Surgical Technique of Supine Percutaneous Nephrolithotomy in Children / Técnica quirúrgica de la nefrolitotomía percutánea en supino en niños

Percutaneous nephrolithotomy (PCNL) in children has becomemore widely used due to its high efficacy and safety and to the development of miniaturized instruments. A supine approach is promising due to advantages such as better ventilation, reproducibility, and ergonomics. The purpose of the present study is to describe our surgical technique with special considerations in the pediatric population. We used an oblique supine position supported by one silicone gel positioning pad under the hip and another under the ipsilateral flank. The anatomical landmarks used to guide the puncture were the 11th and 12th ribs, the posterior axillary line, and the iliac crest. Initially, a ureteral catheter was introduced endoscopically. A retrograde pyelography was performed to guide the puncture, which was performed using a biplanar technique. A hydrophilic guide wire was then advanced through the needle. Dilation was performed with Alken telescopic dilators until 14 Ch. Fragmentation was performed either with a 13 Ch semirigid cystoscope or a flexible ureteroscope using a holmium: yttrium aluminum garnet (Ho:Yag) laser.We left a double J catheter. Supine PCNL in the pediatric population has comparable efficacy in terms of stone free rate to that of the prone approach as well as less complications. Certain considerations in children are careful padding and placement of the patient close to the edge of the table. Puncture should be guided by ultrasound to reduce radiation exposure. Miniaturized equipment is not widely available, so adaptation of adult equipment for the pediatric population is sometimes necessary.

La nefrolitotomía percutánea en niños se ha vuelto ampliamente utilizada por su alta efectividad, seguridad, y por la miniaturización de los instrumentos endoscópicos. El abordaje en supino es prometedor por sus ventajas, como mejor ventilación, reproducibilidad, y ergonomía. El propósito es describir nuestra técnica quirúrgica con las consideraciones especiales a tener en cuenta en la población pediátrica. Todos nuestros pacientes han sido intervenidos bajo la siguiente técnica quirúrgica: en una posición oblicua en supino, utilizando soportes de silicona ubicados debajo de la cadera y del flanco ipsilateral, se marcan los reparos anatómicos: las costillas once y doce, la línea axilar posterior y la cresta ilíaca. Inicialmente se introduce un cateter ureteral por vía endoscópica, con el cual se realiza una pielografía retrógrada para guiar la punción con una técnica biplanar. Se avanza una guía hidrofílica y, sobre esta, los dilatadores telescopados de Alken hasta un tracto de 14 Ch. Se realiza la fragmentación con un cistoscopio semirígido de 13 Ch o con un ureteroscopio flexible utilizando el láser Ho:Yag. Se deja un cateter JJ. La nefrolitotomía percutánea en la población pediátrica es comparable en términos de tasa libre de cálculos al abordaje en prono, con menos complicaciones. Una consideración importante en niños es una adecuada posición, cerca al eje de la mesa. La punción debe ser guiada por ultrasonido para disminuir la exposición a radiación. La disponibilidad de equipos miniaturizados es limitada, por lo cual usualmente es necesario adaptar los equipos de adultos.

Retrograde pyelography before radical nephroureterectomy for upper tract urothelial carcinoma is associated with intravesical tumor recurrence

