Evaluation of suspected appendicitis in children using limited helical CT and colonic contrast material.

OBJECTIVE: Colonic contrast material evaluation of suspected appendicitis in pediatric patients is technically more challenging than in adults because less intraabdominal fat is present. To determine the accuracy and feasibility of focused CT for pediatric patients, we carried out this retrospective investigation. MATERIALS AND METHODS: Between November 1995 and July 1999, 199 pediatric patients (1-18 years old; mean age, 12 years) were examined with focused CT in the emergency division for suspected appendicitis. The findings on CT were compared with the findings at surgery, pathology, and clinical follow-up. RESULTS: There were 64 true-positive CT scans, two false-negative, 128 true-negative, one false-positive, and four indeterminate. Seventy-four patients underwent appendectomy, with a negative appendectomy rate of 9%. One hundred twenty-five patients without appendicitis were treated nonoperatively. The true-positive rate was 32%, true-negative rate was 64%, sensitivity was 97%, specificity was 99%, positive predictive value was 98%, negative predictive value was 98%, and overall accuracy was 96%. Pediatric patients tolerated the procedure well. Colonic contrast material saved time and provided improved identification of the cecum and appendix. In 62 patients without appendicitis, focused CT provided alternative diagnoses. CONCLUSION: Focused CT appears to be nearly as accurate in pediatric patients as in adults. Focused CT provided alternative diagnoses in 48% of the patients for whom CT findings were negative for appendicitis.

Helical CT in emergency radiology.

Today, a wide range of traumatic and nontraumatic emergency conditions are quickly and accurately diagnosed with helical computed tomography (CT). Many traditional emergency imaging procedures have been replaced with newer helical CT techniques that can be performed in less time and with greater accuracy, less patient discomfort, and decreased cost. The speed of helical technology permits CT examination of seriously ill patients in the emergency department, as well as patients who might not have been taken to CT previously because of the length of the examinations of the past. Also, helical technology permits multiple, sequential CT scans to be quickly obtained in the same patient, a great advance for the multiple-trauma patient. Higher quality CT examinations result from decreased respiratory misregistration, enhanced intravenous contrast material opacification of vascular structures and parenchymal organs, greater flexibility in image reconstruction, and improved multiplanar and three-dimensional reformations. This report summarizes the role and recommended protocols for the helical CT diagnosis of thoracic aortic trauma; aortic dissection; pulmonary embolism; acute conditions of the neck soft tissues; abdominal trauma; urinary tract stones; appendicitis; diverticulitis; abdominal aortic aneurysm; fractures of the face, spine, and extremities; and acute stroke.

Helical CT of appendicitis and diverticulitis.

The clinical diagnosis of appendicitis and diverticulitis remains challenging. Clinical diagnosis alone can lead to unnecessary hospitalizations and surgeries, prolonged periods of hospital observation, and delays prior to necessary medical or surgical treatment. Helical CT combined with recently reported techniques for imaging appendicitis and diverticulitis offers rapid and accurate confirmation or exclusion of these entities as well as identification of alternative conditions that can clinically mimic them. More routine use of helical CT holds great promise for improving patient care and lowering hospital resource use in patients with clinically suspected appendicitis and diverticulitis.

Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT.

This study determined the diagnostic utility and hospital resource impact of plain abdominal radiography in emergency department patients with suspected appendicitis. The authors reviewed medical records of 821 consecutive patients hospitalized for suspected appendicitis; 78% had plain abdominal radiography. Sixty-four percent had appendicitis. Radiographic findings were noted in 51% of patients with, and 47% of patients without appendicitis; no individual radiographic finding was sensitive or specific. Specific conditions were suggested in 10% of impressions; these failed to correlate with final clinical diagnoses 57% of the time. Hospital cost per abdominal radiograph was $67; cost per specific, correct radiographic diagnosis was $1,593. This is compared with $270 per appendiceal computed tomography scan (based on recent literature data). The authors conclude that plain abdominal radiographs in patients with suspected appendicitis are neither sensitive nor specific, are frequently misleading, are costly per specific and correct diagnosis, and should not be routinely obtained on patients with suspected appendicitis.

Helical CT and three-dimensional CT of facial and orbital injury.

Knowledge of the regions of the face and their buttresses and knowledge of the types of facial injuries frequently encountered simplifies the diagnostic task. The indications for CT include detection of suspected fractures and preoperative planning. The cost of facial CT to the hospital has declined and is little different than the cost of plain films. CT may become the screening modality of choice depending on the cost structure at any given hospital.

