Here are the top 5 most read ultrasound posts of 2018

With only a few hours left for the calendar year 2018 to come to an end, take a look at the top 5 most read ultrasound posts of the year as we gear up to look forward to another year of medical advances and health research. 

Blob and Bagel sign on Ultrasound can be labeled as definitive for Ectopic Pregnancy

Women with the Blob and Bagel ultrasound sign should be reclassified from having ‘probable’ ectopic pregnancy (EP) to ‘definitive’ EP and should be treated as such reports the result of a large retrospective cohort study published March 11, 2018, in Journal of Ultrasound in Obstetrics and Gynecology.

Ectopic Pregnancy is still the leading cause of first-trimester maternal deaths and constitutes 4% of all pregnancy-related deaths. The incidence of ectopic is highest in women undergoing In-Vitro Fertilization (IVF) and ranges from 4% to 11% of all pregnancies.

https://obgynupdated.blogspot.com/2018/03/blob-and-bagel-sign-on-ultrasound-can.html

Novel cross-over sign in cesarean scar pregnancy helps predicts the risk of invasive placentation

First trimester ultrasound scan evaluating the relationship between the gestational sac and the endometrial line in women with cesarean scar pregnancy(CSP) helps predicts the development of abnormally invasive placenta (AIP) and consecutive intra and post-operative surgical morbidities reports the results of a retrospective case series published in the Journal of International Society of Ultrasound in Obstetrics and Gynecology.

Recent advances in prenatal imaging and increase rate of cesarean sections have led to increased diagnosis of CSP. Although, most of the patients with CSP present with severe hemorrhage or rupture uterus, that requires emergency surgical management, few advances further, evolving into AIP. 

https://obgynupdated.blogspot.com/2018/02/novel-cross-over-sign-in-cesarean-scar.html

Negative sliding sign by ultrasound in repeat cesarean section predicts the presence of severe intrabdominal adhesions

A negative sliding sign by ultrasonography (USG) in patients with previous cesarean section helps alert the surgeon to expect massive intraabdominal adhesions, difficult repeat cesarean section and need of blood transfusion during surgery reports the results of a prospective observational study published ahead of print in the February issue of Journal Obstetrics and Gynecology.

Postoperative adhesion formation is quite prevalent after an abdominal or pelvic surgery and any method which can predict the existence of such adhesion could optimize the outcome of current surgery.

https://obgynupdated.blogspot.com/2018/02/negative-sliding-sign-by-ultrasound-in.html

GE Healthcare introduces its new automated breast ultrasound for dense breast

There could not have been a more appropriate time for the launch of GE Healthcare new Invenia Automated Breast Ultrasound (ABUS) 2.0 than October, which is celebrated as breast cancer awareness month. The Invenia ABUS is the only FDA approved 3D ultrasound system for supplemental screening for breast cancer along with mammography.

In conjunction with mammography, it increases the chances of cancer detection in the dense breast by 55%. All breasts are not the same, the density of breast is determined by a proportion of fat and breast tissue—when the percentage of breast tissue exceeds that of fat, breasts are labeled as being dense.

https://obgynupdated.blogspot.com/2018/10/ge-healthcare-introduces-its-new.html

A practical guide to count ovarian antral follicles by ultrasound

A consensus opinion highlighting the main techniques of ovarian antral follicle count (AFC), and providing recommendations for future research is published in the special issue on Reproductive Medicine of the journal Ultrasound in Obstetrics and Gynecology.

The consensus makes several recommendations for varied methods used in counting the antral follicles, but no single method is superior over others and the choice should make the best use of resources available in a setting.

https://obgynupdated.blogspot.com/2018/02/a-practical-guide-to-count-ovarian.html

Novel cross-over sign in cesarean scar pregnancy helps predicts the risk of invasive placentation

power-point slide by ISUOG

First trimester ultrasound scan evaluating the relationship between the gestational sac and the endometrial line in women with cesarean scar pregnancy(CSP) helps predicts the development of abnormally invasive placenta (AIP) and consecutive intra and post-operative surgical morbidities reports the results of a retrospective case series published in Journal of International Society of Ultrasound in Obstetrics and Gynecology.

Recent advances in prenatal imaging and increase rate of cesarean sections have led to increased diagnosis of CSP. Although, most of the patients with CSP present with severe hemorrhage or rupture uterus, that requires emergency surgical management, few advance further, evolving into AIP.

There is no reliable marker that can predict whether a woman with CSP will end up in early abortion or further progress to develop placenta percreta or other less severe forms of AIP.

A novel ultrasound cross-over sign (COS) has recently been thought to predict the evolution of CSP into different forms of AIP so that the intraoperative and postoperative risk can be stratified.

A straight line is drawn from internal cervical os to the fundus of the uterus in sagittal view through the endometrium. The gestational sac is identified, and its superior-inferior diameter measured. The COS is classified according to the relationship of ectopic sac diameter with the endometrial straight line into COS-1 and COS-2.

