Initial Abdominal CT Research Articles

WP4.11 - Oral Gastrograffin Usage in Adhesive Small Bowel Obstruction: a re-audit

Abstract Aim to establish the successful usage of oral gastrograffin in patients presenting with adhesive small bowel obstruction (SBO). Methods This is a retrospective follow-up study, using a combined data collected from two NHS Trusts, from July 2022 to January 2024. Patients presented with adhesive SBO were included in this study, who were given 100 ml of oral gastrograffin after diagnosis for SBO. Patients were arranged to have plain abdominal x-ray approximately 8-hours post-gastrograffin drinks/or infusion via nasogastric (NG) tube to ascertain if oral contrast had passed the transition point, identified on initial abdominal CT scan. Patients were then reviewed for their symptomatic relief including bowels movement. Results 132 patients were identified but 108 patients were included, who had surgery. 24 patients were excluded because they did not have post-gastrograffin x-ray. Average age of patients was 63+/-14 years. It was observed that 82 patients (75.9%) opened their bowels after administration of first dose of gastrograffin, while 26 patients (24%) did not. 16 out of these 26 patients required surgery; and the remaining 10 (38.4%) had 2nd dose of gastrograffin, of which 4 patients (40%) moved bowels but 6 (60%) still did not and required surgery. Post-contrast x-rays, showed that contrast passed through into large bowel in 76 patients (70.3%) after 1st dose of gastrograffin and in further 40% after 2nd dose. Conclusion clinically significant number of patients responded to such conservative measures. Therefore, routine oral gastrograffin usage is suggested as an effective adjunct to non-operative measures in adhesive SBO management.

Fully automated CT imaging biomarkers for opportunistic prediction of future hip fractures.

Assess automated CT imaging biomarkers in patients who went on to hip fracture, compared with controls. In this retrospective case-control study, 6926 total patients underwent initial abdominal CT over a 20-year interval at one institution. A total of 1308 patients (mean age at initial CT, 70.5 ± 12.0 years; 64.4% female) went on to hip fracture (mean time to fracture, 5.2 years); 5618 were controls (mean age 70.3 ± 12.0 years; 61.2% female; mean follow-up interval 7.6 years). Validated fully automated quantitative CT algorithms for trabecular bone attenuation (at L1), skeletal muscle attenuation (at L3), and subcutaneous adipose tissue area (SAT) (at L3) were applied to all scans. Hazard ratios (HRs) comparing highest to lowest risk quartiles and receiver operating characteristic (ROC) curve analysis including area under the curve (AUC) were derived. Hip fracture HRs (95% CI) were 3.18 (2.69-3.76) for low trabecular bone HU, 1.50 (1.28-1.75) for low muscle HU, and 2.18 (1.86-2.56) for low SAT. 10-year ROC AUC values for predicting hip fracture were 0.702, 0.603, and 0.603 for these CT-based biomarkers, respectively. Multivariate combinations of these biomarkers further improved predictive value; the 10-year ROC AUC combining bone/muscle/SAT was 0.733, while combining muscle/SAT was 0.686. Opportunistic use of automated CT bone, muscle, and fat measures can identify patients at higher risk for future hip fracture, regardless of the indication for CT imaging. CT data can be leveraged opportunistically for further patient evaluation, with early intervention as needed. These novel AI tools analyse CT data to determine a patient's future hip fracture risk.

CT image-based biomarkers acquired by AI-based algorithms for the opportunistic prediction of falls.

