Using Occlusion-Based Saliency Maps to Explain an Artificial Intelligence Tool in Lung Cancer Screening: Agreement Between Radiologists, Labels, and Visual Prompts

Occlusion-based saliency maps (OBSMs) are one of the approaches for interpreting decision-making process of an artificial intelligence (AI) system. This study explores the agreement among text responses from a cohort of radiologists to describe diagnostically relevant areas on low-dose CT (LDCT) images. It also explores if radiologists’ descriptions of cases misclassified by the AI provide a rationale for ruling out the AI’s output. The OBSM indicating the importance of different pixels on the final decision made by an AI were generated for 10 benign cases (3 misclassified by the AI tool as malignant) and 10 malignant cases (2 misclassified by the AI tool as benign). Thirty-six radiologists were asked to use radiological vocabulary, typical to reporting LDCT scans, to describe the mapped regions of interest (ROI). The radiologists’ annotations were then grouped by using a clustering-based technique. Topics were extracted from the annotations and for each ROI, a percentage of annotations containing each topic were found. Radiologists annotated 17 and 24 unique ROIs on benign and malignant cases, respectively. Agreement on the main label (e.g., “vessel,” “nodule”) by radiologists was only seen in only in 12% of all areas (5/41 ROI). Topic analyses identified six descriptors which are commonly associated with a lower malignancy likelihood. Eight common topics related to a higher malignancy likelihood were also determined. Occlusion-based saliency maps were used to explain an AI decision-making process to radiologists, who in turn have provided insight into the level of agreement between the AI’s decision and radiological lexicon.

Brain Microstructural Changes Associated With Neurocognitive Outcome in Intracranial Germ Cell Tumor Survivors

Background

Childhood intracranial germ cell tumor (GCT) survivors are prone to radiotherapy-related neurotoxicity, which can lead to neurocognitive dysfunctions. Diffusion kurtosis imaging (DKI) is a diffusion MRI technique that is sensitive to brain microstructural changes. This study aimed to investigate the association between DKI metrics versus cognitive and functional outcomes of childhood intracranial GCT survivors.

Methods

DKI was performed on childhood intracranial GCT survivors (n = 20) who had received cranial radiotherapy, and age and gender-matched healthy control subjects (n = 14). Neurocognitive assessment was performed using the Hong Kong Wechsler Intelligence Scales, and functional assessment was performed using the Lansky/Karnofsky performance scales (KPS). Survivors and healthy controls were compared using mixed effects model. Multiple regression analyses were performed to determine the effects of microstructural brain changes of the whole brain as well as the association between IQ and Karnofsky scores and the thereof.

Results

The mean Intelligence Quotient (IQ) of GCT survivors was 91.7 (95% CI 84.5 – 98.8), which was below the age-specific normative expected mean IQ (P = 0.013). The mean KPS score of GCT survivors was 85.5, which was significantly lower than that of controls (P < 0.001). Cognitive impairments were significantly associated with the presence of microstructural changes in white and grey matter, whereas functional impairments were mostly associated with microstructural changes in white matter. There were significant correlations between IQ versus the mean diffusivity (MD) and mean kurtosis (MK) of specific white matter regions. The IQ scores were negatively correlated with the MD of extensive grey matter regions.

Conclusion

Our study identified vulnerable brain regions whose microstructural changes in white and grey matter were significantly associated with impaired cognitive and physical functioning in survivors of pediatric intracranial GCT.

QOL-25. MICROSTRUCTURAL BRAIN CHANGES ASSOCIATED WITH NEUROCOGNITIVE AND FUNCTIONAL OUTCOMES OF INTRACRANIAL GERM CELL TUMUOR SURVIVORS – A DIFFUSIONAL KURTOSIS IMAGING STUDY

BACKGROUND

Childhood intracranial germ cell tumour (iGCT) survivors are prone to radiotherapy-related neurotoxicity which can lead to neurocognitive dysfunction. Diffusion kurtosis imaging (DKI) is a MRI technique that quantifies microstructural changes in the grey and white matter of the brain. This study aims to investigate the associations between MR-DKI metrics, the cognitive and functional outcomes of childhood iGCT survivors.

METHOD

20 childhood iGCT survivors who had received cranial radiotherapy were recruited. DKI parameters were determined for iGCT survivors and 18 control subjects. Neurocognitive assessment using the Hong Kong Wechsler Intelligence Scales for Children (HKWISC)/ Wechsler Adult Intelligence Scale – Revised (WAIS-R) and functional assessment using the Lansky/ Karnofsky performance scales were performed for GCT survivors.

RESULTS

There were significant negative correlation between the IQ scores and the mean diffusivity (MD) in multiple white matter regions of iGCT survivors including: anterior limb of internal capsule, superior fronto-occipital fasciculus, anterior corona radiata, uncinate fasciculus, cingulum and hippocampus. Mean kurtosis (MK) values of the superior fronto-occipital fasciculus were positively correlated with IQ scores. For grey matter, the MD of the olfactory, insula, caudate, heschl gyrus, parahippocampal gyrus, hippocampus, anterior cingulum, frontal inferior operculum, middle and superior temporal gyrus, middle and superior frontal orbital gyri, cuneus and precentral gyrus were negatively correlated with IQ scores. Most of the microstructural changes with associated functional impairment were white matter regions.

CONCLUSION

Our study identified vulnerable brain regions with significant white and grey matter microstructural changes that were associated with impaired cognitive function or deficits in physical functioning.

Development and validation of risk prediction models for COVID-19 positivity in a hospital setting

OBJECTIVES

To develop: (1) two validated risk prediction models for coronavirus disease-2019 (COVID-19) positivity using readily available parameters in a general hospital setting; (2) nomograms and probabilities to allow clinical utilisation.

METHODS

Patients with and without COVID-19 were included from 4 Hong Kong hospitals. The database was randomly split into 2:1: for model development database (n = 895) and validation database (n = 435). Multivariable logistic regression was utilised for model creation and validated with the Hosmer-Lemeshow (H-L) test and calibration plot. Nomograms and probabilities set at 0.1, 0.2, 0.4 and 0.6 were calculated to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

A total of 1330 patients (mean age 58.2 ± 24.5 years; 50.7% males; 296 COVID-19 positive) were recruited. The first prediction model developed had age, total white blood cell count, chest x-ray appearances and contact history as significant predictors (AUC = 0.911 [CI = 0.880-0.941]). The second model developed has the same variables except contact history (AUC = 0.880 [CI = 0.844-0.916]). Both were externally validated on the H-L test (p = 0.781 and 0.155, respectively) and calibration plot. Models were converted to nomograms. Lower probabilities give higher sensitivity and NPV; higher probabilities give higher specificity and PPV.

