The encountered acute abdominal non-renal pathologies were overall seen in 236 patients (8.5%). These were pancreatitis in 15, appendix related pathologies in 46, cholelithiasis in 108, cholecystitis in 1, epiploic appendagitis in 8 and hernia in 58 patients. Other non-KUB findings included psoas abscess (2), bowel perforation (2), Liver masses (1), Bone metastasis(2), Dermoid ovarian cysts (2, one of which had torsion), cervical stenosis with fluid distended uterine cavity (1), Prostate mass (2), uterine fibroids, adrenal adenomas(2) and degenerative bone changes, few with osteoporotic collapse. Signfiicant findings were also observed as incidentally noted findings in visualized lower chest sections like pleural effusions, pulmonary nodules and a malignat looking basal lung mass in one case.

In 2776 patients who had CT KUB for suspected urolithiasis, 236 (8.5%) had alternative diagnoses non- GU findings, besides urolithiasis and obstruction, there were 63% males and 37% females. Majority patients were in the age group 21-40 years followed by age group of 41-60 years.The incidental findings were also divided into KUB and non-urological findings.

All relevant radiological examinations and laboratory analyses were analysed for the confirmation of patient’s incidental/additional findings. Patient’s medical record files and radiology referral forms were evaluated for the clinical history and pre-clinical and follow-up examinations.

Findings were grouped as follows:

1. FINDINGS REQUIRING IMMEDIATE ATTENTION OF REFERRING PHYSICIAN:
   
   Group of patients with significant findings that required the immediate attention of the referring physician for further management or evaluation. Appendicitis, Bowel perforation, Abscess, Fluid collections, Cholecystitis, Bowel obstruction, Torsion of masses etc. were given high importance. Urgent surgical referral was suggested and conveyed via phonecall too.
   
   
   

   Fig. 1: CT KUB in a patient with right flank pain. Axial and reformatted images alongwith cropped magnified sections showing features of acute Appendicitis (Arrows). Fluid filled distended appendix is seen in right iliac fossa with periappendiceal fat stranding (better appreciated on sagittal image) and minimal free fluid (better seen on axial image). It is important to compare both iliac fossa, when in doubt. The clue here is the increased diameter of appendix alongwith surrounding soft tissue haze.
   
   
   
   
   
   

   Fig. 2: Subhepatic Appendicitis diagnosed on CT KUB in a patient with pain in right hypochondrium. Coronal reformatted images showing thick walled appendix located at subhepatic level along lateral perinephric fascia with associated fat stranding, inflammatory reaction in right perinephric fascia and mild free fluid.Cropped magnified image showing curved blind ending loop. Here, the marked right perinephric fat stranding could have been misleading towards pyelonephritis but careful identification of high located appendix and that too with abnormal features confirmed the diagnosis.
   
   
   
   
   

   Fig. 3: Ovarian Dermoid with possible Torsion diagnosed on CT KUB in an elderly female with pain in left flank and left iliac fossa. Arrow points to fat containing well defined lesion, located in cul de sac and left adnexal bed. Surrounding free fluid and fat stranding raises concern for Torsion. Note age related small calcific foci in uterus.
   
   
   
   

   Fig. 4: Large left Psoas abscess. Axial and reformatted sections of CT KUB showing large fluid collection in left psoas muscle with mass effect.
   
   
   
   
   

   Fig. 5: Duodenal Perforation. Axial CT KUB images (upper two images) showing multiple retroperitoneal fluid collections along right perinephric fascia, pancreatic head and duodenum.The possible differentials here included pancreatitis with pseudocysts and retroperitoneal perforation of bowel. Latter was confirmed with MRI seen in the lower most image, where a defect is clearly visualized in the medial wall of second part of duodenum.
   
   
   
   

   Fig. 6: Duodenal Perforation. Axial CT images showing small air and fluid loculations along anterior perinephric fascia and posterior to pancreatic head and doduodenum. Presence of air in loculations and sudden onset pain confirmed the diagnosis of duodenal perforation.
   
   
2. FINDINGS REQUIRING DEFERRED TREATMENT:
   
   Those patients with findings where the treatment could be delayed, i.e. such diagnosis where just CT KUB was not enough and further imaging or work up required.
   Tumours, enlarged lymph nodes (>1 cm), chronic inflammatory disease, Bone metastases were defined as findings requiring deferred treatment. Further workup was suggested in such cases with contrast enhancd studies or MRI, depending on the finding and suspected clinical picture.
   
   
   

   Fig. 7: Liver lesions. Axial CT images in apatient with pain in bilateral flanks. Multiple hypodense lesions are seen in both hepatic lobes and concern for metastases with ascites.Such finding on plain CT scan should be further investigated with dynamic CT Liver for characterization.
   
