Presentation on theme: "INFECTIONS URINAIRES DU HAUT APPAREIL URINAIRE : ASPECTS EN IMAGERIE TOMODENSITOMETRIQUES SUR UNE REVUE ICONOGRAPHIQUE DE 88 CAS R.BENMOUSSA, M.SABIRI,"— Presentation transcript:
1INFECTIONS URINAIRES DU HAUT APPAREIL URINAIRE : ASPECTS EN IMAGERIE TOMODENSITOMETRIQUES SUR UNE REVUE ICONOGRAPHIQUE DE 88 CASR.BENMOUSSA, M.SABIRI, N.TOUIL, O.KACIMI, N.CHIKHAOUIService de Radiologie des UrgencesCHU Ibn Rochd - Casablanca - Maroc
2INTRODUCTIONAcute pyelonephritis (APN) is known as an inflammation of the kidney and upper urinary tract, most commonly resulting from bacterial infection of the bladder.10% to 30% of patients with APN require hospitalisation and may even present with life-threatening complications including shock, septicemia and multi-organ dysfunction syndromes, what shows the importance of assessing diagnosis.Bacterial nephritis or renal infection can be regarded as a spectrum of clinical entities, progressing from mild APN to renal abscesses or emphysematous pyelonephritis.
3PURPOSESTo provide through an iconographic review, a support showing different aspects of this disease.Grading radiological facts as in Picolli’s classification according to severity of lesions.To demonstrate impact of imaging, especially CT on APN and renal infection radiological analysis.To recognize on imaging the most common complications of APN and main differentials.
4PATIENTS AND METHODS Inclusion criterias: We studied patients showing with suspected diagnosis of APN, during a period of two years (from May 2011 to May 2013).Inclusion criterias:Clinical criterias: presence of classical symptoms of APNFeverPresence of loin or flank pain with or without lower urinary tract symptomsPositive urine dipstick for leukocytes and/or nitritesBiological criterias:Cytobacteriological urine examination realized but not necesserally positiveAll patients underwent first an ultrasound examination then Computed Tomography scanning.
6RESULTS 88 patients were included in the study. The diagnosis of APN was established half of cases (44 cases)Age: 33,2±8,6 yearsGender:-Women: 78%-Men: 22%
7RESULTS Ultrasonography: -diagnosis of APN established: 65,9% -dismissed diagnosis: 34,1%The abdominal CT showed in 34,1% of dismissed ultrasonographic diagnosis of APN, 4 cases of perinephitic abscess and many perfusion troubles in the other cases.Ultrasonographic signsn%Increase of kidney size with hypoechoic areas4753,6Blurred margins2124,4Reduction of Doppler vascularity3236,6
9DEFINING APN ?APN can be defined clinically, pathologically or radiologically:The British Medical Research Concil Bacteriuria Committee defined APN as a clinical syndrome of flank pain, costovertebral tenderness and fever accompanied by laboratory evidences of renal infection including leukocytosis, pyuria, haematuria, bacteriruria, positive urine culture and sometimes bacteraemia.Hill defined APN pathologically as a suppurative inflammation of the renal parenchyma and pyelocaliceal system typically distributed along one or more medullary rays supporting as ascending route of infection.Radiologically, APN manifests on contrasted computed tomography (CT) scans as hypoenhancing regions with or without renal swelling, and may be focal or diffused.
10ROLE OF CTCT imaging is often the modality of choice for the evaluation of APN and renal abcesses.It is superior to intravenous urogram or renal ultrasonography in detecting renal parenchymal abnormalities like perinephric stranding, inflammatory masses, decreased or delayed cortical enhancement, kidney enlargement or gas formation, all of which may indicate more severe APN.Non-contrast CT imaging will be able to rule out an obstructed collecting system requiring urgent decompression and drainage but it is not ideal for diagnosing renal abcesses or APN.