CONCLUSION

Two simple-to-use validated nomograms were developed with excellent AUCs based on readily available parameters and can be considered for clinical utilisation.

Therapeutic evaluation of palbociclib and its compatibility with other chemotherapies for primary and recurrent nasopharyngeal carcinoma

BACKGROUND

Recent genomic analyses revealed that druggable molecule targets were only detectable in approximately 6% of patients with nasopharyngeal carcinoma (NPC). However, a dependency on dysregulated CDK4/6-cyclinD1 pathway signaling is an essential event in the pathogenesis of NPC. In this study, we aimed to evaluate the therapeutic efficacy of a specific CDK4/6 inhibitor, palbociclib, and its compatibility with other chemotherapeutic drugs for the treatment of NPC by using newly established xenograft models and cell lines derived from primary, recurrent, and metastatic NPC.

METHODS

We evaluated the efficacies of palbociclib monotherapy and concurrent treatment with palbociclib and cisplatin or suberanilohydroxamic acid (SAHA) in NPC cell lines and xenograft models. RNA sequencing was then used to profile the drug response-related pathways. Palbociclib-resistant NPC cell lines were established to determine the potential use of cisplatin as a second-line treatment after the development of palbociclib resistance. We further examined the efficacy of palbociclib treatment against cisplatin-resistant NPC cells.

RESULTS

In NPC cells, palbociclib monotherapy was confirmed to induce cell cycle arrest in the G1 phase in vitro. Palbociclib monotherapy also had significant inhibitory effects in all six tested NPC tumor models in vivo, as indicated by substantial reductions in the total tumor volumes and in Ki-67 proliferation marker expression. In NPC cells, concurrent palbociclib treatment mitigated the cytotoxic effect of cisplatin in vitro. Notably, concurrent treatment with palbociclib and SAHA synergistically promoted NPC cell death both in vitro and in vivo. This combination also further inhibited tumor growth by inducing autophagy-associated cell death. NPC cell lines with induced palbociclib or cisplatin resistance remained sensitive to treatment with cisplatin or palbociclib, respectively.

CONCLUSIONS

Our study findings provide essential support for the use of palbociclib as an alternative therapy for NPC and increase awareness of the effective timing of palbociclib administration with other chemotherapeutic drugs. Our results provide a foundation for the design of first-in-human clinical trials of palbociclib regimens in patients with NPC.

Introducing point-of-care ultrasound through structured multifaceted ultrasound module in the undergraduate medical curriculum at the University of Hong Kong

Incorporation of point-of-care ultrasound in the undergraduate medical curriculum is of great importance to ensure early exposure and safe use of the modality. We aimed to assess the students' learning experiences following implementing an ultrasound module in the medical curriculum at the University of Hong Kong. Medical students in semester 6 (n = 221) were enrolled in the module in 2018. It consisted of 1 hour of didactic lecture, followed by 3 hours of hands-on session. The students had the opportunity to enroll into a four-week Special Study Module to further practice their skills. The students had access to an e-learning platform to assist in their learning. Outcome measures include task-based performance, quizzes, feedback, and round-table discussion to assess the learning experiences. The module was highly rated by over 90% of students (response rate of 96%). Students practiced on peer subject on upper abdominal scanning. Post-training assessment showed an increment of 16% in their understanding of the modality. Students were motivated to enroll into the Special Study Module, where they were trained and became proficient with Focused Assessment with Sonography with Trauma. More than 86% of the students found the e-learning platform easy to use and assisted the training session. Round-table discussion suggested more simulated clinical cases to be added and expansion of future modules. Ultrasound module was successfully implemented into the undergraduate medical curriculum at the University of Hong Kong through new pedagogical approaches. This integration was highly rated by the medical students with improved awareness and better understanding of point-of-care ultrasound.

Megaconial congenital muscular dystrophy: Same novel homozygous mutation in CHKB gene in two unrelated Chinese patients

Megaconial congenital muscular dystrophy (CMD) is a rare form of congenital muscular dystrophy attributed to an autosomal recessive CHKB mutation. We report two unrelated Chinese girls with Megaconial CMD who harbored the same novel homozygous CHKB mutation but exhibited different phenotypes. Patient 1, who is now 8 years old, has autism, intellectual disabilities, mild girdle weakness, and characteristic muscle biopsy with COX-negative fibers. Patient 2, now 12 years old, has limited intelligence and marked weakness, with scoliosis, hip subluxation and early loss of ambulation. Both exhibited mildly elevated creatine kinase levels, have relative sparing of adductor longus and extensor digitorum longus on MRI leg muscles, and a c.598del (p.Gln200Argfs*11) homozygous CHKB loss-of-function mutation. Their parents are heterozygous carriers. This is the first report of Megaconial CMD in Chinese patients demonstrating the pathogenicity of the identified homozygous CHKB variant. A case review of all previously reported patients of different ethnicities is also included.

Exploring the experience of medical students as peer teachers in clinical ultrasonography: why do they do it and how do they perform?

This article was migrated. The article was not marked as recommended. BackgroundA pilot project aimed to understand the experience and performance of medical students as peer tutors (Student In Medical Education Program, SIME) in the undergraduate ultrasound module at the University of Hong Kong.MethodsFour SIME tutors contributed to teaching of third year medical students (n=184) via a 3-hour hands-on session. Pre-module training was given to SIME tutors. Students were divided into small groups to practise abdominal ultrasound scanning on each other under the guidance of senior tutors (radiologists/sonographers) or SIME tutors. Learning outcomes were assessed through pre- and post-module quizzes. Qualitative exploration was undertaken through thematic coding of dedicated observers' notes from teaching sessions and the round table discussion conducted with SIME tutors to discuss the project effectiveness.ResultsSeventy-five percent (n=138) of the medical students submitted both pre- and post-module quizzes. The senior tutors' and the SIME tutors' groups scored similarly on the post-module quiz, 8.26 and 7.93 respectively. Themes emerging from the qualitative analysis included SIME tutors motivations for teaching such as giving them insight to the limitations of their own knowledge. They valued the proximity of age to their students and understood the learning needs of the students. Some barriers to peer-teaching were also identified such as concerns over sufficiency of knowledge to teach, and logistic arrangements.DiscussionSIME program was successfully introduced in the ultrasound module, improving SIME tutors' self-confidence in teaching and better understanding of ultrasound without affecting the quality of teaching.

Successful Treatment of a Pararenal Pregnancy Using High-Dose Methotrexate Regimen: A Case Report

BACKGROUND

Upper abdominal pregnancy is rare. Most patients present with hemoperitoneum, requiring emergency laparotomy.

