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.

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.