11NORMAL NEPHROGRAPHIC DEVELOPMENT ON CT Before CMINON ENHANCEDVASCULAR PHASE10-15 seconds after CMICORTICAL NEPHROGRAPHIC PHASE20-45 seconds after CMIPARENCHYMAL NEPHROGRAPHIC PHASE45 seconds to 2 minutes after CMIEXCRETORY PHASE2-3 minutes after CMI
13CT SCAN OBTAINED SECONDS AFTER BEGINNING CONTRAST MATERIEL ADMINISTRATION : CORTICAL NEPHROGRAM WITH A CLEAR CORTICOMEDULLARY INTERFACE
14CT SCAN OBTAINED AT 45 SECONDS TO 2 MINUTES: GENERALIZED NEPHROGRAM
15CT SCAN OBTAINED AT 2-3 MINUTES: CONTRAST MATERIAL IN THE COLLECTING SYSTEM
16ACUTE PYELONEPHRITIS (APN) Clinical and biological presentationClinical signs:Lumbar pain is unilateral more often than bilateral.High temperature (fever of 39°C).Pyuria.Functional urinary signs (pollakiuria, dysuria).Positive urine dipstick (screening): positive for leukocytes and nitrites.Biological Signs:Cytobacteriological urine examination: bacteriuria ≥ 105/mL, leukocyturia ≥ 104/mL and antibiogram.Inflammatory signs (polynucleosis, raised CRP and procalcitonin).
17ACUTE PYELONEPHRITIS (APN) When do I use CT Scan for diagnosis?Patients whose clinical diagnosis is unclear.Patients who fail to respond to conventional médical treatment.Diabetic patients.Immunocompromised patients« The primary value of CT scan is in delineating the extent of the disease process and identifying significant complications such as renal emphysema and abscesses with or without perirenal extension or the presence of urinary obstruction »Objective
18ACUTE PYELONEPHRITIS (APN) CT findingsTypical: « a striated nephrogram on a conventionel CT scan obtained during the excretory phase »Other signs:Soft-tissue stranding and thickening of the Gerota’s fasciaObliteration of the renal sinusCaliceal effacement due to adjacent affected renal parenchymaThickening of the walls of the pelvis and calicesMild dilatation of the renal pelvis and ureterCT phaseaspectCortical and parenchymal nephrographic phasesWedge-shaped areas of hypoattenuating cortex and poor corticomedullary differentiationExcretory phaseSmaller wedge-shaped areas of diminished enhancement and linear band of alternating hyper and hypoattenuation parallel to the axes of tubules and collecting ducts
19Acute Pyelonephritis in a 42 year-old-woman Enhanced abdominal CT Scan during the cortical nephrographic phase showing wedge-shaped areas of hypoattenuating cortex in the left kidney which volume is increased
20Acute pyelonephritis in a 29 year-old-woman Enhanced helical CT Scan during excretory phase: sriated nephrogram
21Acute pyelonephritis in a 34 year-old-woman Enhanced CT Scan in excretory phase: smaller wedge-shaped areas of diminished enhancement and linear band of alternating hyper and hypoattenuation parallel to the axes of tubules and collecting ducts
22Main differential of APN: RENAL INFARCTION « Cortical rim sign » is a fine layer of cortical enhancement and is highly suggestive of renal infarctionRight kidney infarctionContrast-enhanced CT Scan in axial plane: Wedge-shaped enhancement defect of the postérior lip of the right kidney with cortical contrast uptake showing the « cortical rim sign » confirming thet ischaemia is the mechanism of the lesionIfergan J, Pommier R, Imaging in upper urinary tract infections. Diagnostic and Interventional Imaging. 2012;93:
23ACUTE PYELONEPHRITIS (APN) Keypoints of analysisIdentify the typical lesionChatecterize CT finding: Society of UroradiologyUnilateral or bilateral?Focal or diffuse?Focal swelling or no focal swelling?Renal enlargement or no renal enlargement?Looking for complications:Renal emphysema?Renal abscess?Perirenal extension?Presence of renal obstruction?
24COMPLICATIONSRENAL ABSCESSMechanism: liquefactive necrosis and abscess formation resulting from severe vasospasm and inflammation.CT Scan findings:Well-defined mass of low attenuation with a thick, irregular wall or pseudocapsule, which is better imaged with contrast enhancement.Gas within a low attenuation or cystic mass.Renal parenchyma around the abscess cavity poorly enhanced on early views, hyperattenuating on delayed views.Fascial and septal thickening and perinephric fat obliteration.
