Normal MR appearances of the posterior pituitary in central diabetes insipidus associated with septo-optic dysplasia

Magnetic resonance (MR) imaging of the pituitary in children with central diabetes insipidus usually shows absence of the normal high signal within the posterior gland. The high signal of the normal posterior pituitary is thought to be due to the presence of intra- cellular storage granules of vasopressin. MR imaging has been advocated as a useful investigation to aid in the distinction between central diabetes insipidus and other causes of thirst and polydipsia. We report the case of an infant with central diabetes insipidus in association with septo-optic dysplasia in whom MR imaging showed normal appearances of the posterior pituitary. The mechanism of central diabetes insipidus in this case may be related to a failure of hypothalamic function affecting osmoreception, rather than to a deficiency of vasopressin. Normal MR appearances of the pituitary do not exclude central diabetes insipidus in infants with midline cerebral malformations. Received: 20 November 1995 Accepted: 20 January 1996     

Reconversion of bone marrow in Gaucher disease treated with enzyme therapy documented by MR

Background. Skeletal complications are responsible for significant morbidity in Gaucher patients. Plain radiographs have been unreliable in assessing bone marrow infiltration and activity. A way to assess bone marrow improvement is needed during enzyme therapy. Objective. The purpose of this paper is to assess the usefulness of MR in following improvement of abnormal bone marrow in Gaucher patients on enzyme therapy. Materials and methods. Three patients aged 2, 7, and 24 years underwent serial MR scans of the lower extremities before and during treatment with Alglucerase (two patients) and Imiglucerase (one patient). T1-weighted, T2-weighted, STIR and FSE T2-weighted images were utilized. Two patients were imaged after 16 months of therapy, and one patient was imaged after 6 months of therapy. Results. All patients had improvement in marrow signal consistent with partial reconversion to fatty marrow during treatment. The findings were more marked after prolonged therapy. T1-weighted images demonstrated findings most clearly. Conclusion. MR consistently showed improvement in marrow signal in Gaucher patients on enzyme therapy. As smaller doses of enzyme therapy are the trend, MR can be utilized to determine if therapy is effecting a change in the bone marrow. Received: 20 June 1997 Accepted: 7 November 1997     

Iron overload following bone marrow transplantation in children: MR findings

Objective. The purpose of this study was to determine the incidence of post-transfusional iron overload in children after bone marrow transplantation by reviewing their magnetic resonance imaging (MR) findings. Materials and methods. We reviewed the abdominal MR studies of 13 children after autologous bone marrow transplantation. Nine of the children had also undergone MR prior to transplantation. Iron deposition in the liver, spleen and bone marrow was graded semi-quantitatively on both T1- and T2-weighted images. Serum ferritin levels and number of blood units given after bone marrow transplantation were recorded. Results. None of the pre-transplantation MR studies revealed iron overload. After bone marrow transplantation, three children showed normal liver and spleen. Iron overload in the liver was noted in ten patients (77 %), six of whom also showed iron overload in the spleen (46 %) and five in the bone marrow (38.5 %). The degree of hepatic iron overload was correlated significantly and splenic iron overload was correlated weakly with the number of blood transfusions (P = 0.01 and P > 0.01, respectively), but neither was correlated with the serum ferritin level. Conclusion. Iron overload commonly accompanies bone marrow transplantation. The observed pattern of iron deposition, in which the spleen was uninvolved in 40 % of patients demonstrating iron overload, is not typical of post-transfusional hemochromatosis. Received: 10 June 1997 Accepted: 10 June 1997     

