Jeffrey Forris Beecham Chick

The thoracic duct: clinical importance, anatomic variation, imaging, and embolization

The thoracic duct is the body’s largest lymphatic conduit, draining upwards of 75xa0% of lymphatic fluid and extending from the cisterna chyli to the left jugulovenous angle. While a typical course has been described, it is estimated that it is present in only 40-60% of patients, often complicating already challenging interventional procedures. The lengthy course predisposes the thoracic duct to injury from a variety of iatrogenic disruptions, as well as spontaneous benign and malignant lymphatic obstructions and idiopathic causes. Disruption of the thoracic duct frequently results in chylothoraces, which subsequently cause an immunocompromised state, contribute to nutritional depletion, and impair respiratory function. Although conservative dietary treatments exist, the majority of thoracic duct disruptions require embolization in the interventional suite. This article provides a comprehensive review of the clinical importance of the thoracic duct, relevant anatomic variants, imaging, and embolization techniques for both diagnostic and interventional radiologists as well as for the general medical practitioner.Key Points• Describe clinical importance, embryologic origin, and typical course of the thoracic duct.• Depict common/lesser-known thoracic duct anatomic variants and discuss their clinical significance.• Outline the common causes of thoracic duct injury and indications for embolization.• Review the thoracic duct embolization procedure including both pedal and intranodal approaches.• Present and illustrate the success rates and complications associated with the procedure.

Necrotizing Pancreatitis: Diagnosis, Imaging, and Intervention

Acute necrotizing pancreatitis is a severe form of acute pancreatitis characterized by necrosis in and around the pancreas and is associated with high rates of morbidity and mortality. Although acute interstitial edematous pancreatitis is diagnosed primarily on the basis of signs, symptoms, and laboratory test findings, the diagnosis and severity assessment of acute necrotizing pancreatitis are based in large part on imaging findings. On the basis of the revised Atlanta classification system of 2012, necrotizing pancreatitis is subdivided anatomically into parenchymal, peripancreatic, and combined subtypes, and temporally into clinical early (within 1 week of onset) and late (>1 week after onset) phases. Associated collections are categorized as acute necrotic or walled off and can be sterile or infected. Imaging, primarily computed tomography and magnetic resonance imaging, plays an essential role in the diagnosis of necrotizing pancreatitis and the identification of complications, including infection, bowel and biliary obstruction, hemorrhage, pseudoaneurysm formation, and venous thrombosis. Imaging is also used to help triage patients and guide both temporizing and definitive management. A step-up method for the management of necrotizing pancreatitis that makes use of imaging-guided percutaneous catheter drainage of fluid collections prior to endoscopic or surgical necrosectomy has been shown to improve clinical outcomes. The authors present an algorithmic approach to the care of patients with necrotizing pancreatitis and review the use of imaging and interventional techniques in the diagnosis and management of this pathologic condition.

Solitary fibrous tumors of the thorax: Nomenclature, epidemiology, radiologic and pathologic findings, differential diagnoses, and management

AJR:200, March 2013 Epidemiology It is difficult to ascertain the true incidence and prevalence of solitary fibrous tumors because the majority of patients with these masses are asymptomatic. Solitary fibrous tumors arising from the pleura, however, have been estimated to occur with a frequency of 2.8 per 100,000 individuals, with only eight hundred cases reported between 1931 and 2002 [4]. Moreover, these tumors account for less than 5% of all tumors arising from the pleura [5]. Overall, solitary fibrous tumors account for less than 2% of all softtissue tumors [6]. These tumors occur equally in both men and women, most frequently in the 6th and 7th decades of life [7]. There is no known association with tobacco, asbestos, or any other toxicant.

Demystifying NUT Midline Carcinoma: Radiologic and Pathologic Correlations of an Aggressive Malignancy

OBJECTIVEnNUT midline carcinoma is a rare poorly differentiated aggressive subtype of squamous cell carcinoma. To date, fewer than 100 total cases have been reported.nnnCONCLUSIONnGiven the rarity of this disease process and lack of pathognomonic imaging findings, a definitive diagnosis based solely on imaging findings alone is untenable. Select cases are used to emphasize the particularly infiltrative and aggressive nature of NUT midline carcinoma, which shows a complete disregard for normal tissue boundaries and rapid progression during brief intervals.

Giant left atrium in rheumatic heart disease: the classic signs of left atrial enlargement.

*Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, †Department of Medicine, Stanford University Hospital andClinics, Stanford University School of Medicine, Stanford, California, and ‡Department of Radiation andCellular Oncology, University of Chicago Medical Center, Pritzker School of Medicine, Chicago, Illinois Reprint Address: Jeffrey F. B. Chick, MD, Department of Radiology, Brigham andWomen’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115

Complex iatrogenic esophageal injuries: an imaging spectrum.

