Presentations

Abstract

Introduction: Volvulus of the gastrointestinal tract continues to pose a diagnostic challenge for many radiologists. The clinical symptoms associated with volvulus, such as pain, nausea, and vomiting, are nonspecific and can complicate the diagnosis. Imaging plays a crucial role in identifying volvulus, relying heavily on the radiologist's interpretation. Prompt diagnosis is essential to prevent severe complications, including bowel ischemia, infarction, and perforation. In this paper, we present four cases of patients with different types of volvulus to illustrate common imaging findings. These examples aim to assist radiologists in making timely and accurate diagnoses, ultimately improving patient care.

Case Information: Case #1: A 15-year-old female with no significant medical history presented with severe left upper abdominal pain, nausea, and vomiting. Her initial CT of the abdomen/pelvis showed a massively distended stomach with multiple radiodense foci, likely ingested content, and rotation along the short axis, with the antrum over the gastroesophageal junction, indicative of mesenteroaxial volvulus causing gastric outlet obstruction. She underwent urgent laparoscopic gastric detorsion and was discharged within two days post-surgery. No follow-up CT was performed after discharge. Case #2: A 92-year-old female with a history of peripheral artery disease, hypertension, chronic kidney disease stage 3, and diastolic heart failure presented with acute abdominal pain. Her CT of the abdomen/pelvis revealed a thickened antral wall of the stomach, a swirl sign compressing the venous system, and narrowing of the superior mesenteric artery. Additionally, multiple small bowel loops exhibited diffuse mesenteric edema. The findings suggested possible small bowel volvulus leading to superior mesenteric vein compression. She was managed conservatively and discussed for potential elective surgery in the future. Case #3: A 53-year-old female with no significant medical history presented with acute abdominal distension and pain. Initial lab tests showed no leukocytosis and a negative urinalysis. CT of the abdomen/pelvis revealed decompression of the distal rectum with no small bowel dilatation or thickening. However, the CT showed mesenteric twisting in the right lower quadrant consistent with cecal volvulus. The patient underwent urgent exploratory laparoscopy with right hemicolectomy and was successfully treated, being discharged after 6 days. Case #4: A 74-year-old female with a history of Parkinson's disease presented with increasing abdominal distension, pain, nausea, and vomiting. CT of the abdomen/pelvis revealed twisting of the vascular pedicle, a reversal of the sigmoid segment's position with a transition point in the left pelvis and dilated large bowel loops with fluid-filled areas. She was urgently treated with sigmoidoscopy for decompression and was discharged after 7 days.

Discussion/Clinical Findings: Volvulus of the gastrointestinal tract can present in multiple ways, including gastric, midgut, cecal, and sigmoid volvulus. Each of the presentation differs significantly in the CT of abdomen/pelvis. All of these conditions can lead to acute abdomen changes, such as bowel infarction, perforation, and even death if not treated on time. Most cases of volvulus cannot be diagnosed clinically since the symptoms are rather nonspecific. CT of abdomen/pelvis is commonly used to find the abnormalities of the gastrointestinal tract and the findings differ case by case depending on the type of volvulus. Gastric volvulus is rare, often presenting with epigastric pain, nausea, and vomiting. Diagnosis is aided by Borchardt's triad: sudden epigastric pain, intractable retching, and difficulty passing a nasogastric tube. The two main types are organoaxial volvulus, where the stomach rotates along the long axis, shifting the greater curvature above the lesser curvature, and mesenteroaxial volvulus, where rotation along the short axis displaces the antrum above the gastroesophageal junction. Radiographic findings may show herniation of a large portion of the stomach above the diaphragm, with an upper gastrointestinal series helping to determine the type of rotation. Midgut volvulus primarily affects infants, presenting with bilious vomiting and intermittent abdominal pain within the first month of life. However, due to the increased use of CT imaging, it is now also being identified more frequently in adults. Conventional radiography often yields nonspecific results, so an upper gastrointestinal series with fluoroscopy is essential for diagnosis. On fluoroscopic imaging, the ligament of Treitz is abnormally positioned below and to the right of the left lumbar pedicle, and a twisted segment of the bowel may appear with a corkscrew-like appearance. CT imaging can reveal swirling of the vessels in the mesenteric root, which is indicative of volvulus. Cecal volvulus results from abnormal fixation and motility of the right colon. Factors such as pregnancy or recent colonoscopy can trigger this condition. Unlike other types of volvulus, cecal volvulus is typically diagnosed with a CT scan of the abdomen/pelvis. The CT will reveal a dilated, gas-filled viscus located abnormally in the left upper quadrant and mid-abdomen. A whirl sign may be observed, indicating the presence of volvulus. A contrast enema can further assist in diagnosis by showing a decompressed distal colon and a beak-like tapering at the site of the volvulus. Sigmoid volvulus is the most common type of colonic volvulus, accounting for 60-75% of cases. It is often associated with chronic constipation and sigmoid colonic redundancy, which can result from a low-fiber diet, pregnancy, hospitalization, or Chagas disease. Patients typically present with nonspecific abdominal pain and signs of obstruction. CT imaging of the abdomen/pelvis usually reveals a large, air-filled bowel loop extending from the pelvis to the level of the transverse colon, a finding known as the "northern exposure sign." Additionally, the "coffee bean sign" may be observed, indicating a dilated sigmoid colon that resembles a coffee bean. A U-shaped closed-loop appearance of the colon can also be seen. If the diagnosis remains unclear, a water-soluble contrast enema can be used. This may reveal a beak-shaped narrowing at the distal aspect of the twisted sigmoid colon.

Conclusion: In patients with gastrointestinal volvulus, a CT scan of the abdomen and pelvis is crucial for accurate diagnosis. Clinicians often suspect other conditions before seeing the CT results. Recognizing the imaging features of volvulus is essential to prevent serious complications such as bowel infarction, perforation, and ischemia.