51������β�鵰�������ϰ���ƶѪ���� ������Ѫȥ�������������صĹ�ϵ�о�

目的探讨重型β珠蛋白生成障碍性贫血(beta-thalassaemia,简称β-TM)患儿长期输血、去铁治疗与铁过载的关系。方法深圳市第二人民医院2001年成立"地贫之友"与"地贫服务队",对β-TM患儿进行规范性的长期输血和去铁治疗。每3个月监测血清铁蛋白浓度(SF)、肝肾功能、心肌酶谱、心功能、心脏和肝脾B超、血糖和尿糖。2001年2月至2010年6月对其中51例患儿进行核磁共振检测心脏T2*、左心室射血分数(LVEF)、肝脏T2*、胰腺T2*和垂体T2*。根据治疗方法分为足疗程去铁胺+去铁酮(DFO+DFP)联合去铁治疗组(足疗程联合组)10例、不足疗程DFO+DFP联合去铁治疗组(不足疗程联合组)31例、单用足疗程地拉罗司(DFX)去铁治疗组(单用DFX组)10例。根据SF质量浓度分为SF≤2000μg/L组(A组)12例、SF~3000μg/L组(B组)17例、SF>3000μg/L组(C组)22例。结果各组LVEF、心脏T2*、垂体T2*值差异无统计学意义(P>0.05);足疗程联合组肝脏T2*高于不足疗程联合组(P<0.05),单用DFX组肝脏T2*、胰腺T2*、垂体T2*均高于足疗程联合组和不足疗程联合组(P<0.05)。足疗程联合组SF低于不足疗程联合组,单用DFX组SF低于足疗程联合组和不足疗程联合组,差异均具有统计学意义(P<0.05)。C组肝脏T2*和胰腺T2*明显低于A组和B组,差异具有统计学意义(P<0.05)。心肌铁过载11例(21.6%),肝脏铁过载43例(84.3%)。SF与心脏T2*无相关性(r=0.254,P>0.05),与肝脏T2*呈中度负相关(r=0.558,P<0.01)。结论足疗程DFO+DFP联合去铁治疗和单用足疗程DFX去铁治疗均能有效降低血清铁蛋白浓度,动员肝脏组织铁,效果优于不足疗程DFO+DFP联合去铁治疗。不同去铁方式均能减轻心脏铁过载。     

Ultrasound and MR imaging of fibromatosis colli (sternomastoid tumor of infancy)

The sonographic and CT findings of fibromatosis colli (sternomastoid tumor of infancy) have been described, but the MRI appearance has been reported in only one case in which the mass resolved over time. This case describes the detailed MRI findings in a biopsy-proven case of fibromatosis colli; the signal intensity of the mass on T2-weighted images was slightly less than on gradient-recalled T1-weighted images, consistent with the presence of some fibrous tissue within the muscle mass. The involved portion of the muscle was better defined on MRI than sonography. MRI was helpful in demonstrating the signal characteristics of the mass; localizing the mass to within the sternocleidomastoid muscle; and demonstrating clear surrounding fascial planes with lack of associated lymphadenopathy, airway compression, vascular encasement, bone involvement or intracranial/intraspinal extension associated with other neck masses. Received: 12 August 1997 Accepted: 21 November 1997     

Focal cortical dysplasia and hemimegalencephaly: histological and neuroimaging correlations

Background. The classification of cerebral cortical dysplasia is difficult and there are histological similarities between focal cortical dysplasia (FCD) and hemimegalencephaly. Objectives. To correlate the MR features and histological data of cortical dysplasias. Materials and methods. The MR appearances of 17 brains were examined. According to the signal intensity within the pathological area on T2-weighted (T2-W) sequences we selected two groups. Results. Group 1 comprised ten patients with high signal in the dysplastic area on T2-W images. This group included five hemimegalencephalies, three frontal quadramegalencephalies, and one gyral dysplasia. The pathological hemisphere was reduced in size in one case. The cortex was thickened in all cases on T1-weighted (T1-W) images. There was loss of delineation between white matter (WM) and grey matter (GM) in all cases on both T1-W and T2-W sequences. The differential diagnosis with tumour, neoplastic-like malformation or polymicrogyria was questionable. Group 2 comprised seven patients presenting without increased signal within the dysplastic area on T2-W images. WM and GM were of similar signal intensity in six cases, and delineation between white and grey matter was absent in all cases. There were mild abnormalities on T1-W sequences in all cases. The dysplasias were limited to a lobe in five cases and a gyrus in two cases. In all cases, depiction of the malformation was a greater diagnostic problem than the differential diagnosis. Conclusions. A constant MR sign in our series was the loss of delineation between WM and GM in the dysplastic area. This correlated well with the observed histological disorganisation. Markedly high signal within the dysplastic area seems to be related to myelin abnormalities rather than glial cell abnormalities. Received: 25 July 1997 Accepted: 9 January 1998     

