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INFECTIONS URINAIRES DU HAUT APPAREIL URINAIRE : ASPECTS EN IMAGERIE TOMODENSITOMETRIQUES SUR UNE REVUE ICONOGRAPHIQUE DE 88 CAS R.BENMOUSSA, M.SABIRI, N.TOUIL, O.KACIMI, N.CHIKHAOUI Service de Radiologie des Urgences Service de Radiologie des Urgences CHU Ibn Rochd - Casablanca - Maroc Slide 2 INTRODUCTION Acute pyelonephritis (APN) is known as an inflammation of the kidney and upper urinary tract, most commonly resulting from bacterial infection of the bladder. Acute 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. 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. Bacterial nephritis or renal infection can be regarded as a spectrum of clinical entities, progressing from mild APN to renal abscesses or emphysematous pyelonephritis. Slide 3 PURPOSES To provide through an iconographic review, a support showing different aspects of this disease. To provide through an iconographic review, a support showing different aspects of this disease. Grading radiological facts as in Picollis classification according to severity of lesions. Grading radiological facts as in Picollis classification according to severity of lesions. To demonstrate impact of imaging, especially CT on APN and renal infection radiological analysis. 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. To recognize on imaging the most common complications of APN and main differentials. Slide 4 PATIENTS AND METHODS We studied patients showing with suspected diagnosis of APN, during a period of two years (from May 2011 to May 2013).We studied patients showing with suspected diagnosis of APN, during a period of two years (from May 2011 to May 2013). Inclusion criterias: Inclusion criterias: Clinical criterias: presence of classical symptoms of APN Fever Fever Presence of loin or flank pain with or without lower urinary tract symptoms Presence of loin or flank pain with or without lower urinary tract symptoms Positive urine dipstick for leukocytes and/or nitrites Positive urine dipstick for leukocytes and/or nitrites Biological criterias: Cytobacteriological urine examination realized but not necesserally positive Cytobacteriological urine examination realized but not necesserally positive All patients underwent first an ultrasound examination then Computed Tomography scanning.All patients underwent first an ultrasound examination then Computed Tomography scanning. Slide 5 CT SCAN TECHNIQUE PARAMETERSPELVIS Scan duration (s)32 40 Pitch1 2 Section thickness (mm)3 Table speed (mm/s)3 6 Reconstruction interval (mm)2 3 Kilovolt peak120 Milliampere seconds280 Use of intravenous contrast+ Reconstruction algorithmStandard soft tissue Slide 6 RESULTS 88 patients were included in the study.88 patients were included in the study. The diagnosis of APN was established half of cases (44 cases)The diagnosis of APN was established half of cases (44 cases) Age: 33,28,6 yearsAge: 33,28,6 years Gender:Gender: -Women: 78% -Women: 78% -Men: 22% -Men: 22% Slide 7 RESULTS Ultrasonography:Ultrasonography: -diagnosis of APN -diagnosis of APN established: 65,9% -dismissed diagnosis: 34,1% -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.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 areas 4753,6 Blurred margins2124,4 Reduction of Doppler vascularity 3236,6 Slide 8 RESULTS Microbiological exams:Microbiological exams: -Escherichia coli: 85,3% -Others: 6,1% -None: 8,6% Slide 9 DEFINING 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. 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. 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. Radiologically, APN manifests on contrasted computed tomography (CT) scans as hypoenhancing regions with or without renal swelling, and may be focal or diffused. Slide 10 ROLE OF CT CT imaging is often the modality of choice for the evaluation of APN and renal abcesses.CT 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.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.