Evaluate whether biomarkers measured by automated artificial intelligence (AI)-based algorithms are suggestive of future fall risk. In this retrospective age- and sex-matched case-control study, 9029 total patients underwent initial abdominal CT for a variety of indications over a 20-year interval at one institution. 3535 case patients (mean age at initial CT, 66.5 ± 9.6 years; 63.4% female) who went on to fall (mean interval to fall, 6.5 years) and 5494 controls (mean age at initial CT, 66.7 ± 9.8 years; 63.4% females; mean follow-up interval, 6.6 years) were included. Falls were identified by electronic health record review. Validated and fully automated quantitative CT algorithms for skeletal muscle, adipose tissue, and trabecular bone attenuation at the level of L1 were applied to all scans. Uni- and multivariate assessment included hazard ratios (HRs) and area under the receiver operating characteristic (AUROC) curve. Fall HRs (with 95% CI) for low muscle Hounsfield unit, high total adipose area, and low bone Hounsfield unit were 1.82 (1.65-2.00), 1.31 (1.19-1.44) and 1.91 (1.74-2.11), respectively, and the 10-year AUROC values for predicting falls were 0.619, 0.556, and 0.639, respectively. Combining all these CT biomarkers further improved the predictive value, including 10-year AUROC of 0.657. Automated abdominal CT-based opportunistic measures of muscle, fat, and bone offer a novel approach to risk stratification for future falls, potentially by identifying patients with osteosarcopenic obesity. There are few well-established clinical tools to predict falls. We use novel AI-based body composition algorithms to leverage incidental CT data to help determine a patient's future fall risk.

Does the endoscopic view reflect the size of the gastric varix?

A 55-year-old man with a known history of HCV cirrhosis was admitted with hematemesis. His initial abdominal CT showed a huge gastric varix (A), with a maximum diameter of the varix of 8 mm (although from our experience, cross-sectional imaging is not a good indication of the volume), and CT portography also demonstrated a gastro-renal shunt (B). Eight ampules of N-butyl-2-cyanoacrylate (Histoacryl, B. Braun, Melsungen, Germany) were used (each 0.5 mL mixed with 0.8 mL Lipiodol, Guerbet, Villepinte, France).

Massive Mixed Adenoneuroendocrine Carcinoma: A Case Report

Mixed adenoneuroendocrine carcinoma (MANEC) of the gastrointestinal (GI) tract is a rare subtype of mixed tumors, and it is scarcely described in the literature. MANEC tumors are composed of adenocarcinoma and neuroendocrine carcinoma components, each of which comprises at least 30% of the lesion. Diagnosing MANEC requires specific histological and immunohistochemistry (IHC) analysis. Typically, MANEC tumors carry a poor prognosis due to their very aggressive nature.We report the case of a 70-year-old female patient with no past medical history who presented with a three-week history of abdominal pain and one episode of hematemesis one week prior to presentation. Initial CT of the abdomen showed a large, 8 x 6 x 6-cm mass arising from the stomach and extending to the lesser sac as well as the central crus of the diaphragm with bilateral retroperitoneal lymphadenopathy. Upper endoscopy revealed an excavated, ulcerated, and partially necrotic mass on the lesser curvature of the proximal gastric body. Tissue biopsy of the lesion showed infiltrating mixed poorly differentiated adenocarcinoma and neuroendocrine carcinoma. On IHC, the adenocarcinoma component stained positively for CDX2 and pancytokeratin, and the neuroendocrine component stained positively for synaptophysin and chromogranin. Further workup included CT of the chest, which demonstrated extensive bilateral pulmonary emboli and new liver lesions with moderate ascites not seen on the initial abdominal CT. The latter was repeated and showed remarkable enlargement of the gastric mass (up to 12 cm) with extensive retroperitoneal adenopathy and mesenteric implants. Given the rapid clinical deterioration and progression of tumor burden, comfort measures were offered and the patient passed away soon after. MANEC tumors are highly aggressive subtypes of "collision" tumors, which are not well described in the medical literature due to their rarity. The etiology is poorly understood with various theories proposing different pathophysiological mechanisms. Standard therapy is not well developed at present; however, a few reports have demonstrated successful outcomes with surgery or combined chemotherapy (cisplatin with irinotecan or etoposide) if diagnosed at an early stage.