CASE

A 32-year-old woman presented with acute abdominal pain and an elevated beta-human chorionic gonadotropin (β-hCG) level. Ultrasound, computerized tomography (CT) scans, and laparoscopy failed to locate the source of elevated hCG. Subsequent positron emission tomography (PET)-CT demonstrated a cystic mass in the left pararenal region with no increased uptake. Repeated ultrasound scan revealed a live fetus implanted laterally to the abdominal aorta. After failing to respond to methotrexate at the usual dosage, a regimen used in gestational trophoblastic neoplasia was given. The pregnancy underwent miscarriage afterwards, and the hCG level gradually returned to normal.

CONCLUSION

The site of an ectopic pregnancy should be sought thoroughly to avoid missing an abdominal pregnancy and hence disastrous hemoperitoneum. While medical therapy with high-dose methotrexate is not a standard treatment, it can be considered after failing the traditional therapy, provided that there is adequate treatment monitoring and expertise in handling the side effects of the medication.

Interstitial lung disease in systemic sclerosis: An HRCT-clinical correlative study

Purpose: To evaluate high-resolution CT (HRCT) parameters of inflammation and fibrosis in systemic sclerosis (SSc), for correlation with lung function, skin scores and exercise tolerance.

Material and Methods: 45 SSc patients (40 women, 48.5±13.4 years), underwent thoracic HRCT, lung function assessment, and modified Rodnan skin scores. Exercise tolerance was also graded. HRCT were scored for extent of 4 HRCT patterns of interstitial lung disease (ILD): ground glass opacification (GGO), reticular, mixed and honeycomb pattern in each lobe. Total HRCT score, inflammation index (GGO and mixed score) and fibrosis index (reticular and honeycomb scores) were correlated with lung function and clinical parameters.

Results: ILD was present in 39/45 (86.7%) patients. Abnormal (<80% predicted) forced vital capacity (FVC), total lung capacity (TLC) and carbon monoxide diffusion factor (DLco) were detected in 30%, 22% and 46% of patients. Total HRCT score correlated with FVC ( r=−0.43, p=0.008), FEV1 (forced expiratory volume) ( r=–0.37, p=0.03), TLC ( r=–0.47, p=0.003), and DLCO ( r=–0.43, p=0.008); inflammatory index with DLCO ( r=–0.43, p=0.008) and exercise tolerance ( r=–0.39, p < 0.05); and fibrosis index with FVC ( r=–0.31, p=0.05) and TLC ( r=–0.38, p=0.02). Higher total HRCT score, and inflammation and fibrosis indices were found in patients with abnormal lung function.

Conclusion: Qualitative HRCT is able to evaluate inflammation and fibrosis, showing important relationships with diffusion capacity and lung volume, respectively.

Aerobic exercise and yoga improve neurocognitive function in women with early psychosis

Impairments of attention and memory are evident in early psychosis, and are associated with functional disability. In a group of stable, medicated women patients, we aimed to determine whether participating in aerobic exercise or yoga improved cognitive impairments and clinical symptoms. A total of 140 female patients were recruited, and 124 received the allocated intervention in a randomized controlled study of 12 weeks of yoga or aerobic exercise compared with a waitlist group. The primary outcomes were cognitive functions including memory and attention. Secondary outcome measures were the severity of psychotic and depressive symptoms, and hippocampal volume. Data from 124 patients were included in the final analysis based on the intention-to-treat principle. Both yoga and aerobic exercise groups demonstrated significant improvements in working memory (P<0.01) with moderate to large effect sizes compared with the waitlist control group. The yoga group showed additional benefits in verbal acquisition (P<0.01) and attention (P=0.01). Both types of exercise improved overall and depressive symptoms (all P⩽0.01) after 12 weeks. Small increases in hippocampal volume were observed in the aerobic exercise group compared with waitlist (P=0.01). Both types of exercise improved working memory in early psychosis patients, with yoga having a larger effect on verbal acquisition and attention than aerobic exercise. The application of yoga and aerobic exercise as adjunctive treatments for early psychosis merits serious consideration. This study was supported by the Small Research Funding of the University of Hong Kong (201007176229), and RGC funding (C00240/762412) by the Authority of Research, Hong Kong.

Prognostic role of coronary calcification in patients with rheumatoid arthritis and systemic lupus erythematosus

OBJECTIVES

To study the predictive value of coronary calcification score (CCS) for future cardiovascular (CVS) events as detected by multi-detector computed tomography (MDCT) in patients with rheumatoid arthritis(RA) and systemic lupus erythematosus (SLE).

METHODS

A total of 152 patients with RA and SLE, and 106 healthy controls underwent MDCT to measure CCS. All patients were prospectively followed up for major CVS events.

RESULTS

Compared with controls, patients with RA and SLE had a significantly higher mean CCS (42.2±154.3 vs. 1.4±13.0, p<0.01) and prevalence of CCS 1-10, CCS 11-100 and CCS>100 (all p<0.05). After a mean period of 4.3±0.6 years, major CVS events occurred in 10 patients with RA and SLE. In patients with RA and SLE, a higher major CVS events rate occurred in patients with CCS 1-10 (5.0%), CCS 11-100 (14.3%) and CCS >100 (40.0%) than those with CCS=0 (1.0%, p<0.01). Multivariate Cox regression analysis revealed that hypercholesterolemia (hazard ratio (HR) 11.2, confidence interval (CI 1.4-89.3, p=0.02) and CCS>100 (HR 11.1, CI 1.31-95.0, p=0.03) were independent predictors of combined events.

CONCLUSIONS

Coronary calcification detected by MDCT independently predicts CVS events in patients with RA and SLE. Risk stratification by assessment of CCS may have an important role in patients with systemic inflammatory disease.

18F-FDG-PET-CT imaging findings of recurrent intracranial haemangiopericytoma with distant metastases

A 42-year-old woman presented with local recurrence and distant lung and liver metastases 7 years after resection of a primary intracranial haemangiopericytoma. Whole-body (18)F-fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET)-CT scan showed no increased uptake in local recurrence or distant metastases except for a focus of increased FDG uptake within a hepatic metastasis. The hypermetabolic area correlated with an intratumoral hypoenhancing area on the CT scan. PET-CT scan may be useful to allow further understanding of the tumour.