Helical CT of abdominal trauma.

CT has revolutionized the diagnostic work-up of trauma patients with suspected abdominal injuries. A wide range of intraperitoneal and retroperitoneal organ injuries can be quickly and accurately diagnosed with CT. Today, helical CT technology permits even faster examinations, with improved intravenous contrast opacification of parenchymal organs and vascular structures and reduced CT artifacts caused by patient motion, respiration, and arterial pulsation. Severely injured and potentially unstable patients, who might not have been able to tolerate the long CT examinations of the past, may be quickly evaluated today with helical CT. Accurate diagnosis requires high quality CT examinations that are performed with optimum CT protocols. This article reviews the currently recommended helical CT protocols for evaluating patients with suspected abdominal injuries, and the CT findings when injuries are present.

Cost comparison of radiologic versus surgical placement of long-term hemodialysis catheters.

OBJECTIVE: The purpose of this study was to compare the cost of radiologic versus surgical placement of long-term hemodialysis catheters. MATERIALS AND METHODS: Our cost analysis was based on 47 long-term hemodialysis catheters radiologically placed in 45 patients and 25 catheters surgically placed in 25 patients from October 1996 through March 1997. Variable and total costs were calculated using data from the hospital administrative computer system that records the actual costs incurred by the hospital in caring for patients. RESULTS: The average total hospital cost was $926 for each radiologic placement and $1849 for each surgical placement of long-term hemodialysis catheters. The total cost saving for radiologic placement was $923 for each catheter. CONCLUSION: Radiologic placement of long-term hemodialysis catheters resulted in substantial savings over surgical placement.

Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates.

UNLABELLED: OBJECTIVE To evaluate the impact of appendiceal computed tomography (CT) availability on negative appendectomy and appendiceal perforation rates. SUMMARY BACKGROUND DATA: Appendiceal CT is 98% accurate. However, its impact on negative appendectomy and appendiceal perforation rates has not been reported. METHODS: The authors reviewed the medical records of 493 consecutive patients who underwent appendectomy between 1992 and 1995, 209 consecutive patients who underwent appendectomy in 1997 (59% of whom had appendiceal CT), and 206 patients who underwent appendiceal CT in 1997 without subsequent appendectomy. RESULTS: Before appendiceal CT, 98/493 patients (20%) taken to surgery had a normal appendix. After CT availability, 15/209 patients (7%) taken to surgery had a normal appendix; 7 patients did not have CT, 5 patients had surgery despite a negative CT, and 3 patients had a false-positive CT. Negative appendectomy rates were lowered overall (20% to 7%), in men (11% to 5%), in women (35% to 11%), in boys (10% to 5%), and in girls (18% to 12%). Appendiceal perforation rates dropped from 22% to 14% after CT availability. CT excluded appendicitis in 206 patients in 1997 who avoided appendectomy and identified alternative diagnoses in 105 of these patients (51%). CONCLUSION: The availability of appendiceal CT coincided with a drop in the negative appendectomy rate from 20% to 7% in all patients, and to only 3% in patients with a positive CT. Perforation rates decreased from 22% to 14%. Appendiceal CT can be advocated in nearly all female and many male patients.

Helical computed tomography in differentiating appendicitis and acute gynecologic conditions.

OBJECTIVE: To determine the accuracy and effect of helical computed tomography (CT) in women clinically suspected of having either appendicitis or an acute gynecologic condition. METHODS: One hundred consecutive nonpregnant women suspected of having appendicitis or an acute gynecologic condition prospectively had helical CT. Interpretations were correlated with surgical and pathologic findings (41 cases) and clinical follow-up for at least 2 months (59 cases). The accuracy for confirming or excluding both appendicitis and acute gynecologic conditions was determined. The effect on patient care was determined by comparing pre-CT plans with actual treatment. RESULTS: Thirty-two women had appendicitis, 15 had acute gynecologic conditions, 27 had other specific diagnoses, and 26 had nonspecific abdominal pain. For diagnosing appendicitis or acute gynecologic conditions, CT had 100% and 87% sensitivity, 97% and 100% specificity, 94% and 100% positive predictive value, 100% and 98% negative predictive value, and 98% and 98% accuracy, respectively. After CT was done, 36 planned hospital admissions, 25 planned hospital observations, and six planned appendectomies were deferred; six women had alternative surgical procedures on the basis of CT results. One patient had an unnecessary appendectomy on the basis of CT findings. CONCLUSION: Helical CT is an excellent imaging option for differentiating appendicitis from most acute gynecologic conditions.