S1441 Emphysematous Pancreatitis Complicated by Gastroduodenal Artery Pseudoaneurysm and Extra-Pancreatic Involvement

INTRODUCTION: Emphysematous pancreatitis (EP) is a rare form of necrotizing pancreatitis associated with gas-forming bacteria and a high mortality rate. Extra-pancreatic complications include pleural effusion, ascites, vascular and gastrointestinal involvement. Disruption of the pancreatic duct can cause pancreatic ascites and pleural effusion. Gastroduodenal artery (GDA) pseudoaneurysms are rare complications of EP caused by release of proteolytic enzymes leading to weakening and ballooning of the vessel wall. CASE DESCRIPTION/METHODS: We present a case of an 82-year-old male ex-smoker with a history of hyperlipidemia, peptic ulcer disease, and noninsulin-dependent diabetes mellitus, who presented with postprandial epigastric pain. During the first 24 hours of onset, he met three out of the five Ranson criteria: age greater than 55, LDH above 350, glucose of 393 mg/dl, with additional findings of AST 46 IU/L, WBC 14.64, amylase 2,378, and lipase greater than 600. CT revealed pancreatic gas, bilateral pleural effusions, and cholelithiasis, the latter of which was determined to be the cause of acute EP (Figure 1). The patient required surgical debridement and ERCP with stenting of biliary and pancreatic ducts (Figure 2). Intraoperative cultures were negative for enteric, fungal, or anaerobic organisms. One month later, the patient presented with septic shock and leukocytosis. Abdominal CT revealed sequelae of necrotizing pancreatitis with increased extent of fluid collection. Upper endoscopic ultrasound identified a 35 mm fluid-filled lesion in the pancreatic head positive for gram-negative rods and Streptococcus anginosus. The following week, the patient presented with melena and painless bleeding from his Davol drain. Abdominal CT angiography showed a pseudoaneurysm arising from the distal GDA and endovascular coil embolization was performed (Figure 3). One year later, the patient presented with weight loss. Abdominal CT identified a 7.0 cm pancreatic pseudocyst causing extrinsic compression in the gastric body and antrum leading to LA Grade C stasis esophagitis. A 15 mm cystgastrostomy metal stent was placed across the posterior gastric wall to relieve gastric outlet obstruction. DISCUSSION: Our case offers a unique sequela of EP causing GDA pseudoaneurysm with delayed formation of a pancreatic pseudocyst leading to severe esophagitis and gastric outlet obstruction. Effective diagnostic and therapeutic management helped this patient survive his multiple, life-threatening complications associated with EP.Figure 1.: Figure 1. Abdominal CTs in coronal view performed 6 hours apart. (A) Initial abdominal CT without contrast showed extensive inflammatory and air (white arrow) around the pancreatic head concerning for emphysematous pancreatitis versus duodenal perforation. (B) Subsequent same-day CT examination with oral contrast only demonstrated marked increase in pancreatic gas and inflammatory changes (white arrow) concerning for rapid progression. There was no extravasation of oral contrast (dashed white arrows) thereby ruling out perforated viscus as a cause for the air.Figure 2.: Figure 2. ERCP and sphincterotomy were performed given the known pancreatic head necrosis. The main pancreatic duct (A) and common bile duct (B) were cannulated, and temporary pancreatic and biliary stents were placed.Figure 3.: Figure 3. (A) Abdominal CT angiography showed pseudoaneurysm (white arrow) arising from a branch of the gastroduodenal artery in the region of peripancreatic inflammatory changes. (B) The gastroduodenal artery was embolized with multiple coils (dashed white arrow) endovascularly to treat the pseudoaneurysm.

Atypical Obstructive Pseudotumors in AIDS as the Initial Manifestation of Gastrointestinal Histoplasmosis

Histoplasma capsulatum is a dysmorphic fungus distributed worldwide commonly associated with pulmonary histoplasmosis. We report the case of an unusual presentation of gastrointestinal histoplasmosis leading to the obstruction of the intestinal lumen in a 30-year-old female, HIV positive, admitted to the hospital due to chronic abdominal pain and constipation. An initial abdominal CT revealed a mass in the sigmoid colon. A further colonoscopy showed an infiltrating, friable mass obstructing 80% of the lumen staining positive for H. capsulatum. The unspecific nature of the patient's symptoms along with the unusual presentation of the infection raises awareness about the importance of including new pathologies to differential diagnoses when treating AIDS patients.

