Multidetector CT urography in urogenital tuberculosis: use of reformatted images for the assessment of the radiological findings. A pictorial essay.

Urogenital tuberculosis (UGTB) is the most common form of extrapulmonary TB and is responsible for a destructive inflammation of the renal parenchyma and urinary tract often leading to the loss of kidney function. For these reasons, the early diagnosis of this disease, once considered disappeared in developed countries, is very important to establish a prompt and efficient treatment. However, the subtle and non-specific symptoms, often represented by recurrent and persistent lower urinary tract symptoms, can confound and delay the diagnosis. Therefore, an adequate and comprehensive imaging study is necessary in patients with persistent urinary tract infections not responding to the antibiotics and can suggest the hypothesis although bacteriological and/or histologic analysis is required for a definitive diagnosis. In the past years, intravenous urography (IVU) has allowed a comprehensive study of the urinary excretory tract, promoting the knowledge of the radiological findings of this disease. Nowadays, computed tomography urography (CTU), with the implementation of multidetector (MD) technology, has replaced IVU in all its indications; the MDCTU improves the assessment of renal and urinary tract lesions using reformatted images [such as multiplanar reconstruction (MPR) and maximum intensity projection (MIP)]. Therefore, our paper aims to provide a guide for radiologist for searching the classic signs of UGTB on MDCTU, encouraging the use of the MPR and MIP reformatted images.

Can the multiphasic computed tomography be useful in the clinical management of small renal masses?

Background Small renal masses (SRMs; ≤4 cm) represent a challenging issue. Computed tomography (CT) is widely used for investigating renal tumors even if its ability to differentiate among the different subtypes has not yet been definitively established. Purpose To assess the potential role of the morphological features and angiodynamic behavior on multiphasic CT in the preoperative evaluation of SRMs. Material and Methods The CT images of 80 patients with SRMs who underwent surgical resection at our institution were retrospectively reviewed. The morphological features, the pattern, and the quantitative analysis of enhancement were assessed for each lesion and were correlated with the histological subtypes. Results Overall, 81 SRMs were evaluated. Final pathological examination showed 30 (37%) oncocytomas, 22 (27.2%) clear cell renal cell carcinomas (ccRCCs), 16 (19.8%) papillary RCCs (pRCCs), and 13 (16%) chromophobe RCCs (chRCCs). Of the morphological features, only necrosis was significantly associated with ccRCC ( P = 0.047). The analysis of enhancement allowed the identification of two groups of lesions, based on arterial behavior: hypervascular (oncocytomas/ccRCC) and hypovascular (chRCC/pRCC) lesions. A significant difference between the two groups in terms of degree of enhancement on CT phases was found ( P < 0.05); this was also confirmed by the receiver operating characteristic (ROC) analysis. Conclusion Except for necrosis, the morphological features are not useful in making a correct diagnosis in the case of SRMs. The angiodynamic behavior on multiphasic CT showed high accuracy in differentiating between hypovascular and hypervascular tumors; this differentiation could be useful for deciding on the most appropriate clinical management of SRMs.

Ectopic Prostatic Tissue May Cause Hydroureteronephrosis.

A 60-year-old man with left flank pain, fever, and nausea underwent an abdominal ultrasound and showed left hydroureteronephrosis without urinary calculi. Computed tomography urography showed moderate left hydroureteronephrosis and a hypodense paravesical mass of 1.7 cm with mild contrast enhancement just below the ipsilateral ureterovesical junction. Contrast-enhanced magnetic resonance imaging showed a 48 cc prostate and confirmed a roundish mass, protruding into the bladder, hyperintense on T2-weighted images, hypointense on T1-weighted images, and with mild inhomogeneous contrast enhancement. Cystoscopy with cold cup biopsy was carried out. Histologic analysis revealed the presence of ectopic prostatic tissue with no evidence of malignancy.

Three Unusual Cases of Nutcracker Syndrome Caused by Increased Blood Flow within the Left Renal Vein.

Nutcracker syndrome (NCS) refers to the compression of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It can cause both microscopic and gross haematuria, with or without flank pain. The diagnosis is often delayed in a majority of symptomatic patients. On the other hand, the use of CT in routine abdominal explorations has increased the detection of the compression of the LRV in healthy and asymptomatic patients, but its diagnostic value remains uncertain. In this paper, we report 3 cases of the NCS associated with an increased blood flow in the LRV, due to different conditions, which we believe could produce the appearance of clinical symptoms.

