Objective: To investigate the utility of the Appendicitis Computed Tomography (ACT) scoring system in the diagnosis of perforated appendicitis and prediction of surgical outcome. Methods: A retrospective study was conducted on 102 subjects who underwent computed tomography (CT) scan and appendectomy for acute appendicitis between May 2011 and January 2012. Images were reviewed for five individual CT signs (appendiceal wall defect, phlegmon, abscess, extraluminal gas, and extraluminal appendicolith) and a score (ACT score) was assigned for each patient based on the number of detectable findings. Correlation of ACT score and individual CT signs with appendiceal perforation and surgical outcome was evaluated statistically. Diagnostic power was assessed using receiving operating characteristic (ROC) curve. Results: A total of 84 subjects were included in the final study after exclusion. ACT score was significantly higher for the perforated group compared with the non-perforated group (2.52 vs. 0.40, p < 0.001) and also higher for the open surgery group than the laparoscopic surgery group (2.78 vs. 0.93, p < 0.001). ACT score was an independent predictor of perforation (odds ratio [OR] = 7.05, p < 0.001), need for open surgery (OR = 2.99, p = 0.002), and operating time (increase of 12.93 minutes, p < 0.001). On ROC curves, ACT score showed a higher discriminating power for both appendiceal perforation (area under the curve [AUC] = 0.939) and need for open surgery (AUC = 0.858) than individual CT signs. An ACT score of 0 was 100% sensitive for excluding appendiceal perforation and open surgery in our study, whereas an ACT score of >3 was diagnostic for perforated appendix. Conclusions: The ACT score is a practical and accurate tool for diagnosis of appendiceal perforation and prediction of surgical outcome.

Objective : We sought to improve the aortic enhancement to allow proper assessment and detection of vascular injury in whole-body contrast-enhanced computed tomography (WBCT) of trauma patients without increasing the radiation dose by using a single-pass combined arterial and venous phase split-bolus protocol, instead of a conventional venous phase single-bolus protocol. Methods: A retrospective study assessed consecutive trauma patients who underwent WBCT in two 6-month periods, one in which patients underwent the single-bolus protocol and one in which they underwent the split-bolus protocol. In the split-bolus group, 80 mL iohexol (300 mgI/mL) was injected after the plain CT scan and additional 40 mL iohexol was injected 60 s later. Post-contrast CT images were acquired at 90 s after starting the first contrast injection. Enhancement of the aorta, liver, spleen and kidneys and dose-length product (DLP) of WBCT were measured and compared between patients in the two scan protocols. Results: A total of 95 patients were included. There was statistically significant improvement of the enhancement of the ascending aorta, descending thoracic aorta (177±36 vs. 249±63 HU, p < 0.001), infrarenal aorta, spleen (123±16 vs. 146±21 HU, p < 0.001), right renal cortex (194±34 vs. 227±42 HU, p < 0.001) and left renal cortex (193±37 vs. 228±40 HU, p < 0.001) in the split-bolus group. In the split-bolus group, the aortic enhancement was >200 HU, which was considered to be sufficient for proper assessment and detection of vascular injury in literature. There was no statistically significant difference in the DLP (3406±1076 vs. 3194±1261 mGycm, p = 0.152), which is an effective dose of 64.7 mSv in the single-bolus group and 60.7 mSv in the split-bolus group. Conclusion:The split-bolus protocol increased the aortic enhancement to allow proper assessment and detection of vascular injury of trauma patients without increasing the radiation dose. Our study used the lowest possible contrast dose to achieve diagnostic images among different studies.

In imaging of the head and neck regions, the dental space is an area which many radiologists are less familiar with and which often does not receive adequate attention. Dental and periodontal pathologies are hence often overlooked and underreported in daily practice. This article reviews the normal anatomy and imaging findings of the common pathologies in the dental region. Dental infection and inflammation are commonly encountered and have a variety of manifestations with different degrees of severity, ranging from asymptomatic incidental findings, local infection confined within the dental space, and inflammation of the adjacent paranasal sinuses (i.e. odontogenic sinusitis), to severe and extensive deep neck infection. Odontogenic cysts and neoplasms are occasionally seen, most of which are benign. The challenge in the imaging of these lesions is to distinguish them from other mandibular lesions that demonstrate similar radiological appearances. A detailed clinical history and careful imaging interpretation are very helpful in narrowing the differential diagnosis and guiding management. Developmental anomalies (eg, supernumerary teeth, ectopic tooth) of the dentition are usually isolated incidental findings or a manifestation of a syndromal disease such as Gorlin-Goltz syndrome and cleidocranial dysostosis. Finally, dental injury should be carefully evaluated in the context of head and neck trauma, including injury to the tooth itself, the periodontal structures and the associated complications (eg, aspiration of fractured tooth). Learning and becoming familiar with the basic dental anatomy and common pathologies are essential in identifying diseases and making accurate diagnoses.

Extranodal lymphoma is relatively uncommon and has a wide radiological spectrum in various organs. In this pictorial review, the radiological features across various imaging modalities and the differential diagnoses of extranodal lymphomatous involvement of different organs are described.