This case series identified 102 women over a period of 8 years with AIP diagnosis confirmed by histopathological examination (HPE), of whom 68 patients had a first-trimester ultrasound with a diagnosis of CSP. The scans were read by sonographers who did not have any idea about the pregnancy outcome and pathology reports.  

COS sign was assessed as mentioned, and all patients received counseling regarding the prognosis, risk, and post-operative complications. Women with severe AIP were delivered early, as compared to less severe variants.

All women underwent cesarean hysterectomy with temporary occlusion of the internal iliac artery and ureteric stent in place. At HPE, 34 cases were diagnosed with placenta percreta, 13 with placenta increta and 21 with placenta accreta.

Pregnancies with COS-1 had early deliveries, longer operating time, more blood loss and required much more packed red blood cells during surgery mean as compared with those with COS-2+ or COS-2–.

Thus, predicting the likely course CSP diagnosed by COS sign in the first trimester can improve shared decision making between the patient and provider about the surgical difficulties endured, amount of blood loss and need for cesarean hysterectomy.

Large, multi-center studies to determine the role of COS sign in predicting the severity of AIP in CSP is needed in future.

Full text

This article has been selected for Journal Club. Click here to view slides and discussion points. 

Differentiating between intrauterine pregnancy and cesarean scar pregnancy in the early first trimester by Ultrasongraphy.

Cesarean scar pregnancy (CSP) consists of implantation of the gestational sac in the previous hysterotomy scar, with some serious complications as the pregnancy progresses. 

CSP was first described by Larsen and Salomon in 1978. The incidence currently is 1/1800 to 1/2200 pregnancies with 0.15% of women with previous Caesarean sections ending in CSP. But, as the rates of cesearean section rates are increasing world wide, with some countries reporting as high as 50%, the incidence of CSPs is bound to increase!

Risk factors for  CSPs are those  with a history of multiple Caesarean sections and Caesarean breech delivery but scar pregnancies have also been reported after dilation and curettage, myomectomy, metroplasty, hysteroscopy, and manual removal of the placenta.

In fact up to 72% of cesarean scar pregnancies occur in women who have had 2 or more cesarean deliveries.

Transvaginal Sonography and color Doppler are the best diagnostic tools at present, but the clinician should have a high index of suspicion to use them.

According to a paper by Osborn D.A et al the following sonographic criteria have been put forward for early diagnosis of cesarean scar pregnancies in the first trimester.

1. Empty uterus with a clearly visualized endometrium;
2. Empty cervical canal;
3. Gestational sac within the anterior portion of the lower uterine segment at the presumed site of the cesarean scar; and
4. Thinned or absent myometrium between the gestational sac and bladder (<5 mm in two-thirds of cases).
5. Other findings include marked peritrophoblastic color Doppler flow around the sac with low-impedance (pulsatility <1), high-velocity flow (>20 cm/s), a resistive index of less than 0.5, and a peak systolic to diastolic blood flow ratio of less than 3.

MRI being useful as a troubleshooting tool when sonography is equivocal or inconclusive before intervention or therapy.

This paper by  Timor-Tritsch I.E et al in the forthcoming issue of American Journal of Obstetrics & Gynecology describe a sonographic method for the differential diagnosis of CSP vs IUP in early gestation.

The study tests the hypothesis that in a first trimester sonography between 5-10 weeks of pregnancy the relative location of the center of gestational sac to the midpoint of the uterus along a longitudinal line between the external cervical os and the fundus can be used for early detection of CSPs.

This is a retrospective study reviewing the electronic record of 242 ultrasound images from 20004- 2015 were analyzed. A total of 57 cases of CSP diagnosed. The following measurements were made for each case:

1. distance from the external cervical os to the uterine fundus,
2. the midpoint axis of the uterus,
3. the distance from the external cervical os to the center of gestational sacs, and
4. the distance from the external cervical os to the most distant edge of the gestational sacs from the cervix.

It was seen that the location of the center of gestational sac relative to the midpoint axis of the uterus between 5-10 weeks of gestation differentiated between IUP and CSP (mean 17.8 vs –10.6 mm, respectively, P = .0001).

Most CSPs are located proximally to the midpoint axis of the uterus and most IUPs are located distally to the midpoint axis.

The diagnostic accuracy of the method:  accuracy: sensitivity 93.0% and specificity 98.9%.

The authors strongly believe that the mounting anecdotal evidence supports instituting a simple, relatively inexpensive very early transvaginal screening ultrasound of every pregnant patient with a previous history of cesarean delivery.

References:

https://med.stanford.edu/news/all-news/2015/12/optimal-c-section-rate-may-be-as-high-as-19-percent-to-save-lives.html

http://www.jultrasoundmed.org/content/31/9/1449.full

http://www.ajog.org/article/S0002-9378%2816%2900316-1/abstract