Trabekuläre Knochendichte der Lendenwirbelsäule bei Kindern und Jugendlichen in der quantitativen CT: Referenzwerte und Peak Bone Mass

PURPOSE

The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass.

MATERIALS AND METHODS

We performed quantitative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra.

RESULTS

Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p < 0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5, SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g.

CONCLUSION

The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone density is higher in young female adults than in young male adults.

[Assessment of bone density in children and adolescents by quantitative CT of one lumbar vertebra only]

AIM

The aim of this study was to determine whether measuring the trabecular bone density in one lumbar vertebra (L) instead of three has an effect on the assessment of bone density in children.

MATERIALS AND METHODS

Bone density was measured in 70 patients (38 male, 32 female), ages 1 to 22 years (mean age 12.4, median 13 years) using a Somatom Balance Scanner (Siemens). The trabecular bone density was measured (1-cm slice, 80 kV, 81 mAs) in L1 through L3.

RESULTS

The mean bone density in the lumbar vertebrae was 139.9 mg/ml calcium-hydroxylapatite per ml bone in L1, 133.9 in L2, and 131.7 in L3, and the mean of all three vertebrae was 135.2 mg/ml. Measurements in L1 were 4.7 mg/ml (standard deviation [SD] 4.7 mg/ml) above the mean value of the three upper lumbar vertebrae. The density in L2 was 1.3 mg/ml below the mean (SD 3.1 mg/ml). On average, L3 was 3.5 mg/ml below the mean (SD 4.6 mg/ml). This minor systematic deviation in the measurement values for the individual vertebrae from the mean value was so low that there was no statistical evidence for a deviation from an ideal regression line.

CONCLUSIONS

When using an adequate technique, especially accurate analysis of the topogram (scout view) and the tomogram, measurement of the bone density of one lumbar vertebra provides satisfactory information regarding the trabecular bone density in children, but the values differ in the three upper lumbar vertebrae. The bone density of L2 is close to the mean of the upper three vertebrae. In the case of pathologic values or a pathologic trabecular pattern, three vertebrae should be measured.

[Sonography of the optical nerve -- experience in 483 children]

INTRODUCTION

In case of increased intracranial pressure (IICP), the inflow of cerebrospinal fluid widens the space between the optic nerve (ON) itself and the surrounding dura mater leading to the sonographic appearance of increased diameter of the ON. The purpose of the study was to gain clinical experience in children and to determine (a) the mean values for patients without proven IICP and (b) pathologic values of those with proven IICP.

MATERIALS AND METHODS

Ultrasound of the optic nerve was performed in 483 children with symptoms consistent with IICP, comprising 287 males and 196 females at an age ranging from 4 days to 24 years with a mean age of 7.5 + 5.1 years. The measured diameter of the ON of both eyes and the morphologic criteria concerning nerve sheath and papilla were evaluated retrospectively.

RESULTS

Most of the investigated patients (n = 466) had no IICP as confirmed by neurological examination, EEG, sometimes CCT and/or MRI and clinical follow-up. The typical morphological findings in patients with normal intracranial pressure (ICP) were a clear and longitudinally extended demarcation of the ON with a well-delimited nerve sheath and without prominent papilla. The mean diameter of the ON in patients with normal ICP was 3.4 mm + 0.7 mm. In 17 patients with proven IICP, the mean diameter of the ON increased to 5.6 mm + 0.9 mm. Typically, the nerve sheath was indistinguishable from the hypoechoic ON, often but not invariably associated with a prominent papilla. In patients with IICP, the diameter of the ON alone matches the diameter of the ON plus nerve sheath in patients with normal ICP.

CONCLUSION

IICP was detected with a high sensitivity by ultrasound using the diameter and the morphological criteria of an indistinguishable nerve sheath. A diameter of more than 4.5 mm is definitely pathologic and requires further investigation. Prominence of the papilla is an unreliable criterion for acute IICP.

X-linked lissencephaly with abnormal genitalia associated with renal phosphate wasting

X-linked lissencephaly with abnormal genitalia (XLAG) is a rare disorder caused by mutations in the aristaless-related homeobox (ARX) gene. We report on the clinical data of a boy with a 1-bp deletion (790 delC) resulting in a frame shift in the ARX gene and prolonged survival until age 18 months. Similar to other patients, the boy showed postnatal microcephaly, hypothalamic dysfunction, intractable neonatal seizures, and chronic diarrhoea. In addition, he suffered from exocrine pancreatic insufficiency and renal phosphate wasting became apparent from age 5 months, both of which have not been described previously in XLAG. This allows us to speculate that the phenotype of XLAG is more complex than hitherto known and may include renal phosphate wasting which might not have been observed in other patients due to early death.