ABSTRACT Purpose: To investigate the association between preoperative retrograde pyelography (RGP), conducted to evaluate upper tract urothelial carcinoma (UTUC), and intravesical recurrence (IVR) after radical nephroureterectomy (RNU). Materials and Methods: Of 114 patients that underwent RNU, 72 patients without preoperative ureteroscopy and a history of bladder tumor were selectively enrolled. Variables associated with IVR were identified. Results: RGP was performed at a mean duration of 24.9 days prior to RNU in 41 (56.1%) of study subjects. During the mean follow-up period of 64.5 months, IVRs were identified in 32 (44.4%) patients at 22.3±18.8 (mean±SD) months after RNU. Despite similar tumor characteristics in the RGP and non-RGP groups, the incidence of IVR was considerably higher in the RGP group (63.4%) than in the non-RGP group (19.4%, p <0.001). The following variables differed significantly between the IVR and non-IVR groups: age (64.6±8.51 vs. 59.6±9.65 years), tumor location (lower or upper; 53.1% vs. 20%), tumor invasiveness (> pT2; 53.1% vs. 17.5%), preoperative hemoglobin (12.8±1.36 vs. 13.9±1.65), preoperative creatinine (1.29±0.32 vs. 1.11±0.22), and preoperative RGP (81.3% vs. 37.5%), respectively. Multivariate Cox regression model showed that tumor location (p=0.020, HR=2.742), preoperative creatinine level (p=0.004, HR=6.351), and preoperative RGP (p=0.045, HR=3.134) independently predicted IVR. Conclusion: Given the limitations of retrospective single-center series, performance of RGP before RNU was shown to have a negative effect on IVR after surgery.

Ureteropelvic junction obstruction caused by metastatic cholangiocarcinoma

ABSTRACT We describe the rare case of a 61-year-old female with right ureteropelvic junction (UPJ) obstruction caused by metastatic cholangiocarcinoma. Her past medical history was notable for cholangiocarcinoma treated with neoadjuvant chemoradiation and two orthotopic liver transplants six years earlier. Urology was consulted when she presented with flank pain and urinary tract infection. Diagnostic workup demonstrated right UPJ obstruction. She was managed acutely with percutaneous nephrostomy. She subsequently underwent robotic pyeloplasty and intrinsic obstruction of the UPJ was discovered. Histological examination revealed adenocarcinoma, consistent with systemic recurrence of the patient's known cholangiocarcinoma.

Crossed renal ectopia with fusion in a female feline: case report / Ectopia renal cruzada com fusão em uma gata: relato de caso

A 3 year old female feline of mixed breed was sent to the diagnostic imaging sector under suspicion of bleeding due to ovariohysterectomy. An abdominal ultrasonography was performed to confirm the initial suspicion. However, no signs of bleeding were found, instead it was observed that the left renal silhouette had two pelvises and was elongated and larger than normal. The right kidney was not found. Excretory urography was requested to evaluate the condition of the ureters. The final diagnosis was crossed renal ectopia with fusion in an asymptomatic cat with no changes in renal function.(AU)

Uma gata, sem raça definida, com três anos de idade, foi encaminhada para o setor de diagnóstico por imagem sob suspeita de hemorragia devido à ovário-histerectomia. Foi realizada ultrasonografia abdominal para confirmar a suspeita inicial, mas nenhum sinal de hemorragia foi encontrado; visibilizou-se, entretanto, a silhueta renal esquerda alongada, com presença de duas pelves. O rim direito não foi encontrado. Solicitou-se exame de urografia excretora para avaliação de ureteres. O diagnóstico foi de ectopia renal cruzada com fusão em um felino assintomático e sem alterações na função renal.(AU)

Balloon dilation for failed pyeloplasty in children?

ABSTRACT Objective: Pyeloplasty is considered the gold standard treatment for ureteropelvic junction obstruction (UPJO). However, the failure rate of pyeloplasty is as high as 10% and repeat pyeloplasty is more difficult. This study aimed to evaluate the efficacy of balloon dilatation for failed pyeloplasty in children. Materials and Methods: Between 2011 and 2017, 15 patients, aged 6 months to 14 years, were treated with balloon dilation for restenosis of UPJO after a failed pyeloplasty. Ultrasound and intravenous urography were used to evaluate the primary outcome. Success was defined as the relief of symptoms and improvement of hydronephrosis, which was identified by ultrasound at the last follow-up. Results: All patients successfully completed the operation, 13 patients by retrograde approach and 2 patients by antegrade approach. Thirteen patients were followed for a median of 15 (4 to 57) months and 2 patients were lost to follow-up. Resolution of the hydronephrosis was observed in 5 cases. The anteroposterior diameter (APD) of the pelvis decreased by an average of 12.4 ± 14.4mm. Eight patients needed another surgery. The average postoperative hospital stay was 1.78 ± 1.4 days. Two patients experienced fever after balloon dilation. No other complications were found. Conclusions: Balloon dilatation surgery is safe for children, but it is not recommended for failed pyeloplasty in that group of patients, owing to the low success rate.