Colonic diverticulitis: evaluation of the arrowhead sign and the inflamed diverticulum for CT diagnosis.

PURPOSE: To determine the frequency of visualization of the arrowhead sign and an inflamed diverticulum on abdominal computed tomographic (CT) scans in patients with acute colonic diverticulitis and to assess the specificity of these signs. MATERIALS AND METHODS: One hundred fifty consecutive patients suspected of having diverticulitis prospectively underwent helical CT after the administration of contrast material by means of an enema. Sixty-four patients (43%) had a final clinical diagnosis of colonic diverticulitis. Each scan was reviewed for the arrowhead sign, an arrowhead-shaped collection of contrast material within focal colonic wall thickening, and for an inflamed diverticulum, a rounded, paracolic outpouching centered within fat stranding. RESULTS: The arrowhead sign was noted at CT in 17 (27%) of the 64 patients with diverticulitis. An inflamed diverticulum was noted in 21 patients (33%) at CT, with either calcium or similar high-attenuation material in 10 (48%) of the 21 patients, soft-tissue attenuation in six patients (29%), air attenuation in four patients (19%), and barium attenuation in one patient (5%). Neither sign was demonstrated in patients with alternative conditions (100% specificity). CONCLUSION: The arrowhead sign and an inflamed diverticulum are occasional, specific CT signs of colonic diverticulitis. Their identification can add diagnostic specificity to CT of acute colonic processes.

Misdiagnosis of primary epiploic appendagitis.

BACKGROUND: The authors determined the radiological misdiagnosis rate of primary epiploic appendagitis (PEA) and its impact on patient management and hospital resource use. METHODS: A total of 660 computed tomography scans performed for clinically suspected diverticulitis (348 cases) or appendicitis (312 cases) were reviewed for cases meeting strict radiological criteria for PEA. Retrospective interpretations were compared with radiological reports. Medical records and hospital cost data were reviewed to estimate impact on patient management and resource use. RESULTS: Eleven scans (2%) met criteria for PEA. Seven scans were initially misdiagnosed as diverticulitis (6 patients) or appendicitis (1 patient). All misdiagnosed patients were hospitalized (mean 4.3 days); 6 received antibiotic therapy. Average cost per patient was $4,117. Four scans were initially correctly diagnosed as PEA. One patient was hospitalized (1 day); none received antibiotic therapy. Average cost per patient was $1,205. CONCLUSIONS: Radiological misdiagnosis of PEA leads to unnecessary hospitalization, medical treatment, and overuse of hospital resources.

Helical CT with only colonic contrast material for diagnosing diverticulitis: prospective evaluation of 150 patients.

OBJECTIVE: We prospectively evaluated a helical CT technique in which contrast material is administered only through the colon for the imaging of suspected diverticulitis. SUBJECTS AND METHODS: One hundred fifty consecutive patients who presented to our emergency department with clinically suspected diverticulitis underwent helical abdominal CT after contrast material was administered only through the colon. CT findings of diverticulitis included diverticula, muscular wall hypertrophy, focal colonic wall thickening, and pericolonic fat stranding. CT results were correlated with clinical follow-up (all patients) and with pathologic findings (41 patients). RESULTS: A final clinical diagnosis of diverticulitis was made in 64 patients (43%), of whom 62 (97%) had CT results positive for diverticulitis. Of the 86 patients for whom diverticulitis was clinically excluded, all (100%) had CT results that were negative for diverticulitis. CT interpretations had a sensitivity of 97%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 98%, and an overall accuracy of 99%. Alternative diagnoses were noted on CT in 50 (58%) of 86 patients who did not have diverticulitis and included 50 (78%) of the 64 patients in whom an alternative condition other than nonspecific abdominal pain was established. CONCLUSION: Helical CT obtained after contrast material administered only through the colon is accurate (99%) for confirming or excluding clinically suspected diverticulitis and for suggesting alternative conditions (78%) when they are present. This CT technique avoids the risks, discomforts, and costs of oral and i.v. contrast material administration and allows immediate scanning.

The computed tomography appearance of recurrent and chronic appendicitis.

