans under 45 years of age and the third most common cause of death for all Americans. Diagnostic imaging, in particular computed tomography (CT), has become essential in the evaluation of trauma patients because of its ability to provide rapid, accurate, and detailed information. CT scanning plays an important role in detecting injuries to the genitourinary system, including the adrenal glands, kidneys, ureters, urinary bladder, urethra, and genitalia. In addition, CT scanning can help identify actionable complications such as active hemorrhage, organ dysfunction, and fluid collections.
