Assessment of the sacroiliac joint with computed tomography motion analysis: a diagnostic study of 12 patients.

BACKGROUND AND PURPOSE: Pain in the sacroiliac joint may be caused by abnormal joint motion. Diagnosis is mainly based on clinical tests. The aims of this study were to examine whether low-dose computed tomography with provocation of the hip could detect sacroiliac joint motion, and to study whether provocation of the hip results in greater sacroiliac joint motion in the ipsilateral than in the contralateral sacroiliac joint. PATIENTS AND METHODS: 12 patients with sacroiliac joint pain were examined with low-dose computed tomography scans of the sacroiliac joint, one with the hips in the neutral position, and one each in provocation with the left or the right hip in a figure-of-4 position. Accuracy was tested by comparing internal rotation of the sacrum with internal rotation in the sacroiliac joint. Motion in the sacroiliac joint was assessed by comparing the position of each of the ilia with the reference, the sacrum. Data is shown as mean with 95% confidence interval (CI). RESULTS: We observed greater motion in the sacroiliac joint than internally in the sacrum, i.e., 0.57° (CI 0.43-0.71) vs. 0.20° (CI 0.11-0.28). The motion of the geometric center of the moving object for the sacroiliac joint was larger on the provoked side; mean difference 0.17 mm (CI 0.01-0.33), P = 0.04. Corresponding figures for rotation were mean difference 0.19° (CI 0.10-0.28), P < 0.001. Compared with the sacrum, the largest motion was seen at the anterior superior iliac spine; mean difference 0.38 mm (CI 0.10-0.66), P = 0.001. CONCLUSION: Provocation in the figure-of-4 position of the hip results in sacroiliac joint motion measurable with computed tomography motion analysis. Provocation of the hip induces larger motion on the ipsilateral than on the contralateral sacroiliac joint.

Ventriculoperitoneal shunt survey in pediatric patients in an emergency setting: a comparison between ultra-low-dose CT using a tin filter and plain radiography.

OBJECTIVE: The aim of this study was to investigate the diagnostic performance, effective radiation dose, and examination time of ventriculoperitoneal shunt evaluation using full-body ultra-low-dose CT (ULD CT) with a tin filter compared with digital plain radiography in a pediatric population. METHODS: A retrospective cross-sectional study was conducted in an emergency setting. Data from 143 children were collected. Sixty were examined with ULD CT with a tin filter and 83 with digital plain radiography methods. Effective doses and times were compared between the two methods. Two observers in pediatric radiology evaluated the patient images. Clinical findings and results from shunt revision, if it was performed, were used to evaluate the diagnostic performance between modalities. An examination-room simulation was performed of the two methods to estimate representative examination times. RESULTS: The mean effective radiation dose for ULD CT with the tin filter was estimated to be 0.29 ± 0.16 mSv compared with 0.16 ± 0.19 mSv for digital plain radiography, with both examinations associated with a very low lifetime attributable risk (< 0.01%). The shunt tip could be more reliably located with ULD CT. ULD CT also allowed assessment of additional findings to explain patient symptoms, such as a cyst at the tip of the shunt catheter and the presence of an obstructing rubber nipple in the duodenum that could not have been observed on a plain radiograph. The examination time with ULD CT of the shunt was estimated to be 20 minutes. The examination time of the shunt with digital plain radiography, including the examination itself time and transfer of the patient between rooms, was estimated to be 60 minutes. CONCLUSIONS: ULD CT using a tin filter allows good visualization of the position or disruption of the shunt catheter that is comparable or superior to plain radiography, at a higher dose, while providing additional findings and reduced patient discomfort.

Computed tomography micromotion analysis in the follow-up of patients with surgically treated pelvic fractures: a prospective clinical study.

PURPOSE: High-energy pelvic fractures are complex injuries often requiring surgical treatment. Different radiological methods exist to evaluate the reduction and healing process postoperatively but with certain limitations. The aim of this study was to evaluate Computed Tomography Micromotion Analysis (CTMA) in a clinical setting for follow-up of surgically treated pelvic fracture patients. METHODS: 10 patients surgically treated for a pelvic fracture were included and prospectively followed with Computed Tomography (CT) at 0, 6, 12 and 52 weeks postoperatively. CTMA was used to measure postoperative translation and rotation of the pelvic fracture during the 52 weeks follow-up. Clinical outcomes were collected through the questionnaires EQ-5D index score and Majeed score. RESULTS: 10 patients were included with mean age (± SD, min-max) 52 (16, 31-80) years and 70% (n = 7) were males. The median (IQR, min-max) global translation from 0 to 52 weeks was 6.0 (4.6, 1.4-12.6) millimeters and median global rotation was 2.6 (2.4, 0.7-4.7) degrees. The general trend was a larger translation between 0 and 6 weeks postoperatively compared to 6-12 and 12-52 weeks. For the clinical outcomes, the general trend was that all patients started from high scores which decreased in the first postoperative follow-up and recovered to different extent during the study period. CONCLUSION: CTMA was successfully used in the follow-up of surgically treated pelvic fracture patients. Movement in the pelvic fractures after surgical fixation was largest between 0 and 6 weeks.