1270 Unexpected Microorganism in an Unexpected Place

INTRODUCTION: Candida Parapsilosis (CP) has been implicated in several intra- and extra- vascular infections and rarely been the cause of intraabdominal infections. We describe a case of CP infection complicating acute severe necrotizing pancreatitis. CASE DESCRIPTION/METHODS: A 68-year-old man presented with acute onset epigastric pain associated with nausea and vomiting. Physical examination revealed epigastric tenderness. Lipase was elevated at 7352 mg/dl and initial abdominal CT scan revealed changes consistent with acute edematous pancreatitis with possible early necrosis. His clinical course was complicated by acute respiratory failure, septic shock, and AKI requiring hemodialysis. He was in and out of the intensive care unit despite medical management including nutrition support and broad spectrum antibiotics. A repeat CT scan 4 weeks later showed acute necrotizing pancreatitis with walled-off necrosis (WON). After an episode of acute decompensation, a percutaneous drain was placed prior to necrosectomy. The aspirated fluid grew Candida Parapsilosis and patient was started initially on Micafungin, and then transitioned to oral fluconazole. Soon after starting antifungals the patient stabilized, clinically improved and was able to be discharged home. He subsequently underwent a video assisted retroperitoneal dissection, which revealed a small amount of necrosis and a pancreatic duct leak into the WON. He underwent ERCP with pancreas duct stent bypassing the leak. Upon most recent visit, patient showed considerable improvement. DISCUSSION: The incidence of CP infections has been greatly increased over the last decade. Primarily, CP is implicated in cases of fungemia accounting for 3–27% of all cases of in large studies and to lesser extent in extravascular infections like osteomyelitis. Intraabdominal infections are unusual and mostly associated with peritonitis complicating surgery and peritoneal dialysis. Despite the organism normally colonizes the GI tract, pancreatic infections by CP are rare, and are usually complicating acute pancreatitis. They could be explained by portal extension and be predisposed by use of broad spectrum antibiotics, surgery, and instrumentation. In conclusion, it is important to consider fungal infections in cases of complicated infected pancreatitis especially those not responding to broad spectrum antibiotics as they share similar clinical features with bacterial causes and prompt diagnosis and treatment are key to a better outcome.

Introducing “K-shaped sign”, a new finding on CT to detect a pancreatic cancer at the early state

Introduction: We found and evaluated a specific change of the pancreas on CT just before a pancreatic cancer appears. Methods: We selected 32 patients among 241 patients with advanced pancreatic cancer. All 32 patients took abdominal CT more than one time, before their pancreatic cancers were diagnosed. Eight of the 32 patients underwent pancreatic resection.We reviewed all patients' abdominal CT and checked how abnormal findings appeared in the pancreas before finding their pancreatic cancer. Results: Twenty-three (71.8%) of the 32 patients had a localized constriction of the pancreatic parenchyma before appearing the pancreatic cancer. We named it “K-shaped sign” based on the figure. All of the 23 patients showed focal fatty changes around the area the K-shaped sign appeared. Four (17.3%) of the 23 patients had both K-shape sign and a partial main pancreatic duct dilatation. Nineteen of the 32 patients had a normal pancreas without focal fatty change on CT before the K-shaped sign occurred. Thirteen of the 32 patients had detected the K-shaped sign since the initial abdominal CT. All the 32 patients had the pancreatic cancer in the K-shaped sign's area. Conclusion: We introduced new CT finding before pancreatic cancer could be found, and named it “K-shaped sign” on CT. Although the “K-shaped sign” phenomenon has to be associated with early pancreatic cancer, it is unclear what the cause of the phenomenon is. When the K-shaped sign is observed on CT, the onset of a pancreatic cancer should be considered and determined by using more precise modalities.

