OBJECTIVE: To report preliminary results of aneurysm neck remodeling in the management of wide-necked renal artery aneurysms. MATERIALS AND METHODS: Five patients (three women and two men between 49-72 years; mean age, 62 years) with wide-necked renal artery aneurysms measuring from 10 to 25 mm in diameter were submitted to balloon-assisted coil embolization along a three-year period. The micro-balloon was placed along the aneurysm neck and temporarily inflated for introduction of detachable microcoils into the aneurysmal sac. RESULTS: Balloon positioning and microcoil embolization were successfully completed in all of the cases with achievement of complete aneurysm occlusion without coil protrusion or parent vessel obstruction. CONCLUSION: The present preliminary experiment indicates that the "aneurysm neck remodeling" is technically feasible and effective in the management of complex renal artery aneurysms without sacrificing any arterial branch.

Keywords: Aneurysms, Renal, Endovascular treatment, Remodeling technique

OBJECTIVE: To experimentally determine the 99mTc and 111In activity recovery coefficients in SPECT imaging. MATERIALS AND METHODS: Four different 99mTc and 111In concentrations were utilized for quantifying activity in spheres of four different sizes. Images were obtained with a hybrid dual-head SPECT-CT imaging system. The ordered subset expectation maximization (OSEM) iterative method was utilized for images reconstruction. An attenuation map was utilized for attenuation correction, and the multiple energy window technique for scattering correction. RESULTS: Results for spheres < 6 ml in volume were significantly affected by the partial volume effect. For 111In quantification, results show a dependence on sphere concentrations and background levels. For 99mTc quantification, there was a tendency towards values underestimation with higher background levels. CONCLUSION: Correction factors must be utilized for compensating the partial volume effect on objects with < 6 ml in volume for both radionuclides. Background subtraction to compensate spurious count present on SPECT images has a significant influence on the quantification of activity, especially for the smaller objects.

Keywords: SPECT, 111In, 99mTc, Recovery factors

OBJECTIVE: To present computed tomography findings observed in four patients submitted to radical nephrectomy for renal cell carcinoma who developed pancreatic metastases afterwards. MATERIALS AND METHODS: The four patients underwent radical nephrectomy for stage T1 (n=2) and stage T3a (n=2) renal cell carcinoma. The mean interval between nephrectomy and detection of pancreatic metastases was eight years. Two asymptomatic patients presented with solitary pancreatic metastases (confined to the pancreas). Two symptomatic patients presented with single and multiple pancreatic metastases, both with tumor recurrence in the contralateral kidney. RESULTS: Computed tomography studies demonstrated pancreatic metastases as solitary (n=2), single (n=1) or multiple (n=1) hypervascular lesions. Partial pancreatectomy was performed in two patients with solitary pancreatic metastases and both are free of disease at four and two years after surgery. CONCLUSION: Pancreatic metastases from renal cell carcinoma are rare and can occur many years after the primary tumor presentation. Multiple pancreatic metastases and pancreatic metastases associated with tumor recurrence in the contralateral kidney are uncommon. Usually, on computed tomography images pancreatic metastases are visualized as solitary hypervascular lesions, simulating islet-cell tumors. Surgical management should be considered for patients with solitary pancreatic lesions.

Keywords: Pancreatic metastases, Renal cell carcinoma, Computed tomography

OBJECTIVE: To standardize a method and determine normal values for absolute renal uptake of 99mTc-DMSA in children with normal creatinine clearance. MATERIALS AND METHODS: Twenty-two children (between 7 months and 10 years of age; mean 4.5 years) without clinical evidence of renal disease were studied using 99mTc-DMSA scintigraphy. Eighteen had normal renal ultrasonography, micturating urethrocystography, creatinine clearance and visual interpretation of the scintigraphy with 99mTc-DMSA. Four children were excluded, one with incomplete creatinine clearance and three due to reduction in the creatinine clearance. Absolute renal uptake of 99mTc-DMSA (DMSA-Abs) was expressed as the fraction of the administered dose retained by each kidney six hours after administration of the radiopharmaceutical. RESULTS: DMSA-Abs was 21.8 ± 3.2% for the right kidney and 23.1 ±3.3% for the left kidney. There was no correlation between renal uptake and the age groups studied, although there was a tendency to an increase in the creatinine clearance with age. CONCLUSION: Normal values of DMSA-Abs can be used as an additional parameter for the initial diagnostic evaluation and during follow-up of renal diseases, mainly when bilateral impairment of renal function is suspected or in a patient with a single functioning kidney (in which renal differential function is of limited value).