Divertículo calicial y su diagnóstico incidental / Calyceal diverticulum and its incidental diagnosis

Introducción: El divérticulo calicial se detecta en 0,21 a 0.60 por ciento de los urogramas excretores. Objetivos: Describir una paciente con diagnóstico incidental de esta anomalía y su seguimiento durante 11 años. Presentación del caso: Durante la realización de un urograma excretor para el estudio de una hidronefrosis en una niña de siete años de edad, se detectó un divertículo calicial en el riñón contralateral y después de 11 años de seguimiento ultrasonográfico no se ha demostrado modificación ni complicación del divertículo. Conclusiones: El divertículo calicial es una anomalía congénita que puede mantenerse sin complicaciones durante años por lo que debe tratarse conservadoramente(AU)

ABSTRACT Introduction: Calyceal diverticulum is detected in 0,21 percent to 0.60 percent of excretory urogram. Objectives: To describe a patient with an incidental diagnosis of this anomaly and her follow up during 11 years. Case presentation: During the performance of an excretory urogram for studying a hydronefrosis in a seven years old girl, a calyceal diverticulum was detected in the contralateral kidney; and after 11 years of ultrasonographic follow-up there has been no modifications or complication related with the diverticulum. Conclusions: Calycial diverticulum is a congenital anomaly that can last years without presenting complications. That is why it must be treated conservatively(AU)

Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography

OBJECTIVE: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. MATERIALS AND METHODS: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. RESULTS: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. CONCLUSION: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

Urorresonancia en 3 Tesla, técnica, aplicaciones clínicas / Magnetic Resonance Urography (MRU) at 3 Tesla, Technique, Clinical Applications

Introducción: La ausencia de radiación ionizante y de medios de contraste yodados son las ventajas más grandes de la urografía por resonancia magnética (uroRM) frente a la urografía por escanografía (uroTAC). Objetivo: Informar la utilidad de la uroRM, sus ventajas y limitaciones mediante diferentes casos, así como las características imaginológicas propias de este estudio en el magneto de 3 Tesla (3T). Métodos: Se inició una recolección de los casos de uroRM desde agosto de 2013 hasta julio de 2014, realizados en resonador de 3T. Conclusiones: La uroRM en 3T proporciona una excelente definición del sistema urinario y permite establecer las etiologías de patología obstructiva y otras lesiones renales.

Introduction: The absence of ionizing radiation and iodinated contrast media are the biggest advantages of magnetic resonance urography (UroRM) against urography scans (UroCT). Objective: Inform the utility of UroRM, its advantages and limitations through different cases and imaging characteristics typical of this study in the 3 Tesla magneto (3T). Methods: A collection of cases of UroRM was started from August 2013 to July 2014, conducted in 3T resonator. Conclusions: 3T UroRM provides an excellent definition of the urinary system and allows for the etiologies of obstructive disease and other renal lesions.

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.

