Median accessory digastric muscle: radiological and surgical correlation.

A median accessory digastric muscle was revealed during a dissection of the submental region. The muscle was located between the anterior bellies of the digastrics, external to the mylohyoid and deep to the platysma. It appeared as a flat quadrilateral sheet. Its base arose from the front of the body of the hyoid bone near its upper border. Lower portion of the fibers, at the right base of the muscle, initially traveled perpendicular to the lower fibers of the right mylohyoid. The rest of the muscle had a median course, with the cranial end inserting into the mandible between the digastric fossae. The muscle elevated the hyoid bone and depressed the mandible when appropriate stress was applied. No other morphologic abnormalities were found in this region. Aberrant anterior bellies of the digastric muscles are uncommon and occur bilaterally or unilaterally. This observation of a median accessory digastric muscle has not previously been reported. Knowledge of this variant will help to avoid confusion with pathological conditions of the floor of the mouth and the submental region. It is relevant both for the interpretation of radiological images and during surgical procedures such as dissection of the anterior belly of the digastric for a malignant disease and graft positioning.

Acute appendicitis in children: comparison of clinical diagnosis with ultrasound and CT imaging.

BACKGROUND: There is strong evidence that imaging with ultrasound and CT can be of substantial diagnostic value in the diagnosis of acute appendicitis in children, but there is limited information of the impact of imaging on the management of these patients and its possible effect on surgical findings. OBJECTIVE: We studied the impact of imaging in the management of acute appendicitis, in particular its effect on the rate of negative appendectomies and perforations. PATIENTS AND METHODS: We reviewed retrospectively the clinical records and imaging findings of 633 consecutive children and adolescents seen on an emergency basis with clinical suspicion of acute appendicitis. Two hundred seventy patients were operated upon on clinical evidence alone, while 360 were referred for US or CT, and occasionally both, because of doubtful clinical findings. RESULTS: Acute appendicitis was found in 237 of those on clinical grounds alone, 68 of whom had perforation and related complications. Thus the rate of negative exploration and the rate of perforation were13 % and 29 %, respectively. One hundred eighty-two patients had preoperative US (sensitivity 74 %, specificity 94 %), 119 had CT (sensitivity 84 %, specificity 99 %), and 59 had both US and CT (sensitivity 75 %, specificity 100 %, but often with interpretation at variance with each other). The rate of negative appendectomy and perforation was 8 % and 23 %, respectively, for US, 5 % and 54 % for CT, and 9 % and 71 % when both examinations were performed. There is no statistical significance between the rates of diagnostic performance of US, CT, or their combination, nor between the negative appendectomy rates of each group, but the rate of perforation was significantly higher when CT was performed, alone or after US. CONCLUSION: The retrospective nature of the study prevents precise definition of the clinical characteristics and selection criteria for diagnostic examinations that may contribute to the management of children with suspected acute appendicitis. It was designed, however, to reflect the diagnostic approach and management of these patients, under the care of many decision makers and interpreters of imaging examinations, prevalent today in most hospital-based clinical practices. It is suggested that imaging increases diagnostic accuracy in difficult cases, but it might be one of the factors increasing the rate of perforations.