Answer for BIR CoW 05 Mar 2023
LEFT PYELONEPHRITIS WITH INTRAPARENCHYMAL ABSCESSES
Findings
Enlarged edematous left kidney with relatively decreased enhancement of the parenchyma noted Perinephric fat stranding with thickening of left anterior pararenal fascia and lateral conal fascia noted Multiple peripherally enhancing lesions with internal diffusion restriction in left kidney predominantly involving upper pole and interpolar region Multiple enlarged paraaortic lymphadenopathy Delayed excretion of contrast by the lower pole calyces noted.
Discussion
The term pyelonephritis implies that there is inflammation of the renal pelvis and kidney. APN often presents with signs and symptoms of both systemic inflammation (eg, fever, chills, and fatigue) and bladder inflammation (eg, urgency, dysuria, and urinary frequency) The recommended phases of CT scan for evaluating renal infections are a non-contrast scan, nephrographic phase at 50-90 s and excretory phase at 2 min if there is obstruction. Striated nephrogram which is an appearance described for acute pyelonephritis shows discrete rays of alternating hypoattenuation and hyperattenuation radiating from the papilla to the cortex along the direction of the excretory tubules Pyelonephritis may manifest as wedge shaped zones of decreased attenuation or a hypodense mass in its focal form.The diffuse form of acute pyelonephritis may cause global enlargement, poor enhancement of renal parenchyma, absent excretion of contrast and streakiness of fat. Renal and perinephric abscesses develop as a complication of focal pyelonephritis or hematogenous infection. DW-MRI can readily pick up abscesses showing restriction of diffusion
REFERENCES:
1. Kawashima A, Sandler CM, Goldman SM, Raval BK, Fishman EK. CT of renal inflammatory disease. Radiographics. 1997;17:851–866; discussion 867-868.] 2. Stunell H, Buckley O, Feeney J, Geoghegan T, Browne RF, Torreggiani WC. Imaging of acute pyelonephritis in the adult. Eur Radiol. 2007;17:1820–1828. 3. Gold RP, Mcclennan BL, Kenney PJ, Breatnach ES, Stanley RJ, Lebowitz RI. Acute infections of the renal parenchyma. In: Pollack HM, editor. Clinical urography. Philadelphia, Pa: Saunders; 1990. pp. 799–821. 4. Saunders HS, Dyer RB, Shifrin RY, Scharling ES, Bechtold RE, Zagoria RJ. The CT nephrogram: implications for evaluation of urinary tract disease. Radiographics. 1995;15:1069–185; discussion 1069-1085. 5. Rigsby CM, Rosenfield AT, Glickman MG, Hodson J. Hemorrhagic focal bacterial nephritis: findings on gray-scale sonography and CT. AJR Am J Roentgenol. 1986;146:1173–1177. 6. Browne RF, Zwirewich C, Torreggiani WC. Imaging of urinary tract infection in the adult. Eur Radiol. 2004;14 Suppl 3:E168–E183.
Findings
Enlarged edematous left kidney with relatively decreased enhancement of the parenchyma noted Perinephric fat stranding with thickening of left anterior pararenal fascia and lateral conal fascia noted Multiple peripherally enhancing lesions with internal diffusion restriction in left kidney predominantly involving upper pole and interpolar region Multiple enlarged paraaortic lymphadenopathy Delayed excretion of contrast by the lower pole calyces noted.
Discussion
The term pyelonephritis implies that there is inflammation of the renal pelvis and kidney. APN often presents with signs and symptoms of both systemic inflammation (eg, fever, chills, and fatigue) and bladder inflammation (eg, urgency, dysuria, and urinary frequency) The recommended phases of CT scan for evaluating renal infections are a non-contrast scan, nephrographic phase at 50-90 s and excretory phase at 2 min if there is obstruction. Striated nephrogram which is an appearance described for acute pyelonephritis shows discrete rays of alternating hypoattenuation and hyperattenuation radiating from the papilla to the cortex along the direction of the excretory tubules Pyelonephritis may manifest as wedge shaped zones of decreased attenuation or a hypodense mass in its focal form.The diffuse form of acute pyelonephritis may cause global enlargement, poor enhancement of renal parenchyma, absent excretion of contrast and streakiness of fat. Renal and perinephric abscesses develop as a complication of focal pyelonephritis or hematogenous infection. DW-MRI can readily pick up abscesses showing restriction of diffusion
REFERENCES:
1. Kawashima A, Sandler CM, Goldman SM, Raval BK, Fishman EK. CT of renal inflammatory disease. Radiographics. 1997;17:851–866; discussion 867-868.] 2. Stunell H, Buckley O, Feeney J, Geoghegan T, Browne RF, Torreggiani WC. Imaging of acute pyelonephritis in the adult. Eur Radiol. 2007;17:1820–1828. 3. Gold RP, Mcclennan BL, Kenney PJ, Breatnach ES, Stanley RJ, Lebowitz RI. Acute infections of the renal parenchyma. In: Pollack HM, editor. Clinical urography. Philadelphia, Pa: Saunders; 1990. pp. 799–821. 4. Saunders HS, Dyer RB, Shifrin RY, Scharling ES, Bechtold RE, Zagoria RJ. The CT nephrogram: implications for evaluation of urinary tract disease. Radiographics. 1995;15:1069–185; discussion 1069-1085. 5. Rigsby CM, Rosenfield AT, Glickman MG, Hodson J. Hemorrhagic focal bacterial nephritis: findings on gray-scale sonography and CT. AJR Am J Roentgenol. 1986;146:1173–1177. 6. Browne RF, Zwirewich C, Torreggiani WC. Imaging of urinary tract infection in the adult. Eur Radiol. 2004;14 Suppl 3:E168–E183.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!