Radiation dose and cancer risk in retrospectively and prospectively ECG-gated coronary angiography using 64-slice multidetector CT

This study aimed to estimate the radiation dose and cancer risk to adults in England, the USA and Hong Kong associated with retrospectively and prospectively electrocardiogram (ECG)-gated coronary computed tomography angiography (CTA) using currently practised protocols in Hong Kong. The doses were simulated using the ImPACT spreadsheet. For retrospectively ECG-gated CTA with pitches of 0.2, 0.22 and 0.24, the effective doses were 27.7, 23.6 and 20.7 mSv, respectively, for males and 23.6, 20.0 and 18.8 mSv, respectively, for females. For prospectively ECG-gated CTA, the effective dose was 3.7 mSv for both males and females. A table of lifetime attributable risks (LAR) of cancer incidence was set up for the English population for the purpose of estimating cancer risk induced by low-dose radiation exposure, as previously reported for US and Hong Kong populations. From the tables, the LAR of cancer incidence for a representative 50-year-old subject was calculated for retrospectively ECG-gated CTA to be 0.112% and 0.227% for English males and females, respectively, 0.103% and 0.228% for US males and females, respectively, and was comparatively higher at 0.137% and 0.370% for Hong Kong males and females, respectively; for prospectively ECG-gated CTA, the corresponding values were calculated to be 0.014% and 0.035% for English males and females, respectively, and 0.013% and 0.036% for US males and females, respectively, and again were higher at 0.017% and 0.060% for Hong Kong males and females, respectively. Our study shows that prospectively ECG-gated CTA reduces radiation dose and cancer risks by up to 87% compared with retrospectively ECG-gated CTA.

Coronary atherosclerosis using computed tomography coronary angiography in patients with systemic sclerosis

BACKGROUND

Impaired coronary artery reserve has previously been demonstrated in patients with systemic sclerosis (SSc). Both micro- and macrovascular factors are probably contributory to the underlying pathogenesis.

OBJECTIVES

To examine the frequency of coronary atherosclerosis in a series of SSc patients by computed tomography coronary angiography (CTCA), a less invasive method than conventional coronary angiography, the current gold standard in the detection of coronary atherosclerosis, and to explore its clinical associations.

METHODS

Nineteen consecutive SSc patients [six with diffuse (dSSc) and 13 with limited disease (lSSc)] with disease duration of >or= 3 years were recruited. Coronary calcium score and contrast angiography were examined by CT scan. Conventional cardiovascular factors and inflammatory markers were measured and correlated with CT findings.

RESULTS

The mean+/-SD age of these patients was 52.5+/-12.5 years with median disease duration of 12.5 years. Six (31.6%) patients were found to have coronary artery calcification (calcium score 13-2008). Coronary calcium was detected in one dSSc patient but contrast angiography was not performed because of interference from an in situ implantable cardiac device. Some parts of the coronary arteries were not assessable in two patients who had ectopic cardiac rhythm. Five lSSc patients had calcified plaques causing variable coronary luminal stenosis. All patients were asymptomatic. Patients with abnormal CTCA findings were more likely to be older (p < 0.001) and were less likely to have serum anti-Scl70 antibodies (p = 0.003) than those without, after Bonferroni correction.

CONCLUSIONS

Coronary atherosclerosis is not uncommon in asymptomatic SSc patients. CTCA is a convenient and non-invasive method for studying coronary atherosclerosis.

White matter fractional anisotrophy differences and correlates of diagnostic symptoms in autism

BACKGROUND

Individuals with autism have impairments in 3 domains: communication, social interaction and repetitive behaviours. Our previous work suggested early structural and connectivity abnormalities in prefrontal-striato-temporal-cerebellar networks but it is not clear how these are linked to diagnostic indices.

METHOD

Children with autism (IQ > 70) aged 6 to 14 years old and matched typically developing controls were studied using diffusion tensor imaging. Voxel-based methods were used to compare fractional anisotrophy (FA) measures in each group and to correlate FA measures in the autism group with the diagnostic phenotype described by the Autism Diagnostic Interview - Revised (ADI-R) algorithm for ICD-10.

RESULTS

After controlling for the effects of age and white matter volume, we found that FA in the autism group was significantly lower than controls in bilateral prefrontal and temporal regions, especially in the right ventral temporal lobe adjacent to the fusiform gyrus. FA was greater in autism in the right inferior frontal gyrus and left occipital lobe. We observed a tight correlation between lower FA and higher ADI-R diagnostic algorithm scores across white matter tracts extending from these focal regions of group difference. Communication and social reciprocity impairments correlated with lower FA throughout fronto-striato-temporal pathways. Repetitive behaviours correlated with white matter indices in more posterior brain pathways, including splenium of the corpus callosum and cerebellum.

CONCLUSIONS

Our data support the position that diagnostic symptoms of autism are associated with a core disruption of white matter development.

C-reactive protein is associated with obstructive sleep apnea independent of visceral obesity

BACKGROUND

Obstructive sleep apnea (OSA) is associated with adverse cardiovascular outcomes. C-reactive protein (CRP) predicts atherosclerotic complications. Our study evaluates whether OSA is associated with an elevated CRP level, after elimination of known confounders including visceral obesity.

METHODS

Men without significant chronic medical illness, regular medications, or illness in the preceding 4 weeks were enrolled. Subjects with morbid obesity, newly detected high BP, or fasting glucose were excluded. They underwent polysomnography and MRI of abdomen to quantify visceral fat volume. High-sensitivity CRP levels were measured.

RESULTS

111 men with mean body mass index (BMI) 26.3 +/- 3.8 kg/m(2) were evaluated. After adjustment for age, smoking, BMI, waist circumference, and sleep efficiency, CRP correlated positively with the apnea-hypopnea index (AHI) [r = 0.35, p < 0.001], duration of O(2) saturation < 90% (r = 0.29, p = 0.002), and arousal index (r = 0.32, p = 0.001), and it correlated negatively with minimal O(2) saturation (r = -0.29, p = 0.002). These correlations were consistent when adjustment was made for MRI visceral fat volume instead of waist circumference. In the regression model, significant predictors of CRP included AHI, waist circumference, and triglycerides (adjusted R(2), 0.33, p = 0.001, p = 0.002, p = 0.018, respectively). Among the 111 subjects, 32 subjects with no or mild OSA (AHI < 15 events/h) were matched with 32 subjects with moderate-to-severe OSA (AHI > or = 15 events/h) in MRI visceral fat volume. CRP was higher in subjects with moderate-to-severe OSA (median, 1.32; 0.45 to 2.34 mg/L) when compared to subjects with no or mild OSA (median, 0.54; 0.25 to 0.89 mg/L; p = 0.001).

CONCLUSIONS

In healthy middle-aged men, elevated CRP level is associated with OSA independent of visceral obesity.

Improvement in sleep apnea during nocturnal peritoneal dialysis is associated with reduced airway congestion and better uremic clearance

BACKGROUND AND OBJECTIVES

Among peritoneal dialysis (PD) patients, nocturnal PD (NPD) is known to improve sleep apnea compared with continuous ambulatory peritoneal dialysis (CAPD), but the contributing factors are unclear.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Thirty-eight incident ESRD patients underwent overnight polysomnography (PSG) during NPD and CAPD. Bioelectrical impedance analysis, magnetic resonance imaging of the upper airway, and urea kinetics (Kt/V) during sleep were measured on both occasions.

