[Changes in renal tumor contrasting in multiphasic SCT]

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Renal tumors require accurate diagnostic imaging.
• Contrast enhancement patterns in computed tomography (CT) can aid in characterizing renal neoplasms.

Purpose of the Study:

• To evaluate changes in renal tumor contrast enhancement and parenchyma-tumor density gradients using multiphasic spiral computed tomography (SCT).
• To determine the optimal CT phase for differentiating renal tumors and hypovascular lesions.

Main Methods:

• A hundred and seven patients with renal tumors underwent multiphasic SCT, including native, corticomedullary, nephrographic, and early excretory phases.
• Renal neoplasms were categorized into intensive, moderate, and low contrast-enhancement groups based on corticomedullary phase enhancement.
• Analysis focused on contrast enhancement dynamics and parenchyma-tumor density gradients across different CT phases.

Main Results:

• Intensively and moderately enhancing tumors peaked in the corticomedullary phase, with subsequent density reduction.
• Lowly enhancing tumors showed gradual enhancement from native to nephrographic phases, with minimal change between nephrographic and excretory phases.
• The nephrographic phase demonstrated the maximal intact renal parenchyma-tumor density gradient, indicating its high diagnostic value.

Conclusions:

• The nephrographic phase of multiphasic SCT is crucial for detecting renal tumors due to the maximal parenchyma-tumor density gradient.
• Combining native and nephrographic or early excretory phases is useful for differentiating hypovascular renal tumors from cysts.