Multifocal Neuroblastoma and Central Hypoventilation in An Infant with Germline ALK F1174I Mutation.

A preterm infant with central hypoventilation was diagnosed with multifocal neuroblastoma. Congenital anomalies of the autonomic nervous system in association with neuroblastoma are commonly associated with germline mutations in PHOX2B. Further, the ALK gene is frequently mutated in both familial and sporadic neuroblastoma. Sanger sequencing of ALK and PHOX2B, SNP microarray of three tumor samples and whole genome sequencing of tumor and blood were performed. Genetic testing revealed a germline ALK F1174I mutation that was present in all tumor samples as well as in normal tissue samples from the patient. Neither of the patient's parents presented the ALK variant. Array profiling of the three tumor samples showed that two of them had only numerical aberrations, whereas one sample displayed segmental alterations, including a gain at chromosome 2p, resulting in two copies of the ALK-mutated allele. Whole genome sequencing confirmed the presence of the ALK variant and did not detect any aberrations in the coding or promotor region of PHOX2B. This study is to our knowledge the first to report a de novoALK F1174I germline mutation. This may not only predispose to congenital multifocal neuroblastoma but may also contribute to the respiratory dysfunction seen in this patient.

Amplification of CDK4 and MDM2: a detailed study of a high-risk neuroblastoma subgroup.

In neuroblastoma, MYCN amplification and 11q-deletion are important, although incomplete, markers of high-risk disease. It is therefore relevant to characterize additional alterations that can function as prognostic and/or predictive markers. Using SNP-microarrays, a group of neuroblastoma patients showing amplification of one or multiple 12q loci was identified. Two loci containing CDK4 and MDM2 were commonly co-amplified, although amplification of either locus in the absence of the other was observed. Pharmacological inhibition of CDK4/6 with ribociclib or abemaciclib decreased proliferation in a broad set of neuroblastoma cell lines, including CDK4/MDM2-amplified, whereas MDM2 inhibition by Nutlin-3a was only effective in p53wild-type cells. Combined CDK4/MDM2 targeting had an additive effect in p53wild-type cell lines, while no or negative additive effect was observed in p53mutated cells. Most 12q-amplified primary tumors were of abdominal origin, including those of intrarenal origin initially suspected of being Wilms' tumor. An atypical metastatic pattern was also observed with low degree of bone marrow involvement, favoring other sites such as the lungs. Here we present detailed biological data of an aggressive neuroblastoma subgroup hallmarked by 12q amplification and atypical clinical presentation for which our in vitro studies indicate that CDK4 and/or MDM2 inhibition also could be beneficial.

Optimizing Contrast-Enhanced Thoracoabdominal CT in Patients During Extracorporeal Membrane Oxygenation.

RATIONALE AND OBJECTIVES: To evaluate the quality and value of contrast-enhanced (CE) chest- and abdominal computed tomography (CT) and CT angiography in neonates, children, and adults undergoing extracorporeal membrane oxygenation (ECMO) using a customized protocol for contrast delivery. MATERIALS AND METHODS: All patients admitted for CE thoracic- and/or abdominal CT while on ECMO were prospectively included in the study. A protocol for contrast delivery adapted for the type of ECMO circulation, cannulation sites, anatomy of interest, and desired contrast phase was applied. Clinical information, ECMO and CT technique, including contrast administration strategy, was noted for each patient. Two radiologists separately evaluated the quality of the scan. The value of the examination was decided in consensus with the referring ECMO physician. RESULTS: One hundred thirty CE thoracoabdominal scans were performed at 103 different occasions during the study time. Eighty-nine scans were performed during veno-arterial ECMO and 41 during veno-venous ECMO. In the majority, contrast was delivered to the oxygenator with preserved ECMO flow. A peripheral or central venous line with reduced flow was utilized in the remaining cases. Mean scan quality was graded 4.2 on a five-grade scale. In 56% of the examinations, the findings affected the immediate treatment of the patient. CONCLUSION: High-quality CT and CT angiography can be achieved in ECMO patients of different ages and clinical issues considering the type of ECMO circulation, ECMO cannulation sites, preferred contrast phase and anatomy of interest. CT diagnoses affect the treatment of the patient.