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

Urothelial-phase thin-section MDCT of the bladder in patients with hematuria: added value of multiplanar reformatted images

PURPOSE

To evaluate the diagnostic performance of MDCT with axial images and multiplanar reformatted (MPR) images from the urothelial phase of the bladder in patients with hematuria using cystoscopy as the reference standard.

MATERIALS AND METHODS

Our IRB for human investigation approved this study, and informed consent was waived. We included 192 patients (121 men, 71 women; age range 17-90 years; mean age ± SD: 60 ± 14 years) who underwent contrast-enhanced MDCT (scan delay: 70 s; section thickness: 2 mm) and conventional cystoscopy examination for painless gross hematuria or recurrent microscopic hematuria. Two radiologists in consensus interpreted the images for the presence or absence of bladder lesions. Using the kappa statistic, the patient-based agreement was determined between the CT and cystoscopic findings. We compared the diagnostic performance of axial images to those with coronal and sagittal reformations to detect bladder lesions.

RESULTS

MDCT showed excellent agreement between cystoscopy-axial scans (κ = 0.896) and axial with reformatted images (κ = 0.948). The sensitivity, specificity, and accuracy of MDCT were 94%, 96%, and 95% in the axial scans and 98%, 97%, and 97% in the axial with reformatted images, respectively. All statistical parameters of diagnostic performance were similar between the axial and the reformatted images (p > .05).

CONCLUSION

Axial MDCT imaging demonstrates high diagnostic performance in detecting bladder lesions, but additional reformatted images can improve diagnostic accuracy.

A pictorial essay of the most atypical variants of the vermiform appendix position in computed tomography with their possible clinical implications

Purpose

The tip of the appendix may be located in various areas of the abdominal cavity due to its variable length and/or the changeable position of the caecum. Although in the case of an atypical position the tip is usually located behind the caecum, there are possible locations that occur very rarely. Therefore, in the case of appendicitis the symptoms may lead to the wrong diagnosis. The aim of this study is to present the most atypical locations of the tip of the appendix found on CT (computed tomography) scans and thus help to avoid misdiagnoses.

Imaging findings

The most unusual locations of the tip of the appendix found in healthy subjects included: left inferior quadrant, along the lower edge of the liver near the gallbladder and the right kidney, the tip touching the duodenum, the rectum or appendages, and a long appendix located in the scrotum as the content of a hernia. In these positions, appendicitis may mimic acute diverticulitis, cholecystitis, duodenal ulcer, duodenitis, enteritis, or adnexal or testis pathologies.

Conclusions

It is important to be aware of atypical locations of the appendix because appendicitis in an unusual area may mimic other acute abdominal diseases and delay the proper treatment.

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

PURPOSE

The aims of the study were to evaluate the usefulness of low-dose (LD) nonenhanced CT (NECT) with coronal reformation in diagnosing acute appendicitis and to compare LD NECT with standard-dose (SD) NECT and SD contrast-enhanced CT (CECT).

METHODS

A total of 452 patients suspected of having acute appendicitis underwent CT using a scan 1 (SD NECT and SD CECT1, n = 182) or a scan 2 protocol (LD NECT and SD CECT2, n = 270). The diagnostic performance and interobserver agreement for diagnosing acute appendicitis were compared.

RESULTS

Although the area under the curves of both reviewers of LD NECT were lower than those of SD CECT2, area under the curves of both reviewers for SD NECT were not significantly different for SD CECT1 and LD NECT (all P > 0.05). The interobserver agreements within each scan were excellent (all κ > 0.8).

CONCLUSIONS

Low-dose NECT with coronal reformation showed high diagnostic performance and can be used as the first-line imaging tool in the work-up of patients with suspected acute appendicitis.

Morphology of the distal thoracic duct and the right lymphatic duct in different head and neck pathologies: an imaging based study

Background

The purpose of this study was to assess the influence of head and neck pathologies on the detection rate, configuration and diameter of the thoracic duct (TD) and right lymphatic duct (RLD) in computed tomography (CT) of the head and neck.

Methods

One hundred ninety-seven patients were divided into the subgroups "healthy", "benign disease" and "malignant disease". The interpretation of the images was performed at a slice thickness of 3 mm in the axial and coronal plane. In each case we looked for the distal part of the TD and RLD respectively and subsequently evaluated their configuration (tubular, sacciform, dendritic) as well as their maximum diameter and correlated the results with age, gender and diagnosis group.

Results

The detection rate in the study population was 81.2 % for the TD and 64.2 % for the RLD and did not differ significantly in any of the subgroups. The predominant configuration was tubular. The configuration distribution did not differ significantly between the diagnosis groups. The mean diameter of the TD was 4.79 ± 2.41 mm and that of the RLD was 3.98 ± 1.96 mm. No significant influence of a diagnosis on the diameter could be determined.

Conclusions

There is no significant influence of head/neck pathologies on the CT detection rate, morphology or size of the TD and RLD. However our study emphasizes that both the RLD and the TD are detectable in the majority of routine head and neck CTs and therefore reading physicians and radiologists should be familiar with their various imaging appearances.

Can outer-to-outer diameter be used alone in diagnosing appendicitis on 128-slice MDCT?

