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Learning Modules ❯ Gastrointestinal

MDCT Evaluation of Gastric Malignancies: Pearls and Pitfalls

Elliot K. Fishman M.D.
Johns Hopkins Hospital

Click here to view this module as a video lecture.

The key to the successful CT examination of the stomach centers around study technique and study interpretation

Normal Gastric Antrum

”Computed tomography is the imaging method of choice for evaluating stomach neoplasms, and traditional 3D methodologies have previously been shown to have value in lesion detection, staging, and follow-up for treatment response. With the addition of enhanced surface detail intrinsic to CR, the role of 3D CT visualizations in stomach neoplasm imaging may be expanded. Prospective trials with pathologic correlation that evaluate the ability of CR to enhance detection of subtle mucosal irregularities, study whether CR provides better lesion characterization through highlighting intratumoral texture, and lead to improved preoperative planning would be of value.”
Evaluation of Stomach Neoplasms With 3-Dimensional Computed Tomography: Focus on the Potential Role of Cinematic Rendering
Steven P. Rowe, Linda C. Chu, Elliot K. Fishman
J Comput Assist Tomogr 2018;42: 661–666

MDCT Analysis of the Stomach

Distension
Opacification
Display
Enhancement Pattern

MDCT of the Normal Stomach

Classic definition: wall thickness less than 7-10 mm
Current definition: wall thickness less than 3-5 mm
Caveat: the stomach must be well distended to use the criteria for wall thickness

Normal Stomach in a 45 year old female with RUQ pain

Gastric Adenocarcinoma

Gastric Adenocarcinoma in an ER Patient

“ Our findings suggest that irregular or eccentric antral thickening that exceeds 12 mm on CT should be considered abnormal.”
Wall Thickening of the Gastric Antrum as a Normal Finding: Multidetector CT with Cadaveric Comparison
Pickhardt PJ et al.
AJR 2003;181:973-979

“In an adequately distended stomach, the normal nondependent gastric body is less than or equal to 5 mm in thickness. The antral wall, in contrast, may normally measure less than or equal to 12 mm in thickness.”
CT of Gastric Emergencies
Guniganti PG et al.
RadioGraphics 2015; 35:1909–1921

Gastric Antrum Simulates Thickened Antrum

Gastric Adenocarcinoma in the Antrum

Gastric Adenocarcinoma with Gastric Outlet Obstruction

MDCT of the Stomach: Study Design (JHH)

1000 cc of water or Omnipaque oral solution given over 20 minutes
100-120 cc of Omnipaque-350 injected at 4-5 cc/sec
Data acquisition typically obtained with a 60 second delay and single phase acquisition (arterial phase of value in select cases)

When would water not be an ideal contrast agent?

Phase of Scan Acquisition

Portal venous phase at around 60-70 seconds after initiation of contrast injection
Arterial phase imaging usually provides little if any additional staging information and dual phase imaging is usually not needed for staging. But …………

Arterial vs. Venous Phase Imaging of the Stomach (adenocarcinoma)

Venous phase is best for detection of liver metastases
Venous phase is best for defining the presence of small nodes (node vs. vascular structure)
Arterial phase may be too early to appreciate changes in mucosal and submucosal enhancement as seen in carcinoma

Cirrhosis with Gastric Varices