Gallbladder opacification on gadoxetate disodium-enhanced CT scan.

This study aimed to evaluate the radiologist's ability to identify excreted gadoxetate disodium within the gallbladder on CT scan. Thirty three healthy adults underwent imaging of the liver during work-up for potential liver donation. Three patients had undergone prior cholecystectomy and therefore were excluded. Imaging consisted of gadoxetate disodium-enhanced magnetic resonance cholangiography (MRC) and multiphase contrast-enhanced CT scan of the abdomen and pelvis. Two fellowship-trained abdominal imaging radiologists, who were blinded to the MRC images and the contrast agent used during MRC, independently reviewed the CT scans of the 30 patients that were included. The scans were evaluated for the presence or absence of abnormal hyperdensity within the gallbladder. Three patients did not receive intravenous gadoxetate disodium, 4 patients had their MRC after the CT scan, and 1 patient had the CT scans 5 days following the MRC. Twenty two patients had the CT scan within 24 h following the gadoxetate disodium-enhanced MRC. Of the 22 patients expected to have gadolinium in the gallbladder, both reviewers identified hyperdensity in the same 20 patients (90%). Both reviewers reported no abnormal hyperdensity within the gallbladder in the remaining 10 patients. CT scan can reveal excreted gadoxetate disodium within the gallbladder lumen and therefore gadoxetate disodium-enhanced CT scan can potentially play a role in the evaluation of cystic duct patency and work-up of acute cholecystitis.

Pelvic ultrasonography of the postpartum uterus in patients presenting to the emergency room with vaginal bleeding and pelvic pain.

Pelvic pain and vaginal bleeding are common symptoms in postpartum women presenting to the emergency room (ER). Pelvic ultrasonography plays a crucial role in evaluating symptomatic postpartum patients by allowing a rapid diagnosis and treatment initiation. The main goal of imaging is to distinguish between causes of pelvic pain and vaginal bleeding that may be managed conservatively and those requiring emergent intervention. This pictural essay focuses on the ultrasonographic features of common postpartum conditions for which patients may present to the ER with vaginal bleeding and pelvic pain, including retained products of conception, endometritis, uterine arteriovenous malformation, uterine artery pseudoaneurysm, ovarian vein thrombosis, bladder flap hematoma, and uterine dehiscence/rupture.

Ultrasonographic evaluation of patients with abnormal liver function tests in the emergency department.

Ultrasonography is often the initial modality used to evaluate patients found to have abnormal liver function tests (LFTs) in the emergency department. While an assessment for biliary ductal dilatation and obstruction remains one of the main questions to answer, radiologists should also be aware of the ultrasonographic appearance of other conditions that can cause abnormal LFTs. This may be crucial for the management and disposition of patients in the emergency department. This article reviews the ultrasonographic features of diseases that may cause abnormal LFTs.

Role of ultrasound in the evaluation of first-trimester pregnancies in the acute setting.

In patients presenting for an evaluation of pregnancy in the first trimester, transvaginal ultrasound is the modality of choice for establishing the presence of an intrauterine pregnancy; evaluating pregnancy viability, gestational age, and multiplicity; detecting pregnancy-related complications; and diagnosing ectopic pregnancy. In this pictorial review article, the sonographic appearance of a normal intrauterine gestation and the most common complications of pregnancy in the first trimester in the acute setting are discussed.

Injuries and conditions of the extensor mechanism of the pediatric knee.

The extensor mechanism of the knee is essential to ambulation and is subject to a number of traumatic, congenital, and inflammatory processes. In the pediatric population, the spectrum of pathologic conditions affecting the extensor mechanism is specific to skeletally immature patients. In addition, certain congenital and developmental disorders may further predispose the knee extensor mechanism to injury. The pathologic processes can be subdivided into categories: conditions of the attachments and insertions of the quadriceps and patellar tendons, conditions of the patella, conditions of the quadriceps muscle group, and avulsions of the superior attachments of the quadriceps. Cases of conditions affecting the extensor mechanism of the pediatric knee were collected at two large trauma centers, and the clinical and radiologic features were reviewed. Initial evaluation of these conditions is performed with radiography, but magnetic resonance imaging has evolved into a useful adjunct for assessing the soft tissues for a more precise evaluation of the true extent of an injury, thereby affecting decisions about surgical intervention and prognosis.

