Learning objectives
1.To learn the indications of imaging in infections of urinary tract in immunocompetent and immunosuppressed patients
2.The journey from ultrasound to diffusion weighted MRI-when do we use a particular modality and the indications for which conventional modalities still hold strong
3.To demonstrate the imaging spectrum of infections of the urinary tract
Background
Imaging is not routinely indicated in uncomplicated renal infection
Essential under special situations like treatment non-responders,
equivocal diagnosis,
transplant imaging,
and for evaluating extent of disease
Intravenous urography(IVU) provides anatomical details of the calyces,
pelvis and ureter
Ultrasound is important in the emergency setting and in the first episode of infection
CT and MRI are the most precise methods for anatomical characterisation and prediction of likely etiology
Of these two CT is the most commonly used modality,
while MRI is used as a problem solving...
Imaging findings OR Procedure details
Imaging modalities including Intravenous urography (IVU) and Computed tomography (CT) technique,
sonography and Magnetic resonance imaging (MRI) are used in imaging of renal infections(1)
CT TECHNIQUE
Non-contrast scan
Nephrographic phase at 50-90 sec
Excretory phase at 2 min if there is distal urinary tract obstruction (2)
ROLE OF MRI
Apart from routine imaging sequences diffusion-weighted imaging has been applied as a problem solving tool to differentiate between hydronephrosis and pyonephrosis(Figure 1) and between focal pyelonephritis and renal cell carcinoma
Pregnant patients
Contraindication for iodinated contrast...
Conclusion
Over the years imaging modalities used for renal inflammatory lesions have evolved from ultrasound and intravenous pyelography (IVP) to computed tomography (CT) and diffusion weighted magnetic resonance imaging (DW-MRI)
CT is the mainstay in evaluation of evaluation of inflammatory disease of kidney and urinary bladder
Ultrasonography (US) forms a good screening tool for evaluation in the emergency setting
IVP still holds strong in some indications like tuberculosis and papillary necrosis
Upcoming role of DW-MRI deserves mention in differentiating pyonephrosis from hydronephrosis
References
1.
Kawashima A,
Sandler CM,
Goldman MS et al.CT of Renal Inflammatory Disease.Radiographics 1997; 17:851-866
2.
Stunell H,
Buckley O,
Feeney J et al.
Imaging of acute Pyelonephritis in the adult.
Eur Radiol 2007;17(7):1820–1828
3.Saunders HS,
Dye RB,
Shifrin RY et al.The CT Nephrogram- Implications for evaluation of urinary tract disease.Radiographics 1995; 15:1069-1085
4.
Grayson DE,
Abbott RM,
Levy AD et al.
Emphysematous infections of the abdomen and pelvis:a pictorial review.Radiographics 2002; 22(3):543-61
5.
Craig WD,
Wagner BJ,
Travis MD et al.
Pyelonephritis: Radiologic-Pathologic review...
Personal Information
Zohra Ahmad MBBS,
Third year Junior Resident
CJ Das MD,
DNB,
Assistant Professor
Ankur Goyal MD,
DNB,
Senior Resident
S Sharma MD,
Associate Professor
AK Gupta MD,
Professor and Head
V Baliyan MBBS,Third year Junior Resident
K.
Rangarajan MBBS,Secondyear Junior Resident
Department of Radiodiagnosis,
All India Institute of Medical Sciences ,
New Delhi