Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI

Background

Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease.

Objective

To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease.

Materials and methods

This retrospective study included 33 children and young adults with Crohn disease ages 17?±?3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease.

Results

DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments.

Conclusion

DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.     

MRI diffusion-weighted imaging (DWI) in pediatric small bowel Crohn disease: correlation with MRI findings of active bowel wall inflammation

Background

Restricted diffusion on diffusion-weighted imaging (DWI) sequences during magnetic resonance enterography (MRE) has been shown in segments of bowel affected by Crohn disease. However, the exact meaning of this finding, particularly within the pediatric Crohn disease population, is poorly understood.

Objective

The purpose of this study was to determine the significance of bowel wall restricted diffusion in children with small bowel Crohn disease by correlating apparent diffusion coefficient (ADC) values with other MRI markers of disease activity.

Materials and methods

A retrospective review of pediatric patients (≤ 18 years of age) with Crohn disease terminal ileitis who underwent MRE with DWI at our institution between May 1, 2009 and May 31, 2011 was undertaken. All of the children had either biopsy-proven Crohn disease terminal ileitis or clinically diagnosed Crohn disease, including terminal ileal involvement by imaging. The mean minimum ADC value within the wall of the terminal ileum was determined for each examination. ADC values were tested for correlation/association with other MRI findings to determine whether a relationship exists between bowel wall restricted diffusion and disease activity.

Results

Forty-six MRE examinations with DWI in children with terminal ileitis were identified (23 girls and 23 boys; mean age, 14.3 years). There was significant negative correlation or association between bowel wall minimum ADC value and established MRI markers of disease activity, including degree of bowel wall thickening (R?=?(?)0.43; P?=?0.003), striated pattern of arterial enhancement (P?=?0.01), degree of arterial enhancement (P?=?0.01), degree of delayed enhancement (P?=?0.045), amount of mesenteric inflammatory changes (P?<?0.0001) and presence of a stricture (P?=?0.02). ADC values were not significantly associated with bowel wall T2-weighted signal intensity, length of disease involvement or mesenteric fibrofatty proliferation.

Conclusion

Increasing bowel wall restricted diffusion (lower ADC values) is associated with multiple MRI findings that are traditionally associated with active inflammation in pediatric small bowel Crohn disease.     

Diffusion-weighted MRI of abscess formations in children and young adults

Background

Diffusion-weighted MRI (DWI) is helpful for detection of brain abscess and pelvic abscess in adults. In the present study, we evaluated the diagnostic performance of DWI in children and young adults with abdominal and soft tissue abscess formations.

Methods

Seventeen patients (11 females, aged 13 ± 6 years) with suspected abdominal or soft-tissue abscess underwent routine MRI including free-breathing DWI and contrast-enhanced T1w imaging. Seventeen random age-matched patients with non-purulent abdominal fluid collections served as controls. Mean apparent diffusion coefficent (ADC) was measured for abscess, muscle, liver, spleen and kidney tissue as well as for cerebrospinal fluid, urine and free abdominal fluid.

Results

All fluid collections were identified on diffusion-weighted images. Thirteen of 14 confirmed abscess formations showed an ADC < 1.0 × 10^?3 mm²/s with a mean value of 0.80 ± 0.38 mm²/s. One tuberculous softtissue abscess had a higher ADC of 1.85 × 10^?3 mm²/s. Ring enhancement on T1w imaging was seen in three nonpurulent fluid collections. There were no false-positive findings in the control group.

Conclusions

Diffusion-weighted MRI is highly sensitive for abscess and may add specificity to contrast-enhanced T1w imaging of ring-enhancing fluid collections. DWI with free-breathing rapid image acquisition and without the need of intravenous contrast application constitutes a particularly useful choice in pediatric imaging.     

MRI for the diagnosis of recurrent middle ear cholesteatoma in children—can we optimize the technique? Preliminary study

Background

Recurrent cholesteatoma after surgical excision occurs frequently in children. Until recently, a surgical second look was mandatory and considered as standard reference. MRI including a delayed T1 sequence after gadolinium injection and diffusion-weighted imaging (DWI) has proved its efficiency but has been evaluated mainly in adults.

Objective

Our purpose was to evaluate the accuracy of DWI to diagnose recurrence of cholesteatoma in children.

