Acute appendicitis: sonographic criteria based on 250 cases

Clinical validity of ultrasound in children with suspected appendicitis

STUDY OBJECTIVE

To determine the accuracy of diagnosing appendicitis in the pediatric population by using graded compression ultrasonography.

DESIGN

Retrospective case review.

SETTING

University-affiliated community hospital with an emergency department census of approximately 19,000 pediatric visits per year.

TYPE OF PARTICIPANTS

Ninety-eight children (age less than 13 years) with clinically suspected appendicitis who had graded compression sonographic studies during the 24-month study period.

INTERVENTIONS

Medical records were reviewed for patient demographics, presenting signs and symptoms, sonographic findings, surgical results, and hospital course. Patients who did not undergo surgery were followed up by telephone for a minimum of two months.

RESULTS

Ninety-eight children (42 boys and 56 girls; age range, 2 to 12 years; mean age, 8.0 years) with clinical signs and symptoms of acute appendicitis were examined sonographically. Of the 26 patients whose appendicitis was verified at surgery, ultrasound was positive in 22, with an overall sensitivity of 85%. Of the 72 patients who did not have appendicitis, ultrasound was negative in 68, with a specificity of 94%. Two patients with false-positive ultrasound went to surgery and were found to have acute ileitis and perforated Meckel's diverticulum. The overall diagnostic accuracy was 91.8% (90 of 98).

CONCLUSION

Use of ultrasound to diagnose acute appendicitis was performed with a sensitivity of 85% and a specificity of 94%. This allows the same accuracy in children as has been reported with adults.

Perforation associated with barium enema in acute appendicitis

A child with the suspected diagnosis of atypical acute appendicitis underwent a diagnostic barium enema. The study was complicated by perforation with leakage of a large amount of barium into the peritoneal cavity. The complex hospital course that resulted has prompted us to reevaluate the barium enema in the diagnosis of appendicitis and review the literature for contraindications. We conclude that this particular complication is extremely rare and that barium enema still has a part to play in some patients where the clinical diagnosis is uncertain.

Visualization of enlarged mesenteric lymph nodes at US examination. Clinical significance

PURPOSE

To identify conditions associated with enlarged mesenteric lymph nodes in children with acute abdominal pain and determine the ability of US to detect associated abnormalities.

METHODS

Two hundred and fifty children with acute abdominal pain were evaluated for the presence of enlarged mesenteric lymph nodes (AP diameter > 4 mm). Additionally, a reference group of 50 asymptomatic children was also studied for the presence of enlarged mesenteric lymph nodes.

RESULTS

Enlarged mesenteric lymph nodes were noted in 35 (14%) symptomatic children and two (4%) asymptomatic children. A specific diagnosis was established in 16/35 (46%) symptomatic children with mesenteric lymphadenopathy. Acute appendicitis was the most common diagnosis. The discharge diagnosis in the remaining 19 children was abdominal pain or gastroenteritis of unknown origin. US suggested the correct diagnosis in 12/16 (75%) children in whom a definite diagnosis was established. Histopathologic examination of enlarged mesenteric lymph nodes in three patients demonstrated non-specific inflammatory changes.

CONCLUSION

Enlarged mesenteric lymph nodes in children with acute abdominal pain represents a nonspecific finding. Mesenteric lymphadenopathy is associated with a variety of medical and surgical conditions in symptomatic children and is occasionally seen in asymptomatic children. Sonography is useful in establishing a primary diagnosis in these children.

Ultrasound documentation of spontaneously resolving appendicitis

Diagnostic ultrasound has been reported to be a highly specific technique for the confirmation of acute appendicitis. The authors report the case of a 27-year-old male who presented with clinical, laboratory, and classic ultrasound findings indicating early acute appendicitis. The patient's condition resolved spontaneously without operative intervention, and repeat sonography 2 weeks later was entirely normal. Ultrasound examination may allow documentation of spontaneously resolving appendicitis.