Keywords: Renal function, Quantification, 99mTc-DMSA, Children, Scintigraphy

Renal allograft acute rejection must be promptly diagnosed since its reversibility is related to the readiness in which treatment is initiated. The aim of this study was: 1) to establish a quantitative method to evaluate kidney rejection and acute tubular necrosis (ATN); 2) to assess the potential role of 99mTc-mononuclear leukocytes scintigraphy in the diagnosis of renal rejection and differential diagnosis of ATN. One hundred and sixty studies were performed in 80 renal transplant patients at the first and fifth day after transplantation. Autologous cells were used for labeling. Images were obtained at 30 minutes, 3 hours and 24 hours after intravenous administration of 444 MBq (12 mCi) of labeled cells. There was abnormal labeled cells uptake in 27 of 31 cases of rejection and in 6 of 8 cases of ATN. The results of each patient were compared with clinical findings. Doppler scanning detected 18 of 31 cases of rejection. Rejection diagnosis sensitivity and specificity rates using scintigraphy were 87.1% and 100%, respectively, and 58.1% and 100%, respectively using ultrasound. Renal biopsy was performed in eight patients which demonstrated seven cases of rejection and one case of ATN. These results suggest that 99mTc-mononuclear leukocytes imaging may be useful in the early diagnosis of rejection and in the differential diagnosis of ATN.

Keywords: 99mTc-mononuclear leukocytes, Renal allograft, Rejection, Diagnosis

The authors report a case of congenital hydrocolpos due to vaginal malformation (vaginal septae) associated with ectopic ureter and renal displasia. Several imaging diagnostic procedures (ultrasonography, nuclear medicine, intravenous urography and computed tomography) were performed. A review of the literature on hydrocolpos and its association with urinary malformations is also presented.

Keywords: Hydrocolpos, Vaginal malformation, Renal displasia

Although rare, transitional cell carcinoma of the urinary tract is the second most common tumor of the kidneys. We studied retrospectively the computed tomography images of 10 patients with confirmed transitional cell carcinoma of the urinary tract. There was involvement of the bladder in 60% of the cases whereas the calyceal system and the ureters were involved in 60% and 10% of the cases, respectively. Concomitant tumors were present in 40% of the cases. The findings were sessile masses, ureteral wall thickening and renal infiltrative lesions. Calcified tumors were seen in two patients and a transitional cell tumor arising from a bladder diverticulum was identified in another patient. Local tumor dissemination was observed in 80% of the patients and distant dissemination in 20% of the patients. Computed tomography allowed the detection of local and distant tumor dissemination, thus allowing a selected group of patients to be treated conservatively.

Keywords: Transitional cell carcinoma, Computed tomography, Renal tumors

Dynamic renal scintigraphy allows the diagnosis of complications in patients submitted to organ transplantation, such as perfusion abnormalities, acute tubular necrosis and rejection. In this study we employed 99mTc-DTPA scintigraphy to study patients submitted to kidney transplantation. The results obtained and the clinical findings were conjunctly analyzed in order to detect graft rejection or other complications. The type of immunosuppressive scheme used was also correlated with the observed complications. Fifty-five patients submitted to kidney transplantation from 1989 to 1999 were evaluated. All patients with nephrotoxicity received a 3-drug immunosuppressive scheme. In this study, acute rejection was the most frequent complication (40.4%) observed following transplantation. Thirteen of 15 recipients of cadaveric kidney grafts presented acute tubular necrosis. Only one false-positive case was observed when scintigraphy and clinical findings were not concordant. We suggest carrying out renal scintigraphy to follow-up post-transplantation patients.

Keywords: Dynamic renal scintigraphy, 99mTc-DTPA, Kidney transplantation, Immunosuppression

Renal lymphangiectasia is a rare condition characterized by parapyelic and perirenal fluid collections, which may progress from asymptomatic condition to chronic renal failure. The present report describes a case of incidental computed tomography finding of bilateral lymphangiectasia in an asymptomatic patient, as well as the main imaging findings with a comprehensive literature review.

Keywords: Renal lymphangiectasia; Renal lymphangiomatosis; Malformation; Lymphatic system; Kidney; Computed tomography.

The present report describes the case of a 48-year-old female patient suffering from chronic renal failure on dialysis for 13 years. She presented with hemoptysis, fever, productive cough and dyspnea. Chest radiography showed predominance of ill-defined opacities in the middle and lower lung fields, bilaterally. Chest computed tomography showed groundglass opacities associated with poorly defined centrilobular nodules with ground-glass attenuation. The patient was submitted to bronchoalveolar lavage that was negative for mycobacteria and fungi. On the basis of such findings, open lung biopsy was performed, which revealed metastatic pulmonary calcification.

Keywords: Chronic renal failure; Metastatic pulmonary calcification.