The Role of the Immunohistochemical Examination in the Diagnosis of Castleman`s Disease

Castleman�s disease is characterized by benign angiolymphoid hyperplasia. There are two clinical forms: the localized form in which one lymph node is affected, often paucisimptomatic, treated by radical surgical excision, without recurrence in most cases, and the multicentric form, characterized by systemic manifestations, polyadenopathy (mediastin, cervical region, abdomen, etc.) , organomegaly (e.g. spleen, liver), with a less favorable prognosis than the localized form. The etiology of the disease remains unknown; recent studies suggest the implication of human herpes virus 8 (HHV-8), especially in multicenter forms. We shall present the case of women, aged 23, with Castleman�s disease with retroperitoneal localization, who was admitted to the surgery clinic due to abdominal pains. The initial abdominal CT raised the suspicion of a hepatic lobus caudatus tumor, but the anatomical-pathological result confirmed the diagnosis of angiofolicular hyperplasia of the lymph nodes. Diagnostic methods, histological forms, treatment and prognosis aspects of Castleman�s disease are described below.

交通外傷により腹腔内他臓器損傷を伴わない胆嚢損傷を来した1例―既報告27例の集計とともに―(Gallbladder perforation caused by a traffic injury: a case report)

要旨胆嚢は解剖学的に外力の影響を受けにくいため，鈍的外傷による胆嚢損傷はまれであり，また他臓器損傷を伴う場合が多い。我々は腹腔内他臓器損傷を伴わない外傷性胆嚢損傷を経験したので報告する。症例は76歳の男性。飲酒後に路上で臥床中，自動車に轢かれたところを目撃され，当院救命救急センターに搬送された。CTにて肝表面，Morrison窩，右傍結腸溝に少量の腹水を認め，経過観察としたが，第3病日のCTで経時的な増加を認め，第4病日に緊急開腹手術を行った。胆嚢体部に穿孔を認めたが腹腔内他臓器には損傷を認めず，胆嚢摘出術，腹腔内ドレナージ術を施行した。術後経過は良好であった。胆嚢は外力を受けにくい臓器であるが，飲酒は胆嚢の緊満と腹壁の弛緩をもたらすため，外傷性胆嚢損傷の誘因の一つとなりうる。本症例でも過量飲酒が一因となった可能性が示唆された。治療としては，原則的には可及的早期の外科的加療が望ましいと考えられる。

Peritoneal Mesothelioma: A Challenge to Medical Profession

Malignant peritoneal mesothelioma (MPM) is an extremely rare cancer of peritoneum. It is associated with very poor prognosis due to late presentation and non-specific symptoms. We present a case of primary peritoneal mesothelioma in a 54 year old Hispanic female. She presented with epigastric abdominal pain and bloating for 5 months in the background of chronic non-specific abdominal discomfort. She had no history of occupational asbestos exposure, family history of cancer, smoking or weight loss. Her hemoglobin and chemistry were normal. Initial abdominal CT showed non-specific changes including loculated intra-abdominal ascites and mild epiphrenic adenopathy. Patient was referred for diagnostic laparoscopy. However, surgeons did not proceed with a surgical intervention initially. Her upper endoscopy and cystoscopy were performed and were normal. Her prior colonoscopy was normal. Repeat abdominal CT scan 3 month later revealed moderate volume of abdominal and pelvic ascites, worsening epiphrenic adenopathy, and mildly thickened anterior urinary bladder wall. Diagnostic laparoscopy was performed. Numerous implants were found on serosal surface of internal organs, peritoneum and omentum. Pathology specimen was consistent with malignant mesothelioma-Epithelioid type. Patient underwent debulking surgery, including resection and reconstructions of right hemi-diaphragm, cholecystectomy, right colectomy, partial gastrectomy, distal pancreatectomy, splenectomy, transverse colectomy, with temporary loop ileostomy followed by hyperthermic intraperitoneal chemotherapy (HIPEC) and cisplatin therapy for 6 months. Patient is disease free at 3 years postoperatively, and she is doing well with close follow-up. Malignant peritoneal mesothelioma is very difficult to diagnose due to nonspecific clinical presentation and clinical course. Diagnosis requires high level of clinical suspicion. Diagnosis is based on good quality imaging, pathology and immunohistochemistry. MPM can be treated with debulking surgery and intra-peritoneal chemotherapy or radiotherapy.