Graded compression sonography of abdominal neoplasms mimicking acute appendicitis

Over a 3-year period nine patients (mean age of 43 years) with acute abdominal pain and unsuspected abdominal neoplasms were referred for graded compression sonography to rule out appendicitis. Six of the nine patients had right lower quadrant neoplasms involving the cecum, terminal ileum, iliacus muscle, or iliac lymph nodes. However, in three patients neoplasm was noted outside the right iliac fossa involving the liver, right kidney, and upper abdominal mesentery. This study underscores the fact that in patients without sonographic evidence of acute appendicitis, a survey of the upper abdomen and right flank should routinely be performed in addition to scanning the right iliac fossa and pelvis. In patients more than 50 years of age neoplasm must also be kept in mind in the differential diagnosis of appendicitis.

Sonography in acute colonic diverticulitis. A prospective study

The clinical value of high-resolution real-time sonography for the diagnosis of acute and complicated colonic diverticulitis was prospectively studied in 130 consecutive patients with abdominal complaints, because of which the disease entered into differential consideration. The results of ultrasound investigation were compared with those of clinical examination on admission. Regarding history and initial clinical evaluation, diverticulitis was graded as "highly suspected" in 19 (36.5 percent) out of a total of 52 patients with later proven colonic diverticulitis (prevalence 40 percent), as "possible but equivocal" in 24 (46.2 percent), and as "very unlikely" in the remaining nine (17.3 percent) patients. Ultrasonography enabled the diagnosis of diverticulitis with an overall accuracy of 97.7 percent, a sensitivity of 98.1 percent, and a specificity of 97.5 percent. The predictive values of positive and negative ultrasound examinations were 96.2 percent and 98.5 percent, respectively. The echomorphologic features of acute diverticulitis include visualization of a colon segment presenting with local tenderness on gradual compression, which showed hypoechogenic thickening of the wall and a targetlike appearance in transverse view due to inflammatory changes and muscular thickening. Sonographic signs of peridiverticulitis (hyperechoic halo) were found in 96 percent of patients, echogenic diverticula in 86 percent. Twelve (92 percent) of 13 abdominal abscesses were detected on initial ultrasound examination and could be treated by percutaneous drainage in seven cases, while six required surgical intervention. These results indicate that high-resolution sonography with graded compression is highly sensitive and specific for the imaging diagnoses of acute colonic diverticulitis and complicating abscess.

Ultrasound in the investigation of the right iliac fossa mass

Patients presenting with a right iliac fossa (RIF) mass are a diagnostic problem. The objective of this study was to assess the role of ultrasound (US) in their investigation. A prospective series of 50 patients presenting with a clinically suspected RIF mass was examined by US and the finding correlated with the final diagnosis. There was a positive finding in 34 patients (68%). Ultrasound correctly identified the organ of origin in 33 (97%) and was able to guide the patients' further management. In 12 cases no abnormality was found in the RIF, of which 11 had no positive findings at follow-up and one was shown to have an unrelated abnormality at laparotomy. In four cases the findings were due to normal variants. Ultrasound is the imaging modality of first choice in patients presenting with a RIF mass.

Evaluation of women with possible appendicitis using technetium-99m leukocyte scan

The authors evaluated the use of technetium-99m albumin colloid white blood cell (TAC-WBC) scan in women with possible appendicitis. One hundred and nine women underwent 110 TAC-WBC scans. One woman had a second scan on a separate admission and was considered two individual patients in the analysis. Twenty-six women had appendicitis, 10 of whom had a perforated appendix at surgery. The TAC-WBC scan was indeterminate (abnormal but nondiagnostic for appendicitis) in 52 women (47%), nine of whom had appendicitis. Fifty-eight scans were read as positive or negative for appendiceal pathology. There were 16 true positives, 5 false positives, 36 true negatives, and 1 false negative. The predictive value of a positive scan was 76%, and the predictive value of a negative scan was 97%. The TAC-WBC scan was positive in 62% of patients with appendicitis and negative in 43% of the patients without appendicitis resulting in an overall accuracy of 47% in the 109 women. The main value of TAC-WBC scan in women with possible appendicitis is its high negative predictive value and the main problem with the TAC-WBC scan is its high indeterminate rate.