Dynamic renal scintigraphy versus dual-plasma sample clearance for determining glomerular filtration rates in patients with nonfunctioning kidneys shown by intravenous pyelography / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the actual glomerular filtration rates (GFR) in patients with nonfunctioning kidneys as shown by intravenous pyelography (IVP) using single photon emission computed tomography (SPECT) dynamic renal scintigraphy and dual-plasma sample clearance method.</p><p><b>METHODS</b>We retrospectively analyzed 107 patients with nonfunctioning kidneys shown by IVP who underwent renal dynamic 99Tcm-DTPA SPECT imaging. GFR was measured by Gates' methods (GFRGates') and dual-plasma sample clearance method (GFRdual-plasma). Based on the dynamic functional images and GFRdual-plasma measurements, the patients were categorized into mild renal impairment (GFRdual-plasma≥30 mL/min), moderate renal impairment group (GFRdual-plasma of 20-30 mL/min), severe renal impairment group (GFRdual-plasma of 10 to 20 mL/min), and nonfunctioning kidney group (GFRdual-plasma≤10 mL/min), and GFRGates' were compared among the groups.</p><p><b>RESULTS</b>According to GFRdual-plasma, the numbers of patients having mild, moderate, and severe renal impairment and nonfunctioning kidneys were 12(11.2%), 33(30.8%), 41(38.3%), and 21(19.6%), respectively. GFRdual-plasma and GFRGates' were not significantly different in mild and moderate renal impairment groups, but in patients with severe renal impairment, GFRdual-plasma was significantly lower than GFRGates' (13.9∓6.2 vs 18.8∓4.2 mL/min; t=-2.73, P=0.03), which was also the case with patients with nonfunctinging kidneys (4.5∓2.1 vs 7.2∓3.2 mL/min; t=-3.81, P=0.005).</p><p><b>CONCLUSION</b>Of the patients with nonfunctinging kidneys shown by IVP, only 58% of them actually have severe renal impairment or worse, and further SPECT dynamic renal scintigraphy is necessary to assess the actual risk of renal function impairment before operation.</p>

Quiste gigante de vesícula seminal: presentación atípica de una patología infrecuente / Giant seminal vesicle cyst: atypical presentation of a rare disease

Se presenta el caso de un niño de 14 años que hizo una consulta de control por un encondroma en el fémur izquierdo. La resonancia magnética (RM) de caderas reveló, accidentalmente, un quiste gigante de la vesícula seminal derecha. Si bien se indicó una urografía por RM, esta fue suspendida por un cuadro de claustrofobia del paciente y se realizó una tomografía computada abdómino-pélvica con y sin contraste endovenoso. La patología de las vesículas seminales (VS) puede clasificarse en congénita o adquirida. El primer tipo tiene baja prevalencia (siendo el quiste y la agenesia los más comunes en la práctica diaria) y puede coexistir, a menudo, con anomalías ipsilaterales del tracto urinario superior y genital, debido a la estrecha relación en los hombres de los sistemas reproductor y urinario durante la embriogénesis. También se ha descrito su vinculación con anomalías óseas y vasculares. La escasa frecuencia de presentación y el amplio espectro de potenciales hallazgos asociados suelen dificultar el diagnóstico. Lo habitual es iniciar la evaluación con una ecografía abdominal o transrectal, según la edad y tolerancia del paciente, y continuar con una RM, aunque para confirmar los hallazgos pueden ser necesarios otros procedimientos, como la vesículo-deferentografía (VDG). Esta fue tradicionalmente el método de referencia para el diagnóstico, pero en la actualidad se aplica en casos seleccionados. El tratamiento de las malformaciones está restringido a pacientes sintomáticos y usualmente consiste en una vesiculectomía, con o sin extirpación del riñón displásico o hipoplásico

The case is presented of a 14 year-old boy with a previous diagnosis of left femur enchondroma. The pelvic and hip magnetic resonance imaging (MRI) unexpectedly revealed a right giant seminal vesicle cyst. He was evaluated by performing abdominal-pelvic computed tomography, with and without intravenous contrast. The pathology of the seminal vesicles (SV) can be classified as congenital and acquired. The first type has low prevalence (cyst and agenesis being the most frequently encountered in daily practice) and often co-exists with ipsilateral abnormalities in the upper urinary tract and genital organs, due to the close relationship of the male reproductive and urinary systems during embryogenesis. The association with bone and vascular anomalies has also been described. Abdominal and trans-rectal ultrasound, followed by abdominal and pelvic MRI, are the most accurate methods for preoperative diagnosis. Vesiculo-de/erentography (traditionally the gold standard test for diagnosis) is only applied in selected cases. The treatment, vesiculectomy, with or without removal of dysplastic or hypoplastic kidney, is restricted to symptomatic patients

Right sided double inferior vena cava with obstructed retrocaval ureter: Managed with single incision multiple port laparoscopic technique using "Santosh Postgraduate Institute tacking ureteric fixation technique"

Right double inferior vena cava with obstructed retrocaval ureter is an extremely rare anomaly with only a few reported cases in the literature. To the best of our knowledge, this is the first case report describing ureteric repair by use of a single-incision laparoscopic technique. In addition, this report addresses the underlying surgical challenges of this repair and provides a brief review of the embryology of this anomaly. The "Santosh Postgraduate Institute ureteric tacking fixation technique" provides ease of end-to-end uretero-ureteric anastomosis in a single-incision laparoscopic surgery.

