Chee-Wai Mak

Clinical Significance of Poor CT Enhancement of the Thickened Small-Bowel Wall in Patients with Acute Abdominal Pain

OBJECTIVE Our purpose was to compare clinical outcomes in patients with acute abdominal pain and inner-layer enhancement of a thickened small-bowel wall, as shown on CT, with outcomes in similar patients without such enhancement. MATERIALS AND METHODS We retrospectively studied outcomes in 126 patients with acute abdominal pain and small-bowel wall thickening on CT: 84 with inner-layer enhancement and 42 without this enhancement. We compared the surgical, small-bowel resection, small-bowel necrosis, and mortality rates between the two groups using the chi-square test. RESULTS Among the 42 patients without inner-layer enhancement, 32 (76%) underwent an operation, 27 (64%) received segmental small-bowel resection, 26 (62%) had small-bowel necrosis, and seven (17%) died. All of these proportions were significantly higher (p < 0.01) than the corresponding rates-34 (40%), nine (11%), five (6%), and two (2%), respectively-in the 84 patients with inner-layer enhancement. All 31 patients with necrotic small bowel had pathologic evidence of ischemic necrosis involving the mucosa. CONCLUSION Among patients with acute abdominal pain, those whose CT scans did not show inner-layer enhancement of a thickened small-bowel wall were more prone to undergo surgery and small-bowel resection and were more likely to have small-bowel necrosis than those with such enhancement. Poor inner-layer enhancement on CT might be consistent with sloughed or necrotic mucosa, as observed on pathology.

Computed Tomography Appearance of Ovarian Fibrothecomas With and Without Torsion

Background: Fibrothecomas are the most common solid ovarian tumors and may undergo torsion. Early diagnosis of these tumors is important in order to allow prompt surgical treatment. Purpose: To describe the features of ovarian fibrothecoma on computed tomography (CT) and to determine the possibility of detecting tumor torsion in this kind of tumor. Material and Methods: The CT images of 11 patients with ovarian fibrothecomas in the past 8 years at our hospital were retrospectively reviewed. The CT attenuation values of each tumor were measured in both non-enhanced and enhanced scans. The size and degree of enhancement were evaluated and correlated with tumor torsion. All cases were pathologically proven. Results: Three kinds of tumor pattern were found: 1) homogeneous tumor with significant enhancement containing scattered, low-attenuated regions after contrast injection; 2) heterogeneous tumor with mild enhancement after contrast injection; and 3) low-attenuated soft-tissue mass with no obvious enhancement after contrast injection. Conclusion: Fibrothecomas usually appear as a homogeneous solid tumor with varying degrees of enhancement. Calcification may be present and, as these tumors enlarge, myxoid or cystic degeneration may occur, resulting in a heterogeneous pattern. The larger the tumor, the greater is the chance of torsion. Lack of tumor enhancement is the most reliable sign for detection of ovarian torsion and should facilitate prompt surgical intervention to remove damaged tissue.

CT-guided transthoracic cutting needle biopsy of intrathoracic lesions: Comparison between coaxial and single needle technique

PURPOSE To evaluate the complication rates and diagnostic accuracy of two different CT-guided transthoracic cutting needle biopsy techniques: coaxial method and single needle method. METHODS This study involved 198 consecutive subjects with 198 intrathoracic lesions. The first 98 consecutive subjects received a single needle cutting technique and the next 100 consecutive subjects received a coaxial technique. Both groups were compared in relation the diagnostic accuracy and complication rates. RESULTS No significant difference was found between the two groups concerning patient characteristics, lesions and procedure variables. There was a borderline statistical difference in the incidence of pneumothorax at within 24-h post biopsy between patients in the single needle group (5%) and the coaxial group (13%) (P=0.053). Little difference was found in the pneumothorax rate at immediately post biopsy between the two groups, which was 28% in the single needle group and 31% in the coaxial group. There was no significant difference in the hemoptysis rate between the two groups, which was 9.2% in the single needle group and 11% in the coaxial group. Both techniques yielded an overall diagnostic accuracy of 98% for malignant lesions with similar sensitivity (single needle: 96.9% vs. coaxial: 96.4%) and specificity (single needle: 100% vs. coaxial: 100%). CONCLUSION There is little difference in the pneumothorax rates and bleeding complications between patients who either received a single needle or a coaxial transthoracic cutting biopsy. Both techniques produce an overall diagnostic accuracy of 98% for malignant lesions.

Sonographic appearance of angiolymphoid hyperplasia with eosinophilia in the upper arm

Angiolymphoid hyperplasia with eosinophilia is an uncommon benign condition characterized by cutaneous nodules involving primarily the head and neck regions of young adults. We report thecase of a 49‐year‐old woman with such a lesion in the arm. Sonographically, the lesion exhibited a hypoechoic rim and an echogenic central portion. On color Doppler imaging, the central portion was markedly vascular.

Renal capsular leiomyoma: report of a case with unusual CT appearance

Clinically symptomatic renal capsular leiomyomas are rare. Previous research has shown that these tumors are usually well-defined cystic lesions, solid lesions, or a mixture of the two. We report an unusual case of renal capsular leiomyoma which was well defined by ultrasonography, but lacked a well-defined edge in CT. The reason for the absence of a well-defined tumor edge is probably due to degeneration in certain parts of the tumor resulting in a different degree of enhancement. Thus, the possibility of renal capsular leiomyoma should be included in the differential diagnosis whenever a renal mass is found, especially when either CT or ultrasonography shows that the tumor has a smooth, well-defined contour.

A comparison of pyelography and various reconstructions of multidetector helical computed tomography urography images for diagnosing urinary obstruction

Radiologists and urologists require practical and helpful image reconstructions for diagnosing urinary obstruction. We performed different types of imaging and reconstruction, then used a self-designed urinary obstruction-specific questionnaire to evaluate the diagnostic outcome of them. Our results suggested that two-dimensional (2D) axial computed tomography (CT) is clinically superior to retrograde pyelography or antegrade pyelography, and to other modes of image reconstruction that are often used for diagnosing urinary obstruction.