The objective of this study was to determine computed tomography (CT) appearance of recurrent and chronic appendicitis. In 100 consecutive appendiceal CT examinations of proven appendicitis, 18 patients met criteria for recurrent (multiple discrete episodes) or chronic (continuous symptoms > 3 weeks, pathological findings) appendicitis. CT findings were reviewed. Ten patients had recurrent appendicitis, 3 had chronic appendicitis, 3 had both, and 2 had pathological chronic appendicitis. CT findings in 18 recurrent/chronic cases were identical to 82 acute appendicitis cases, including pericecal stranding (both 100%), dilated (> 6 mm) appendix (88.9% versus 93.9%), apical thickening (66.7% versus 69.5%), adenopathy (66.7% versus 61.0%), appendolith(s) (50% versus 42.7%), arrowhead (27.8% versus 22.0%), abscess (11.1% versus 11.0%), phlegmon (11.1% versus 6.1%), and fluid (5.6% versus 19.5%). CT findings in recurrent and chronic appendicitis are the same as those in acute appendicitis. Appendiceal CT can be beneficial for evaluating patients with suspected recurrent or chronic appendicitis.

Effect of computed tomography of the appendix on treatment of patients and use of hospital resources.

BACKGROUND: In patients with clinically suspected appendicitis, computed tomography (CT) is diagnostically accurate. However, the effect of routine CT of the appendix on the treatment of such patients and the use of hospital resources is unknown. METHODS: We performed appendiceal CT on 100 consecutive patients in the emergency department who, on the basis of history, physical examination, and laboratory results, were to be hospitalized for observation for suspected appendicitis or for urgent appendectomy. Outcomes were determined at surgery and by pathological examination in 59 patients, and by clinical follow-up two months later in 41 patients. Treatment plans made before CT were compared with the patients' actual treatment. We also determined the costs of surgery that revealed no appendicitis (from data on 61 patients), one day of observation in the hospital (from data on 350 patient-days in patients with suspected appendicitis), and appendiceal CT (from data on all pelvic CT examinations in 1996). RESULTS: Fifty-three patients had appendicitis, and 47 did not. The interpretations of the appendiceal CT scans were 98 percent accurate. The results of CT led to changes in the treatment of 59 patients. These changes resulted in the prevention of unnecessary appendectomy in 13 patients, admission to the hospital for observation in 18 patients, admission to the hospital for observation before necessary appendectomy in 21 patients, and admission to the hospital for observation before the diagnosis of other conditions by CT in 11 patients. The effects of performing appendiceal CT on the use of hospital resources included the prevention of unnecessary appendectomy in 13 patients (for a savings of $47,281) and the prevention of unnecessary hospital admission for 50 patient-days (for a savings of $20,250). After the cost of 100 appendiceal CT studies ($22,800) was subtracted, the overall savings was $447 per patient. CONCLUSIONS: Routine appendiceal CT performed in patients who present with suspected appendicitis improves patient care and reduces the use of hospital resources.

Appendiceal and peri-appendiceal air at CT: prevalence, appearance and clinical significance.

AIM: Appendiceal air has been reported as both a sign of appendicitis and of a normal appendix both at plain radiography and computed tomography (CT). It is the aim of this investigation to determine the prevalence, range of appearances, and significance of appendiceal and peri-appendiceal air at CT. PATIENTS AND METHODS: Appendiceal CT scans of 100 patients with proven appendicitis and 100 patients with a normal appendix were reviewed for the presence of appendiceal and peri-appendiceal air. All cases were correlated with surgical and pathological findings or clinical follow-up. RESULTS: In 100 CT cases of appendicitis, appendiceal and/or peri-appendiceal air was present in one or more forms in 31% of cases. When present, it appeared as intraluminal air bubbles (38.7%) or air-fluid levels (22.6%), appendolith air (41.9%), intramural air (16.1%), peri-appendiceal air bubbles (12.9%), or extraluminal air-fluid level(s) (29.0%). Intramural and extraluminal air correlated with perforation in 60% and 100%, respectively. In 100 CT cases of a normal appendix, air was present in 57%. It was always intraluminal and appeared as small bubbles of air (52.6%), a tubular-shaped air collection (43.9%), or as an air-fluid level (3.5%). The appendiceal lumen was either airless (43%), or minimally (32%), moderately (18%), or completely filled with air (7%). CONCLUSION: Air is a common finding at appendiceal CT in both the normal and inflamed appendix. Intraluminal air is seen in both appendicitis and normal appendices, and cannot be presumed to indicate a patent lumen and thus a normal appendix. Appendolith, intramural and peri-appendiceal air appear diagnostic of appendicitis.

Helical CT combined with contrast material administered only through the colon for imaging of suspected appendicitis.