Diagnosing ectopic pregnancy in the emergency setting.

Ectopic pregnancy is the implantation of a fertilized egg outside the uterine endometrial cavity. For women presenting to the emergency department with abdominal pain and/or vaginal bleeding, ectopic pregnancy is an important diagnostic consideration. The diagnosis is made based on laboratory values and ultrasound imaging findings. The ultrasound appearance of both normal early pregnancy and ectopic pregnancy are variable and often subtle, presenting diagnostic challenges for radiologists. This pictorial essay describes and illustrates the sonographic findings of ectopic pregnancy and reviews the differential diagnoses that can mimic ectopic pregnancy on ultrasound. With the possibility of medical management, the value of early detection and prompt initiation of treatment has increased in improving clinical outcomes and preventing the complications of ectopic pregnancy.

What to Expect When They are Expecting: Magnetic Resonance Imaging of the Acute Abdomen and Pelvis in Pregnancy.

In this article, we discuss the challenges in the diagnosis of acute abdominopelvic pain in pregnant patients, role of imaging, and advantages of MRI over other modalities. Methods consist of pictorial review. We review the differential diagnoses and illustrate the MRI findings in pregnant patients with acute abdominopelvic pain, including gastrointestinal, gynecologic, urologic, and vascular etiologies.

Ultrasonography of adnexal causes of acute pelvic pain in pre-menopausal non-pregnant women.

Acute-onset pelvic pain is an extremely common symptom in premenopausal women presenting to the emergency department. After excluding pregnancy in reproductive-age women, ultrasonography plays a major role in the prompt and accurate diagnosis of adnexal causes of acute pelvic pain, such as hemorrhagic ovarian cysts, endometriosis, ovarian torsion, and tubo-ovarian abscess. Its availability, relatively low cost, and lack of ionizing radiation make ultrasonography an ideal imaging modality in women of reproductive age. The primary goal of imaging in these patients is to distinguish between adnexal causes of acute pelvic pain that may be managed conservatively or medically, and those requiring emergency/urgent surgical or percutaneous intervention.

Efficient integration of recombinant adeno-associated virus DNA vectors requires a p5-rep sequence in cis.

The initial aim of this study was to combine attributes of adeno-associated virus (AAV) and adenovirus (Ad) gene therapy vectors to generate an Ad-AAV hybrid vector allowing efficient site-specific integration with Ad vectors. In executing our experimental strategy, we found that, in addition to the known incompatibility of Rep expression and Ad growth, an equally large obstacle was presented by the inefficiency of the integration event when using traditional recombinant AAV (rAAV) vectors. This study has addressed both of these problems. We have shown that a first-generation Ad can be generated that expresses Rep proteins at levels consistent with those found in wild-type AAV (wtAAV) infections and that Rep-mediated AAV persistence can occur in the presence of first-generation Ad vectors. Our finding that traditional rAAV plasmid vectors lack integration potency compared to wtAAV plasmid constructs (10- to 100-fold differences) was unexpected but led to the discovery of a previously unidentified AAV integration enhancer sequence element which functions in cis to an AAV inverted terminal repeat-flanked target gene. rAAV constructs containing left-end AAV sequence, including the p5-rep promoter sequence, integrate efficiently in a site-specific manner. The identification of this novel AAV integration enhancer element is consistent with previous studies, which have indicated that a high frequency of wtAAV recombinant junction formation occurs in the vicinity of the p5 promoter, and recent studies have demonstrated a role for this region in AAV DNA replication. Understanding the contribution of this element to the mechanism of AAV integration will be critical to the use of AAV vectors for targeted gene transfer applications.