Gastrointestinal - Learning Modules - CTisus.com CT Scanning

Learning Modules ❯ Gastrointestinal

Pancreatic Mass Detection

Pancreatic mass vs peripancreatic tumor
Undiagnosed islet cell tumor
Misdiagnosis of splenic artery aneurysm as an islet cell tumor or splenule as a islet cell tumor

Pancreatic Mass Detection

Pancreatic mass vs peripancreatic tumor
Undiagnosed islet cell tumor
Misdiagnosis of splenic artery aneurysm as an islet cell tumor or splenule as a islet cell tumor

5 mm Neuroendocrine Tumor HOP

Do you see a mass?

Neuroendocrine Tumor HOP Seen Only On Arterial Phase

Pitfalls in CT Scanning: Wrong Phase of Acquisition

In the ER especially the full sequence of phases (or greater than one phase) is often not available.
Potential errors are numerous including lack of “the best phase for lesion detection”

PNET Only Seen on Venous Phase with Cinematic Rendering

Hx- Renal Cell CarcinomaDo you see a pancreatic mass?

Metastatic RCC to Pancreas only Seen on Arterial Phase

Right Nephrectomy for Clear Cell RCC: Routine Follow-up

Challenging Cases: Pancreatitis vs Pancreatic Neoplasms

Autoimmune pancreatitis
Groove pancreatitis
Concurrent pancreatitis and pancreatic cancer in the same patient (up to 5%)

Autoimmune Pancreatitis

Type of chronic pancreatitis that is characterized by an autoimmune inflammatory process with lymphoplasmacytic infiltration associated with fibrosis of the pancreas
Key findings absence of classic hx of prior pancreatitis, elevated immunoglobulin G4, dramatic response to steroid therapy, and difficulty distinguishing from pancreatic cancer

Autoimmune Pancreatitis: Facts

Age range 14-77 but most patients over 50
Male affected 2x compared to woman
Signs and symptoms at presentation include jaundice (63%), abdominal pain (35%), weight loss (35%), and diabetes mellitus (42-76%)
Extra-pancreatic processes include sclerosing cholangitis and PBC (68-88%) of cases, IBD (usually ulcerative colitis), Sjogren syndrome, renal involvement, retroperitoneal fibrosis

Autoimmune Pancreatitis can be confused with Pancreatic Cancer

Hx of weight loss
No good hx of pancreatitis
CEA 19-9 may be elevated
CT appearance often mass like and looks like pancreatic cancer

Autoimmune Pancreatitis: CT Findings

Diffuse glandular enlargement with loss of lobular texture (“featureless gland)
Homogeneously iso- or hypoattenuating parenchyma with a nondilated or diffusely narrowed pancreatic duct
“halo” around gland is not uncommon

Autoimmune Pancreatitis

Pre and Post Treatment

Autoimmune Pancreatitis and Renal Involvement

“ Radiology departments are encouraged to develop reliable means of identifying challenging and missed diagnoses and using these cases as an education resource in an ongoing effort to mitigate misdiagnosis. A monthly CME conference with pathology and/or surgical correlation and clinical follow-up is an excellent means of providing meaningful peer review to improve practice of the entire division and reduce interpretative errors.”
Mitigating Misdiagnosis in Radiology: Educational CT CME Case Conference for Peer Review and Interpretative Improvement
Pamela T. Johnson, MD, , David Badger, MD, Karen M. Horton, MD, Elliot K. Fishman, MD
JACR: Volume 13, Issue 10, October 2016, Pages 1244–1246

“As opposed to standard peer review, where the reviewing radiologist informs the primary reader that he or she believes a diagnosis was missed or an interpretation provided the wrong information, a CT case conference that includes correlation with other diagnostic information (pathology, surgical findings, clinical follow-up) provides accurate peer review based on gold standards, from which everyone in the division can learn to improve their interpretative skills.”
Mitigating Misdiagnosis in Radiology: Educational CT CME Case Conference for Peer Review and Interpretative Improvement
Pamela T. Johnson, MD, , David Badger, MD, Karen M. Horton, MD, Elliot K. Fishman, MD
JACR: Volume 13, Issue 10, October 2016, Pages 1244–1246

CT Reading and Checklists

Should you use checklists for specific clinical applications?
Will checklists help decrease errors especially “missed CT findings”?
Are checklists only for the resident and fellow?

“We advocate the use of checklists for different types of radiologic examinations, depending on the body part imaged, to facilitate active search patterns to decrease the incidence of this type of error.”
Fool Me Twice: Delayed Diagnoses in Radiology With Emphasis on Perpetuated Errors
Kim YW, Mansfield LT
AJR 2014;202:465-470

“This study found that a novel AI algorithm was associated with improved accuracy and AUCs for junior and senior radiologists for detecting pulmonary nodules. Four of 9 radiologists had a lower number of missed and false positive pulmonary nodules with help from AI-aided interpretation of chest radiographs.”
An Artificial Intelligence–Based Chest X-ray Model on Human Nodule Detection Accuracy From a Multicenter Study
Fatemeh Homayounieh et al.
JAMA Network Open. 2021;4(12):e2141096.

Training the Computer with Organ Segmentation for the Pancreas

Example of Pancreas Segmentation