By: 1 December 2010

Dr. Sarah Russell, Consultant Radiologist in Obstetrics, Gynaecology and Paediatrics at Saint Mary’s Hospital, highlights her experience of returning to linear array techniques and sets out the clinical advantages in gaining diagnostic certainty.

Introducing refreshed linear array transducer technology
Linear array transducers that give a rectangular field of view were popular in the 1980s but were superseded by curved array formats, which gave a wider field of view combined with a smaller footprint than the conventional linear probes. A recent revision in the physics of linear technology has heralded a resurgence in interest, particularly for focused target scanning of congenital abnormalities in obstetrics.

Transducer technology that revisits linear format delivers high frequency imaging resolution for superb clarity and detail for greater information and interpretation. A trapezoid field of view can also be used, quickly providing an extended sector format. With more anatomical information on the patient case, the clinician can deliver a more confident diagnosis.

A case of Pulmonary Sequestration at 20+6 gestation using the 9L4 Transducer

Greater information for interpretation
“Referrals from 20 week anomaly scans are incredibly anxious times for patients but by having an extra tool in our ultrasound kitbag – the 9L4 transduceri – we can give a more confident and assertive diagnosis that will impact significantly on our ability to give accurate counselling to parents,” states Dr. Russell.

“In obstetrics we should always consider using more than one transducer and constantly ask ourselves, can we get more information by using another probe of a different format? By opting for both curved and linear array technologies, plus trans-vaginal probes, we are gaining all the possible information to interpret and help parents make important and difficult decisions.”

Target scanning increases clinical confidence
Dr Russell also states that the new linear technology is particularly helpful in the assessment of the fetal brain, spine and abdomen. “The detail of the structures of the posterior fossa, the cranio-cervical junction and the periventricular region of the brain gives a new perspective and additional diagnostic information to the neurosonographer.

“Enhanced clarity of the abdominal contents, including the ability to reliably distinguish the retroperitoneum from the peritoneal cavity, has assisted in the diagnosis of abdominal anomalies. This has included the ability to confidently identify bowel loops in the thorax in a baby with diaphragmatic hernia at 20 weeks when the fetal stomach remained in the abdomen. This detailed evaluation of pathology can speed up the identification of malformations to assist in case planning and pregnancy management.”

She concludes: “Shedding more light on areas of concern is very welcome in high risk fetal medicine. Achieving greater certainty in the diagnosis of fetal anomalies is beneficial both to the family and to us the professionals. Using the 9L4 for target scanning, particularly of the brain and spine, has been very helpful in gaining extra diagnostic confidence.”

Andrew Pattison, North West Europe Business Manger for Ultrasound at Siemens Healthcare states: “Scanning techniques using linear transducers are slightly different to routine scanning, but once knowledge is gained and procedures underway, the benefits to clinical confidence are delivered.

“The breadth of benefits that diagnostic ultrasound can deliver in obstetrics is being powered by not only the ultrasound unit itself, but the innovation in transducer technologies and software applications.”

He continues: “With ultrasound image quality now comparable with other imaging modalities, questions are more seriously being asked about ultrasound as an alternative to MRI. Easy access, low cost examinations and the delivery of never before seen detail in the finest anatomical structures mean that the next decade of ultrasound innovation is one to watch.”

High standard of care to local community
Saint Mary’s Hospital for Women and Children, part of Central Manchester University Hospitals NHS Foundation Trust, delivers obstetrics, maternity, gynaecology and newborn intensive care services to the local community of Central and Greater Manchester. Saint Mary’s Hospital has more than 1,200 doctors, nurses, midwives, scientists and non-clinical staff, with Dr. Russell and her team focused on specialist obstetric referrals.

i. The 9L4 transducer integrates with the ACUSON S2000™ diagnostic ultrasound system from Siemens Healthcare.