Anterior Nutcracker Syndrome with Left Gonadal Vein Varicosities on Multiphasic Computed Tomography: An Unexpected Cause of Pyeloureteral Junction Obstruction.

The anterior nutcracker syndrome is defined by the compression of the left renal vein between the aorta and superior mesenteric artery, usually related to the occurrence of hematuria. We report the case of an uncommon complication of the nutcracker syndrome. A 75-year-old woman was referred to our institution for left flank pain without hematuria. Multiphasic computer tomography urography showed a condition of left renal vein entrapment between the aorta and superior mesenteric artery with the development of left gonadal vein varicosities at the level of the renal hilum; a pyeloureteral junction compression with dilation of the pyelocalyceal system coexisted. To our knowledge, this is the first report of the association between nutcracker syndrome and pyeloureteral junction obstruction.

3D FIESTA pulse sequence for assessing renal artery stenosis: is it a reliable application in unenhanced magnetic resonance angiography?

OBJECTIVES: To assess the capability of the three-dimensional (3D) Fast Imaging Employing Steady-State Acquisition (FIESTA) sequence in evaluating renal artery stenosis (RAS). METHODS: We retrospectively analysed 79 patients referred for suspected RAS, examined by 3D FIESTA and contrast-enhanced magnetic resonance angiography (CE-MRA), using a 1.5T whole-body scanner. Image quality was assessed as well as the presence and grade of RAS. Patients with RAS ≥ 50% were evaluated for possible digital subtraction angiography (DSA). Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of 3D FIESTA were calculated with ROC analysis using CE-MRA and DSA as the standard of reference. RESULTS: A total of 186 renal arteries were assessed; 36 had RAS ≥ 50 % demonstrated by CE-MRA. Ten patients underwent DSA, for a total evaluation of 22 arteries. Sensitivity, specificity, NPV, PPV, and accuracy of 3D FIESTA were 91.7%, 100%, 98%, 100%, and 98%, respectively, as compared to CE-MRA, and 88.2%, 100%, 71.4%, 100%, and 91%, respectively, as compared to DSA. The area under the ROC curve (AUC) of 3D FIESTA as compared to CE-MRA and DSA was 0.958 and 0.941, respectively. CONCLUSIONS: Our study demonstrated the capability of the 3D FIESTA sequence in evaluating RAS, with high-quality images and good diagnostic accuracy. KEY POINTS: The 3D FIESTA sequence provides a robust evaluation of RAS. The 3D FIESTA sequence allows non-invasive evaluation of the renal arteries. The 3D FIESTA sequence could be a useful tool in evaluating RAS.

Diffusion tensor imaging and tractography of the kidneys: assessment of chronic parenchymal diseases.

OBJECTIVE: To assess renal dysfunction in chronic kidney diseases using diffusion tensor imaging (DTI). METHODS: Forty-seven patients with impaired renal function (study group) and 17 patients without renal diseases (control group) were examined using DTI sequences. Cortical and medullary regions of interest (ROIs) were located to obtain the corresponding values of the apparent diffusion coefficient (ADC) and the fractional anisotropy (FA). The mean values of the ADC and FA, for each ROI site, were obtained in each group and were compared. Furthermore, the correlations between the diffusion parameters and the estimated glomerular filtration rate (eGFR) were determined. RESULTS: In both the normal and affected kidneys, we obtained the cortico-medullary difference of the ADC and the FA values. The FA value in the medulla was significantly lower (P = 0.0149) in patients with renal function impairment as compared to patients with normal renal function. A direct correlation between DTI parameters and the eGFR was not found. Tractography visualised disruption of the regular arrangement of the tracts in patient with renal function alteration. CONCLUSION: DTI could be a useful tool in the evaluation of chronic kidney disease and, in particular, the medullary FA value seems to be the main parameter for assessing renal damage. KEY POINTS: • Magnetic resonance diffusion tensor imaging (MRDTI) provides new information about renal problems. • DTI allows non-invasive repeatable evaluation of the renal parenchyma, without contrast media. • DTI could become useful in the management of chronic parenchymal disease. • DTI seems more appropriate for renal evaluation than diffusion-weighted imaging.