Renal Problems in Early Adult Patients with Turner Syndrome

PURPOSE: This study aimed to evaluate the status of renal function and the presence of urinary abnormalities in early adult patients with Turner syndrome (TS). METHODS: Sixty-three girls with TS, who are attending pediatric endocrine clinics in Busan Paik Hosp., were studied. Urine and blood chemistry tests were performed in every visiting times. Renal ultrasonography was performed in all patients at the initial diagnosis, and intravenous pyelography, DMSA renal scan and renal CT were also performed, if necessary. RESULTS: Of the 63 patients, the karyotype showed 45,X in 32 (50.8%) , mosaicism in 22 (34.9%) and structural aberration in 9 (14.3%). The renal function at the latest visit was shown as normal in all patients. Nephrotic syndrome had developed in one patient. Hematuria was observed in seven patients. Renal anomalies were observed in 20 of the 63 TS (31.7%). Of the 32 TS patients with 45,X karyotype, 13 (40.6%) had renal anomalies, while these were found in 7 (22.6%) of 31 TS patients with mosaicism/structural aberration. But there was no significant statistical difference between two karyotype groups. CONCLUSION: Based on this study, most of the patients with TS do not have any significant problems related to renal function until early adulthood, regardless of renal malformation or hematuria.

Intravenous misplacement of nephrostomy tube following percutaneous nephrolithotomy: Three new cases and review of seven cases in the literature

Purpose We investigated the characteristics and management of patients with intravenous misplacement of a nephrostomy tube. Materials and Methods Between July 2007 and July 2013, 4148 patients with urolithiasis underwent percutaneous nephrolithotomy (PCNL) in our hospital. Intravenous misplacement of a nephrostomy tube occurred in two of these patients. Another patient with intravenous misplacement of a nephrostomy tube, who underwent PCNL in another hospital, was transferred to our hospital. The data of the three patients were retrospectively analyzed. Results The incidence of intravenous misplacement of a nephrostomy tube following PCNL was 0.5% (2/4148) at our hospital. A solitary kidney was present in one of the three patients. The tip of tube was located into the inferior vena cava (IVC) in two patients and into the renal vein in one patient. All three patients were successfully managed with strict bed rest, intravenous antibiotics and one-step (one patient) or two-step (two patients) tube withdrawal under close monitoring. None of the patients underwent antithrombotic therapy. The original operations were performed successfully under close observation in two patients and changed to another operation in one patient. All patients were discharged uneventfully. Conclusions The incidence of intravenous misplacement of a nephrostomy tube following PCNL is 0.5% at our hospital. Intravenous nephrostomy tube misplacement is an uncommon complication of PCNL. A solitary kidney may render patients susceptible to this complication. Most patients may be managed conservatively with strict bed rest, intravenous antibiotics and one-step or two-step tube withdrawal under close monitoring. .

Urothelial carcinoma in a pyelocaliceal diverticulum discovered by magnetic resonance urography

Neither computed tomography (CT) nor intravenous pyelography (IVP) alone can diagnose tumors of renal pelvic diverticula, but magnetic resonance urography (MRU) can obtain accurate preoperative information.

Laparoscopic repair of massive inguinal hernia containing the urinary bladder

Inguinal herniation of the urinary bladder is an extremely rare occurrence involving less than 5% of inguinal hernias reported in literature. These hernias require a high index of suspicion for their diagnosis and pose significant challenges to the operating surgeon. The majority of these hernias have been repaired by an open technique. We report two cases managed laparoscopically

Medullary Sponge Kidney on Retrograde Pyelography / 전남의대학술지

A woman aged 31 had recurrent urinary tract infection with bloody urine. A series image of medullary sponge kidney presented by intravenous urography (IVU) was detected dynamically by retrograde pyelography (RP). Other than ultrasonography and IVU, RP is also a reliable method to detect medullary sponge kidney.

