CT-derived textural analysis parameters discriminate high-attenuation renal cysts from solid renal neoplasms

AIM

To assess the utility of textural features on computed tomography (CT) to differentiate high-attenuation cysts from solid renal neoplasms among indeterminate renal lesions detected incidentally on CT.

MATERIALS AND METHODS

Patients were included if they had an indeterminate renal lesion on CT that was subsequently characterised on ultrasound or magnetic resonance imaging (MRI). Up to three lesions per patient were included if they had a size ≥10 mm and density of 20-70 HU on unenhanced CT or any single phase of contrast-enhanced CT. Cases were categorised as benign or most likely benign cysts (Bosniak II and IIF) versus indeterminate (Bosniak III), mixed solid and cystic (Bosniak IV), or solid renal lesions. A random forest model was generated using 95 textural parameters and four clinical parameters for each lesion.

RESULTS

Two hundred and thirty-four patients were included who had a total of 278 lesions. Of these, 193 (69%) were benign or most likely benign cysts and 85 (31%) were indeterminate, mixed cystic and solid, or solid renal lesions. The random forest model had an area under the curve of 0.71 (95% confidence interval [CI]: 0.65, 0.78), with a sensitivity and specificity of 81.2% and 38.9%, respectively.

CONCLUSION

A multivariate model including textural and clinical parameters had moderate overall performance for discriminating benign or likely benign cysts from indeterminate, mixed solid and cystic, or solid renal lesions. This study serves as a proof of concept and may reduce the need for further follow-up by characterising a significant portion of indeterminate lesions on CT as benign.

Imaging features of marginal ulcers on multidetector CT

AIM

To assess the inter-reader agreement and frequency of various imaging findings of marginal ulcers on computed tomography (CT) in a series of patients with endoscopically or surgically confirmed marginal ulcer disease.

MATERIALS AND METHODS

This was a institutional review board-approved retrospective analysis involving a single academic institution. Eighty patients with a gastro-enteric anastomosis with confirmed marginal ulcer on endoscopy or surgery and multidetector (MD)CT performed within a month reviewed by two fellowship-trained abdominal radiologists to assess for the presence or absence of predetermined imaging characteristics categorised under signs of inflammation, signs of penetration, signs of perforation, and signs of obstruction. Inter-rater reliability was assessed using the Cohen kappa test.

RESULTS

Findings of perforation had moderate to substantial agreement, including the presence of extraluminal air, extraluminal fluid, and leakage of oral contrast medium (kappa 0.83 [0.61, 1.05], 0.57 [0.35, 0.79] and 0.75 [0.18, 1.31], respectively) although these were present relatively infrequently (23-26%, 30-43%, 3-4%, respectively). Additional imaging characteristics with moderate agreement were the presence of perienteric fat stranding, a dilated stomach proximal to the anastomosis, and penetration into adjacent organ (kappa 0.45 [0.23, 0.69], 0.47 [0.26, 0.69], and 0.47 [0.25, 0.69], respectively) which were variably present (80-88%, 11-16%, 5%, respectively). Wall thickening and contour abnormalities, although frequently present (61-90% and 60-80%, respectively) had only slight to fair agreement (kappa 0.09 [-0.14, 0.30] and 0.29 [0.07, 0.51]).

CONCLUSION

Signs of perforation have high inter-reader agreement but occur relatively infrequently. Fat stranding, wall thickening, and contour abnormalities are much more common; however, only fat stranding had moderate agreement.