Materials and methods

We evaluated prospectively with MRI 20 ears in 18 children who had had surgery for cholesteatoma. We compared DWI and delayed T1-weighted images following gadolinium administration with intraoperative or follow-up findings. We calculated the sensitivity and specificity of each sequence for the diagnosis of recurrent cholesteatoma.

Results

Sensitivity to diagnose recurrent cholesteatoma was 87% for both DWI and delayed post-gadolinium sequences, specificity was 71% and 83%, respectively. Adding both sequences, the sensitivity was 87%, the specificity 100%. There was one false negative probably due to small size recurrence.

Conclusion

In our series, DWI was reliable to diagnose recurrent cholesteatoma in children and allows avoiding surgery when negative. However, because small recurrences less than 5 mm may be missed, follow-up must be prolonged (5 years).     

Renal sonography with Doppler for detecting suspected pediatric renin-mediated hypertension – is it adequate?

Background

Renal Doppler US is used to evaluate suspected vascular causes of hypertension in children, despite mostly unknown diagnostic performance characteristics.

Objective

To evaluate renal Doppler US for detecting vascular causes of hypertension in children with high clinical suspicion of aortic or renal artery narrowing.

Materials and methods

We identified pediatric renal Doppler US examinations performed for hypertension between January 1995 and June 2010 at our institution. We excluded children without follow-up angiography (CT-, MR-, or catheter-based). Two pediatric radiologists reviewed imaging studies and documented relevant findings. Intrarenal spectral Doppler resistive index measurement <0.5 or tardus parvus waveform constituted a positive examination.

Results

Thirty-five boys and 13 girls underwent renal Doppler US and confirmatory imaging (mean age? =? 9.0 years). Nineteen US examinations were truly negative, two were falsely negative, 18 were truly positive (16 involved narrowing of the aorta or main renal artery) and nine were falsely positive. Sonography had a sensitivity and specificity of 90% and 68%, respectively, for detecting a vascular cause of hypertension.

Conclusion

Renal Doppler sonography reliably detects renin-mediated hypertension caused by aortic or main renal artery narrowing in children. More studies are needed to determine its ability to detect intrarenal and accessory renal artery stenoses.     

MRI features of atypical teratoid/rhabdoid tumors in children

Background

Atypical teratoid/rhabdoid tumors (AT/RTs) are rare, highly malignant tumors of the central nervous system, usually occurring in young children.

Objective

To investigate the MRI features of AT/RT, with special emphasis on diffusion-weighted imaging (DWI) and MR spectroscopy (MRS).

Materials and methods

MRI findings of 11 children with AT/RT were reviewed retrospectively, including DWI in 9 AT/RT children and MRS in 6 children.

Results

The neoplasms were infratentorial in 4 children and supratentorial in 5 children, both infra- and supratentorial in 1 child and multifocal in 1 child. AT/RT produced heterogeneous signal intensity from peripheral cysts in 7/11 (63%) and hemorrhage in 7/11 (63%). All lesions showed contrast enhancement of varying degrees. Seven (63%) had peritumoral edema. Nine (82%) were hyperintense on DWI with a mean ± SD ADC of 0.60 ± 0.13 × 10^?3?mm² s^?1. Six lesions (55%) exhibited elevated levels of choline and decreased NAA, and three had lipid peaks.

Conclusions

A childhood intracranial tumor with off-midline location, peripheral cystic components, hemorrhage, low ADC, and lipid peaks on MRS suggests AT/RT to be considered a differential diagnosis.     

Safety and adverse effects during 24 hours after contrast-enhanced MRI with gadobenate dimeglumine (MultiHance®) in children

Background

Gadolinium-based MR contrast agents have long been considered safe for routine diagnostic imaging. However, the advent of nephrogenic systemic fibrosis (NSF) among certain patients with severe renal insufficiency has brought the issue of safety into question. Nowhere is safety of greater concern than among children who frequently require multiple contrast-enhanced MRI examinations over an extended period of time.

Objective

To retrospectively evaluate the safety of gadobenate dimeglumine for contrast-enhanced (CE) MRI across a range of indications.

