This document discusses different types of filling defects that can appear in the inferior vena cava (IVC) on medical imaging. It provides 6 figures showing examples of laminar flow artifacts, bland thrombus, tumor thrombus from renal cell carcinoma and leiomyosarcoma, and how these defects appear on CT and MRI scans. The images illustrate how laminar blood flow, thrombus, and tumors can cause abnormalities in the IVC that must be differentiated through medical imaging.

1. 91Inferior Vena Cava (IVC)
Filling Defects

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig GI 91-1 Laminar flow artifact. (A) Axial
enhanced CT image shows a filling defect (arrow)
caused by inflow of opacified blood from the
renal veins mixing with poorly opacified blood in
the IVC. (B) Curved multiplanar image reveals
opacified blood from the renal veins streaming
into the IVC (arrows), illustrating how the axial
image can show an apparent IVC filling defect.201

4. • Fig GI 91-2 Artifact due to high injection rate. Early arterial
phase CT image shows an IVC filling defect (arrowhead) due
to laminar flow of refluxed contrast from the hepatic veins.
Bright enhancement in the hepatic veins (arrows) is seen
because of reflux of contrast from the heart.201

5. • Fig GI 91-3 Bland thrombus. (A) Axial enhanced CT
image before IVC filter placement shows bland
thrombus (arrow) in the IVC. (B) Coronal multiplanar
image reconstructed from CT data after IVC filter
placement shows extension of bland thrombus into
both renal veins (arrowheads) and the infrahepatic
portion of the IVC. Note the IVC filter (arrow) and
decreased enhancement of the right kidney due to
hypoperfusion

6. • Fig GI 91-4 Bland and tumor thrombus. Coronal T1-
weighted MR image reveals bland thrombus
(arrowheads) that formed inferior relative to tumor
thrombus (arrows) in the infrahepatic portion of the
IVC. The low-signal-intensity lesion in the right kidney
(*) represented renal cell carcinoma.201

7. • Fig GI 91-5 Renal cell carcinoma. Axial T2-
weighted MR image with fat saturation shows a
large, right renal mass (arrowheads) with
heterogeneous high signal intensity. Note the
tumor thrombus in the adjacent portion of the
IVC (arrow).201

8. Fig GI 91-6 Leiomyosarcoma. Contrast CT scan demonstrates a
heterogeneously enhancing mass (arrow) that arose in the IVC.201