CT characteristics of primary splenic torsion in eight dogs

Abstract

Splenic torsion is a rare potentially life‐threatening condition characterized by rotation of the spleen around the gastrosplenic and phrenosplenic ligaments leading to occlusion of venous drainage and arterial supply. This retrospective study describes the CT characteristics for dogs with surgically confirmed splenic torsion from 2013 to 2018 using the submissions to a large multinational teleradiology database. Eight dogs had the splenic torsion confirmed with surgery. Seven of eight cases had histology confirming congestion, hemorrhage, and necrosis, and one had concurrent myelolipoma infiltration. The CT characteristics included an enlarged (8/8), rounded (7/8), folded C‐shaped spleen (8/8) with a difference of median parenchymal attenuation between pre‐ and postcontrast of +1.15 HU (Hounsfield units). Other common features included a mainly homogeneous parenchyma on pre‐ and post‐contrast images (6/8), lack of subjective and objective vascular and parenchymal contrast enhancement (6/8) and free peritoneal fluid (6/8). A “whirl sign” was seen in the majority of cases (7/8) alongside a strongly hyperattenuating center (95‐416 HU) on the precontrast images (5/7), which has not been previously described in the veterinary literature. Gastric position was normal in all cases. More variable CT characteristics of the confirmed torsions were attributable to suspected partial torsion and myelolipomatous infiltration. Overall, primary splenic torsion confirmed with surgery showed consistent characteristics on CT.

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

“…This case had similar CT findings to those previously described, but also displayed a ‘whirl sign’. 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.…”

“…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).…”

“…Ultrasonography and CT have been previously used in the work‐up of LLT,1 8–13 but diagnosis often relies on confirmation during surgery or postmortem 9. To the authors’ knowledge, this is the first case of a suspected LLT displaying a ‘whirl sign’ on CT, which is highly specific for diagnosing visceral torsion 17–19. The dog was presumptively diagnosed with disseminated intravascular coagulation (DIC) causing renal and myocardial infarction and pulmonary thromboembolism.…”

“…9 To the authors' knowledge, this is the first case of a suspected LLT displaying a 'whirl sign' on CT, which is highly specific for diagnosing visceral torsion. [17][18][19] The dog was presumptively diagnosed with disseminated intravascular coagulation (DIC) causing renal and myocardial infarction and pulmonary thromboembolism. This is also the first CT description of a presumed myocardial infarction in a dog.…”

CT angiography identifies collaterals in dogs with splenic vein obstruction and presumed regional splenic vein hypertension

“…Cases of chronic splenic torsion have been reported with clinical signs being more subtle compared to acute splenic torsion. 12,13 Authors propose that the In people, isolated SV hypertension usually arises in the pancreas and common etiologies include pancreatitis and pancreatic neoplasms. 14,15 Two dogs of the present study had pancreatic insulinoma with secondary invasion of the SV and obstruction with no collateral SV circulation.…”