Biomedical subjects

J N Lawrason

Publications and source records attributed to J N Lawrason.

4 recordsLinked to original sources

PubMed1998

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.

Adult↗

PubMed1997

Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination.

PURPOSE: To evaluate a focused, helical computed tomographic (CT) technique for imaging the appendix in patients suspected of having appendicitis. MATERIALS AND METHODS: One hundred patients prospectively underwent appendix CT examination, with use of oral and colon contrast media and contiguous, thin-collimation, helical CT imaging of the right lower quadrant. Results were correlated with the results of surgery and pathologic examination from 61 patients or from clinical follow-up in 39 patients. RESULTS: CT scans were positive for appendicitis in 59 patients: true-positive in 56 patients on the basis of surgery and pathologic examination, and false-positive in two patients on the basis of clinical follow-up; in the case of the other positive scan, the clinical outcome was indeterminate. CT scans were negative for appendicitis in 41 patients: true-negative in five patients on the basis of surgery and pathologic examination, and true-negative in 36 patients on the basis of clinical follow-up. CT had a sensitivity of 100%, a specificity of 95%, a positive predictive value of 97%, a negative predictive value of 100%, and an accuracy of 98%. The normal appendix was always identified. CT helped establish alternative diagnoses in 33 of the 41 patients (80%) in whom the results of CT were negative for appendicitis. CONCLUSION: Appendix CT examination can help diagnose or exclude appendicitis and establish an alternative diagnosis.

Acute Disease↗

PubMed1997

Primary epiploic appendagitis: evolutionary changes in CT appearance.

PURPOSE: To determine the changes in the computed tomographic (CT) appearance of primary epiploic appendagitis. MATERIALS AND METHODS: Clinical records and CT scans were reviewed in 10 patients who were initially suspected of having diverticulitis or appendicitis but were later determined to have primary epiploic appendagitis. The scans were obtained at the time of presentation and at follow-up 1-84 weeks later. RESULTS: Initial CT characteristics included mean size of 14 x 21 mm, oval (n = 9) or round (n = 1) shape, mean attenuation of -53 HU, visceral (n = 10) or parietal (n = 7) peritoneal thickening, periappendageal fat stranding (n = 10), adjacent bowel wall thickening (n = 4) or compression (n = 2), and central high-attenuating dot (n = 2). Follow-up CT characteristics included residual abnormality (n = 9); mean size of 10 x 15 mm; oval (n = 6), round (n = 2), or indistinct (n = 1) shape; mean attenuation of -68 HU; visceral (n = 5) or parietal (n = 3) peritoneal thickening; periappendageal fat stranding (n = 1); and central high-attenuating dot (n = 1). CT characteristics of the remnant lesion included smaller lesion with fat attenuation (n = 6), nugget with soft-tissue attenuation (n = 2), and nondescript fat stranding (n = 1). CONCLUSION: Awareness of the CT appearance of acute and healing primary epiploic appendagitis may help in the differential diagnosis of pericolonic abnormality.

Adult↗

PubMed1997

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.

Adult↗