AJR:204, February 2015 Disease Epidemiology Esophageal injuries are classified into two broad subcategories: iatrogenic and noniatrogenic. Iatrogenic injuries represent more than half of all cases and have been reported to represent as many as 59% of cases, with endoscopic injury being the most common cause [1]. Although the relative incidence of esophageal injury during endoscopy is low (< 0.04%), because of its overall prevalence, it represents the most common cause of iatrogenic esophageal injury [2]. Noniatrogenic esophageal injuries are most commonly spontaneous perforations occurring after foreign body ingestion (15% of cases), food impaction or vomiting (12% of cases), and trauma (9% of cases) [1]. The average mortality rate is 19% for iatrogenic esophageal injury, compared with 36% for noniatrogenic causes. This difference in mortality results from the subacute nature of many noniatrogenic injuries leading to a delay in diagnosis and treatment [3].

Teaching NeuroImages: massive abdominal CSFoma.

A 31-year-old woman with congenital hydrocephalus status post ventriculoperitoneal shunt placement 23 years earlier presented with abdominal distention. The patient denied fever, headache, or sensory or motor abnormalities. Examination was notable for a tense abdomen. CT of the abdomen and pelvis demonstrated a massive, loculated, CSFoma, or CSF pseudocyst (figure). Ventriculoperitoneal shunts are associated with a variety of complications including disruption of the tube, obstruction of the tip, infection, intestinal perforation, tip migration, and CSFoma development.1 CSFoma is a rare complication, thought to be caused by low-grade shunt infection, chronic inflammation, increased CSF protein, or peritoneal adhesions, and is estimated to occur in 1.0% to 4.5% of cases, with a typical occurrence within 3 weeks to 5 years of shunt placement.2,3 Treatment consists of external drainage or surgical excision followed by reconstruction of the shunt system.4

Traffic Jam in the Duodenum: Imaging and Pathogenesis of Bouveret Syndrome

A 90-year-old woman with a history of cholelithiasis and chronic cholecystitis presented to the hospital with nausea, bilious vomiting, and anorexia for 3 days. The patient denied fevers, chills, hematemesis, hematochezia, or melena. Physical examination was notable for an uncomfortable woman with epigastric tenderness. An abdominal radiograph was obtained and demonstrated pneumobilia and an enlarged gastric bubble (Figure 1). Subsequent computed tomography with intravenous contrast material was obtained and demonstrated a gallstone in the proximal duodenum causing gastric distention, consistent with Bouveret syndrome (Figure 2). The patient underwent endoscopic-guided lithotripsy with resolution of symptoms.

Cholecystocolonic fistula mimicking acute cholecystitis diagnosed unequivocally by computed tomography

Cholecystocolonic fistula is an uncommon potential complication of cholecystitis found intraoperatively in 0.06–0.14xa0% of patients undergoing cholecystectomy and 0.1–0.5xa0% of autopsy series. Although cholecystocolonic fistula is the second most common cholecystoenteric fistula, second only to cholecystoduodenal fistula, it is diagnosed preoperatively in only 7.9xa0% of patients. Failure to preoperatively diagnose cholecystocolonic fistula places surgeons in precarious positions, as they may be forced to convert a seemingly routine cholecystectomy to a more sophisticated procedure coupled with adhesiolysis, colonic suturing, or colonic resection. We report a young patient who presented to the emergency department with complaints indicative of acute cholecystitis; however, preoperative ultrasound was suggestive of a cholecystoenteric fistula. Computed tomography and pathology were pathognomonic with clear visualization of the cholecystocolonic fistulous tract.

Incarcerated Morgagni hernia mimicking acute cholecystitis

A 64-year-old man presented with sharp, constant right upper quadrant pain, nausea, and constipation for 2 days. The patient reported intermittent right upper quadrant pain for the prior 6 years, which was exacerbated by eating, but noted that over the past 2 days the pain had become more severe. The patient had previously undergone three right upper quadrant ultrasound studies that were all negative for acute cholecystitis. On presentation, examination was notable for focal tenderness to palpation over the xiphoid process. A right upper quadrant ultrasound study was completed, and demonstrated a single hepatic cyst and gallbladder sludge without evidence of gallstones, gallbladder wall thickening, pericholecystic fluid, or a sonographic Murphy’s sign (Fig. 1). A chest radiograph was obtained, and demonstrated elevation of the right hemidiaphragm with colonic interposition in the right upper quadrant (Fig. 2). Computed tomography of the abdomen and pelvis with intravenous and oral contrast was performed, and demonstrated a large right-sided anterior diaphragmatic hernia containing distended loops of colon with short segment narrowing at the entrance as well as soft tissue stranding and simple fluid within the herniation sac, consistent with an incarcerated Morgagni hernia (Fig. 3). The patient underwent laparoscopic diaphragmatic hernia repair with mesh, which was complicated by postoperative development of a right pneumothorax, but with eventual normalization of the chest radiograph (Fig. 4) and resolution of the right upper quadrant pain.