Computed tomographic features of urinary bladder torsion in two dogs

Abstract

Urinary bladder torsion is rare in dogs. It is characterised by rotation of the organ along its longitudinal axis and is potentially life-threatening because of urinary flow obstruction with subsequent urine retention, hydroureter, hydronephrosis and azotaemia. This report describes the computed tomographic features of urinary bladder torsion in two dogs. In both cases, the hallmark indicative of torsion was the "whirl sign," originating from the twisted pelvic urethra and urinary bladder neck encircling the ureters, blood vessels and bladder ligaments in a characteristic spiral pattern. The imaging features correlated well with surgical findings, demonstrating high sensitivity of computed tomography in the preoperative diagnosis of urinary bladder torsion.

Computed tomographic and clinical findings in a dog with suspected liver lobe torsion, secondary disseminated intravascular coagulation and multiorgan infarction

“…The ‘whirl sign’ is a unique characteristic seen on CT which describes the path of twisted soft tissues around a point and is highly specific for diagnosing visceral torsion 17–19. It has been described in cases involving the spleen,23 gastrointestinal tract,17 24 urinary bladder25 and testicles,26 but never in relation to LLT. In the case presented here, the ‘whirl sign’ was due to the twisting of the left lateral lobe of the liver around its axis.…”

“…Total bilirubin was within normal limits (5.0 μmol/l; RI: <5). A coagulation profile revealed mildly prolonged prothrombin time (PT) of 15 seconds (RI: 7-12), but normal activated partial thromboplastin time of 21.6 seconds (RI: [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Fibrinogen was reduced (0.77 g/l; RI: 1-5) and D-dimers were severely increased (3.518 µg/ml; RI: <0.25).…”

CT findings in five dogs with surgically confirmed colonic torsion

“…The "whirl sign" is specific to CT evaluation and cannot be identified using either radiographs or ultrasound. It has been previously described in different conditions [7][8][9][10][11] and it is also considered a key feature of bowel volvulus in human patients. 16 The authors suggest that the "whirl sign" may be used to aid in the diagnosis of canine colonic torsion.…”

“…2 A CT "whirl sign" has been considered a specific feature of organ torsion or volvulus as it reflects the spiral path of the twisted tissue and associated blood vessels. 7 It has been previously reported in dogs with splenic torsion, ileocecocolic volvulus, mesenteric volvulus, urinary bladder torsion, and testicular torsion. [7][8][9][10][11] Published studies describing CT characteristics of colonic torsion in dogs were lacking at the time of the current study.…”

“…A “torsion sign,” described as helical striations within the colonic wall, may also be present following the administration of a barium enema . A CT “whirl sign” has been considered a specific feature of organ torsion or volvulus as it reflects the spiral path of the twisted tissue and associated blood vessels . It has been previously reported in dogs with splenic torsion, ileocecocolic volvulus, mesenteric volvulus, urinary bladder torsion, and testicular torsion .…”