Application of single-bolus dual-source dual-energy CT urography in upper tract opacification and diagnostic performance for painless hematuria / 中国医学科学院学报

<p><b>OBJECTIVE</b>To assess the upper urinary tract opacification and the diagnostic performance of one-bolus dual-source dual-energy CT urography (CTU) for painless hematuria.</p><p><b>METHODS</b>Totally 205 patients who underwent dual-source dual-energy CTU for painless hematuria were enrolled in this study. CTU included true non-enhanced phase, dual-energy mode nephrographic phase, and FLASH mode excretory phase imaging of the urinary tract. Two radiologists independently evaluated the degree of upper urinary tract opacification. Prospective interpretations using true non-enhanced, nephrographic and excretory phase imaging for hematuria were recorded, as well as retrospective diagnosis using virtual non-enhanced, nephrographic and excretory phase imaging. The standard of reference included all available clinical, imaging, laboratory and follow-up data for up to 36 months after CTU exam. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were calculated. Receiver-operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated. The prospective and retrospective diagnostic performance for hematuria and the radiation dose of two CTU protocols were compared.</p><p><b>RESULTS</b>It was found that 87.8% and 86.8% of segments were at least 50% opacified, respectively. The sensitivity, specificity, PPV, NPV and accuracy for hematuria for prospective interpretation were 95.2%, 91.9%, 98.2%, 81.0% and 94.6%, respectively. Comparable figures for retrospective diagnosis were 98.8%, 91.9%,98.2%, 94.4% and 97.6%. The AUC for prospective and retrospective diagnosis were 0.931±0.027 and 0.940±0.026, respectively (z=1.425, Bonferroni-corrected P>0.05). The radiation dose of the CTU protocol using in retrospective diagnosis[(12.732±3.485)mSv] was significantly lower than that of prospective diagnosis [(17.002±4.013)mSv] (P<0.05), with dose reduction of (32.74±8.92)%.</p><p><b>CONCLUSION</b>One-bolus two-phase dual-source dual-energy CT urography provides at least 50% opacification of upper urinary tract segments and has high diagnostic performance for painless hematuria with relatively low radiation dose.</p>

Clinical application of high-pitch excretory phase images during dual-source CT urography with stellar photon detector / 中国医学科学院学报

<p><b>OBJECTIVE</b>To retrospectively evaluate the clinical feasibility of high-pitch excretory phase images during dual-source CT urography with Stellar photon detector.</p><p><b>METHODS</b>Totally 100 patients received dual-source CT high-pitch urinary excretory phase scanning with Stellar photon detector [80 kV, ref.92 mAs, CARE Dose 4D and CARE kV, pitch of 3.0, filter back projection reconstruction algorithm (FBP)] (group A). Another 100 patients received dual-source CT high-pitch urinary excretory phase scanning with common detector(100 kV, ref.140 mAs, CARE Dose 4D, pitch of 3.0, FBP) (group B). Quantitative measurement of CT value of urinary segments (Hounsfield units), image noise (Hounsfield units), and effective radiation dose (millisievert) were compared using independent-samples t test between two groups. Urinary system subjective opacification scores were compared using Mann-Whitney U test between two groups.</p><p><b>RESULTS</b>There was no significant difference in subjective opacification score of intrarenal collecting system and ureters between two groups (all P>0.05). The group A images yielded significantly higher CT values of all urinary segments (all P<0.01). There was no significant difference in image noise (P>0.05). The effective radiation dose of group A (1.1 mSv) was significantly lower than that of group B (3.79 mSv) (P<0.01).</p><p><b>CONCLUSION</b>High-pitch low-tube-voltage during excretory phase dual-source CT urography with Stellar photon detector is feasible, with acceptable image noise and lower radiation dose.</p>