TL;DR: Imaging should, in general, be reserved for those patients in whom conventional treatment has failed or those who have recurrent or unusually severe symptoms, and patients with conditions predisposing to infection, or complications thereof, may also benefit from early imaging.
Abstract: The diagnosis of urinary tract infection (UTI) in the adult is primarily based on typical patient symptomatology and urinary evaluation for the presence of bacteria and white blood cells. Uncomplicated UTI usually does not require radiological evaluation unless it is recurrent. Imaging should, in general, be reserved for those patients in whom conventional treatment has failed or those who have recurrent or unusually severe symptoms. Patients with conditions predisposing to infection, or complications thereof, such as diabetes mellitus or immunocompromised states, may also benefit from early imaging. If pyonephrosis is suspected, early imaging and possible urgent drainage is also warranted. Intravenous urogram and ultrasound have traditionally been used in the assessment of these patients, allowing detection of calculi, obstruction and incomplete bladder emptying. These imaging techniques, while useful, have limitations in the evaluation of renal inflammation and infection in the adult. Computerised tomography has now become accepted as a more sensitive modality for diagnosis and follow-up of complicated renal tract infection. Contrast-enhanced CT allows different phases of excretion to be studied and can define extent of disease and identify significant complications or obstruction. Nuclear medicine has a limited role in the evaluation of urinary tract infection in adults. Its main role is in the assessment of renal function, often prior to surgery. Magnetic resonance imaging has a limited but increasing role. It is particularly useful in those with iodinated contrast allergies, offering an ionising radiation free alternative in the diagnosis of both medical and surgical diseases of the kidney.
TL;DR: US is not an adequate screening test for detecting lesions that may require invasive therapy and CT is more sensitive for the detection of acute renal inflammatory disease and for defining the extent of disease for planning of radiologic or surgical intervention.
Abstract: The imaging studies done on 62 patients hospitalized for acute renal infections were retrospectively reviewed. Thirty-six (58%) had one or more abscesses, 17 (27%) had focal or diffuse acute bacterial nephritis, five (8%) had pyonephrosis, and four (6%) had pyelonephritis. All had prolonged fever (greater than or equal to 72 hours) and leukocytosis. Among 25 patients examined with both ultrasound (US) and computed tomography (CT), US failed to depict three of five (60%) cases of acute bacterial nephritis and seven of 15 (47%) intrarenal and extrarenal abscesses. One renal abscess was misdiagnosed as a tumor at CT. US is not an adequate screening test for detecting lesions that may require invasive therapy. CT is more sensitive for the detection of acute renal inflammatory disease and for defining the extent of disease for planning of radiologic or surgical intervention.
TL;DR: The MR diffusion-weighted imaging may be a reliable tool to differentiate py onephrosis from hydronephrosis in patients who had dilatation of the renal pelvis and calyces detected by ultrasonography.
TL;DR: It is suggested that SUB device placement may be a viable option for treatment of cats with benign ureteral obstruction and a high postoperative serum ionized calcium concentration was significantly associated with SUB device occlusion.
Abstract: OBJECTIVE To determine outcomes of subcutaneous ureteral bypass (SUB) device placement for treatment of benign ureteral obstruction in cats. DESIGN Retrospective case series. ANIMALS 134 cats with SUB devices placed in 174 obstructed ureters during 144 hospitalizations. PROCEDURES Medical records of cats that underwent SUB device placement for treatment of benign ureteral obstruction between 2009 and 2015 were reviewed. The SUB device was placed by use of fluoroscopic and surgical methods. Signalment, history, diagnostic imaging results, postprocedural results, duration of hospitalization, complications, and short- and long-term outcomes were recorded. RESULTS Ureteral obstructions were caused by ureterolithiasis (114/174 [65.5%]), stricture (28/174 [16.1%]), both ureterolithiasis and stricture (29/174 [16.7%]), or pyonephrosis (1/174 [0.6%]); in 2 (1.1%) cats, the cause was not recorded. Fifty-two of the 134 (39%) cats had bilateral ureteral obstruction. At admission, 127 (95%) cats were azotemic. Median serum creatinine concentrations at admission and 3 months after SUB device placement were 6.6 and 2.6 mg/dL, respectively. Median renal pelvis diameters before and after the procedure were 9.2 and 1.5 mm, respectively. Postsurgical complications included device occlusion with blood clots (14/172 [8.1%]), device leakage (6/172 [3.5%]), and kinking of the device tubing (8/174 [4.6%]). Cats survived to hospital discharge after 135 of the 144 (94%) hospital admissions. The most common long-term complication was catheter mineralization (40/165 [24.2%]), which was documented a median of 463 days after device placement. A high postoperative serum ionized calcium concentration was significantly associated with SUB device occlusion. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that SUB device placement may be a viable option for treatment of cats with benign ureteral obstruction.