Materials and methods

Two hundred pediatric inpatients (age: 4 days to 15 years) underwent CE MRI as part of clinical routine. The children received a gadobenate dimeglumine dose of either 0.05 mmol/kg body weight (liver, abdominal imaging, musculoskeletal imaging, brain and other rare indications) or 0.1 mmol/kg bodyweight (cardiovascular imaging, MR-urography). Young (< 8 years) children with congenital heart disease were intubated and underwent MRA evaluation with controlled ventilation. Monitoring for adverse events was performed for at least 24 h after each gadobenate dimeglumine injection. Depending on clinical necessity, laboratory measurements and, in some cases, vital sign and ECG determinations were made before and after contrast injection. Safety was evaluated by age group, indication and dose administered.

Results

No clinically adverse events were reported among children who had one MRI scan only or among children who had several examinations. There were no changes in creatinine or bilirubin levels even in very young children.

Conclusions

No adverse events were recorded during the first 24 h following administration of gadobenate dimeglumine in 200 children.     

How specific is the MRI appearance of supratentorial atypical teratoid rhabdoid tumors?

Background

Supratentorial atypical teratoid rhabdoid tumor (ATRT) in many cases has a distinctive appearance on post-gadolinium MRI.

Objective

We sought to determine whether this is a unique appearance allowing ATRT to be distinguished accurately from other types of pediatric supratentorial tumors.

Materials and methods

Retrospective review of all available preoperative MRI of pediatric supratentorial tumors at two tertiary children’s hospitals, and systematic literature review of case series and reports describing the MRI imaging appearances of supratentorial ATRT.

Results

We had 61 supratentorial tumors, including 32 gliomas, 6 ATRT, 8 ependymomas, 6 gangliogliomas, 2 pilomyxoid astrocytomas, 3 primitive neuro-ectodermal tumors, 2 choroid plexus papillomas, and 2 meningiomas. ATRT presented in significantly younger patients than astrocytomas (mean age 2.6 years vs. 9.9 years, P?<?0.05). The visual pattern of a thick, wavy (irregular) heterogeneously enhancing wall around a cystic center was seen in 5/6 (83%) ATRTs and only 3/55 (5.4%) other tumors (P?<?0.0001), for specificity of 95%, sensitivity of 83%, positive predictive value of 63% and a negative predictive value of 95%.

Conclusion

A supratentorial tumor with a thick, wavy (irregular) heterogeneously enhancing wall surrounding a central cystic region is suggestive of ATRT in the appropriate clinical setting, especially in a child of preschool age.     

Reversible lesions of the corpus callosum with initially restricted diffusion in a series of Caucasian children

Background

Reversible lesions of the corpus callosum with initial restricted diffusion on diffusion-weighted imaging (DWI) are rare and mainly described in the south Asiatic population.

Objective

The purpose of this study was to describe the clinical presentation, imaging findings, prognosis and etiology of transient restricted diffusion lesions of the corpus callosum in a series of Caucasian children.

Materials and methods

Seven children presenting with a transient restricted DWI lesion of the corpus callosum were included. Their clinical presentations and paraclinical examinations were investigated in addition to their MRI findings during the acute phase and at follow-up.

Results

Five patients initially presenting with prodromal flu-like symptoms were diagnosed with mild encephalopathy with reversible corpus callosum lesions, three of which were due to the influenza virus. For two patients (twins) with a stroke-like presentation and without febrile illness, a central nervous system manifestation of X-linked Charcot-Marie-Tooth disease with connexin 32 mutation was diagnosed. All patients had a good clinical prognosis without clinical sequelae or residual MRI lesion for all patients at follow-up.

Conclusion

A transient lesion of the corpus callosum with restricted diffusion should prompt the radiologist to suggest an infectious trigger in children. The prognosis of these patients was good with normalization of clinical symptoms and MRI without any specific treatment.

     

Imaging features of juxtacortical chondroma in children

Background

Juxtacortical chondroma is a rare benign bone lesion in children. Children usually present with a mildly painful mass, which prompts diagnostic imaging studies. The rarity of this condition often presents a diagnostic challenge. Correct diagnosis is crucial in guiding surgical management.

Objective

To describe the characteristic imaging findings of juxtacortical chondroma in children.

Materials and methods

We identified all children who were diagnosed with juxtacortical chondroma between 1998 and 2012. A single experienced pediatric radiologist reviewed all diagnostic imaging studies, including plain radiographs, CT, MR and bone scans.

