Percentiles of intrauterine placental volume and placental volume relative to fetal volume: A prospective magnetic resonance imaging study.

INTRODUCTION: We aimed to provide percentiles of intrauterine placental growth and placental growth relative to fetal growth (placental to fetal ratio) by measuring placental and fetal volumes by magnetic resonance imaging (MRI). METHODS: In this prospective study, 107 unselected singleton pregnancies were examined by MRI at gestational week 27 and 37. Based on the estimated volumes of the placenta and the fetus, we calculated median and percentiles at gestational weeks 27 and 37. RESULTS: Median placental volume at gestational week 27 was 513 cm3 (Inter Quartile Range (IQR) 182 cm3), and 831 cm3 (IQR 252 cm3) at week 37. The 10th - 90th percentiles included placental volumes between 392 and 717 cm3 at gestational week 27, and 631-1087 cm3 at week 37. The placental to fetal ratio was significantly higher at gestational week 27 than at week 37, with a median ratio of 0.54 (IQR 0.18) and 0.31 (IQR 0.08), respectively (p < 0.001). The 10th-90th percentiles included placental to fetal ratios between 0.43 and 0.73 at gestational week 27 and 0.25-0.39 at week 37. DISCUSSION: At gestational week 27, the placental volume was about half the size of the fetal volume, whereas at week 37, the placental volume was about one third of the fetal volume. This finding suggests that placental growth was less prominent than fetal growth after gestational week 27. Knowledge about the distribution of intrauterine placental size in the general population of pregnancies are prerequisites for diagnosing abnormal placental size.

Bowel MR imaging with oral Gastrografin: an experimental study with healthy volunteers.

Our objective was to evaluate Gastrografin for MR bowel imaging. Twenty-three healthy volunteers in two randomised groups received 300 or 400 ml 50% Gastrografin, drunk continuously during 2 and 3 h, respectively. Images were applied during breath-hold in three orthogonal orientations. The balanced fast-field echo (BFFE) and balanced turbo field-echo (BTFE) sequences, with acquisition times from 13 to 25 s, were used before gadolinium (Gd) DTPA implying 1- to 2-mm-thick slices locally or 6-mm-thick slices through the entire gastrointestinal tract. The Gd-enhanced images were performed using a 3D T1-weighted FFE sequence with water selective excitation (Proset). Image quality, including bowel distention, homogeneity of opacification and wall conspicuity, were evaluated by two experienced reviewers, and the adverse reactions were recorded. Very good or excellent distention, homogeneity and wall conspicuity were achieved in the central segments from the ileum to the left colon flexure in 83-96% of cases, due to the adequate contrast media supply in these regions. Distention, homogeneity and delineation were good in the central segments of the remaining bowels. Diarrhoea was a major problem affecting all participants, followed by nausea. Provided that there is modern fast sequential technology, excellent MR imaging of the bowel can be achieved by the oral administration 50% diluted Gastrografin. Further studies are needed to refine the technique and optimise the quantity and concentration of Gastrografin in order to avoid or reduce adverse reactions.

Necrotizing fasciitis: unreliable MRI findings in the preoperative diagnosis.

The authors present two cases of necrotizing fasciitis (NF), one case of dermatomyositis and one case of posttraumatic muscle injury, which have similar magnetic resonance imaging findings in terms of skin, subcutaneous fat, superficial and deep fasciae and muscle involvement. These cases highlight the need for cautious interpretation of magnetic resonance imaging (MRI) findings, for they are nonspecific and the preoperative decision should be based mostly on the evolution of the clinical status.

[Magnetic tomography--new imaging techniques and future perspectives]. / Magnettomografi innenfor pediatrisk radiologisk diagnostikk.

BACKGROUND: MRI is a promising imaging technique for diseases in most organ systems in children. MATERIAL AND METHODS: This review discusses MRI on the basis of the literature and our own experience. RESULTS: The value of MRI in paediatric neuroradiology is firmly established. In congenital heart defects and other reasons for cardiovascular imaging in children, the non-invasiveness of the method is appealing. MRI is already included in most international paediatric oncology protocols. Paediatric applications for MRI differ from those in adults as they focus on developmental and congenital abnormalities. Furthermore, some pathological conditions are unique to children. MRI is also a promising alternative to established methods for evaluation of the urinary tract. There are some specific problems with MRI in children. Immobilisation and sedation techniques include tight wrapping of the newborn with soft elastic bands, feeding immediately prior to the study, and allowing one parent into the magnet with the child. Midazolam and oral chloral hydrate are usually used for sedation. INTERPRETATION: MRI is of particular value in the paediatric age group as the method is capable of highly accurate imaging in a variety of congenital and paediatric diseases without the use of ionising radiation. Faster sequences and better resolution will further increase the use of MRI in children.