[Wilson-Mikity syndrome as a cause of respiratory insufficiency of prematurity]

The Wilson-Mikity syndrome is a differential diagnosis of chronic lung disease in the neonate and primarily related to immaturity. It is characterized by the absence of typical clinical and radiological findings of the respiratory distress syndrome (RDS). Infectious causes are being discussed.

[Small bowel intussusception in childhood]

BACKGROUND

Intussusception is the most common cause of abdominal emergency in early childhood. The majority of cases are ileocolic type of intussusception. Only few reports concerning small bowel intussusception have been reported.

PATIENTS AND METHOD

We retrospectively reviewed the clinical records and imaging findings of all patients with the diagnosis of intussusception (comparing small bowel intussusception with ileocolic type of intussusception), which were documented by ultrasound in the period April 1997 to January 2001. The routine ultrasound scans included an evaluation of the entire abdomen using sector and linear transducers of high frequency (5 - 7.5 MHz) and power doppler ultrasound.

RESULTS

A total of 22 patients with small bowel intussusception (9 female, 13 male) and 29 patients diagnosed to suffer from ileocolic intussusception (10 female, 19 male) were identified and treated. Children with small bowel intussusception were significant older in comparison to children with ileocolic type of intussusception (median age 50 vs. 11 months). In our series the presenting symptoms of patients with small bowel intussusception consisted of abdominal pain (86 %) and vomiting (36 %). The initial clinical symptoms of patients with ileocolic intussusception were abdominal pain (100 %), vomiting (72 %) and/or rectal fresh blood (35 %). Small bowel intussusception was an incidental finding in 3 asymptomatic patients (14 %). Hydrostatic reduction was attempted in 14 % of children with small bowel intussusception (vs. 93 % of children with ileocolic intussusception), one patient needed operative treatment (vs. 21 %). Outcome in all patients was favorable.

CONCLUSION

The high percentage of patients with small bowel intussusception observed may relate to increased use of abdominal ultrasound in children presenting with abdominal pain and improvements in resolution and quality of the images. Small bowel intussusceptions in our series were in the majority of cases short-segmented, self-limited and without a lead point. In comparison to patients with ileocolic intussusception the presenting symptoms of small bowel intussusception are less acute.

[Congenital, solitary hepatic cyst: Observation of the development from birth upon the intervention in the 5th year of life]

BACKGROUND

Sonographic screening helps to discover pathological findings in asymptomatic patients. In these cases the decision about diagnostic and therapeutic consequences is difficult.

CASE REPORT

We describe a girl with a congenital small solitary hepatic cyst with rapidly increasing size after the second year, which was interventionally sclerosed at the age of five years.

CONCLUSION

Even in cases of small cysts long term follow up investigations are necessary, because the growth rate of the cyst can change.

Esophageal foreign bodies: removal of the new euro coins with a magnet tube

AIM OF THIS STUDY

We use a magnet tube to extract esophageal coins. It is smaller than the Foley balloon catheter and easier to handle than a forceps. We present the magnet tube maneuver and investigate whether the new euro coins can be removed with a magnet.

METHOD

We take radiographs of coins and measure the adhesive force of the magnet and compare with the 10 Pfennig German coin which we most often removed successfully from the esophagus.

RESULTS

The 1, 2, and 5 euro cent pieces are magnetic and can possibly be removed with a magnet tube. The non-magnetic pieces can be identified based on the rim and size.

DISCUSSION

When an esophageal foreign body is not round and smooth like a coin, the fluoroscopic guided procedure becomes more risky with respect to mucosal injury. When a large object is stuck in the esophagus for more than 24 hours, an endoscopy must be considered to rule out any severe damage to the esophageal wall.

[Solid-pseudopapillary tumors in childhood]

We report on fife female patients with solid pseudopapillary tumors of the pancreas. The tumors are extremely rare in children. They occur mainly in adolescent and young adult females. The tumors are neoplasms of low malignancy with infrequent metastases, for instance, in the liver or the peritoneum. Although the tumors had reached a large diameter, all of them underwent complete tumor resection. After that the patients have a very good prognosis. Thus, so it is important to distinguish solid-pseudopapillary tumors from other tumors of the pancreas.

[Hereditary deficiency of C1-esterase inhibitor presenting with recurrent abdominal pain]

Hereditary deficiency of C1-esterase inhibitor (C1-INH) which clinically manifests as hereditary angioedema is a rare disorder. In previously not diagnosed cases, a fatality rate of up to 30 % has been reported. The diagnosis of C1-esterase inhibitor deficiency should not be missed in patients presenting with angioedema in the face, stem or extremities. We report the case of a 17-year-old girl with recurrent abdominal pain and swelling of the hands.