[Accuracy of endorectal Magnetic Resonance Imaging (MRI) and Dynamic Contrast Enhanced-MRI (DCE-MRI) in the preoperative local staging of prostate cancer]. / Accuratezza della RMN 1,5 T con bobina endorettale e della RMN dinamica (DCE MRI) nella stadiazione preoperatoria dei pazienti affetti da carcinoma prostatico.

BACKGROUND: The proper management of newly diagnosed prostate cancer (PCa) requires the choice of the appropriate treatment plan. A crucial factor is the accurate evaluation of the tumor local extension. The Magnetic Resonance Imaging (MRI) plays an important role in the local staging of prostate cancer, although its use in clinical practice is widely debated. Therefore, the purpose of our study was to evaluate the diagnostic accuracy of T2-weighted MR imaging in association with DCE-MRI, performed using an endorectal coil, in preoperative local staging of patients with prostate cancer, by using the histopathologic findings as the reference standard. MATERIALS AND METHODS: From April 2010 to May 2011, 65 patients (mean age, 65 years; range, 51-77 years) with clinical localized PCa, underwent radical prostatectomy at our institution, performed by 2 experienced surgeons. All patients were prospectively evaluated with eMRI in association with DCE-MRI prior to radical prostatectomy. In all patients MRI was performed at least 6 weeks after biopsy and within 2 weeks before Radical Prostatectomy (RP). Histologic analysis was our diagnostic "gold standard". To ensure that the histopathological findings matched with MR images, the assessment of radiological images and the RP specimens were performed dividing the prostate in 14 regions. RESULTS: First, we performed a "per-patient" analysis, considering the entire prostate as a single region. Then, we performed a "per-emigland" analysis, finally a "per-region" analysis. The sensitivity, specificity, PPV, NPV and AUC in predicting ECE in the analysis "per-emigland" were respectively 66.7, 95.7, 66.7, 95.7, 0.824. The evaluation of SVI reported similar results: 62.5, 97.5, 62.5, 97.5, 0.797. DCE-MRI did not improve the diagnostic accuracy of T1-T2-weighted MR images in the evaluation of ECE or SVI. CONCLUSIONS: T1-, T2-weighted MRI adds important information regarding the preoperative local staging of PCa. DCE-MRI does not improve the diagnostic accuracy of MRI in the local staging of PCa.

An unusual case of right retrocaval ureter associated with ipsilateral ureterocele.

A 36-year-old man with right flank pain presented to our institution. Intravenous urography showed mild dilatation of the right pyelocaliceal system and large filling defect in the vesical lumen. Computed tomography revealed the right kidney to be smaller than the left, and with chronic pyelonephritis. The right ureter passed behind the inferior vena cava at the level of the pelvic-ureteral junction. The middle and lower ureter was dilated above a large ureterocele. Cystourethrography showed right vesicoureteral reflux. The patient underwent a resection of the ureterocele with reimplantation of the ureter. Follow-up at 3 months demonstrated resolution of the dilatation of the right ureter.

Renal diffusion tensor imaging: is it possible to define the tubular pathway? A case report.

The authors report a case of unilateral xanthogranulomatous pyelonephritis, associated with chronic lithiasis studied by standard clinical magnetic resonance imaging protocol and diffusion tensor imaging (DTI). Maps of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) and tractography were reconstructed on both healthy and pathologic kidney. ADC and FA values are in agreement with the literature. Tractography reconstruction of tubular renal architecture was confirmed by histology. This result suggests the potential ability of DTI to detect structural alterations in the architecture of the kidney, as noninvasive tool, preceding the onset of clinical-laboratory alterations.

11C-acetate PET for early prediction of sunitinib response in metastatic renal cell carcinoma.

Sunitinib is an oral multitargeted tyrosine kinase inhibitor with antiangiogenic properties used for treatment of renal cell carcinoma and gastrointestinal stromal tumors at a dose of 50 mg/day consecutively for 4 weeks followed by 2 weeks off per cycle. At present, no data are available on the early prediction of sunitinib response in renal cell carcinoma. We report a clinical case of a patient with metastatic renal cell carcinoma diagnosed with 11C-acetate PET and conventional CT and treated with sunitinib. Partial and complete remission documented by CT was preceded by early functional tumor inhibition shown by 11C-acetate-PET after only 14 days of therapy. This case report highlights some interesting points related to the potential role of a novel non-FDG PET tracer, 11C-acetate, in the early prediction of the response to targeted therapies in metastatic renal cell carcinoma.