Filling defect

Radiographic contrast studies are the most accurate and reliable method for diagnosis of VTE. Contrast venography allows visualization of the entire venous system in the lower extremity and abdomen. Pulmonary angiography allows visualization of the pulmonary arteries. The diagnosis of VTE can be made if there is a persistent intraluminal filling defect on multiple x-ray films. 

Pacchioni granulations may be seen as circum-script intraluminal filling defects or gaps. 

Fig. 18.12. Circumscript filling defects within a dural sinus, a Incidental finding in contrast-enhanced CT. The bilateral well-defined filling defects in the lateral sinuses (arrows) most probably represent Pacchioni granulations, b Contrast-enhanced Tl-weighted image with incidentally demonstrated hypointense, round and circumscript structures within the lateral sinus (arrow). They most likely represent hypertrophic Pacchioni granulations and not thrombus, c In the T2-weighted images of the same patient the structures appear strongly hyperintense (arrow)...

HIC occurs when H atoms diffusing through a linepipe steel become trapped as H2 molecules at inhomogeneities in the steel. A planar, gas-filled defect is created, which grows parallel with the vessel surfaces as it traps more diffusing H atoms. If the... 

Benign focal lesions usually lead to a smoothly curved displacement of arteries (and veins). In the parenchymal phase, they show more or less sharply delineated filling defects. (132, 145, 156)... 

Fig. 14.9 Moderately dilated oesophagus with irregular surface. Numerous, differently sized filling defects as a result of varices...

Peltier, L.F. (1961) The use of plaster of Paris to fill defects in bone. Clin. Orthop., 21, 1-31. 

Kim, Y.Y., et al.. Left atrial appendage filling defects identified by multidetector computed tomography in patients undergoing radiofrequency pulmonary vein antral isolation a comparison with transesophageal echocardiography. Am Heart J, 2007. 154(6) p. 1199-205. 

Fig. 6.1 Basilar occlusion, (a) The T2 weighted image shows loss of the signal flow void in the basilar artery in this patient with basilar occlusion and hyperacute pontine infarct. No parenchymal abnormality is noted at this early time point, (b) Coronal MIP image from the CT angiogram demonstrates the occlusion as a filling defect (arrow)...

Radioisotope scanning was used in the early days to detect filling defects in organs, such as the liver and spleen. Radioactive sodium iodide was used to image the thyroid. Radioactive particles were used to image the reticuloendothelial system. The dye, radio-iodinated Rose Bengal, was used to image the liver. 

Fig. 31.3 Cathodic delamination potential profiles of an unmodified epoxy adhesive layer (adhesive as in Fig. 31.2, about 50 pm thick) on an iron substrate (purity 99.99%) with 0.5 M NaCI as electrolyte measured (a) 20 h after the addition of the electrolyte (b) 50 h after the addition, x increases positively with distance from the electrolyte-filled defect.

Fig. 1.22a,b. Meconium ileus, a Water-soluble contrast enema showing a microcolon with scattered filling defects that correspond to inspissated meconium, b The enema was continued with reflux of the contrast medium into the terminal ileum, showing Ailing defects that represent meconium pellets. The patient was discharged within 48 h of successful treatment... 

Fig. 1.33a-d. Meconium plug syndrome. Anteroposterior (a) and lateral (b) plain radiographs show distension of bowel loop consistent with low obstruction. c Isosmolar water-soluble contrast enema, lateral view outlines the characteristic long filling defect (arrows) within the colon, d Clinical image of a meconium plug surgically obtained in a patient in whom several attempts to conservatively solve the obstruction failed... 

Barium studies will reveal serpentine filling defects, which are compressible, typically in the fundus and along the lesser curvature or less commonly in the antrum of the stomach or proximal duodenum. US and CT can directly demonstrate the different collaterals. 

Sulfur-colloid liver scintigraphy may show large filling defects in the hepatic parenchyma, with prominent tracer avidity at the site of the tumor within a few seconds of the appearance of the bolus in the abdominal aorta. This increased activity persists into the venous phase. Hepatoblastomas may demonstrate increased uptake on delayed imaging, but this is rare (Suchy 2003). 

On percutaneous transhepatic cholangiography (PTC), extensive filling defects in the biliary tree may be seen with or without obstruction of the extrahepatic bile ducts. PTC can be performed in cases of RMS without biliary dilation and is very useful if there is an obstructive jaundice (Gazelle etal. 1998). 

Plain film is usually unremarkable. Diagnosis maybe made with contrast studies. These may reveal polypoid filling defects or a classic intussusceptum. 

Fig. 6.12a-c. Duplication cyst of the colon, a Contrast enema outlines the filling defect of a caecal duplication cyst, b Ultrasound of a duplication cyst at the hepatic fiexure. c High resolution ultrasound in the same patient shows the layers of the cyst wall and some echogenic debris within it... 

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