MR urography in children: current status and future development.

The normal anatomy and many pathologies of the pediatric genitourinary system can be assessed with different imaging modalities. Most of them are based on the use of ionizing radiation and/or invasive techniques. The contribution of magnetic resonance imaging in this regard has opened new ways of approaching pathological conditions in this patient group. The addition of the newly developed rapid techniques has enhanced the superiority of MRI, and both morphological and functional evaluation of the genitourinary system can be achieved. There are different factors on which rely the optimization and the efficiency of magnetic resonance urography (MRU). Of importance is adequate patient immobilization and the use of optimal imaging sequences. The rapid technical development, including the advent of the post-processing respiratory navigator, allows acquisition of high-quality images independent of the patient's respiratory rate. In the future, it is expected that MRU, due to its non-use of ionizing radiation, will become the most important tool in the diagnostic work-up of genitourinary pathologies in infants and small children.

MR urography: the future gold standard in paediatric urogenital imaging?

BACKGROUND: Examination of the paediatric urogenital tract is traditionally performed using methods that utilise ionising radiation, such as intravenous urography (IVU), computerised tomography (CT), voiding cystourethrography (VCU), and scintigraphy, in addition to ultrasound (US). OBJECTIVE: To determine the potential and effectiveness of MR urography (MRU) in infants and children. Materials and methods. 44 MRU examinations were prospectively performed in 39 patients (21 infants, mean age 3.5 months, and 18 children, mean age 6 years 2 months) with known or suspected pathology of the urinary tract. Non-enhanced, fast spin-echo sequences (TSE) were performed in all patients. In 70 % of the patients a contrast-enhanced, fast gradient-echo sequence (TFE) was included. The dynamic sequence was prolonged and supplemented with furosemide provocation in some patients with suspected urinary-tract obstruction. RESULTS: Nine percent of examinations were non-diagnostic or interrupted due to movement. MRU contributed additional information in 66 %. Nine patients with suspected urinary-tract obstruction were examined with both contrast-enhanced MRU and scintigraphy. Three MRU examinations were less informative and one equal to scintigraphy when obstruction was the diagnosis. When using a technique with a prolonged dynamic sequence, including frusemide provocation, four MRU examinations were equal and one was superior to scintigraphy. CONCLUSIONS: MRU has the potential to replace traditional diagnostic methods which use ionising radiation in paediatric patients. Further studies are needed before definite conclusions can be drawn.

Lipoblastoma: MRI appearances of a rare paediatric soft tissue tumour.

Lipoblastoma is a rare, benign soft-tissue tumour derived from embryonic fat. Four patients with tumours located in the upper limb are reported, with special reference to imaging techniques and histology. Radical surgical excision is essential to prevent local recurrence and exact imaging techniques are thus crucial. MRI appears to be a reliable preoperative investigation and is the recommended radiological examination. In a child under 3 months of age, images showing a predominantly fatty but inhomogeneous soft-tissue mass are suggestive of lipoblastoma.

[Lipoblastoma. A rare, benign tumor in children]. / Lipoblastom. En sjelden, benign tumor hos barn.

Lipoblastoma is a rare, benign tumour of embryonal fat seen almost exclusively in infancy and early childhood. It occurs mostly in the extremities, but it is also seen in other parts of the body. The tumour may grow rapidly, and the fact that lipoblastomas show immature fat cells could lead to the wrong diagnosis of liposarcoma. Complete surgical excision appears to be the treatment of choice. A correct, preoperative diagnosis is possible in most cases. Two cases of lipoblastoma of the upper limb and one case in the scapular region are reported.

Vein of Galen vascular malformations in infants: clinical, radiological and therapeutic aspect.