   
   
   

   Fig. 8: Sagittal reformatted image of CT KUB showing fluid distended endometrial cavity (arrow) and enlarged uterus for the age of patient. Such finding can be due to cervical stenosis and further workup should be done concerning cervical malignancy.Degenerative spine changes are seen with background osteopenia, even appreciated without bone window.Few atheromatous calcifications noted in abdominal aorta.
   
   
   
   

   Fig. 9: Incidental lung finding in visualized lower sections of chest. (a) Upper image shows a consolidating opacity in right lower lobe with atoll sign (inner low attenuation surrounded by high attenuation) suggesting possibility of organizing pneumonia, however detailed chest evaluation should be done in such cases for confirmation and extent of disease process. (b & c) Another patient's CT images in both lung and soft tissue window showing a large mass in right lower lobe. This requires further workup with detailed chest evaluation and biopsy should be done.
   
   
   
   

   Fig. 10: Extensive Bone lesions. Multiplanar reformatted images of a patient with pain in right flank. Multiple lytic lesions are seen in visualized bones, some with soft tissue component. A large soft tissue mass is seen almost replacing right pubic ramus and another mass seen along right sacral ala. Possibility is of bone metastases. In such case, further workup for primary should be done.
   
   
   
   

   Fig. 11: Extensive sclerotic bone lesions. Multiplanar CT images in a patient with generalized weakness and pain in flanks. (b,c,d)Bone window images reveal multiple sclerotic lesions in bones. Increased bone density can even be appreciated in soft tissue window (a) and a soft tissue mass seen in right iliac region, which appears to be nodal metastases. Such generalized bone sclerosis has differentials of metastatic CA prostate or bone marrow infiltrative disease and requires further work up. Umbilical hernia noted on sagittal image (c)
   
   
3. FINDINGS THAT REQUIRED LATER TREATMENT:
   
   Those patients with an insignificant diagnosis of conditions that did not need immediate attention or need to be reconfirmed.

    

   Benign lesions that would require treatment later were defined as findings of little clinical importance e.g. complicated cyst, adrenal adenoma, haemangioma, hernia without incarcerated bowel, cholelithiasis, marked organ enlargement or atrophy (uterus, prostate, liver, spleen or kidney).
   
   
   
   

   Fig. 12: Axial and coronal reformatted images showing incidental finding of right ovarian dermoid cyst. Tooth shaped dense calcification noted within the cyst. Morphology of cyst is better appreciated on cropped out small images. Benign Teratodermoid ovarian cysts have fat density components with calcified foci and some fluid. The cyst here has smooth margins with no CT evidence of Torsion. Left adenexal cyst also noted containing fluid density, for which ultrasound correlation should be done.
   
   
   
   

   Fig. 13: Calcified fibroids. Multiple CT images of different patients showing calcified fibroids of varying size (arrows) and few subserosal in location.The calcification in fibroids is patchy and often called as popcorn-like in appearance.
   
   
   
   

   Fig. 14: Colonic Diverticulosis. Multiple non-inflamed colonic diverticulae seen in visualized segment of transverse and ascending colon. No fat stranding, free air or fluid collection seen, which is important to mention (ruling out diverticulitis) if such finding is encountered as incidental finding.
   
   
   
   

   Fig. 15: Cholelithiasis. CT KUB done for flank pain showing incidental finding of small calculus in GB neck. No CT features of cholecystitis are seen.
   
   
   

   Fig. 16: Inguinal Hernia. Sagittal reformatted image showing right inguinal hernia containing fat.
   
   
   

   Fig. 17: Pneumobilia. CT KUB done for renal colic. Incidental finding of air in biliary ducts seen. In setting of no previous surgery or fever, the underlying cause could be reflux or fistula and requires further work up.
   
   
   

   Fig. 18: Spine related incidental findings like spondylolisthesis, spondylolysis, degenerative disc disease, osteoporotic collapse and sclerotic partly collapsed vertebra due to healed infective spondylodiscitis.
   
   
   
   

   Fig. 19: Fractured bilateral pars inter articularis. Sagittal reformatted images showing incidental finding of grade 1 anterior spondylolisthesis of L5 over S1 vertebra due to bilateral pars defects(arrows).
4. FINDINGS OF NO CLINICAL IMPORTANCE:
   
   Findings of no clinical importance were those considered to be benign and unlikely to require any future treatment or additional assessment e.g. anatomical variants, uncomplicated cysts, benign calcifications, Old healed or non-healed fractures and congenital anomalies.