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. Slide 11 NORMAL NEPHROGRAPHIC DEVELOPMENT ON CT NON ENHANCED Before CMI VASCULAR PHASE 10-15 seconds after CMI CORTICAL NEPHROGRAPHIC PHASE 20-45 seconds after CMI PARENCHYMAL NEPHROGRAPHIC PHASE 45 seconds to 2 minutes after CMI EXCRETORY PHASE 2-3 minutes after CMI Slide 12 UNENHANCED CT SCAN THROUGH THE KIDNEYS Slide 13 CT SCAN OBTAINED 20-45 SECONDS AFTER BEGINNING CONTRAST MATERIEL ADMINISTRATION : CORTICAL NEPHROGRAM WITH A CLEAR CORTICOMEDULLARY INTERFACE Slide 14 CT SCAN OBTAINED AT 45 SECONDS TO 2 MINUTES: GENERALIZED NEPHROGRAM Slide 15 CT SCAN OBTAINED AT 2-3 MINUTES: CONTRAST MATERIAL IN THE COLLECTING SYSTEM Slide 16 ACUTE PYELONEPHRITIS (APN) Clinical signs: Lumbar pain is unilateral more often than bilateral. High temperature (fever of 39C). Pyuria. Functional urinary signs (pollakiuria, dysuria). Positive urine dipstick (screening): positive for leukocytes and nitrites. Biological Signs: o o Cytobacteriological urine examination: bacteriuria 10 5 /mL, leukocyturia 10 4 /mL and antibiogram. o o Inflammatory signs (polynucleosis, raised CRP and procalcitonin). Clinical and biological presentation Slide 17 ACUTE PYELONEPHRITIS (APN) Patients whose clinical diagnosis is unclear. Patients who fail to respond to conventional mdical 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 When do I use CT Scan for diagnosis? Objective Slide 18 ACUTE PYELONEPHRITIS (APN) Typical: a striated nephrogram on a conventionel CT scan obtained during the excretory phase Typical: a striated nephrogram on a conventionel CT scan obtained during the excretory phase Other signs:Other signs: Soft-tissue stranding and thickening of the Gerotas fasciaSoft-tissue stranding and thickening of the Gerotas fascia Obliteration of the renal sinusObliteration of the renal sinus Caliceal effacement due to adjacent affected renal parenchymaCaliceal effacement due to adjacent affected renal parenchyma Thickening of the walls of the pelvis and calicesThickening of the walls of the pelvis and calices Mild dilatation of the renal pelvis and ureterMild dilatation of the renal pelvis and ureter CT findings CT phaseaspect Cortical and parenchymal nephrographic phases Wedge-shaped areas of hypoattenuating cortex and poor corticomedullary differentiation Excretory phaseSmaller wedge-shaped areas of diminished enhancement and linear band of alternating hyper and hypoattenuation parallel to the axes of tubules and collecting ducts Slide 19 Acute 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 Slide 20 Acute pyelonephritis in a 29 year-old-woman Enhanced helical CT Scan during excretory phase: sriated nephrogram Slide 21 Acute 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 Slide 22 Right kidney infarction Contrast-enhanced CT Scan in axial plane: Wedge-shaped enhancement defect of the postrior lip of the right kidney with cortical contrast uptake showing the cortical rim sign confirming thet ischaemia is the mechanism of the lesion Main differential of APN: RENAL INFARCTION Ifergan J, Pommier R, Imaging in upper urinary tract infections. Diagnostic and Interventional Imaging. 2012;93:509-519 Cortical rim sign is a fine layer of cortical enhancement and is highly suggestive of renal infarction Slide 23 ACUTE PYELONEPHRITIS (APN) 1.Identify the typical lesion 2. Chatecterize CT finding: Society of Uroradiology Unilateral or bilateral? Unilateral or bilateral? Focal or diffuse? Focal or diffuse? Focal swelling or no focal swelling? Focal swelling or no focal swelling? Renal enlargement or no renal enlargement? Renal enlargement or no renal enlargement? 3.Looking for complications: Renal emphysema? Renal emphysema? Renal abscess? Renal abscess? Perirenal extension? Perirenal extension? Presence of renal obstruction? Presence of renal obstruction? Keypoints of analysis Slide 24 COMPLICATIONS Mechanism: liquefactive necrosis and abscess formation resulting from severe vasospasm and inflammation. Mechanism: liquefactive necrosis and abscess formation resulting from severe vasospasm and inflammation. CT Scan findings: 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. RENAL ABSCESS Slide 25 Renal 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 Slide 26 Renal 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 Slide 27 Surinfected right kidney cyst Contrast-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 parenchyma Main differential of renal abscess: SURINFECTED RENAL CYST Ifergan J, Pommier R, Imaging in upper urinary tract infections. Diagnostic and Interventional Imaging. 