MR marrow signs of iron overload in transfusion-dependent patients with sickle cell disease

Magnetic resonance (MR) marrow signal in the axial and appendicular skeleton of 13 transfusiondependent and chelated pediatric patients with sickle cell anemia (SSD) was compared with marrow signal in six non-transfusion-dependent patients with SSD. Hepatic, pancreatic, and renal MR signal were also evaluated. Indication for hypertransfusion therapy was primarily prior history of stroke. Transfusion-dependent patients had evidence of iron deposition throughout the imaged marrow and the liver, despite deferoxamine chelation therapy. Non-transfusion-dependent patients did not demonstrate grossly apparent signs of iron overload. Red marrow restoration was present in the spine, pelvis and long bones and, in some patients, within the epiphyses. Marrow edema secondary to vaso-occlusive crises was evident in the metaphyses and diaphyses of long bones in areas of both red and fatty marrow and was best seen using fat-saturated T2-weighted imaging techniques.     

MRI of the hypothalamic-pituitary axis in children

In childhood, the MR characteristics of the normal pituitary gland are well established. During the first 2 months of life the adenohypophysis demonstrates high signal. Pituitary gland height (PGH) decreases during the 1st year of life and then increases, reaching a plateau after puberty. The magnetization transfer ratio (MTR) increases in both sexes up to the age of 20 years. On dynamic contrast-enhanced studies, the posterior pituitary lobe enhances simultaneously with the straight sinus, and the adenohypophysis later, but within 30 s. In genetically determined dysfunctional states, the adenohypophysis may be normal, hypoplastic, or enlarged. Pituitary enlargement, observed in Prop 1 gene mutations, is characterized by a mass interposed between the anterior and posterior lobes. An ectopic posterior lobe (EPP), associated with a hypoplastic or absent pituitary stalk, may be observed in patients with hypopituitarism. Tumors of the hypothalamic-pituitary (HP) axis may be the origin of adenohypophyseal deficiencies. A small hypointense adenohypophysis is found in iron overload states and is often associated with hypogonadotrophic hypogonadism. Absence of the posterior lobe bright signal, with or without a thick pituitary stalk or a mass at any site from the median eminence to the posterior pituitary lobe, may be found in diabetes insipidus. Hydrocephalus, suprasellar arachnoid cysts, hypothalamic hamartomas and craniopharyngiomas may result in central precocious puberty (CPP). Increased PGH in girls with idiopathic CPP is useful for its differential diagnosis from premature thelarche (PT). Pituitary adenomas, observed mainly in adolescents, present the same MR characteristics as those in adults.     

US, CT and MR imaging characteristics of nephroblastomatosis

Objectives. To describe the imaging features of nephroblastomatosis with US, CT and MR, to point out characteristics of differentiation between nephrogenic rests (NR) and Wilms' tumour (WT) and to determine the most appropriate imaging modality. Materials and methods. We reviewed the US, CT and MR images of 29 cases of histopathologically confirmed nephroblastomatosis sent to our department for reference evaluation (German nephroblastoma study). The series included 17 kidneys with NR, 6 kidneys with WT and 32 kidneys with both NR and WT. Results. NR presented as multinodular, peripheral, cortical lesions, the diffuse form of distribution being less common. Foci were homogeneous and of low echogenicity, density or signal intensity. The lesions were most clearly depicted with contrast-enhanced CT and T1-weighted (T1-W) MR images. Lesions smaller than 1 cm were rarely identified by US. The most reliable criterion to differentiate NR from WT was their homogeneity. Conclusions. Contrast-enhanced CT and T1-W MR images are of similar potential and superior to US in the diagnosis of nephroblastomatosis. Due to the significant radiation dose of serial CT, MR imaging should be the method of choice wherever it is available. The cost-effectiveness and availability of US makes it ideal for serial follow-up of known lesions. Received: 6 June 1997 Accepted: 9 January 1998     