Results

Seven children (5 boys and 2 girls) with juxtacortical chondroma were identified, ranging in age from 6 years to 16 years (mean 12.3 years). Mild pain and a palpable mass were present in all seven children. Plain radiographs were available in 6/7, MR in 7/7, CT in 4/7 and skeletal scintigraphy in 5/7 children. Three lesions were located in the proximal humerus, with one each in the distal radius, distal femur, proximal tibia and scapula. Radiographic and CT features deemed highly suggestive of juxtacortical chondroma included cortical scalloping, underlying cortical sclerosis and overhanging margins. MRI features consistent with juxtacortical chondroma included isointensity to skeletal muscle on T1, marked hyperintensity on T2 and peripheral rim enhancement after contrast agent administration. One of seven lesions demonstrated intramedullary extension, and 2/7 showed adjacent soft-tissue edema.

Conclusion

Juxtacortical chondroma is an uncommon benign lesion in children with characteristic features on plain radiographs, CT and MR. Recognition of these features is invaluable in guiding appropriate surgical management.     

Pediatric neuroimaging using magnetic resonance imaging during non-sedated sleep

Background

Etiological studies of many neurological and psychiatric disorders are increasingly turning toward longitudinal investigations of infant brain development in order to discern predisposing structural and/or functional differences prior to the onset of overt clinical symptoms. While MRI provides a noninvasive window into the developing brain, MRI of infants and toddlers is challenging due to the modality’s extreme motion sensitivity and children’s difficulty in remaining still during image acquisition.

Objective

Here, we outline a broad research protocol for successful MRI of children under 4 years of age during natural, non-sedated sleep.

Materials and methods

All children were imaged during natural, non-sedated sleep. Active and passive measures to reduce acoustic noise were implemented to reduce the likelihood of the children waking up during acquisition. Foam cushions and vacuum immobilizers were used to limit intra-scan motion artifacts.

Results

More than 380 MRI datasets have been successfully acquired from 220 children younger than 4 years of age within the past 39 months. Implemented measures permitted children to remain asleep for the duration of the scan and allowed the data to be acquired with an overall 97% success rate.

Conclusion

The proposed method greatly advances current pediatric imaging techniques and may be readily implemented in other research and clinical settings to facilitate and further improve pediatric neuroimaging.     

MRI for clinically suspected pediatric appendicitis: an implemented program

Background

Emergent MRI is now a viable alternative to CT for evaluating appendicitis while avoiding the detrimental effects of ionizing radiation. However, primary employment of MRI in the setting of clinically suspected pediatric appendicitis has remained significantly underutilized.

Objective

To describe our institution’s development and the results of a fully implemented clinical program using MRI as the primary imaging evaluation for children with suspected appendicitis.

Materials and methods

A four-sequence MRI protocol consisting of coronal and axial single-shot turbo spin-echo (SS-TSE) T2, coronal spectral adiabatic inversion recovery (SPAIR), and axial SS-TSE T2 with fat saturation was performed on 208 children, ages 3 to 17?years, with clinically suspected appendicitis. No intravenous or oral contrast material was administered. No sedation was administered. Data collection includes two separate areas: time parameter analysis and MRI diagnostic results.

Results

Diagnostic accuracy of MRI for pediatric appendicitis indicated a sensitivity of 97.6% (CI: 87.1–99.9%), specificity 97.0% (CI: 93.2–99.0%), positive predictive value 88.9% (CI: 76.0–96.3%), and negative predictive value 99.4% (CI: 96.6–99.9%). Time parameter analysis indicated clinical feasibility, with time requested to first sequence obtained mean of 78.7 +/? 52.5?min, median 65?min; first-to-last sequence time stamp mean 14.2 +/? 8.8?min, median 12?min; last sequence to report mean 57.4 +/? 35.2?min, median 46?min. Mean age was 11.2 +/? 3.6?years old. Girls represented 57% of patients.

Conclusion

MRI is an effective and efficient method of imaging children with clinically suspected appendicitis. Using an expedited four-sequence protocol, sensitivity and specificity are comparable to CT while avoiding the detrimental effects of ionizing radiation.     

Gadobenate-dimeglumine-enhanced magnetic resonance imaging for hepatic lesions in children

Background

Magnetic resonance imaging enhanced by hepatocyte-specific contrast media has been found useful to characterize liver lesions in adults and children.

Objective

To present our experience with gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI for evaluation of focal liver lesions in children.