25Renal abscess of the left kidney in a diabetic 43 year-old-man Enhanced helical CT Scan within excretory phase showing a well-defined mass of low attenuation with a thick wall evident with contrast enhancement
26Renal abscess of the right kidney in a 35 year-old-woman Enhanced helical CT Scan within parenchymal phase showing a well-defined mass of low attenuation deforming outline of the right kidney
27Main differential of renal abscess: SURINFECTED RENAL CYST Thickening and enhancement of the cyst wall and inflammatory changes surronding the affected cyst are highly suggestive of surinfected renal cyst.Surinfected right kidney cystContrast-enhanced CT Scan in axial plane during the parenchymal nephrographic phase: Thickening and contrast uptake in the wall of a right kidney cyst with oedema of the perilesional parenchymaIfergan J, Pommier R, Imaging in upper urinary tract infections. Diagnostic and Interventional Imaging. 2012;93:
28PICOLLI’S CLASSIFICATION ACCORDING TO SEVERITY Picolli GB, Colla L, Development of kidney scars after acute uncomplicated pyelonephritis: relationship with clinical, laboratory and imaging data at diagnosis. World J Urol 2006;24:66-73
29COMPLICATIONS PERINEPHRIC ABSCESS Mechanism: Rupture of a renal abscess into the perirenal space.Developing directly from APNContext: Diabetic patients and patients with septic emboliCT Scan findings:Areas of soft-tissue or fluid attenuation within the perirenal space.May involve the psoas muscle and extend to the pelvis.Gas occasionally present.Rarely, a postinflammatory cystic fluid collection < 3cm in diameter without appreciable thickening or enhancement of the wall.
30Perirenal abscess of the left kidney in a 35 year-old-woman, already having renal abscess 6 days beforeEnhanced helical CT Scan within cotical nephographic phase showing a mass of low attenuation deforming outline of the left kidney and extending the perirenal space
31EMPHYSEMATOUS PYELONEPHRITIS COMPLICATIONSEMPHYSEMATOUS PYELONEPHRITISMechanism: fulminant gas-forming infection with commonly E.Coli, Klebsiella pneumoniae and Proteus mirabilis.Context: symptoms of severe APN in uncontrolled diabetes mellitus patientsCT Scan findings: GASRenal or perirenal fluid collections with bubbly or loculated gaz in the parenchyma or collecting system.Localiszed in the renal parenchyma, the subcapsular, perinephric or pararenal space, the collecting system or occasionally the vascular system.Differential: CLASSICAL EMPHYSEMATOUS PYELONEPHRITIS which is characterized by parenchymal destruction, streaky or motted gas, and little or no fluid.
32Emphysematous pyelonephritis in a diabetic 59 year-old-woman presenting with clinical signs of APN Renal ultrasonography showing the presence of gas in the sinus of the right kidney
33Emphysematous pyelonephritis in a diabetes mellitus patient Enhanced CT Scan during parenchymal phase showing the presence of gaz among the right renal parenchyma
34COMPLICATIONS PYONEPHROSIS Mechanism: concomitant suppuration of the parenchyma and the collecting system, usually secondary to a calculus and more rarely to other causes of obstruction.Ultrasonography:Dilation of the pelvicalyceal system.Fine mobile or sloping echoes in the calyces.CT Scan findings:Thickening of the walls of the renal pelvis.
35Pyonephrosis in a 52 year-old-man Contrast-enhanced CT Scan during excretory phase showing a dilated left renal pelvis, with poor excretion and increased density within the renal pelvis.
36SUMMARYAPN is a severe stat responsible for a considerable mortality if not assessed in time.The ultrasonography is often insufficient to define APN, but when realized eartly possesses value for looking for obstruction and indicating Ct Scan and ponctions.Nowadays, abdominal CT Scan is the best exam for assessing upper urinary tract infections and their complications.Therefore, respecting the recommandations for good CT scan technique is essential for good assessment.
37REFERENCESLim SK, Ng FC, Acute pyelonephritis and renal abscesses in adults: correlating clinical parameters with radiological (computed tomography) severity. Ann Acad Med Singapore 2011; 40:407-13Picolli GB, Colla L, Development of kidney scars after acute uncomplicated pyelonephritis: relationship with clinical, laboratory and imaging data at diagnosis. World J Urol 2006;24:66-73Kawashima A, Sandler CM, CT of renal inflammatory disease. Radiographics 1997;17:Wan YL, Lee TY, Acute gas-producing bacterial renal infection: correlation between imaging findings and clinical outcome. Radiology 1996; 198:Ifergan J, Pommier R, Imaging in upper urinary tract infections. Diagnostic and Interventional Imaging. 2012;93:Bruyère F, Carlou G, Boiteux JP, Pyélonéphrites aigues. Prog Urol 2008;18:514-8Craig WD, Wagner BJ, Travis MD? Pyelonephritis: radiologic-pathologic review. Radiographics 2008;28/255-77Kawashima A, Leroi AJ. Radiologic evaluation of patients with renal infections. Infect Dis Clin North Am 2003;17:433-56