OBJECTIVE: Helical CT combined with contrast material administered by mouth and through the colon has been shown to be accurate for appendiceal imaging. This investigation was performed to determine if helical CT combined with contrast material administered only through the colon has comparable accuracy. SUBJECTS AND METHODS: One hundred patients prospectively underwent appendiceal CT imaging with thin-collimation, helical scanning limited to the lower abdomen and upper pelvis after contrast material was administered only through the colon. CT results were correlated with surgical and pathologic findings at appendectomy (56 patients), other surgery (three patients), or clinical follow-up at least 2 months after the CT scan (41 patients). RESULTS: Fifty-three CT scans were interpreted as positive for appendicitis, including 52 true-positives (with surgical-pathologic correlation) and on false-positive (with clinical follow-up). Forty-seven CT scans were interpreted as negative for appendicitis, including 40 true-negatives with clinical follow-up, three true-negatives with appendectomy and pathologic correlation, three true-negatives with other surgery and pathologic correlation, and one false-negative with appendectomy and pathologic correlation. CT had a 98% sensitivity, 98% specificity, 98% positive predictive value, 98% negative predictive value, and 98% accuracy for diagnosing or excluding appendicitis. In 47 normal appendix cases at CT, the appendix was seen in 44 cases (94%), and an alternative diagnosis was identified in 29 cases (62%). CONCLUSION: For diagnosing appendicitis, helical CT combined with contrast material administered only through the colon proved to be as accurate (98%) as helical CT combined with contrast material administered by mouth and through the colon. Helical CT with contrast material administered only through the colon also could be performed immediately and without any of the potential patient risks or discomforts of contrast material administered i.v. or by mouth.

Sensitivity and specificity of the individual CT signs of appendicitis: experience with 200 helical appendiceal CT examinations.

PURPOSE: Our goal was to determine the sensitivity, specificity, and diagnostic value of individual signs at helical appendiceal CT. METHOD: Two hundred helical appendiceal CT scans (100 appendicitis and 100 normal appendix cases) were interpreted for individual signs of appendicitis. Scan findings were correlated with appendectomy or clinical follow-up results. RESULTS: Individual CT signs identified and their sensitivity and specificity, respectively, included fat stranding (100%, 80%), enlarged (> 6 mm) unopacified appendix (93%, 100%), focal cecal apical thickening (69%, 100%), adenopathy (62%, 66%), appendolith(s) (44%, 100%), arrowhead sign (23%, 100%), paracolic gutter fluid (18%, 86%), abscess (11%, 100%), cecal bar (10%, 100%), extraluminal air (8%, 97%), phlegmon (7%, 99%), ileal (3%, 86%) or sigmoid (3%, 95%) wall thickening, and diffuse cecal wall thickening (0%, 91%). CONCLUSION: Individual appendiceal CT signs of appendicitis vary in sensitivity, specificity, and thus diagnostic value. An enlarged appendix with periappendiceal fat stranding occurs in 93% of appendicitis CT cases. Less common but specific signs [cecal apical changes, appendolith(s) are usually present in the remaining appendicitis cases. Some signs seen with appendicitis (adenopathy, fat stranding, adjacent bowel wall thickening, fluid) can also be noted with alternative conditions, and in these cases normal appendix identification is the key to excluding appendicitis.

Distal appendicitis: CT appearance and diagnosis.

PURPOSE: To determine the appearance of appendicitis in the distal part of the organ (distal appendicitis) on computed tomographic (CT) scans and to evaluate the accuracy of diagnosis based on CT findings. MATERIALS AND METHODS: CT scans and medical records in 180 consecutive patients with proved appendicitis were reviewed. Fourteen had distal appendicitis with at least a 3-cm length of normal proximal appendix. Appendiceal CT scans and initial reports were reviewed retrospectively. RESULTS: The proximal appendix was collapsed (n = 6) or was filled with contrast material (n = 6) or air (n = 2). Inflamed distal appendices averaged 13.2 mm in diameter and were associated with periappendiceal fat stranding (n = 14), adenopathy (n = 6), appendolith(s) (n = 4), or fluid (n = 2). Transition points consisted of a progressively narrowed appendiceal lumen and thickened wall (n = 5) or appendiceal diameter enlargement (n = 9). No cecal apical changes were seen. Scans in all 14 patients were prospectively interpreted as indicative of appendicitis, including 12 (86%) interpreted as indicative of distal appendicitis. CONCLUSION: CT findings are useful for the accurate diagnosis of distal appendicitis. Visualization of the proximal appendix alone is insufficient to exclude distal appendicitis.