Frühgeborene im MRT untersuchen
Auszug KTM Krankenhaustechnik & Management Juli/August
Around 1,400 children are born at Jena University Hospital every year - many see the light of day before the 37th week of pregnancy. These premature children have often been born much too soon. Early diagnosis is important for being able to detect and treat any organ damage. A special MR diagnosis incubator system makes it possible to examine in MRT, without radiation, even premature babies who are dependent upon the protective atmosphere of an incubator.
"An MR incubator system extends the examination options for our smallest patients enormously," says Prof. Dr. Hans-Joachim Mentzel, Director of the Child Radiology Section of Jena University Hospital. "Because there are some illnesses in premature and newly born babies that are adequately detectable only when magnetic resonance tomography is used. The still immature brain, in particular, can be optimally displayed with MRT."
Premature babies are frequently subject to seizures. These can be caused by congenital malformations. Undetected brain haemorrhages and strokes are very dangerous for newly born babies. "The brain can be permanently damaged. This can result in lifelong mental and physical handicaps," explains Professor Mentzel. Previously, reports the professor, it was difficult to impossible to examine these babies with MRT: "Many premature babies are so sensitive that they should not be taken from the incubator. Because this provides the climate that it ideal for them." When there was an emergency and a premature baby nevertheless had to be examined in MRT because otherwise no diagnosis would have been possible, there was a great rush. "Everything had to happen very quickly. Because the preemies cooled down very quickly outside the incubator. And back then monitoring was only possible to a very limited degree for the neonatologist in MRT. The examination time was therefore kept as short as possible. This also involved disadvantages for diagnostics, of course. Because sometimes more time is needed to find the actual cause of an illness," says Professor Mentzel.
Special incubator with built-in coil technology
The MR diagnosis incubator system nomag IC from the medical technology company LMT Medical Systems in Lübeck has enormously improved the diagnosis options of the child radiologists in Jena. Professor Mentzel is very happy about this: "We can now examine preemies in the MRT who cannot be removed from the incubator." The apparatus is designed in such a way that it is compatible with MRT equipment. The built-in MR coils and the multi-channel head coil ensure good picture quality. This means that possible brain damage can be detected and treated early on. An earlier start to treatment improves the development prospects for the premature babies.
Magnetic resonance tomography is very popular among child radiologists, neonatologists and paediatricians. The reason for this is that optimal pictures can be produced and at the same time this examination method is radiation-free. Although ultrasound examinations do not use radiation either, and are useful in many cases, ultrasound is subject to certain limitations, particularly when diagnosing subtle brain damage. Professor Mentzel knows: "With ultrasound it is not possible to show the surface and maturation of the brain as well as with MRT. But the use of the MR incubator is also advantageous for the examination of mature newborns with complex malformations or congenital tumours, which sometimes require very time-consuming examinations as whole-body MRTs. In such cases the examination takes place after nursing or feeding in the natural sleep phase of the newborn or with slight sedation under ideal monitoring conditions for the paediatricians."
The nomag IC makes it possible to supply and monitor the patients uninterruptedly during the MRT examination. The incubator system is located immediately on the Neonatal Intensive Care Ward. To be examined, the newborns are only briefly transferred from their incubators on the Neonatal Ward. This is very quick and simple. The incubator system is suitable for premature and newborn babies up to a weight of 4.5 kg, a maximum body length of approx. 55 cm and a head circumference of around 40 cm. The MR compatible chassis, which comes with the incubator system as standard, makes possible swift and stress-free transportation to Child Radiology.
"In order to be able to supply the little patients safely during their transportation, up to four MR-compatible gas bottles can also be carried on the chassis," explains Nina Friedrich, Marketing Director of LMT Medical Systems GmbH. In addition, an MR-compatible respiration device can be placed on top of the control panel. Because the whole system ― including chassis, respiration, electrical and gas supply ― is MR-compatible, the little patient can be rolled right up to the MRT.
For problem-free procedures: UPS and MR-compatible gas bottles
In Radiology, the apparatus is placed on the examination table and the baby receives special ear protectors. The multi-channel coils can also be used in the damp and warm ambient conditions in an incubator. According to the manufacturer, the MR diagnosis incubator system is compatible with 3 Tesla MRTs (Siemens: TIM Trio, Verio, Skyra; Philips: Achieva, Ingenia) as well as 1.5 Tesla MRTs (Siemens: TIM Symphony, Avanto, Espree, Aera, Essenza; Philips: Achieva, Ingenia).
The coil is directly connected to the existing interface. Gas is supplied to the apparatus through the wall connections in the MRT room. The display on the system allows continual monitoring of the baby. Both the oxygen saturation (SpO2) and the heart-rate can be measured and displayed during diagnosis. Thanks to the double-walled structure of the incubator, the noise-level around the patient is reduced by around 12-15 dB (A). Normally, no sedation or hardly any sedation is necessary and there is even no need for a general anaesthetic. "We were already trying to select the most favourable time possible for an MRT examination," says Professor Mentzel. "It helps when the baby has been fed just before. Then they sleep peacefully." This way the radiologist is independent from the anaesthesia team and fewer personnel are needed. Because the little patients can still be supplied in the MR incubator system, longer examinations are also possible. "We recently examined a girl who came into the world in the 30th week of pregnancy with a complex malformation of the kidneys and genitals. It was not possible to clarify the findings using sonography alone, so we carried out an examination in the MR incubator before the operation, in consultation with our paediatric surgeons and neonatologists. For more than an hour, all organs were examined very precisely in the MRT and the functioning of the kidneys was assessed by means of a special contrast agent analysis. The girl slept in the incubator the whole time," reports the doctor.
Multi-channel body coil for chest and stomach area
For such precise examinations of the body, Jena University Hospital has acquired a multi-channel body coil that is designed to be compatible with the incubator system. With this, detailed pictures can be produced of the chest and stomach area of the little patients.
Marketing Manager Nina Friedrich:
"The 12-channel body coil is suitable for examinations of the abdomen, heart and spine. It consists of two parts: The part with eight channels is incorporated into the lying surface and the top part with four channels is placed on a coil-holder above the patient."
For a complete examination of the spine, one can use the head coil and the coil in the lying surface together (simultaneously). The head and flex coil can also be used without the incubator. The image data obtained is precise and largely free of motion artefacts. So as not to waste any time, Professor Mentzel and his team make the diagnosis directly in the MRT Department. The further approach is discussed on the spot with the neonatologist. This means that therapy can be quickly initiated.
Used once a week
Once the examination is over the premature baby is pushed back onto the Neonatal Intensive Care Ward in the special examination incubator and placed back in its usual incubator. "Thanks to its simple handling, diagnosis has become much more relaxed for everyone involved," says Professor Mentzel happily. On average, the system is used once a week in Child Radiology at Jena. "Our experience has been very positive," reports Professor Mentzel.
"I am very happy that we are now able to diagnose many illnesses better in premature and newborn babies. For them it is particularly important that any illnesses are detected and treated early on. Current studies show that premature babies generally have increasingly good chances of survival, but can over the long term suffer from developmental disorders such as seizures, learning disabilities or motor disorders, the causes of which sometimes remain unclear. With the MR incubator we can take a step in the right direction towards researching these causes. I am very pleased about this."