MRA of the intracranial circulation in asymptomatic patients with sickle cell disease

Background. MR angiography (MRA) provides a mechanism for non-invasively studying blood flow, thus providing a new opportunity to study the intracranial circulation in asymptomatic sickle cell disease (SCD) patients. Although conventional angiography is the gold standard for the depiction of vascular anatomy, this is too invasive for an asymptomatic population. Objective. To establish the range of appearances in asymptomatic SCD patients and to correlate brain MRI results (either sub-clinical abnormalities or normal brain parenchyma) with the MRA findings. Materials and methods. Brain MRI and MRA of the intracranial circulation was performed on 22 patients (13 male and 9 female, median age 7.5 years, range 1.3–20 years). Fourteen were homozygous SS and eight were SC. The median haematocrit at the time of MRI was 25.9 (range 13.8–33.3). Results. On MR imaging, four patients had infarcts in eight vascular territories (six anterior and two posterior). In 3/4 of anterior vascular territories with infarction, long ( ≥ 6 mm) segments of abnormal signal were seen at the internal carotid artery bifurcation with associated reduced distal flow. Short focal areas of abnormal signal were commonly seen where vessels branched, bifurcated or curved and were not associated with infarcts. These areas probably represent turbulence-related dephasing secondary to high velocity flow found in SCD. Conclusion. Long segments ( ≥ 6 mm) of abnormal signal with reduced distal flow correlated with sub-clinical infarction. Received: 15 April 1997 Accepted: 14 November 1997     

Magnetic resonance analysis of suprasellar tumors of childhood.

A retrospective analysis of the magnetic resonance (MR) images in 53 pediatric patients with pathologically proven suprasellar tumors was performed, in an attempt to identify the characteristic MR features of these tumors and assess the capability of MR to predict a histologic differentiation. The tumors analyzed included 29 astrocytomas, 11 craniopharyngiomas, 4 germinomas, 3 pituitary adenomas with suprasellar extension, 2 teratomas, 1 spindle cell tumor, 1 primitive neuroectodermal tumor, 1 arachnoid cyst and 1 chordoma of the clivus with suprasellar extension. Thirty patients received intravenous Gd-DTPA as part of their MR exam. Certain MR features, while not pathognomonic, are quite helpful in the differentiation of craniopharyngiomas from chiasmatic/hypothalamic astrocytomas. Presence of a high signal intensity component on T1-weighted images, cyst formation with macrocystic predominance, irregular, heterogeneous solid portion, and smooth ring cyst wall enhancement represent the key characteristics of craniopharyngiomas. Solid predominance with microcysts, long T1 and T2 relaxation times, intense enhancement after contrast administration and extension along the posterior optic pathways are the typical MR findings of chiasmatic/hypothalamic astrocytomas. Presence of diabetes insipidus in correlation with the MR findings of a well-marginated, round or lobular tumor with prolonged T1 and T2 relaxation times, which enhances strongly after Gd-DTPA administration may be the clue in the diagnosis of suprasellar germinomas. Teratomas can be separated from other pediatric suprasellar neoplasms on the basis of internal heterogeneity with presence of fat, calcium and various soft tissue densities. Tumors invading the suprasellar cistern by extension are easily differentiated by identification of the primary site of origin. The above features, while not pathognomonic, are quite helpful in making a specific diagnosis.     

