Pseudo gallbladder sign in biliary atresia--an imaging pitfall.

BACKGROUND: Ultrasound (US) is used to identify causes of neonatal cholestasis. We describe a potential sonographic pitfall, the "pseudo gallbladder," in biliary atresia (BA). OBJECTIVE: To describe the Pseudo Gallbladder sign (PsGB sign). MATERIALS AND METHODS: Sonograms/clinical records of 20 confirmed BA infants and 20 non-BA cases were reviewed retrospectively. For the BA group, preoperative sonography and surgical and pathological findings were examined. For the non-BA group, sonographic features and pathological findings were examined. The PsGB sign is defined as a fluid-filled structure, located in the expected region of the gallbladder, measuring ≤ 15 mm in length but without a well-defined or normal-appearing gallbladder wall. RESULTS: A recognizable gallbladder and normal gallbladder wall were present in all non-BA infants. However, none of the BA infants had a sonographically normal gallbladder. Seventy-three percent of BA patients had a PsGB, and in 27% no gallbladder or gallbladder-like structure was detected. CONCLUSION: A gallbladder-like structure in BA is common and can be misinterpreted as a normal gallbladder, delaying diagnosis and therapy. Recognition of this imaging pitfall, described here as the pseudo gallbladder sign, will help avoid this error.

"Empty" sac in pregnant women with bleeding: are measurements answering the right question?

PURPOSE: To assess the percentage of first-trimester pregnancies with bleeding that demonstrate a visible sac but lack an identifiable embryo and have a mean sac diameter (MSD) in the controversial range of 16-20 mm. METHODS: Retrospective study of all first-trimester sonograms among women with vaginal bleeding during a 4-year interval. RESULTS: The study cohort consisted of 546 first- trimester sonograms. An embryo was not seen in 132 cases (24%). Of these, the MSD in 69 cases (52%) was <16 mm, between 16 and 19 mm in 20 cases (15%), or >or=20 mm in 39 cases (30%). The percentage of women who were threatening to abort who demonstrated a visible sac but lacked an identifiable embryo and had a MSD in the controversial range of 16-20 mm was 3.7% (20/546). CONCLUSION: We found that of 546 sonograms undertaken in pregnant women with vaginal bleeding in the first trimester, only 20 patients (3.7%) fell in the MSD range of 16-20 mm. Therefore, even among those diagnosticians who adopt the most stringent criterion (MSD = 20 mm), an additional examination would be requested in fewer than 1 in 25 patients.

Decidualized endometrioma during pregnancy: recognizing an imaging mimic of ovarian malignancy.

OBJECTIVE: To present the ultrasound and magnetic resonance imaging findings that may allow for a prospective diagnosis and expectant management of decidualized endometriomas because the rare occurrence of decidualization in the ectopic endometrial stroma of an endometrioma during pregnancy can mimic ovarian cancer at imaging. CASE REPORT: Smooth lobulated mural nodules with prominent internal vascularity were noted in an apparent right ovarian endometrioma on serial ultrasound studies in a 34-year-old woman at 12, 21, 27, and 30 weeks of gestation. Magnetic resonance imaging demonstrated the nodules to be strikingly similar in intensity and texture to the decidualized endometrium in the uterus on T2-weighted sequences. A provisional diagnosis of decidualized endometrioma allowed for expectant management with immediate postpartum resection and confirmation of the diagnosis. CONCLUSIONS: Decidualized endometrioma can mimic ovarian malignancy during pregnancy, but a prospective diagnosis may be possible when solid smoothly lobulated nodules with prominent internal vascularity within an endometrioma are seen from early in pregnancy, and the nodules demonstrate marked similarity in signal intensity and texture with the decidualized endometrium in the uterus at magnetic resonance imaging.

Five-millimeter and smaller embryos without embryonic cardiac activity: outcomes in women with vaginal bleeding.

OBJECTIVE: The purpose of this study was to assess outcomes in embryos with a crown-rump length (CRL) of 5 mm or less without embryonic cardiac activity (ECA) among pregnant women with vaginal bleeding in the first trimester. METHODS: A retrospective study of all first-trimester sonograms in women with vaginal bleeding from 1999 to 2002 was conducted. RESULTS: Thirty-seven embryos without detectable ECA that had a CRL of 5 mm or less were identified. All resulted in pregnancy failure. The breakdown of these embryos by CRL was as follows: 13 were 5 mm; 10 ranged from 4 to 4.9 mm; 11 ranged from 3 to 3.9 mm; and 3 ranged from 2 to 2.9 mm. CONCLUSIONS: In pregnant women with vaginal bleeding, embryos of 5 mm and smaller without a heartbeat all resulted in pregnancy failure.

Successful localization of recurrent thyroid cancer in reoperative neck surgery using ultrasound-guided methylene blue dye injection.

BACKGROUND: Reoperation in the neck can be challenging and is associated with increased complication rates and operative times. Here we analyze our methylene blue dye injection method to localize reoperative neck pathology in patients with thyroid cancer and lymph node metastases. STUDY DESIGN: We retrospectively reviewed the records of all patients at a single university tertiary care center who had reoperative neck surgery for recurrent thyroid cancer between 2004 and 2009, and who also underwent intraoperative methylene blue dye injection. Outcomes measured were efficacy and safety of the injection technique as well as complication rates. RESULTS: Fifty-three operations were performed in 44 patients (average age, 51.2 years [range 16 to 83 years]). Ninety-one percent (48 of 53) of the operations resulted in successful resection of recurrent disease. Of these, 96% (46 of 48) were guided successfully by blue dye injection. Thyroglobulin became undetectable in 42% (11 of 26) of patients. Neck pathology included the following thyroid cancers: papillary (48 of 53), follicular (2 of 53), medullary (2 of 53), and tall cell variant (1 of 53). Among these patients, there were a total of 26 central and 38 lateral neck dissections. The average number of previous neck dissections was 2 (range 1 to 5). The mean intraoperative ultrasound/injection time was 21.3 min (n = 13). Median operative time was 90 minutes (range 40 to 300 minutes). Complications included 2 permanent vocal cord paralyses, 1 instance of permanent hypocalcemia, and 3 instances of temporary hypocalcemia. There were no complications related to the dye injection. CONCLUSIONS: Intraoperative, ultrasound-guided, methylene blue dye injection is a safe and effective technique. It facilitates tumor localization and removal especially in patients requiring reoperative neck surgery.