A series of 14 vein of Galen vascular malformations diagnosed in the pediatric populations and treated at the Hospital for Sick Children-Necker, Paris, between 1988 and 1994 is presented. Five of the patients were diagnosed in the neonatal period, of whom 4 presented with life-threatening, intractable cardiac decompensation and high-flow arteriovenous fistulae. Embolization was performed on vital indications in 4 patients during the first week after birth. One embolization failed with fatal outcome. Of the 3 who were embolized, 2 succumbed within 1 week and 1 survived with marked improvement of cardiac symptoms. The older children presented with hydrocephalus and neurologic symptoms. The 10 patients older than 1 year were embolized. These procedures were successful in 90 %, with hemodynamic stabilization and improvement of clinical symptoms. In this group the mortality rate was 10 %. The total mortality rate was 29 %. Hydrocephalus was secondary to a compression of the Sylvian aqueduct in 44 % of cases. Five patients had ventricular drainage before embolization followed by a staged elective embolization. Transarterial embolizations were performed in 11 patients, whereas 2 patients were embolized via the transvenous route.

[Balloon dilatation of postoperative esophageal stenoses in children]. / Ballongdilatasjon av postoperative oesophagusstenoser hos barn.

During the period 1987-92, seven patients (two girls and five boys under one year of age) were dilated for strictures following oesophageal atresia operation. The total number of dilatations was 47. Six out of seven patients were treated successfully. No sedation/anaesthesia was used. There was one episode of cyanosis and brief respiratory arrest, and two incidents of intramural tears. None of these episodes required surgical intervention. Fluoroscopically guided balloon dilatation of oesophageal strictures is considered a safe and efficient treatment, also for outpatients.

[Invagination in children. New diagnostic and therapeutic aspects]. / Invaginasjon hos barn. Nyere diagnostiske og terapeutiske aspekter.

Based on the literature and our own experience, we recommend ultrasound examination as a routine in infants and small children with acute abdominal pain. If a pseudotumour is diagnosed, with suspicion of an intussusception, we verify the diagnosis by an air enema, and also use this for treatment under the surveillance of fluoroscopy and a conventional blood pressure manometer. The results are encouraging.

[Head injuries with delayed intracranial hemorrhage]. / Hodetraumer med intrakraniale senblødninger.

Nine cases of delayed intracranial haematomas were found among 300 patients with head injuries during a two-year period. Six of the nine patients developed delayed traumatic intracerebral haematoma, two epidural haematoma and one subdural haematoma. Delayed intracerebral haematoma was diagnosed from 12 hours to six days after the trauma. The primary CT showed brain contusion in the majority of the patients. The outcome was poor. One patient died and two were severely disabled. The clinical course was more rapid in the two patients with epidural haematoma than in the others. Marked elevation of intracranial pressure was monitored in both cases prior to the second CT examination. In spite of successful evacuation of the haematoma, one patient died and the other developed physical and mental retardation. In one patient a subdural haematoma was diagnosed three months after the trauma. The patient did well postoperatively.

[Simple and efficient cleansing of the large intestine for colonic radiography]. / Enkel og effektiv tømming av tykktarmen før røntgen colon.

A clinical trial documented the excellent cleansing effect of a single low dose of the oral laxative sodium picosulphate. To achieve good preparation of the colon it is essential to ensure a combined regimen including simple diatary restrictions and liberal fluid intake during the two days preceding the radiological examination. An additional mechanical washout lavage is time-consuming and uncomfortable, and usually unnecessary for outpatients.

Salivary gland malignant neoplasms: treatment and prognosis.

A retrospective analysis of 183 patients with malignant salivary gland tumors treated between 1955 and 1978 is presented. The analysis showed that radiation therapy lowered the recurrence rates after surgery and controlled approximately one-third of the inoperable tumors. A dose-response relationship exists and the data suggest that the radiation dose should not be less than that corresponding to a CRE-value of 1950 reu (70 Gy/7 weeks). Histology, location and clinical stage are important prognostic factors.

The treatment of glaucoma with propranolol (Inderal). A clinical trial.

The effect of propranolol (Inderal) on the intraocular pressure (IOP) in glaucoma has been measured. Twenty-two patients completed the clinical trial. Propranolol in doses of 160 mg/d effectively lowered IOP in eyes with various types of open angle glaucoma. The test periods lasted from 4 to 6 days. The ocular hypotensive effect of propranolol was also registered in patients efficiently treated with pilocarpine and acetazolamide (Diamox), and in glaucomas not satisfactorily controlled by this therapy. High positive correlations between mean pretreatment pressure (P1), and pressure fall (delta P) were found (P less than 0.001), and the pressure decrease induced by propranolol treatment tended to be proportional to the pressure gradient between the anterior chamber and the episcleral veins. This pressure gradient was reduced by an average of about 50% following propranolol treatment. There was no change in scleral rigidity after propranolol.