Identification of the normal appendix in healthy adults by 64-slice MDCT: the value of adding coronal reformation images

Abstract

The aim of this study was to assess retrospectively the value of adding coronal reformation images to the identification of the normal appendix using 64-slice multidetector CT (MDCT). 200 consecutive healthy adults with no history of abdominal surgery underwent abdominal CT using 64-slice MDCT without oral contrast administration and were enrolled in the study. Two gastrointestinal radiologists first interpreted the axial images only; after a 2-week interval, they then interpreted both the axial and the coronal images while blinded to the first interpretation. The identification of the normal appendix was interpreted using a four-point scale: 1, not identified; 2, identified with low confidence; 3, probably identified; 4, definitely identified. Agreement between the readers was determined with the use of weighted kappa statistics. Differences in confidence ratings for identification of the appendix were determined with the Wilcoxon signed rank test. The agreement between the readers was higher when both axial and coronal images were reviewed (kappa = 0.85) than when only the axial scans images were reviewed (kappa = 0.43). The mean confidence scores for the identification of the normal appendix by the two readers were significantly higher when both the axial and coronal images were reviewed (mean, 3.81+/-0.498 and 3.83+/-0.485 for the two readers, respectively) than when only the axial images were reviewed (mean, 3.27+/-0.819 and 3.47+/-0.856, respectively) (all p<0.01). Therefore, adding coronal reformation images to 64-slice MDCT significantly improves inter-reader agreement and confidence in the identification of the normal appendix.

Diagnostic Usefulness of Low-Dose Nonenhanced Computed Tomography With Coronal Reformations in Patients With Suspected Acute Appendicitis

“…This finding may be attributable to their use of axial images only, without coronal reformation. Several studies [4][5][6][7][8] have reported that coronal reformatted images are crucial in diagnosing acute appendicitis because they improve appendix visualization. We used both axial and coronal reformatted images in NECT scan to assess the appendix.…”

“…2,3 The diagnostic accuracy of acute appendicitis has improved by using coronal reformatted images. [4][5][6][7][8] Recently, a few studies 9-11 using the sliding slab ray-sum technique to diagnose acute appendicitis reported high area under the curve (AUC) values ranging between 0.96 and 0.98.Despite the high overall accuracy of MDCT, it is still unclear which method of CT is optimal in diagnosing acute appendicitis. Standard-dose (SD) contrast-enhanced CT (CECT) scan with intravenous and oral contrast administration is the most commonly used protocol.…”

“…2,3 The diagnostic accuracy of acute appendicitis has improved by using coronal reformatted images. [4][5][6][7][8] Recently, a few studies 9-11 using the sliding slab ray-sum technique to diagnose acute appendicitis reported high area under the curve (AUC) values ranging between 0.96 and 0.98.…”

Evaluation of Normal Appendix in Adult Jordanians Using Non-Enhanced Dual Source 64-Slice MDCT = تقييم الزائدة الدودية الطبيعية عند الأردنيين البالغين باستخدام الطبقي المحوي

“…This advancement together with commercially available picture archiving and communication system (PACS) that enables rapid reconstruction and viewing of images in various planes has led to significant improvement in the evaluation of normal appendix with identification rates varied from 82% to 98.5% have been reported. 1,2,3 However, in most of these reports, CT evaluation of normal appendix was performed with oral, rectal, and intravenous contrast material administration, with only few studies that have investigated the normal appendix by non-enhanced MDCT have been described in literature. 4,5,6 The aim of this study was to investigate the visualization rate and morphology of normal appendix on non-enhanced MDCT examination in patients not suspected to have appendicitis.…”

Visualization of Normal Appendix during non-Contrast Renal CT Scan at King Hussein Medical Centre

“…(12) With the introduction of multi detector CT (MDCT) technology, visualization of normal appendix was improved as the spatial resolution becomes higher and with the ability to evaluate the appendix by multiplanar reformation images. (4,13) The rate of visualization of normal appendix ranges from 43% to 91%, with few studies found in the literature addressing this issue. (14,15) Several studies show that lack of visualization of appendix on CT reliably excludes the diagnosis of acute appendicitis especially in the absence of secondary inflammatory signs and the visualization of normal appendix suggests a normal scan.…”