Acute and perforated appendicitis: current experience with ultrasound-aided diagnosis

The clinical value of high-resolution real-time sonography for the diagnosis of acute and complicated appendicitis was prospectively investigated in 857 patients admitted with suspected appendicitis. The ultrasound findings were correlated with history and physical examination on admission. Sonography was able to make the diagnosis of appendicitis with a sensitivity of 89.7%, a specificity of 98.2%, an overall accuracy of 96.3%, and a positive and negative predictive value of 93.6% and 97%, respectively. Routine use of ultrasound before making therapeutic decisions has reduced the rate of unnecessary laparotomies from 20.3% to 11.3%. In 48 (24.7%) of 194 patients with proven appendicitis, the disease had progressed to perforation at laparotomy. History and clinical findings on admission classified 30 (62.5%) of these patients as "highly suspect;" however, 9 (18.8%) were classified as "equivocal" and 9 (18.8%) as "very unlikely." Only half (48%) of the patients with appendiceal rupture had white blood cell counts higher than 13,000/mm3 or fever above 38 degrees C (50%). Sonography enabled the visualization of the inflamed appendix and/or appendicular abscess in 44 (91.7%) patients with perforation. In 47 of 48 patients with appendiceal rupture, the ultrasound-aided diagnosis was made on hospital admission. Thus, the incidence of complicated appendicitis (24.7%) in our study population must be attributed to disease progression before admission and preclinical diagnostic delay.

Advances in pelvic ultrasound: endovaginal scanning for ectopic gestation and graded compression sonography for appendicitis

Endovaginal sonography and graded compression sonography for appendicitis are two recent, significant advances in the imaging evaluation of the pelvis. Endovaginal sonography is performed by placing a dedicated high-frequency ultrasound probe within the vagina to evaluate the uterus and adnexa. Much early research with this technique has focused on the evaluation of early pregnancy, where changes related to intrauterine and ectopic gestation are evident at least one week earlier when compared with routine transabdominal ultrasound. Graded compression sonography for appendicitis is an ultrasound search for the inflamed, nonruptured appendix performed by compressing the right lower quadrant with a linear array transducer. Both techniques are fast, safe, and inexpensive evaluations that can be used to evaluate patients with nonspecific clinical findings and are particularly helpful in women of childbearing age.

Computed tomography of the large bowel and appendix

Computed tomography (CT) of the colon is useful in assessment of patients with colonic disease because the entire bowel wall, extraluminal tissues, and adjacent solid organs can be directly visualized. Patients with advanced stage colorectal carcinoma can be reliably identified with CT. This information can assist in surgical planning for intraoperative irradiation and placement of a hepatic artery infusion catheter. CT is an important imaging modality in the postoperative evaluation for recurrent rectal cancer after abdominoperineal resection. CT-guided biopsy often can provide histologic proof of suspected tumor recurrence or metastasis. Patients with diverticulitis or appendicitis can be identified by CT. The extent of disease and the nature of the inflammatory process--factors potentially affecting patient management--can be directly visualized. Percutaneous aspiration and drainage of abscess collections can be curative in appropriately selected patients.

Ultrasonography in the diagnosis of acute appendicitis: a prospective study

The diagnostic accuracy and practical impact of high-resolution sonography were prospectively studied in 523 consecutive patients admitted to the hospital with suspected appendicitis. The criteria for ultrasound diagnosis of acute appendicitis included visualization of a noncompressible aperistaltic appendix, with a targetlike appearance in transverse view and a diameter greater than or equal to 7 mm. In 115 of 130 patients with proven appendicitis the inflamed appendix or appendiceal abscess could be visualized, giving a sensitivity of 88.5%. The mean diameter of ultrasonically visible appendices was 11.4 +/- 3.2 mm. The overall accuracy and specificity of sonography in the diagnosis of acute appendicitis were 95.7% and 98%, respectively. The predictive value of a positive test was 94.5% and that of a negative result 96.3%. In a separate analysis of the results in 121 women of childbearing age, who have a high risk of preoperative misdiagnosis, the overall accuracy was found to be 96.7%, with 82.6% sensitivity and 100% specificity. Twenty-four (89%) of the 27 patients with appendiceal rupture (incidence 20.8%) were correctly diagnosed with ultrasound. The other 3 cases (11%) were missed. Routine use of ultrasonography has significantly improved the diagnostic accuracy in patients with suspected appendicitis and has reduced the negative laparotomy rate from 22.9% to 13.2%.