Non-invasive diagnosis of abdomino-pelvic masses: role of multimodality imaging

Abstract

Recent advances in radiology have greatly increased the ability to make highly accurate diagnosis. Biopsy of many commonly seen lesions is no longer performed as the radiological findings are pathognomonic. This gives rise to the concept of 'virtual biopsy', a term coined on the lines of other imaging techniques such as virtual colonoscopy. Virtual biopsy is not a new imaging technique but a new concept which refers to the use of existing imaging modalities to evaluate the morphological features of tumors and arriving at a non-invasive diagnosis with a high degree of confidence obviating the need for true biopsy. Elements of virtual biopsy have already been incorporated into some evidence-based guidelines, and it is expected that with further technological advancements, an increasing number of tumors may be diagnosed and managed accordingly. A wider acceptance of virtual biopsy could further reduce the need for invasive biopsies and its attendant costs and risks. In this review article, we use index cases to further emphasize this concept.

Keywords: Abdomen; computed tomography; magnetic resonance imaging; ultrasound; virtual biopsy.

Figure 1

Multiple hepatic adenomas. (a) Transverse ultrasound image of the left lobe of the liver shows a heterogeneous, predominantly hyperechoic lesion (arrow) with no overlying liver parenchyma. Another hypoechoic lesion (arrow head) is seen anteriorly. (b and c) Axial contrast-enhanced computed tomography (CT) sections of the liver in (b) hepatic arterial and (c) portal venous phases reveal hypervascular lesions (white arrows and arrowhead) in the left lobe of the liver which are isodense on the venous phase. Note the absence of capsule and peripheral liver parenchyma. Small incidental left renal angiomyolipomas (double lined arrows in c) are also noted. A diagnosis of multiple hepatic adenomas was made. (d) Axial contrast-enhanced CT image demonstrates rupture of the hepatic adenoma (arrow) with perihepatic hematoma. The patient was initially managed with hepatic artery embolization and the lesions were subsequently excised surgically with histopathology confirming adenomas.

Figure 2

Focal nodular hyperplasia. (a and b) Axial contrast-enhanced computed tomography sections of the liver in (a) hepatic arterial and (b) portal venous phase demonstrate a focal lesion (arrow) in the right lobe which is hypervascular in the arterial phase and becomes iso- to hypo-dense to the liver parenchyma in the venous phase.

Figure 3

Focal nodular hyperplasia. (a, b and c) Dynamic contrast-enhanced magnetic resonance imaging with Gadoxetate disodium (Gd-EOB-DTPA) on T1-weighted images (a) Arrow emonstrates an isointense lesion. (b) in arterial phase it is hypervascular and c) on 20 min delayed phase retains contrast. Note the central scar (white arrow) and contrast excretion in the biliary tree (arrow head) on the delayed image (c).

Figure 4

Hepatocellular carcinoma (a) Axial T2-weighted magnetic resonance (MR) image demonstrates a hyperintense lesion (arrow) in the segment III of the liver. Axial fat-suppressed (b) pre and post-gadolinium T1-weighted MR images in the (c) arterial and (d) delayed phases reveal the lesion to be faintly hypointense and hypervascular with washout in the delayed phase. Note the enhancing peripheral tumor capsule on delayed images (black arrow in d).

Figure 5

Clear cell variant of renal cell carcinoma. (a) Coronal T2-weighted magnetic resonance (MR) image demonstrates a hyperintense lesion (arrow) in the lower pole of right kidney. Axial (b) in- and (c) out-of-phase T1-weighted MR images demonstrate areas of drop in signal (arrow head) in the lesion suggestive of intra-lesional fat. (d) Axial fat-suppressed post-gadolinium T1-weighted MR image in the arterial phase reveals the lesion to be hypervascular. Histopathology confirmed clear cell variant of renal cell carcinoma.

Figure 6

Renal angiomyolipoma. Sagittal reformatted image of contrast enhanced computed tomography shows a fat attenuation lesion (black arrow) in the posterior interpolar region of the left kidney. Note the prominent vascular component (arrow head) in the lesion.

Figure 7

Adrenal Adenoma. Axial (a) in- and (b) out-of-phase T1-weighted magnetic resonance images demonstrate (a) left adrenal lesion (arrow) which shows significant drop of signal in the out-of-phase image (b) suggestive of lipid-rich adenoma.

Figure 8

Adrenal myelolipoma. Axial unenhanced computed tomography shows a well-defined lesion with macroscopic fat (arrow) in the left suprarenal region.

Figure 9

Uterine lipoleiomyoma: (a) Sagittal ultra sound image through the pelvis demonstrates a heterogeneous, predominantly hyperechoic lesion (arrow). (b) Sagittal reformatted computed tomography image of the pelvis reveals the mass to be arising from the uterus (arrow head) and contain macroscopic fat (arrow).

Figure 10

Ovarian teratoma. Axial contrast-enhanced computed tomography image of the pelvis reveals a well-defined adnexal lesion with fat (single arrow), fat-fluid level (arrow head) and calcification (double arrow).

Figure 11

Ovarian teratoma. Axial non-fat-suppressed (a) pre- and (b) fat-suppressed post-gadolinium T1-weighted magnetic resonance images demonstrate high signal intensity areas in the lesion (a) on non-fat-suppressed image which are suppressed on the fat-suppressed image suggestive of macroscopic fat in the lesion (black arrow). Note the presence of a smaller teratoma in the left ovary which shows similar signal characteristics (white arrow).

Figure 12

Retroperitoneal liposarcoma. Coronal reformatted image of contrastenhanced computed tomography demonstrates a large retroperitoneal mass with areas of fatty attenuation (single arrow) and heterogeneous soft tissue component (asterisk).