ACE Inhibitor-Induced Angioedema of the Small Bowel

Angiotensin-converting enzyme (ACE) inhibitors are routinely prescribed for patients with hypertension, coronary artery disease (CAD), heart failure with systolic dysfunction, diabetes and chronic kidney disease (CKD). This category of medications is also the leading cause of drug-induced angioedema, occurring in 0.1% to 0.7% of patients. A 49-year-old female presented for evaluation of worsening abdominal pain with nausea, vomiting, and severe bloating, worsening over the next 12 months. Her past medical history included hypertension, depression, hiatal hernia, and an abdominal hysterectomy 20 years prior. Her only medication was Lisinopril 20 mg daily which she had been on for two years. Work up included an EGD and colonoscopy which showed no abnormalities, laboratory workup were all normal except for mildly elevated CRP of 21 and lipase of 73, and the only abnormality seen on imaging came from the CT which showed borderline thickening of distal small bowel loops. She continued to experience symptoms for a total of 15 months, at which point her ACE-inhibitor was stopped. Her symptoms resolved shortly afterwards and did not return, suggesting angioedema caused by her ACE inhibitor. This was likely seen on her initial abdominal CT as the cause for the borderline wall thickening of the small bowel loops. This case demonstrates the angioedema may be exclusive to the GI tract with no overt evidence of swelling elsewhere. We recommend consideration of ACE inhibitor-induced angioedema in any patient using ACE inhibitors presenting with non-specific abdominal complaints without evidence of other causes. Practice recommendations would include reviewing medications while considering ACE inhibitor induced angioedema, checking bradykinin levels which may be elevated with ACE inhibitor use, and a trial off of the ACE inhibitor to see if symptoms resolve. We also recommend discussion of angioedema, including GI symptoms, with patients prior to starting ACE inhibitors.Figure 1Figure 2

MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems

ObjectivesThe purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. MethodsIn this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48–64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. ResultsIn neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p=0.25; mCTSI: 4.0 vs. 4.0, p=0.10; EPIC: 2.0 vs. 2.0, p=0.41; NP: CTSI: 8.0 vs. 7.0, p=0.64; mCTSI: 8.0 vs. 8.0, p=0.10; EPIC: 3.0 vs. 3.0, p=0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. ConclusionsAn initial dual-phase abdominal CT after ≥72h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a single-phase protocol.

Recurrent Isolated Intestinal Angioedema Associated With Splenic Marginal Zone Lymphoma

A 61-year-old woman with history of IgM monoclonal gammopathy presented for evaluation of episodic acute, non-radiating peri-umbilical and epigastric abdominal pain. Each episode last for 4-5 days, and symptoms only were relieved with opioid medications. Initial abdominal CT scan revealed an enlarged spleen (18cm). Laboratory evaluation showed elevated transaminases (AST 53 U/L, ALT 64 U/L) with normal alkaline phosphatase and bilirubin with negative AMA, ASMA, and LKM1 antibodies. Complement C3 level was normal, and C4 was decreased to less than 10 mg/dl during the pain episode. There was no evidence of Budd-Chiari syndrome or portal hypertension on abdominal Doppler or upper endoscopy. Almost two years after the first presentation, she was noted to have recurrent abdominal pain prompting abdominal ultrasound, which showed ascites with a spontaneous decline in ascites volume over 5 days. This ascetic fluid was not sampled by paracentesis due to scant amounts. CT imaging findings confirmed the presence of small amount of ascites and marked bowel wall thickening during two separate acute abdominal pain episodes. Liver biopsy demonstrated bridging fibrosis. In light of her slowly increasing IgM gammopathy, persistent splenomegaly and progressive colicky abdominal pain, peripheral blood flow cytometry and bone marrow biopsy were performed. Findings supported a diagnosis of splenic marginal zone lymphoma. She received 8 cycles of chemotherapy (rituximab, cyclophosphamide, vincristine and prednisone). Abdominal pain episodes continued while she was on chemotherapy, but the final episode occurred 3 weeks after completing chemotherapy. C1-esterase function and C1q were subsequently found to be normal after resolution of the pain, but the patient was noted to have C4 complement level of less than 3 mg/dl. In the presence of bowel wall thickening, ascites and low C4 complement level during pain episodes, we suspected acquired angioedema (AAE) in the setting of splenic marginal zone lymphoma as the cause for her symptoms. This entity has previously been reported. The patient denies a family history of angioedema and has never experienced cutaneous symptoms. Our suspicion for intestinal AAE was confirmed after she remained asymptomatic following lymphoma treatment. AAE is a rare condition manifesting with recurrent episodes of angioedema and may accompany an underlying lymphoproliferative disorder. Gastrointestinal attack is reported in less than 50% of patients with AAE. Clinical awareness of this entity as a cause for acute abdominal pain may improve the quality of care for these patients.