2012;93:509-519 Thickening and enhancement of the cyst wall and inflammatory changes surronding the affected cyst are highly suggestive of surinfected renal cyst. Slide 28 PICOLLIS 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 Slide 29 PERINEPHRIC ABSCESS Mechanism: Mechanism: Rupture of a renal abscess into the perirenal space. Developing directly from APN Context: Diabetic patients and patients with septic emboli Context: Diabetic patients and patients with septic emboli CT Scan findings: CT Scan findings: Areas of soft-tissue or fluid attenuation within the perirenal space. Areas of soft-tissue or fluid attenuation within the perirenal space. May involve the psoas muscle and extend to the pelvis. May involve the psoas muscle and extend to the pelvis. Gas occasionally present. Gas occasionally present. Rarely, a postinflammatory cystic fluid collection < 3cm in diameter without appreciable thickening or enhancement of the wall. Rarely, a postinflammatory cystic fluid collection < 3cm in diameter without appreciable thickening or enhancement of the wall.COMPLICATIONS Slide 30 Perirenal abscess of the left kidney in a 35 year-old-woman, already having renal abscess 6 days before Enhanced helical CT Scan within cotical nephographic phase showing a mass of low attenuation deforming outline of the left kidney and extending the perirenal space Slide 31 EMPHYSEMATOUS PYELONEPHRITIS Mechanism: fulminant gas-forming infection with commonly E.Coli, Klebsiella pneumoniae and Proteus mirabilis. Mechanism: fulminant gas-forming infection with commonly E.Coli, Klebsiella pneumoniae and Proteus mirabilis. Context: symptoms of severe APN in uncontrolled diabetes mellitus patients Context: symptoms of severe APN in uncontrolled diabetes mellitus patients CT Scan findings: GAS CT Scan findings: GAS Renal or perirenal fluid collections with bubbly or loculated gaz in the parenchyma or collecting system. Renal 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. 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. Differential: CLASSICAL EMPHYSEMATOUS PYELONEPHRITIS which is characterized by parenchymal destruction, streaky or motted gas, and little or no fluid.COMPLICATIONS Slide 32 Emphysematous 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 Slide 33 Emphysematous pyelonephritis in a diabetes mellitus patient Enhanced CT Scan during parenchymal phase showing the presence of gaz among the right renal parenchyma Slide 34 PYONEPHROSIS Mechanism: concomitant suppuration of the parenchyma and the collecting system, usually secondary to a calculus and more rarely to other causes of obstruction. Mechanism: concomitant suppuration of the parenchyma and the collecting system, usually secondary to a calculus and more rarely to other causes of obstruction. Ultrasonography: Ultrasonography: Dilation of the pelvicalyceal system. Dilation of the pelvicalyceal system. Fine mobile or sloping echoes in the calyces. Fine mobile or sloping echoes in the calyces. CT Scan findings: CT Scan findings: Dilation of the pelvicalyceal system. Dilation of the pelvicalyceal system. Thickening of the walls of the renal pelvis. Thickening of the walls of the renal pelvis.COMPLICATIONS Slide 35 Pyonephrosis 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. Slide 36 SUMMARY APN is a severe stat responsible for a considerable mortality if not assessed in time.APN 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.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.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.Therefore, respecting the recommandations for good CT scan technique is essential for good assessment. Slide 37 REFERENCES Lim SK, Ng FC, Acute pyelonephritis and renal abscesses in adults: correlating clinical parameters with radiological (computed tomography) severity. 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