OBJETIVO: Este estudo teve por finalidade avaliar a perfusão miocárdica de pacientes com diabetes mellitus tipo 1 (DM1) e tipo 2 (DM2) assintomáticos, sem diagnóstico prévio de doença arterial coronariana (DAC) ou acidente vascular cerebral. MATERIAIS E MÉTODOS: Cinquenta e nove pacientes consecutivos (16 DM1, 43 DM2) foram submetidos a cintilografia de perfusão miocárdica com sestamibi-^99mTc (CPM). Foram avaliados quanto ao índice de massa corpórea, controle metabólico do diabetes, dislipidemia, terapia para o diabetes, hipertensão arterial sistêmica, nefropatia, retinopatia, neuropatia periférica, tabagismo e história familiar de DAC. RESULTADOS: CPM foi anormal em 25,4%: 12 (20,3%) com alterações de perfusão e 3 com disfunção ventricular esquerda isolada. Os mais fortes preditores de perfusão miocárdica anormal foram: idade igual ou maior a 60 anos (p = 0,017, odds ratio [OR] = 6,0), neuropatia periférica (p = 0,028, OR = 6,1), nefropatia (p = 0,031, OR = 5,6) e ECG de esforço positivo para isquemia (p = 0,049, OR = 4,08). CONCLUSÃO: A isquemia miocárdica silenciosa ocorre em mais de um em cada cinco diabéticos assintomáticos. Os mais fortes preditores de isquemia foram: idade avançada, neuropatia periférica, nefropatia, retinopatia e ECG de esforço positivo para isquemia.

Keywords: Diabetes mellitus; Cintilografia de perfusão miocárdica; Isquemia miocárdica silenciosa; Doença arterial coronariana.

OBJECTIVE: To calculate the frequencies of acute pyelonephritis and renal scarring in patients under the age of two, with first episode of urinary tract infection in a Brazilian university hospital, comparing with data reported in the international literature. MATERIALS AND METHODS: Scintigraphic reports of children less than two years old submitted to ^99mTc-DMSA renal scintigraphy in a university hospital in Rio Grande do Sul between 2006 and 2009 were reviewed to investigate acute pyelonephritis/renal scarring. Additionally, the presence of vesicoureteral reflux, early use of antibiotics, and comorbidities were investigated on electronic records. The sample size calculation was based on a systematic review study and obtained a minimum of 147 patients. Patients whose electronic records were not available were excluded. RESULTS: One hundred and fifty-seven children met the inclusion criteria; among them 48 had acute pyelonephritis and 8 of these had renal scars. Neither age nor sex presented any significant association with acute pyelonephritis (p = 0.405 and p = 0.124, respectively). No statistical significance was observed in the association between vesicoureteral reflux and acute pyelonephritis (p = 1.0) and other comorbidities (p = 0.470), and in relation to early use of antibiotics with acute pyelonephritis (p = 0.130) and renal scarring (p = 0.720). CONCLUSION: The frequencies found in the present study for acute pyelonephritis/renal scarring are in agreement with the results reported by most studies in the literature.

Keywords: Pyelonephritis; DMSA; Scar.

Although widely used in the management of bipolar disorder, lithium may cause adverse kidney effects. The importance of the present study is to report the case of a 59-year-old woman who was under regular treatment with lithium for bipolar disorder and whose imaging studies demonstrated the presence of multiple renal microcysts, suggesting lithium nephropathy as main diagnostic hypothesis.

Keywords: Lithium nephropathy; Renal microcysts; Bipolar disorder.

Renal cystic lesions are usually diagnosed in the radiologists' practice and therefore their characterization is crucial to determine the clinical approach to be adopted and prognosis. The Bosniak classification based on computed tomography findings has allowed for standardization and categorization of lesions in increasing order of malignancy (I, II, IIF, III and IV) in a simple and accurate way. The present iconographic essay developed with multidetector computed tomography images of selected cases from the archives of the authors' institution, is aimed at describing imaging findings that can help in the diagnosis of renal cysts.

Keywords: Bosniak classification; Renal cysts; Multidetector computed tomography.

OBJECTIVE: To determine the presence of linear relationship between renal cortical thickness, bipolar length, and parenchymal thickness in chronic kidney disease patients presenting with different estimated glomerular filtration rates (GFRs) and to assess the reproducibility of these measurements using ultrasonography. MATERIALS AND METHODS: Ultrasonography was performed in 54 chronic renal failure patients. The scans were performed by two independent and blinded radiologists. The estimated GFR was calculated using the Cockcroft-Gault equation. Interobserver agreement was calculated and a linear correlation coefficient (r) was determined in order to establish the relationship between the different renal measurements and estimated GFR. RESULTS: The correlation between GFR and measurements of renal cortical thickness, bipolar length, and parenchymal thickness was, respectively, moderate (r = 0.478; p < 0.001), poor (r = 0.380; p = 0.004), and poor (r = 0.277; p = 0.116). The interobserver agreement was considered excellent (0.754) for measurements of cortical thickness and bipolar length (0.833), and satisfactory for parenchymal thickness (0.523). CONCLUSION: The interobserver reproducibility for renal measurements obtained was good. A moderate correlation was observed between estimated GFR and cortical thickness, but bipolar length and parenchymal thickness were poorly correlated.

Keywords: Ultrasonography; Chronic renal disease; Chronic renal failure; Renal cortex; Glomerular filtration rate.