Materials and methods

We retrospectively reviewed gadobenate-dimeglumine-enhanced MR images obtained for evaluation of suspected hepatic lesions in 30 children. Signal characteristics on various sequences including 45- to 60-min hepatobiliary phase images were noted by two radiologists. Chart review identified relevant clinical details including history of cancer treatment, available pathology and stability of lesion size on follow-up imaging.

Results

Of the 30 children who had gadobenate-enhanced MRI, 26 showed focal lesions. Diagnoses in 26 children were focal nodular hyperplasia (FNH) in 15, hemangiomas in 3, regenerating nodules in 3, focal fatty infiltration in 2, indeterminate lesions in 3, and one patient each with adenomas, hepatoblastoma and metastasis. Two patients had multiple diagnoses. All FNH lesions (39), all regenerative nodules (19) and an indeterminate lesion were iso- or hyperintense on hepatobiliary-phase images while all other lesions (28) were hypointense to hepatic parenchyma. The average follow-up period was 21.7 months.

Conclusion

Our experience with gadobenate-enhanced MRI indicates potential utility of gadobenate in the evaluation of pediatric hepatic lesions in differentiating FNH and regenerating nodules from other lesions.     

A retrospective review of pituitary MRI findings in children on growth hormone therapy

Background

Patients with congenital hypopituitarism might have the classic triad of pituitary stalk interruption syndrome, which consists of: (1) an interrupted or thin pituitary stalk, (2) an absent or ectopic posterior pituitary (EPP), and (3) anterior pituitary hypoplasia or aplasia.

Objective

To examine the relationship between pituitary anatomy and the degree of hormonal dysfunction.

Materials and methods

This study involved a retrospective review of MRI findings in all children diagnosed with congenital growth hormone deficiency from 1988 to 2010 at a tertiary-level pediatric hospital.

Results

Of the 52 MRIs reviewed in 52 children, 26 children had normal pituitary anatomy and 26 had one or more elements of the classic triad. Fourteen of fifteen children with multiple pituitary hormone deficiencies had structural anomalies on MRI. Twelve of 37 children with isolated growth hormone deficiency had an abnormal MRI.

Conclusion

Children with multiple pituitary hormone deficiencies were more likely to have the classic triad than children with isolated growth hormone deficiency. A normal MRI was the most common finding in children with isolated growth hormone deficiency.     

High success rates of sedation-free brain MRI scanning in young children using simple subject preparation protocols with and without a commercial mock scanner–the Diabetes Research in Children Network (DirecNet) experience

Background

The ability to lie still in an MRI scanner is essential for obtaining usable image data. To reduce motion, young children are often sedated, adding significant cost and risk.

Objective

We assessed the feasibility of using a simple and affordable behavioral desensitization program to yield high-quality brain MRI scans in sedation-free children.

Materials and methods

222 children (4–9.9 years), 147 with type 1 diabetes and 75 age-matched non-diabetic controls, participated in a multi-site study focused on effects of type 1 diabetes on the developing brain. T1-weighted and diffusion-weighted imaging (DWI) MRI scans were performed. All children underwent behavioral training and practice MRI sessions using either a commercial MRI simulator or an inexpensive mock scanner consisting of a toy tunnel, vibrating mat, and video player to simulate the sounds and feel of the MRI scanner.

Results

205 children (92.3%), mean age 7?±?1.7 years had high-quality T1-W scans and 174 (78.4%) had high-quality diffusion-weighted scans after the first scan session. With a second scan session, success rates were 100% and 92.5% for T1-and diffusion-weighted scans, respectively. Success rates did not differ between children with type 1 diabetes and children without diabetes, or between centers using a commercial MRI scan simulator and those using the inexpensive mock scanner.

Conclusion

Behavioral training can lead to a high success rate for obtaining high-quality T1-and diffusion-weighted brain images from a young population without sedation.     

Diffusion-weighted MRI for detection and differentiation of musculoskeletal tumorous and tumor-like lesions in pediatric patients

Background

MRI is the diagnostic mainstay for detection and differentiation of musculoskeletal tumors. However, a projection regarding the biological dignity of lesions based on standard MRI sequences remains difficult and uncertain. This study was undertaken to analyse whether diffusion-weighted MRI (DWI) can distinguish between benign and malignant musculoskeletal tumorous and tumor-like lesions in pediatric patients.

