BackgroundMucus-producing tumours of the appendix or mucoceles can, if left untreated, lead to dissemination of its contents into the peritoneal cavity causing substantial morbidity to the patient. Symptoms for complicated mucoceles can mimic those of acute appendicitis and the final diagnosis is most likely made intraoperatively. We here present a case that is, to our knowledge, one of only ten described in the literature and the first to characterize torsion of an appendiceal mucocele with abdominal magnetic resonance imaging.Case presentationThe patient, a 34-year-old Caucasian female presented at the emergency department with acute abdominal pain in the right lower quadrant. Initial diagnostic work-up including ultrasonography and abdominal magnetic resonance imaging showed a large tubular mass at the base of the appendix with indirect signs of torsion. A laparoscopic appendectomy was performed the following day where the finding was confirmed. The patient went on to have an uneventful recovery and was discharged from the hospital on the first postoperative day.ConclusionsMagnetic resonance imaging is a useful tool in identifying unknown lesions of the appendix and should be considered the primary imaging modality in especially younger patients requiring diagnostic imaging. In this case the preoperative imaging findings aided in choosing the correct timing and treatment option for the patient.

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BackgroundDigital breast tomosynthesis (DBT) is gaining popularity in breast imaging. There are several different technical approaches for conducting DBT imaging.PurposeTo determine optimal imaging parameters, test patient friendliness, evaluate the initial diagnostic performance, and describe diagnostic advances possible with the new Continuous Sync-and-Shoot method.Material and MethodsThirty-six surgical breast specimens were imaged with digital mammography (DM) and a prototype of a DBT system (Planmed Oy, Helsinki, Finland). We tested the patient friendliness of the sync-and-shoot movement without radiation exposure in eight volunteers. Different imaging parameters were tested with 20 specimens to identify the optimal combination: angular range 30°, 40°, and 60°; pixel binning; Rhodium (Rh) and Silver (Ag) filtrations; and different kV and mAs values. Two breast radiologists evaluated 16 DM and DBT image pairs and rated six different image properties. Imaging modalities were compared with paired t-test.ResultsThe Continuous Sync-and-Shoot method produced diagnostically valid images. Five out of eight volunteers felt no/minimal discomfort, three experienced mild discomfort from the tilting movement of the detector, with the motion being barely recognized. The combination of 30°, Ag filtering, and 2 × 2 pixel binning produced the best image quality at an acceptable dose level. DBT was significantly better in all six evaluated properties (P < 0.05). Mean DoseDBT/DoseDM ratio was 1.22 (SD = 0.42).ConclusionThe evaluated imaging method is feasible for imaging and analysing surgical breast specimens and DBT is significantly better than DM in image evaluation.

Background Previous studies have shown differences in technical image quality between digital breast tomosynthesis (DBT) systems. However, quantitative image quality measurements may not necessarily fully reflect the clinical performance of DBT. Purpose To study the subjective image quality of five DBT systems manufactured by Fujifilm, GE, Hologic, Planmed, and Siemens using phantom images. Material and Methods A TOR MAM test object with polymethyl methacrylate plates was imaged on five DBT systems from different vendors. Three DBT acquisitions were performed at mean glandular doses of 1.0 mGy, 2.0 mGy, and 3.5 mGy while maintaining a constant phantom set-up. Eight DBT acquisitions with different test plate positions and phantom set-up thicknesses were performed at clinically applied dose levels. Additionally, three conventional two-dimensional mammogram images were acquired with different phantom thicknesses. Six radiologists ranked the systems based on the visibilities of the targets seen in the phantom images. Results In the DBT acquisitions performed at comparable dose levels, one system differed significantly from all other systems in microcalcification scores. When using site-specific DBT protocols, significant differences were found between the devices for microcalcification, filament, and low-contrast targets. A strong correlation was observed between the reviewer scores and radiation doses in DBT acquisitions, whereas no such correlation was observed in the 2D acquisitions. Conclusion In DBT acquisitions, dose level was found to be a major factor explaining image quality differences between the systems, regardless of other acquisition parameters. Most DBT systems performed equally well at similar dose levels.