Intracranial aneurysms in infants and children

Background. The diagnosis and imaging of pediatric aneurysms has changed since the advent of MR and MRA. Objective. To update the literature on pediatric aneurysms and better define the appropriate work-up of childhood aneurysms in 1997. Materials and methods. Retrospective review of 21 children (12 boys, 9 girls) with 25 aneurysms from three institutions over a 20-year period was performed. Imaging studies were mixed and included CT (19 patients), MR (11 patients), MRA (6 patients) and angiography (18 patients). Results. Eighteen of 25 aneurysms were congenital saccular, 6 were mycotic, and 1 was post-traumatic. Of these, 44 % were in the posterior circulation. Nine aneurysms arose from distal arterial branches. Forty percent were large (between 1–2.5 cm) and 16 % were giant (> 2.5 cm). CT and MR showed hemorrhage, and frequently revealed the aneurysms as a focal mass with or without enhancement and flow void. Six children had MRA which revealed aneurysms in four patients. All patients with MRA had corresponding conventional angiography. Conclusion. Characteristics of pediatric aneurysms include diversity of type, increased incidence in the posterior fossa, peripheral location, and large size. CT, MR and MRA are useful in the diagnosis with conventional angiography essential for preoperative planning. Received: 14 April 1997 Accepted: 24 November 1997     

MRI of disc space infection in infants and children

The MR aspects of spondylodiscitis in pediatric patients were studied with a 0.5-Tesla supraconductive magnet: 12 patients were divided in two groups; acute disease (9) and period of sequelae (3). The first group was divided into two subgroups according to the age and the clinical findings: infants (2) and children (7). In infants, MR gave good visualization of the destruction of vertebrae and discs. Presuppurative abscesses appeared as light signals, their extent and position relative to the cord being clearly visualized in frontal and sagittal planes in T1-weighted images. In older children, there were a low vertebral signal and disappearance of the disc-vertebra borders on T1-weighted images and a high vertebral signal with a decreased and flattened disc signal on T2-weighted images. Frontal and sagittal planes were used. During the first month of antibiotic therapy, the follow-up scans showed no changes, and even disclosed a spread of the abnormal signal in the vertebral body. At the stage of sequelae, on T1 the spinal signal was normal with a decreased disc width and on T2 the disc signal was low while the vertebrae appeared normal.     

Diagnostic imaging of primitive neuroectodermal tumour of the chest wall (Askin tumour)

Objectives. To describe the radiological features of primitive neuroectodermal tumour (PNET) of the chest wall (Askin tumour) at diagnosis and to analyse the radiological changes occurring as a consequence of treatment and during follow-up. Materials and methods. Nine children with histologically proven PNET were studied. At diagnosis, all patients underwent chest X-ray (CXR), chest CT and bone scintigraphy; three patients also had MR and three had US. During treatment and follow-up, CT was performed in all patients. Results. CT demonstrated a solid heterogeneous chest wall mass in all children at diagnosis and six had a rib lesion. Small nodular densities in the extra-pleural fat were identified in three patients at diagnosis. US, performed in three patients, excluded tumour infiltration of the lung or diaphragm, which had been suspected on CT. On MR, the lesions showed high signal intensity in T1-weighted/proton-density images and intermediate/high signal intensity in T2-weighted images compared with muscle. Minimal chest wall involvement was demonstrated in one case by MRI. Extensive necrosis of tumour mass with pseudo-cystic appearance was documented in the five patients who underwent chemotherapy. Macroscopically complete resection was performed in five patients but there was early local recurrence after surgery in two, identified by CT in one and by MR in the other. Conclusions. PNET of the chest wall should be considered in a child with a chest wall mass. CT is valuable for evaluating tumour extension at diagnosis, the effects of chemotherapy and assessing tumour recurrence after surgery. However, CT can overestimate pleural, lung or diaphragmatic infiltration, which are better evaluated by US. MR was superior to CT in the evaluation of tumour extension in one of three patients and may be considered complementary to CT, particularly in very large chest wall tumours. Received: 23 May 1997 Accepted: 23 February 1998     

Hemolytic uremic syndrome: MR findings of CNS complications

MR findings of a patient with hemolytic uremic syndrome involving the CNS are described. Abnormal high signal intensity on T2-weighted images combined with swelling in the lentiform nucleus, posterior limb of internal capsule, external capsule bilaterally, and left extreme capsule was shown on initial MR; a small low signal intensity in the left putamen on T1-and T2-weighted images and generalized atrophy in the area of high signal intensity on previous T2-weighted images was shown on follow-up MR. These findings indicate infarct with focal hemorrhage, which is one of the histopathological features of CNS complication in hemolytic uremic syndrome.     