RESULTS

The prevalence of severe sleep apnea (apnea-hypopnea index, AHI > or = 15/h) was 21.1% during NPD, and 42.1% during CAPD. Mean AHI increased from 9.6 +/- 2.7/h during NPD to 21.5 +/- 4.2/h during CAPD. Both obstructive and central apnea worsened after conversion to CAPD. NPD achieved greater reductions in total body water, hydration fraction, and net ultrafiltration than CAPD during sleep. Overnight peritoneal Kt/V and creatinine clearance were lower after conversion. Both peritoneal Kt/V and peritoneal creatinine clearance correlated with AHI, as did their changes after conversion. Volumetric magnetic resonance imaging revealed reduced pharyngeal volumes and cross-sectional area, and tongue enlargement after conversion.

CONCLUSIONS

Improvement in sleep apnea during NPD versus CAPD is associated with better fluid and uremic clearance and reduced upper airway congestion during sleep.

A diffusion tensor imaging study of structural dysconnectivity in never-medicated, first-episode schizophrenia

BACKGROUND

Diffusion tensor imaging (DTI) can be used to investigate cerebral structural connectivity in never-medicated individuals with first-episode schizophrenia.

METHOD

Subjects with first-episode schizophrenia according to DSM-IV-R who had never been exposed to antipsychotic medication (n=25) and healthy controls (n=26) were recruited. Groups were matched for age, gender, best parental socio-economic status and ethnicity. All subjects underwent DTI and structural magnetic resonance imaging (MRI) scans. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values differed significantly between groups. A confirmatory region-of-interest (ROI) analysis of FA scores was performed in which regions were placed blind to group membership.

RESULTS

In patients, FA values significantly lower than those in healthy controls were located in the left fronto-occipital fasciculus, left inferior longitudinal fasciculus, white matter adjacent to right precuneus, splenium of corpus callosum, right posterior limb of internal capsule, white matter adjacent to right substantia nigra, and left cerebral peduncle. ROI analysis of the corpus callosum confirmed that the patient group had significantly lower mean FA values than the controls in the splenium but not in the genu. The intra-class correlation coefficient (ICC) for independent ROI measurements was 0.90 (genu) and 0.90 (splenium). There were no regions where FA values were significantly higher in the patients than in the healthy controls.

CONCLUSIONS

Widespread structural dysconnectivity, including the subcortical region, is already present in neuroleptic-naive patients in their first episode of illness.

A prediction rule for clinical diagnosis of severe acute respiratory syndrome

A prospective study was undertaken to identify clinical, radiographical, haematological and biochemical profiles of severe acute respiratory syndrome (SARS) patients. A prediction rule, which demarcates low from high risk patients for SARS in an outbreak situation was developed. A total of 295 patients with unexplained respiratory illnesses, admitted to Queen Mary Hospital, Hong Kong SAR, China, in March to July 2003, were evaluated for clinical, radiological, haematological and alanine transaminase (ALT) data daily for 3 days after hospitalisation. In total, 44 cases were subsequently confirmed to have SARS by RT-PCR (68.2%) and serology (100%). The scoring system of attributing 11, 10, 3, 3 and 3 points to the presence of independent risk factors, namely: epidemiological link, radiographical deterioration, myalgia, lymphopenia and elevated ALT respectively, generated high and low-risk (total score 11-30 and 0-10, respectively) groups for SARS. The sensitivity and specificity of this prediction rule in positively identifying a SARS patient were 97.7 and 81.3%, respectively. The positive and negative predictive values were 47.8 and 99.5%, respectively. The prediction rule appears to be helpful in assessing suspected patients with severe acute respiratory syndrome at the bedside, and should be further validated in other severe acute respiratory syndrome cohorts.

Partial rhombencephalosynapsis and Chiari II malformation

We report a rare case of partial rhombencephalosynapsis coexistent with Chiari II malformation in a 6-year-old girl and discuss the features of these entities on magnetic resonance imaging.

Hyperbilirubinemia and cholelithiasis in Chinese patients with hemoglobin H disease

Hemoglobin H disease (HbH) is a hemoglobinopathy peculiar to parts of the world with high incidence alpha-thalassemia mutations. Among 90 HbH cases, 50 cases suffered from clinically significant jaundice (bilirubin >30 mmol/l), including 14 with severe jaundice (bilirubin >60 mmol/l). Cholelithiasis was found in 38 cases. The incidence is roughly eight times higher than that in background control population but 50% lower than that in beta-thalassemia. The risk of gallstones was related to higher bilirubin levels but not alpha-globin genotype, sex, ferritin, and hemoglobin levels. Homozygotes or double heterozygotes for Gilbert alleles (17.2%), but not heterozgyotes (42.2%), were found to have a significantly increased risk of gallstones and jaundice. However, common Chinese Gilbert syndrome alleles do not completely explain the variable risks.

Post-operative magnetic resonance evaluation of children after laparoscopic anorectoplasty for imperforate anus

BACKGROUND AND AIMS

Laparoscopic anorectoplasty (LAR) is a relatively new procedure in the treatment of imperforate anus. Using magnetic resonance imaging (MRI), we evaluated the anatomical features of the anorectal region of children treated with LAR and compared this with conventional posterior sagittal anorectoplasty (PSARP). The findings were correlated with functional outcome.

PATIENT/METHODS

A retrospective review of ten children with the high/intermediate types of imperforate anus underwent LAR between May 2000 and December 2002. MRI of the pelvis was performed post-operatively and a semi-quantitative score was used to assess the degree of sphincter symmetry, peri-rectal fibrosis, and the position of the pull-through rectum. The defecation status of these patients was also recorded. Eight historical patients who had undergone PSARP served as a control group.

RESULTS/FINDINGS

When compared with PSARP patients, a significantly lower proportion of LAR patients had sphincter asymmetry (40 vs. 100%, p < 0.05) and peri-rectal fibrosis (40 vs. 87.5%, p < 0.05). The positioning of the rectum was, however, central for both groups (90 vs. 87.5%). No statistical correlation was found between defecation status and the degree of sphincter asymmetry or peri-rectal fibrosis.

INTERPRETATION/CONCLUSION

LAR allows more optimal anatomical reconstruction for patients with the high/intermediate types of imperforate anus. However, additional factors that are not correctable by surgery, such as intrinsic innervation deficiency, also influence the clinical outcome.

Exhaled nitric oxide in bronchiectasis: the effects of inhaled corticosteroid therapy

SETTING

While exhaled nitric oxide (eNO) levels are reduced by inhaled corticosteroid therapy in asthma, such treatment effect is unclear in bronchiectasis.

DESIGN

Stable non-smoking bronchiectasis patients were randomised to receive either fluticasone (1 mg/daily) or identical placebo via the Accuhaler device.