AIM: To assess the frequency of visualization, position and diameter of normal appendix on 128-slice multidetector computed tomography (MDCT) in adult population.

METHODS: Retrospective cross sectional study conducted at Radiology Department, Dallah Hospital, Riyadh, Saudi Arabia from March 2013 to October 2013. Non-enhanced computed tomography scans of abdomen and pelvis of 98 patients presenting with hematuria (not associated with abdominal pain, fever or colonic disease) were reviewed by two radiologists, blinded to patient history. The study group included 55 females and 43 males with overall mean age of 54.7 years (range 21 to 94 years). The coronal reformatted images were reviewed in addition to the axial images. The frequency of visualization of appendix was recorded with assessment of position, diameter and luminal contents.

RESULTS: The appendix was recorded as definitely visualized in 99% of patients and mean outer-to-outer diameter of the appendix was 5.6 ± 1.3 mm (range 3.0-11.0 mm).

CONCLUSION: MDCT with its multiplanar reformation display is extremely useful for visualization of normal appendix. The normal appendix is very variable in its position and diameter. In the absence of other signs, the diagnosis of acute appendix should not be made solely on outer-to-outer appendiceal diameter.

Visualization of the normal appendix with MR enterography in children

BACKGROUND

Magnetic resonance (MR) imaging may provide a radiation-sparing alternative to CT in diagnosing appendicitis in children in whom US is equivocal. However, comparability with CT in the detection of the appendix remains to be established.

OBJECTIVE

To determine the detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI.

METHODS

MR imaging of 58 patients who had previously undergone MR enterography was retrospectively reviewed. Detection rate, body mass index, age and gender were recorded.

RESULTS

The normal appendix was detected in 28 cases (48%), with greatest detection rate on the axial fast imaging employing steady-state acquisition (FIESTA) sequence. Children in whom the appendix was detected had significantly higher BMI compared to children in whom the appendix was not seen. Neither age nor gender demonstrated a significant association with detection rate.

CONCLUSION

The detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI was 48%, which is comparable to detection rates on CT, as well as to previously reported detection rates on MR imaging with neither oral nor IV contrast agents. These findings may serve to guide the development of MRI protocols for pediatric appendicitis.

Evaluation of normal appendix vermiformis in adults with multidetector computed tomography

To determine the utility of different contrast enhancement phases (unenhanced, arterial, and venous), slice thicknesses (0.5, 3, and 5 mm), and planes (axial and coronal) in the evaluation of appendix vermiformis (AV) on multidetector computed tomography (MDCT), CT examinations of 600 patients were obtained. No significant difference was found between the different imaging planes, slice thicknesses, and contrast enhancement phases in terms of detection rates of AV. The mean diameter of AV in the axial plane (5.93±0.06 mm) was significantly lower than that in the coronal plane (6.18±0.06 mm). Evaluation of AV on MDCT is enhanced by combined interpretation on axial and coronal planes.

Appendicitis, Body Mass Index, and CT: Is CT More Valuable for Obese Patients than Thin Patients?

The purpose of our study is to determine whether body mass index (BMI = weight in kg/height in meters2) was related to the rate of negative appendectomy in patients who underwent preoperative CT. A surgical database search performed using the procedure code for appendectomy identified 925 patients at least 18 years of age who underwent urgent appendectomy between January 1998 and September 2007. BMI was computed for the 703 of these 925 patients for whom height and weight information was available. Patients were stratified based on body mass index (BMI 15-18.49 = underweight; 18.5-24.9 = normal weight; 25–29.9 = overweight; 30-39.9 = obese; > 40 = morbidly obese). Negative appendectomy rates were computed. Negative appendectomy rates for patients who did and did not undergo preoperative CT were 27 per cent and 50 per cent for underweight patients, 10 per cent and 15 per cent for normal weight patients, 12 per cent and 17 per cent for overweight patients, 7 per cent and 30 per cent for obese patients, and 10 per cent and 100 per cent for morbidly obese patients. The difference in negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT as compared with patients in the same BMI category who did not undergo preoperative CT was statistically significant ( P ≤ 0.001). The negative appendectomy rates for overweight patients, obese patients, and morbidly obese patients who underwent preoperative CT were significantly lower than for patients in these same BMI categories who did not undergo preoperative CT.

Spiral head CT in the evaluation of acute intracranial pathology: a pictorial essay

The purpose of this pictorial essay is to review the benefits of spiral head computed tomography (CT) with routine multiplanar reformations in the evaluation of acute intracranial pathology. This technique is particularly useful in trauma patients for detection of skull base or calvarial fractures, thin tentorial subdural hematomas, or for more specific characterization of intracranial hemorrhage. The benefits of multiplanar reformations have been described for a variety of other diagnoses in the chest, abdomen, extremities, and spine, and their routine use continues to grow with the widespread availability of multi-slice CT scanners. In this article, we describe spiral head CT technique with multiplanar reformations as an alternative to the routinely used sequential technique. Subtle findings and lesions aligned predominantly in the axial plane can often be visualized to better advantage with multiplanar reformations. We also address technical factors for optimizing spiral technique.