Correlative study of iron accumulation in liver, myocardium, and pituitary assessed with MRI in young thalassemic patients

Clinical complications resulting from unevenly iron accumulation in individual organs of patients with beta-thalassemia major can affect both expectancy and quality of life. Magnetic resonance imaging (MRI) offers a quantitative, noninvasive, accurate method for estimating iron levels in various tissues, not easily accessible with other techniques. The aim of this study was to evaluate and correlate the level of iron accumulation in different organs (anterior pituitary, myocardium, and liver) assessed with MRI, in children and young adults with beta-thalassemia major. Thirty children and young adults (13 female and 17 male patients) with homozygous beta-thalassemia, treated conventionally, were studied with hepatic, myocardial, and hypophyseal MRI. For liver and myocardium, we calculated the natural logarithm of the signal-to-air ratio in flash 2-dimensional sequences with electrocardiogram gating, whereas for anterior pituitary, the signal intensity was measured in sagittal T2 sequences. All scans were performed within 3 months. In 13 patients, data regarding liver iron concentrations (LIC) assessed by percutaneous liver biopsy were available. The mean of serum ferritin concentrations for 1 year before scans was calculated for each patient. MRI values in myocardium and liver showed a significant negative correlation to age (r=-0.73 and -0.69, respectively). For pituitary MRI, a linear regression with age was recorded in patients over 14 years of age (r=-0.67), whereas a relatively increased signal intensity reduction was recorded in pubertal subjects. Mean serum ferritin concentrations ranged from 252 to 5872 mug/L with an average of 1525+/-1047 mug/L. No statistical significant correlation was noted between mean ferritin levels versus liver, pituitary, and cardiac MRI values (r=-0.49, -0.28, and -0.1, respectively). Mean LIC values assessed by percutaneous biopsy were 13.76+/-11.6 mg/g of dry tissue. A statistically significant negative correlation was observed between liver MRI readings and LIC determined by biopsy (r=-0.89). None of the 3 organs studied with MRI were significantly correlated to each other. Pituitary to liver MRI values and liver to myocardial MRI values were moderately correlated (r=0.34 and 0.42, respectively). Pituitary MRI was not correlated at all to myocardial MRI (r=-0.001). In conclusion, iron accumulation in thalassemic patients is a procedure progressing with age, which seems to act independently in different organs. MRI represents a reliable, noninvasive method for assessing iron overload in various tissues, non-easily accessible with other techniques. Regular scanning, to recognize preclinically excessive iron deposits and intensified chelation therapy, can prevent serious and fatal complications.     

儿童垂体腺瘤的治疗

目的　总结 13例儿童垂体腺瘤的治疗经验 ,探讨儿童垂体腺瘤的治疗方法及预后。方法　自 1997年 1月～ 2 0 0 3年 11月同济医院共收治 13例垂体腺瘤患儿 ,其中男 8例 ,女 5例 ,年龄 9～ 15岁 ,平均 12 .8岁。病程 3个月～ 5年 ,平均 2年。 12例经口鼻蝶入路显微手术。所有病例通过影像学及内分泌检查 ,随访 1～ 5年。结果　手术病例中 ,肿瘤全切 11例 ,次全切除 1例 ,无手术死亡 ,未出现严重并发症。结论　经蝶显微手术是儿童垂体腺瘤最佳的治疗方法 ,手术后放疗要谨慎。长期、正规的随访具有特别重要的意义     