RESULTS

Sixty non-smoking patients (38 women; mean age 56.4 +/- 12.7 years) were recruited. Of these, half received inhaled fluticasone and half placebo therapy. eNO was measured using a chemiluminescence analyser at 0, 4, 12, 24, 36 and 52 weeks. There was no significant difference in eNO levels between fluticasone and placebo patients over the study period. There was no correlation between baseline eNO with age, FEV1, FVC, 24 h sputum volume or number of bronchiectatic segments. Patients with Pseudomonas aeruginosa (PA) infection, but not their counterparts, displayed a correlation between 0- and 52-week eNO levels. PA infection was associated with significantly lower eNO levels among the patients.

CONCLUSIONS

Inhaled fluticasone therapy, despite being an effective anti-inflammatory agent, has no significant effect on eNO production, either at individual time points or over the entire 52-week profile, in bronchiectasis. It appears that eNO might not reflect the extent of airway inflammation in bronchiectasis.

Pentaglobin in steroid-resistant severe acute respiratory syndrome

SETTING

The treatment of severe acute respiratory syndrome (SARS) is at best controversial, although there is considerable anecdotal experience to show the benefits of corticosteroid therapy for selected patients. Some patients deteriorate relentlessly despite treatment with antibiotic, corticosteroid and mechanical ventilation.

OBJECTIVE

To attempt to determine the clinical efficacy of pentaglobin, an IgM-enriched immunoglobulin preparation, on 12 severe SARS patients who continued to deteriorate despite corticosteroid and ribavirin therapy.

DESIGN

Retrospective analysis of daily quantitative and radiographic data on the cohort in a regional teaching hospital.

RESULTS AND CONCLUSION

There was significant improvement in radiographic scores, when compared with day 1, on days 5, 6 and 7 (P < 0.05) after commencement of pentaglobin treatment. Similarly, there was significant improvement in oxygen requirement, when compared with day 1, on days 6 and 7 (P < 0.05) after commencement of pentaglobin treatment. There were no reported adverse events attributable to pentaglobin administration. Ten patients made an uneventful recovery after treatment. One elderly man died from cardiorespiratory arrest despite clinical and radiological improvement, and another patient is making good progress. Pentaglobin is safe and probably effective in the treatment of steroid-resistant SARS. A double-blind placebo-controlled study should therefore be considered.

A case of cerebellar hypoplasia in a Chinese infant with osteogenesis imperfecta

We report a unique case of unilateral cerebellar hypoplasia in a young Chinese girl with osteogenesis imperfecta type IV. Magnetic resonance imaging showed mild basilar invagination and impression. Although unilateral cerebellar hypoplasia and osteogenesis imperfecta may have been coincidental diagnoses, we propose possible mechanisms for unilateral cerebellar hypoplasia secondary to osteogenesis imperfecta. For example, cerebellar hypoplasia may have been because of vascular disruption or direct compression to the posterior circulation in utero. Foetuses with osteogenesis imperfecta are more susceptible to the above risks compared to the normal foetus because of associated craniocervical anomalies and a poorly ossified skull.

Advances in imaging of the solitary pulmonary nodule

OBJECTIVE

To review the radiological management of a solitary pulmonary nodule.

DATA SOURCES

MEDLINE literature search (1958-2002).

STUDY SELECTION

All review articles and original articles. Key words for the literature search were 'solitary pulmonary nodule' and 'imaging'.

DATA EXTRACTION

All relevant information and data.

DATA SYNTHESIS

The solitary pulmonary nodule remains a perennial problem in radiological practice, particularly with current trends using low-dose computed tomography to screen for lung cancer. Determining the likelihood of malignancy forms the basis of the radiological approach of a solitary pulmonary nodule. Several factors that influence risk analysis include morphological and enhancement characteristics of the solitary pulmonary nodule on imaging, stability of the nodule, age of patient, smoking history, and history of malignant disease. Other ancillary procedures and imaging techniques that assist in the evaluation of a solitary pulmonary nodule include fluorodeoxyglucose positron-emission tomography, technetium Tc 99m depreotide imaging, bronchoscopy with bronchioloalveolar lavage and biopsy, image-guided transthoracic needle aspiration biopsy, video-assisted thorascopic surgery, and thoracotomy.

CONCLUSIONS

The success of any radiological management of a solitary pulmonary nodule rests on careful clinical evaluation and risk stratification for malignancy before the implementation of appropriate imaging techniques.

High-resolution CT findings of severe acute respiratory syndrome at presentation and after admission

OBJECTIVE

The aim of this study was to assess the high-resolution CT (HRCT) findings at presentation and after hospital admission in patients with severe acute respiratory syndrome (SARS).

MATERIALS AND METHODS

We reviewed the HRCT findings at presentation (n = 12) and after hospital admission (n = 25) of 29 patients with SARS and compared the HRCT findings with the radiographic findings. HRCT scans were obtained using 1-mm (n = 28) or 2-mm (n = 1) collimation. The radiographs and HRCT scans were reviewed independently by two observers who reached a decision by consensus.

RESULTS

All patients had abnormal findings on HRCT at presentation. Eight of these 12 patients had normal findings on radiographs. The predominant HRCT findings at presentation consisted of unilateral (n = 6) or bilateral (n = 2) ground-glass opacities or focal unilateral (n = 2) or bilateral (n = 2) areas of consolidation. All patients showed progression of disease on follow-up. The predominant HRCT findings on follow-up CT scans consisted of unilateral (n = 2) or bilateral ground-glass opacities (n = 13), unilateral (n = 2) or bilateral consolidation (n = 5), or a mixed bilateral pattern of ground-glass attenuation, consolidation, and reticulation (n = 3). Reticulation with associated architectural distortion and mild traction bronchiectasis was present in eight patients.

CONCLUSION

HRCT can show parenchymal abnormalities in patients with SARS who have normal findings on radiographs at presentation. Follow-up CT scans obtained in hospitalized patients show findings consistent with fibrosis in a small percentage of patients.

Magnetic resonance screening of iron status in transfusion-dependent β-thalassaemia patients

The clinical utility of dual sequence (T1- and T2-weighted) magnetic resonance (MR) imaging in estimating liver iron concentration (LIC) in 32 transfusion-dependent beta-thalassaemia major (24 females; age 18.5+/-5.9 years) patients on desferrioxamine was evaluated. Signal intensity ratios (SIR) between liver, spleen and pancreas to psoas muscle were determined on both sequences. Relationships between clinical and MR parameters, and accuracy of SIR thresholds in determining adequacy of chelation from LIC were analysed. Liver T1- and T2-SIR were related to LIC (P < 0.001). T1-SIR < 0.60 predicted severe iron overload (LIC > 15 mg/g) with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 87%, 33% and 100% respectively. T2-SIR < 0.1 yielded 100% sensitivity, 93% specificity, 50% PPV and 100% NPV. T1-SIR > or = 1.1 predicted LIC < 7 mg/g with 69% sensitivity, 88% specificity, 85% PPV and 74% NPV. T2-SIR > or = 0.20 yielded 56.5% sensitivity, 94% specificity, 90% PPV and 71% NPV. LIC correlated with liver T1-SIR, liver T2-SIR and serum ferritin (r = -0.76, -0.65, 0.47, respectively; P < 0.01). Serum ferritin was inversely related to liver T1-SIR, liver T2-SIR and spleen T2-SIR (r = -0.35, -0.43, -0.40, respectively; P < 0.05). Mean total transfusion burden was not related to any MR parameter. Although neither MR sequence was a highly accurate predictor of LIC, SIR thresholds are useful to determine presence of iron overload and adequacy of chelation treatment.