Methods

MR examinations of 44 consecutive pediatric patients (26 girls, mean age 11±6 years) including standard sequences and DWI (b=50/800 s/mm²) at 1.5 or 3 Tesla were retrospectively evaluated. The study group contained 10 patients with non-treated malignant tumors and 34 patients with benign lesions. Size, relative signal intensity and apparent diffusion coefficient (ADC, unit ×10^?3 mm²/s) were determined in one lesion per patient.

Results

Mean ADC was 0.78±0.45×10^?3 mm²/s in patients with malignant tumors and 1.71±0.75 ×10^?3 mm²/s in patients with benign lesions (P<0.001). Relative operating characteristics (ROC) analysis showed a sensitivity of 90% and a specificity of 91% for malignancy, based on an ADC cut-off value of ??1.03. On logistic regression, mean ADC and lesion size accounted for 62% of variability in benign vs. malignant tumors. For malignant tumors, the signal intensity ratio was higher on DWI than on T1w post-contrast images (P<0.002). Two cases of local tumor recurrence were diagnosed by DWI only.

Conclusions

DWI shows promising results for determination of biological dignity in musculoskeletal tumors. Mean ADC ??1.03×10^?3 mm²/s is a strong indicator of malignancy at the first diagnosis. The use of DWI for early diagnosis of tumor recurrence in comparison with standard MRI sequences should be evaluated in prospective studies.     

Neuroimaging findings in children with Keutel syndrome

Background

Keutel syndrome is a rare autosomal-recessive condition characterized by abnormal cartilage calcification. Neuroimaging findings associated with this condition have been randomly described in the literature.

Objective

To systematically evaluate the neuroimaging findings in a series of children with Keutel syndrome to broaden our base of knowledge.

Materials and methods

Four children with confirmed Keutel syndrome were reviewed for the brain, head and neck imaging findings.

Results

Three of the four children, all siblings, showed evidence of moyamoya syndrome. All four siblings had pinna cartilage calcification.

Conclusion

We propose that Keutel syndrome be considered and included among the secondary causes of moyamoya syndrome. In children with petrified auricle and neurological symptoms, Keutel syndrome should be considered and brain MRI with MRA is required.     

Imaging features of pancreatic tumors in children: 13-year experience at a pediatric tertiary hospital

Background

Pancreatic tumors are rare in children, resulting in limited information regarding their frequency and imaging appearances.

Objective

To review all pancreatic tumors seen in children over a decade at a large tertiary pediatric institution and to describe multimodality imaging findings.

Materials and methods

We conducted a retrospective review of imaging studies performed in children with pancreatic tumors between January 2000 and December 2012, analyzing imaging features on available US, CT and MR examinations. We reviewed patient charts for clinical features, management and final diagnosis.

Results

We included 23 children in this study. Of these, 12 had solid and papillary epithelial neoplasms (SPEN), 3 had neuroendocrine tumors, 3 had lymphoma, and 1 each had hemangioendothelioma, benign congenital cysts with adipose tissue, dendritic cell sarcoma, metastatic rhabdomyosarcoma, and lipoma. All children with SPEN were teenage girls. SPEN showed characteristic imaging features including well-defined margins with surrounding capsule, solid-cystic components and hemorrhage.

Conclusion

Pancreatic tumors are uncommon in children. SPEN is the most common tumor and is seen predominantly in teenage girls and shows characteristic imaging features.     

Rib head protrusion into the central canal in type 1 neurofibromatosis

Background

Intraspinal rib head dislocation is an important but under-recognized consequence of dystrophic scoliosis in patients with neurofibromatosis 1 (NF1).

Objective

To present clinical and imaging findings of intraspinal rib head dislocation in NF1.

Materials and methods

We retrospectively reviewed clinical presentation, imaging, operative reports and post-operative courses in four NF1 patients with intraspinal rib head dislocation and dystrophic scoliosis. We also reviewed 17 cases from the English literature.

Results

In each of our four cases of intraspinal rib head dislocation, a single rib head was dislocated on the convex apex of the curve, most often in the mid- to lower thoracic region. Cord compression occurred in half of these patients. Analysis of the literature yielded similar findings. Only three cases in the literature demonstrates the MRI appearance of this entity; most employ CT. All of our cases include both MRI and CT; we review the subtle findings on MRI.

Conclusion

Although intraspinal rib head dislocation is readily apparent on CT, sometimes MRI is the only cross-sectional imaging performed. It is essential that radiologists become familiar with this entity, as subtle findings have significant implications for surgical management.