Gynecologic ultrasound

Sister Vascular Anomalies in the Nongravid Uterus

Uterine arteriovenous malformation and arteriovenous fistula are rare vascular lesions that have only recently been described in literature. They are two differentials in reproductive-age women with acute onset of abnormal vaginal bleeding. The sonographic and clinical presentation of these two pathologies can be both varied in appearance and impossible to distinguish from each other. However, a detailed history along with specific sonographic investigation using color and pulse-wave Doppler, as well as a transvaginal scanning technique, can lead to strong suspicion of these vascular malformities. A successful sonogram can provide essential evidence to justify further investigation with a more invasive angiography procedure. This will not only confirm a diagnosis but also give important information regarding the size and exact location of the lesion. These facts will help the interventional radiologist and treating physician decide if different types of embolization are possible or if hysterectomy is necessary.

Artifacts, Pitfalls and Normal Variants

Image artifacts are encountered daily in clinical ultrasonography and may be a source of confusion for the interpreting sonologist. The understanding of the mechanisms behind their production allows recognition of artifacts and avoids misinterpretations and incorrect diagnoses. Some artifacts may be avoidable and arise secondary to improper scanning technique. Other artifacts are generated by the physical limitations of the modality.

Recognition of artifacts in everyday work is of great significance for final diagnosis, since their erroneous interpretation not only compromises the value of ultrasound finding, but may also lead to an inadequate therapeutic approach.

The objective of this article is to describe and illustrate many of the ultrasound artifacts commonly encountered in obstetrical and gynecological ultrasound including Doppler and 3D imaging artifacts.

How to cite this article

Zalud I, Rocha F. Artifacts, Pitfalls and Normal Variants. Donald School J Ultrasound Obstet Gynecol 2012;6(1):1-8.

The medical Doppler in hand surgery: its scientific basis, applications, and the history of its namesake, Christian Johann Doppler

The word Doppler is used synonymously in hand surgery for evaluating patency of vascular structures; however, the science and history behind the Doppler effect are not as well-known. We will present the theories behind the Doppler effect and the history of the person who made this discovery.

Association between ovarian volume and serum insulin levels in ovulatory patients with idiopathic hirsutism

We assessed the influence of insulin on ovarian volume in 45 women with regular, ovulatory menstrual cycles, normal androgen levels, and isolated hirsutism (idiopathic hirsutism). Insulin levels, insulin-to-glucose ratio, and homeostasis model assessment (HOMA) were significantly higher in patients with ovarian volume >9 cm3 than in women with smaller ovaries (P<.05), and insulin levels presented a significant positive correlation with ovarian volume (r = 0.37, P=.02), which was independent of body mass index (BMI) or the luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio.

Gynecologic ultrasound in emergency medicine

The true value of ultrasound in acute abdominal pain lies in its ability to detect gynecologic disorders and effectively rule out other causes of acute abdominal pain that require surgical repair. Although the emergent gynecologic indications discussed in this article are few in number, this does not suggest that the nonpregnant patient presenting to the ED with abdominal pain should not receive an ultrasound examination. On the contrary, the author believes that in a "perfect world," ultrasound should be the initial imaging study in most of these patients. The reality is that it is difficult to convince radiology colleagues to call in a sonologist in the middle of the night for any indication other than ovarian torsion when CT scans can diagnose ovarian cysts and tubo-ovarian abscess. As was pointed out in the section on ovarian torsion, even adequate ovarian blood flow does not rule out this diagnosis.Ideally, an ultrasound of the pelvis could be undertaken at the time of the pelvic examination, adding as little as 5 to 10 minutes. If a gynecologic disorder could be confirmed, other imaging studies might be unnecessary,thereby reducing cost (potential savings on laboratory tests, cervical cultures, or CT scans), length of stay, and adverse complications of CT(contrast material reactions, and radiation exposure).Emergency medicine ultrasound continues to grow at a rapid pace. We are working toward a time when most EPs will be competent and comfortable performing bedside ultrasound examinations in a limited number of applications. The gynecologic application of ultrasound,however, requires skill beyond the level of the primary applications of emergency medicine ultrasound-specifically, mastering Doppler ultra-sound. Although ultrasound has proved to be a valuable imaging modality in the nonpregnant patient with acute abdominal pain when performed by a seasoned sonographer, the role of ED ultrasound has been limited to those EPs with significantly more training. The author believes that even limited expertise in gynecologic ultrasound is valuable in helping direct the management of these patients. Further research by skilled EP sonographers eventually will help define the role of EPs in this particular application of ultrasound. EPs should not be discouraged from developing expertise in this examination when a confirmatory study in radiology will be performed. Miles on the "ultrasound odometer" will not only sharpen sonographic skills but also will help the EP to better communicate with nonpregnant patients presenting with abdominal pain. There is a fairly specific barometer already in place to gauge one's gynecologic ultrasound skills: a seasoned EP sonographer never skips over the chart of a young woman with right lower quadrant pain.

Review of technology: planning for the development of telesonography

Teleradiology allows contemporaneous interpretation of imaging exams performed at some distance from the interpreting radiologist. The transmitted images are usually static. However, there is benefit to real-time review of full-motion ultrasound (US) exams as they are performed. Telesonography is transmission of full-motion sonographic data to a remote site. We hypothesize that US exams, read after having been compressed utilizing Motion Picture Experts Group version 4 (MPEG-4) compression scheme, transmitted over the Internet as streaming multimedia, decompressed, and displayed, are equivalent in diagnostic accuracy to reading the examinations locally. MPEG-4 uses variable compression on each image frame to achieve a constant output bit rate. With less compression, the bit rate rises, and the only way the encoder can contain bit rate within the set bandwidth is by lowering frame rate or reducing image quality. We review the relevant technologies and industry standard components that will enable low-cost telesonography.

Sonographic evaluation of first-trimester bleeding

Vaginal bleeding is a leading cause of presentation for emergency care during the first trimester of the pregnancy. Clinical assessment of the pregnancy outcome at this stage is less reliable. US examination is crucial in establishing IUP and early pregnancy failure and to exclude other causes of bleeding, such as ectopic pregnancy and molar pregnancy. Diagnosis of a normal IUP at this stage not only assists the physician in an expectant management, but also gives a psychologic boost to the patient. With recent advances in US technology and the availability of high-frequency transvaginal transducers, reliable diagnosis of early pregnancy failure can be made even before the embryo is visible.