White-matter diffusion anisotropy after chemo-irradiation: a statistical parametric mapping study and histogram analysis

The aim of the study was to evaluate white-matter (WM) diffusion anisotropy in medulloblastoma survivors after cranial irradiation and chemotherapy using voxel-based analysis with SPM99 and fractional anisotropy (FA) histogram-derived indices, and to identify quantitative indices for detecting and monitoring children with treatment-induced white-matter injury. Familywise error rate (FWE) that corrects for multiple comparisons was used to locate statistically significant regions of P < 0.05 in voxel-based analysis. Subsequently, the false discovery rate (FDR) controlling procedure (corrected P < 0.05) was used. FA map histogram analysis of histogram-derived indices, mean FA, mean FA peak height, and peak location was performed. Two-sample t test was used in all analyses. Using FWE-corrected P < 0.05, there was a cluster of reduced anisotropy in the periventricular white matter lateral to the left ventricular atrium. When FDR-corrected P < 0.05 was used, there were multiple clusters of reduced anisotropy in the periventricular white matter, the corpus callosum, and corona radiata. Simplified voxel-based morphometry (VBM)-like analysis of cerebrospinal fluid (CSF) did not show significant differences between patient and control subjects. 'White-matter FA map' histogram showed significant reduction in mean FA and mean FA peak location and significant increase in mean FA peak height in the patient group compared to control subjects (P = 0.003, P = 0.003, and P = 0.014, respectively). This approach of quantifying FA can be applied to characterize anisotropy in the white matter after cranial irradiation and chemotherapy and can potentially be used to detect and monitor treatment-induced neurotoxicity.

The relationship between mediastinal lymph node attenuation with parenchymal lung parameters in silicosis

OBJECTIVE

Attenuation changes on computed tomography (CT) in mediastinal lymph nodes (LN) may be related to lung alterations and functional impairment in silicosis.

DESIGN

CT and clinical data of 41 (64.2 +/- 8.3 years) males with silicosis were retrieved. Attenuation type (calcified, hyperdense, normodense) and calcification pattern (central, eccentric, dense, eggshell, speckled) of mediastinal LN were evaluated; LN attenuation of uncalcified LNs quantified on CT in six LN stations. Nodular profusion (CT-NP) and progressive massive fibrosis (CT-PMF) were graded. Relationships between LN, CT, lung function and clinical parameters were determined.

RESULTS

LN sites were paratracheal (n = 39), subcarinal (n = 39), tracheobronchial (n = 37), aortopulmonary (n = 37), hilar (n = 27), and peri-oesophageal (n = 21). LNs were calcified, hyperdense and normodense in 107, 85 and 54 LN stations, respectively. Uniformly calcified LN was most common, followed by speckled calcification. Central, eccentric and eggshell calcification was rare. CT-NP scores > or = 16 were associated with higher LN attenuation and number of calcified LN stations than CT-NP scores < 16. PMF had no influence over LN morphology or calcification pattern. LN attenuation correlated with CT-PMF (r = 0.36, P = 0.01), CT-NP (r = 0.54, P < 0.001) and DLCO/VA (r = -0.33, P = 0.02).

CONCLUSION

Uniformly calcified and hyperdense LNs are common in silicosis, and eggshell LN calcification is rare. There are associations between LN attenuation and lung function impairment, and CT grades of nodular profusion and PMF.

MRI of Neonatal Encephalopathy

We present the magnetic resonance imaging (MRI) findings in neonatal encephalopathy, including hypoxic-ischaemic encephalopathy, perinatal/neonatal stroke, metabolic encephalopathy from inborn errors of metabolism, congenital central nervous system infections and birth trauma. The applications of advanced MRI techniques, such as diffusion-weighted imaging and magnetic resonance spectroscopy are emphasized.

Severe acute respiratory syndrome: radiographic and CT findings

OBJECTIVE

We review the radiographic and CT findings in the lungs of 12 patients with severe acute respiratory syndrome (SARS) in an effort to describe the most common radiologic findings for this disease.

CONCLUSION

The most common radiographic findings of SARS patients at presentation are unilateral or bilateral ground-glass opacities or focal unilateral or bilateral areas of consolidation. In hospitalized SARS patients, the abnormalities tend to progress to bilateral air-space consolidation. CT may reveal parenchymal disease in patients whose radiographs show normal results.

Ultrasonography of intra-abdominal cystic lesions in the newborn

Intra-abdominal cystic lesions are increasingly recognized in the newborn because of the advent of routine antenatal ultrasonography. As these lesions are often asymptomatic or non-specific in clinical presentation in the newborn, imaging by ultrasonography has an important role in diagnosis. We present a pictorial review of the commonly encountered intra-abdominal cystic lesions in the newborn, with emphasis on ultrasonographic features that can aid differentiation between the various lesions.

Interstitial lung disease in systemic sclerosis

PURPOSE

To evaluate high-resolution CT (HRCT) parameters of inflammation and fibrosis in systemic sclerosis (SSc), for correlation with lung function, skin scores and exercise tolerance.

MATERIAL AND METHODS

45 SSc patients (40 women, 48.5+/-13.4 years), underwent thoracic HRCT, lung function assessment, and modified Rodnan skin scores. Exercise tolerance was also graded. HRCT were scored for extent of 4 HRCT patterns of interstitial lung disease (ILD): ground glass opacification (GGO), reticular, mixed and honeycomb pattern in each lobe. Total HRCT score, inflammation index (GGO and mixed score) and fibrosis index (reticular and honeycomb scores) were correlated with lung function and clinical parameters.