Hypothalamic-pituitary dwarfism: Comparison between MR imaging and CT findings

Magnetic Resonance (MR) imaging was carried out on 33 patients with idiopathic growth hormone deficiency, in 22 of whom CT scan had been carried-out previously. Twenty-one patients presented some complications at birth. Both MR and CT were positive in the evaluation of the sella. MR imaging exhibited a higher degree of accuracy than CT in the evaluation of pituitary gland, pituitary stalk and brain anomalies.On the basis of pituitary morphology demonstrated by MR imaging, and perinatal histories, a classification is proposed which divides our patients into three group: A) a first group of 13 patients presenting severe hypoplasia of the anterior pituitary lobe, hypoplasia of the stalk and ectopia of posterior lobe. The underlying cause of these anatomic defects might be developmental in origin, and date from early intrauterine life, probably worsened at birth. B) a second group of 10 patients presenting severe hypoplasia of the anterior pituitary lobe. A perinatal event and birth trauma might be responsible for pituitary damage. C) a third group of 10 patients with no morphological abnormalities of the pituitary gland. A derangement of the neuroendocrine mechanism which control the growth hormone secretion might account for these patients.Presented at the ESPR meeting in Dublin 1989. Selected for publication by an International Group of the ESPR     

Comparison of turbo inversion recovery magnitude (TIRM) with T2-weighted turbo spin-echo and T1-weighted spin-echo MR imaging in the early diagnosis of acute osteomyelitis in children

Objective. To compare turbo inversion recovery magnitude (TIRM) with standard T1-weighted (T1-W) and T2-weighted (T2-W) MR sequences in the very early detection of acute osteomyelitis in children. Materials and methods. In 15 children with osteomyelitis, 15 sets of T1-W spin-echo (SE) (TR/TE, 400–640/12–17), T2-W turbo spin-echo (TSE) (TR/TE/ETL, 3290–4465/112–120/11), and TIRM (TR/TE/TI, 4000–6120/60/160) images were acquired with a 1.0-T magnet. Contrast-to-noise (C/N) ratios and percentage of signal between lesion and normal bone marrow were analysed with a computer-assisted image analysing system in a region of interest (ROI). Results. In 13 of 15 patients, the absolute signal enhancement in a ROI on the TIRM images was better than on the T1-W SE and T2-W TSE images and in 14 of 15 cases, C/N ratios were also better on the TIRM images than on the other sequences. In the other cases, the TIRM signal was diagnostically equivalent. On the TIRM images, the signal difference between normal and pathological tissue was increased to 43–281 % (mean 124 %). On the T2-W TSE images, this signal difference was 4–79 % (mean 36 %) and on the T1-W SE images 6–77 % (mean 37 %). Conclusion. The TIRM sequence is highly sensitive for detecting bone marrow oedema in the very early stage of acute osteomyelitis in children. MRI utilising the TIRM sequence allowed for an early diagnosis. With scan time of less than 4 minutes, this sequence is superior to T1-W SE and T2-W TSE images for detecting early osteomyelitis-associated bone marrow oedema. Received: 18 August 1997 Accepted: 17 June 1998     

Pituitary volume prospectively predicts internalizing symptoms in adolescence

Background: Early adolescence is a critical time for the development of both internalizing and externalizing disorders. We aimed to investigate whether pituitary volume, an index of hypothalamic–pituitary–adrenal (HPA) axis function, represents a vulnerability factor for the emergence of internalizing and externalizing symptoms during adolescence using a prospective, longitudinal design. Methods: One hundred and fifty‐five adolescents completed 3T structural magnetic resonance imaging (MRI), symptom rating scales and a diagnostic interview during early adolescence (M age 12.6 years, SD .5 years); symptom rating scales were re‐administered approximately three years later (M age 15.2 years). The volume of the pituitary gland was estimated by manually delineating its structure on MR images. The degree to which pituitary volumes prospectively predicted change in internalizing and externalizing symptoms across the two time‐points was assessed using hierarchal linear regression, after controlling for the influence of gender, age, pubertal stage and intracranial volume. Results: Larger pituitary volumes prospectively predicted an increase in internalizing, but not externalizing, symptoms from early adolescence to mid‐adolescence. Conclusions: This study provides the first evidence that increased pituitary volume might represent a specific vulnerability marker for the development of internalizing symptoms during early to mid‐adolescence.