Markedly Elevated CA 19-9 in a Case of Mirizzi’s Syndrome: An Atypical Presentation

Introduction: The CA 19-9 antigen is commonly used as a tumor marker for malignancies of the pancreas and biliary tract. It has been suggested that high levels of CA 19-9 (>300 U/mL) have a strong correlation with malignant biliary pathology. In this case report, we present a patient with exceptionally elevated levels of tumor marker (CA 19-9 >4000 U/mL) in the setting of Mirizzi’s syndrome. Case Report: A 51-year-old male with a several week history of epigastric pain presented to the emergency department with new onset jaundice, tea-colored urine, and light stools of 1-week duration. Total bilirubin was elevated at 19.6 mg/dL. Initial abdominal CT scan revealed markedly dilated intrahepatic and common bile ducts, the latter measuring 1.5 cm. No stones or masses were visualized. CA 19-9 levels were elevated at 4258 U/mL. Given his presentation, clinical suspicion was high for a biliary tract malignancy, specifically early pancreatic cancer or a lesion at the ampulla of Vater. The patient underwent endoscopic ultrasound examination demonstrating a large stone at the junction of the cystic duct and common bile duct with a markedly enlarged gallbladder concerning for Mirizzi’s syndrome with impending hydrops. ERCP was performed with occlusion cholangiogram and balloon sweep of the bile duct without evidence of stones. The wire was advanced into the cystic duct with contrast injected to confirm the large stone at the junction of the bile duct and cystic duct. Maneuvers to remove the stone were unsuccessful. A stent was placed in the bile duct to achieve adequate drainage upstream from the obstruction. The magnitude of the stone was such that subsequent cholangiogram did not demonstrate cystic duct filling beyond the level of obstruction. The patient subsequently underwent percutaneous cholecystostomy tube placement and was continued on antibiotics. He improved clinically with gradual decrease of his hyperbilirubinemia and underwent a laparoscopic cholecystectomy four weeks later with normalization of his CA 19-9 level and liver-associated tests. Discussion: There is a growing body of data that demonstrates elevated levels of CA 19-9 in benign biliary pathology. To our knowledge, there are only 3 other reports of CA 19-9 elevations of this magnitude secondary to Mirizzi’s syndrome. EUS as a diagnostic tool was not mentioned in any of these reports and diagnosis was discovered intraoperatively during cholecystectomy or, in one case, laparotomy for open liver biopsy. EUS can be a useful tool to evaluate for gallstones impinging on the common bile duct to further distinguish between malignant etiology and Mirizzi’s syndrome, which can be difficult to visualize with other imaging modalities. Disclosure - Dr. Shah - Speakers Bureau: US Endoscopy.

Initial Non-Contrast Abdominal CT Imaging Post-Injury: Who should have Contrast Omitted and at What Expense

Initial Non-Contrast Abdominal CT Imaging Post-Injury: Who should have Contrast Omitted and at What Expense

Surgically proved visually isoattenuating pancreatic adenocarcinoma undetected in both dynamic CT and MRI. Was blind pancreaticoduodenectomy justified?