RESULTS

ILD was present in 39/45 (86.7%) patients. Abnormal (<80% predicted) forced vital capacity (FVC), total lung capacity (TLC) and carbon monoxide diffusion factor (DLco) were detected in 30%, 22% and 46% of patients. Total HRCT score correlated with FVC (r=-0.43, p=0.008), FEV1 (forced expiratory volume) (r=-0.37, p=0.03), TLC (r=-0.47, p=0.003), and DLCO (r=-0.43, p=0.008); inflammatory index with DLCO (r=-0.43, p=0.008) and exercise tolerance (r=-0.39, p < 0.05); and fibrosis index with FVC (r=-0.31, p=0.05) and TLC (r=-0.38, p=0.02). Higher total HRCT score, and inflammation and fibrosis indices were found in patients with abnormal lung function.

CONCLUSION

Qualitative HRCT is able to evaluate inflammation and fibrosis, showing important relationships with diffusion capacity and lung volume, respectively.

Computed tomography characteristics of advanced primary pulmonary lymphoepithelioma-like carcinoma

Our objectives were to document CT features of advanced primary pulmonary lymphoepithelioma-like carcinoma (LELC) and to determine features that may assist differentiation from other non-small cell lung cancers (NSCLC). Imaging and clinical data of all patients with biopsy-proven pulmonary LELC ( n=12) were retrieved from a database of all NSCLC patients over a 2-year period. Twenty-five controls were recruited from other inoperable non-LELC NSCLC patients from the database. Pre-treatment CT scans of the thorax of both study and control patients were reviewed for lobe involved; tumour site, borders and size; and pleural, vascular or pulmonary involvement. Presence of lymphangitis carcinomatosis was noted. Lymph node metastasis was characterised as ipsilateral or contralateral enlarged (>1 cm) mediastinal or hilar nodes, or as peribronchovascular nodal spread. Differences between the two groups were tested using Mann-Whitney rank-sum test. The LELC tumours were significantly larger (45.67 vs 17.71 cm(2)) than controls and were closely associated with the mediastinum. There were more LELC tumours with well-defined borders ( p<0.001) and fewer with spiculated borders ( p<0001) than non-LELC tumours. There was increased peribronchovascular nodal spread ( p=0.01) and vascular encasement ( p=0.02) in LELC compared with non-LELC tumours. Advanced primary pulmonary LELC has distinct radiological features, and can appear as well-defined tumour closely associated with the mediastinum, with peribronchovascular spread and vascular encasement.

Sonographic features of ileal duplication cyst at 12 weeks

Enteric duplication cyst is a congenital abnormality that is believed to arise from abnormal recanalization of the bowel during embryogenesis. Previous reports suggest that the condition may be suspected prenatally by sonographic demonstration of an intra-abdominal cystic mass in the second and third trimesters. We present the sonographic features of a fetus with ileal duplication cyst at 12 weeks of gestation, which show that the condition may present in the first trimester of pregnancy.

Pulmonary iron overload in thalassemia major presenting as small airway disease

Lung function abnormalities that are associated with thalassemia major are variable with etiology that is yet undetermined. Some studies have suggested that pulmonary iron deposition is a probable cause for these lung defects although there has been no antemortem histopathological and radiological evidence for this. We report a case of thalassemia major with biopsy-proven pulmonary iron overload, in which thoracic high-resolution computed tomography revealed a morphological-functional correlation consistent with small airway disease.

Portal venous velocity in the follow-up of patients with biliary atresia after Kasai portoenterostomy

BACKGROUND/PURPOSE

Liver transplantation is the only therapeutic option for biliary atresia (BA) patients with failed Kasai portoenterostomy (PE). The indication for and timing of liver transplantation in these patients are important management issues. The aims of this study are to evaluate the relationship between portal venous velocity (PVV) and clinical and biochemical indicators of liver function in BA, and to examine the role of PVV in the postoperative surveillance of these patients.

METHODS

Twenty-nine children (mean age, 8 years 4 months) who had PE for BA underwent Doppler ultrasonography to evaluate PVV. Using regression analysis, these findings were correlated with biochemical indicators of liver function. The Mann-Whitney test was used to detect any significant differences in PVV between the Child-Pugh A group and combined Child-Pugh B and C group patients.

RESULTS

The mean +/- SD PVV for the Child-Pugh A group and the combined Child-Pugh B and C group was 17.1 cm/s +/- 8.9 cm/s and 10.2 cm/s +/- 3.3 cm/s, respectively, and this difference was statistically significant (P =.037).

CONCLUSIONS

Doppler ultrasonography measurement of PVV provides adjunctive information to the clinical and biochemical assessment of the liver function status in BA. Its use in the postoperative surveillance of these patients is helpful in identifying the need for and in timing of liver transplantation.

Mature teratomas of the adrenal gland: imaging features

BACKGROUND

We describe the imaging features of three, histologically confirmed, mature teratomas of the adrenal gland not described previously in the radiologic literature and discuss the differential diagnosis of lipomatous tumors of the adrenal gland.

METHODS

Computed tomographic (n = 3), magnetic resonance imaging (n = 1), and sonographic (n = 1) features were reviewed retrospectively and the findings correlated with gross pathology and histology.

RESULTS

There were two females (age 8 and 18 years) and one male (age 17 years). Tumor size ranged from 5 to 11 cm (mean = 7.3 cm). All tumors were well circumscribed and contained fat components. Calcification was demonstrated in two tumors and was the predominant component in one. Only one was cystic.

CONCLUSION

The radiologic features of these tumors were typical of mature teratomas occurring elsewhere in the body. This should be considered in the differential diagnosis of lipomatous tumors of the adrenal gland, especially in children and adolescents.

Imaging of peripheral PNET: common and uncommon locations

AIM

We present the imaging features of peripheral primitive neuroectodermal tumour (PNET) in eight children, highlighting the unusual locations of this tumour in three children.

MATERIALS AND METHODS

At presentation, the tumours were studied with magnetic resonance imaging (MRI; n = 6), computed tomography (CT; n = 7) and ultrasound (US; n = 1). The diagnoses were confirmed histologically (n = 8), immunohistochemically (n = 8), by cytogenetics (n = 3) and electron microscopy (n = 1). Correlation with gross pathology, histology, treatment and outcome were obtained.

RESULTS

The tumours were located in the chest wall (n = 2), shoulder, pelvis, small bowel mesentery, adrenal gland, dura mater and skin and subcutaneous tissue of the abdominal wall (n = 1 each). Peripheral PNET arising from the small bowel mesentery, adrenal gland and dura mater have not been previously reported in the English literature. The tumours were mainly large (mean size: 10.6 cm) and infiltrative. All tumours were heterogeneously hyperintense on T2-weighted MRI, heterogeneously iso/hypodense on CT and had variable contrast enhancement. Most tumours were heterogeneously hypointense to muscle on T1-weighted MRI. US showed a hypoechoic mass with a cystic component.

CONCLUSION

Peripheral PNET can occur in unusual locations. The clinical and imaging features of peripheral PNET are non-specific, making tissue diagnosis essential. PNET should be included in the differential diagnosis of aggressive soft tissue tumours in children.