INTRODUCTIONVisually isoattenuating pancreatic adenocarcinoma is defined as a mass not directly visible on CT and recognizable only by secondary imaging signs. The frequency of isoattenuating pancreatic adenocarcinomas at dynamic-enhanced CT has been reported to range from 5.4% to 14%. Furthermore, 80% of the visually isoattenuating pancreatic adenocarcinomas are detectable in dynamic-enhanced MRI. Consequently, a pancreatic adenocarcinoma undetected in both the above imaging studies is an exceptionally rare event. PRESENTATION OF CASEThe present report describes a case of a histologically proved 3.5cm pancreatic adenocarcinoma undetected in both dynamic-enhanced CT and MRI. The patient presented with progressive jaundice over the preceding 20 days. Initial abdominal CT showed a dilated pancreatic and common bile duct without demonstration of a lesion responsible for the clinical and imaging findings. Additional diagnostic work-up with dynamic CT and dynamic MRI failed to reveal a definitive mass. ERCP revealed an irregular interruption of the pancreatic and distal common bile duct with upstream dilation. Blind radical pancreaticoduodenectomy was performed. Histologic examination showed a pT3pN1MO pancreatic ductal adenocarcinoma of the head/neck. DISCUSSIONIsoattenuating pancreatic adenocarcinoma patients represent a small but meaningful subset of patients with pancreatic cancer, as they have better survival. The more favorable postsurgical survival makes it even more imperative to correctly diagnose their cases at early stages by obtaining further diagnostic work-up with dynamic pancreatic CT, dynamic MRI and endoscopic ultrasound. CONCLUSIONWhen the above studies fail to unmask the lesion, blind pancreaticoduodenectomy should be based on strong clinical suspicion and secondary imaging findings.

Acute Gallstone Pancreatitis Misdiagnosed as Acupuncture Induced Traumatic Pancreatitis

Financial support: None. Conflict of interest: None. Fig. 1. Initial abdominal CT scan. (A) Entrapped free air between stomach and pancreas is seen on axial scan, along with (B) edematous change of duodenal wall and swelling of pancreatic head with peripancreatic inflammation. (C) Mildly dilated common bile duct without stone and localized mesenteric infiltrations and haziness can also be observed. 증례: 57세 여자가 이틀 전부터 심해진 복부 통증을 주소로

Clinical Significance of Lung Nodules Reported on Abdominal CT

The objective of our study was to identify the significance of lung nodules reported on abdominal CT. Abdominal CT reports from a 1-year period were reviewed for the terms "nodule," "nodular," or "mass" in reference to the lung bases. Patients with prior chest or abdominal CT examinations were excluded; the study population included patients with an initial abdominal CT study and at least one follow-up chest or abdominal CT examination. Two thoracic radiologists characterized nodules in consensus. Radiology and clinical records were reviewed for nodule growth and clinical diagnoses. The term "nodule," "nodular," or "mass" in reference to the lung bases was reported in 364 of 12,287 abdominal CT studies (3%). Of 125 patients with no prior CT examination, 42 had undergone follow-up chest CT, abdominal CT, or both. Common imaging indications included abdominal pain (13/42, 31%) and preexisting malignancy (n = 7, 16.7%). Regardless of the indication for imaging, 16 (38.1%) had malignancy that was known (n = 13) or newly diagnosed (n = 3) on the initial abdominal CT. Three of 42 patients (7.1%) had malignant nodules representing metastatic disease: Nodule growth was seen in one patient with preexisting colon cancer, one patient with newly diagnosed metastatic pancreatic cancer, and a third with known bladder cancer. The latter patient had suspected lung metastases that were confirmed on chest CT 1 day later. Three of the 16 patients (18.8%) with preexisting or newly diagnosed cancer had malignant nodules. No malignant nodules were identified without such history. Six patients (14.3%) had an infection. Lung nodules incidentally detected on abdominal CT were rarely malignant and were seen only in the setting of an underlying abdominal malignancy. Knowledge of such history is of critical importance to both the clinician and the radiologist. Dedicated chest CT is most useful when assessing pulmonary nodules in patients with localized malignancy.