MRI for Cushing Disease: A Systematic Review.

BACKGROUND: MR imaging is key in the diagnostic work-up of Cushing disease. The sensitivity of MR imaging in Cushing disease is not known nor is the prognostic significance of "MR imaging-negative" disease. PURPOSE: Our aim was to determine the overall sensitivity and prognostic significance of MR imaging localization of Cushing disease. DATA SOURCES: We performed a systematic review of the MEDLINE and PubMed databases for cohort studies reporting the sensitivity of MR imaging for the detection of adenomas in Cushing disease. STUDY SELECTION: This study included 57 studies, comprising 5651 patients. DATA ANALYSIS: Risk of bias was assessed using the methodological index for non-randomized studies criteria. Meta-analysis of proportions and pooled subgroup analysis were performed. DATA SYNTHESIS: Overall sensitivity was 73.4% (95% CI, 68.8%-77.7%), and the sensitivity for microadenomas was 70.6% (66.2%-74.6%). There was a trend toward greater sensitivity in more recent studies and with the use of higher-field-strength scanners. Thinner-section acquisitions and gadolinium-enhanced imaging, particularly dynamic sequences, also increased the sensitivity. The use of FLAIR and newer 3D spoiled gradient-echo and FSE sequences, such as spoiled gradient-echo sequences and sampling perfection with application-optimized contrasts by using different flip angle evolutions, may further increase the sensitivity but appear complementary to standard 2D spin-echo sequences. MR imaging detection conferred a 2.63-fold (95% CI, 2.06-3.35-fold) increase in remission for microadenomas compared with MR imaging-negative Cushing disease. LIMITATIONS: Pooled analysis is limited by heterogeneity among studies. We could not account for variation in image interpretation and tumor characteristics. CONCLUSIONS: Detection on MR imaging improves the chances of curative resection of adenomas in Cushing disease. The evolution of MR imaging technology has improved the sensitivity for adenoma detection. Given the prognostic importance of MR imaging localization, further effort should be made to improve MR imaging protocols for Cushing disease.

The arbuscular mycorrhizal fungi colonising roots and root nodules of New Zealand kauri Agathis australis.

As the only endemic member in New Zealand of the ancient conifer family, Araucariaceae, Agathis australis is an ideal species to study putatively long-evolved mycorrhizal symbioses. However, little is known about A. australis root and nodular arbuscular mycorrhizal fungi (AMF), and how mycorrhizal colonisation occurs. We used light, scanning and transmission electron microscopy to characterise colonisation, and 454-sequencing to identify the AMF associated with A. australis roots and nodules. We interpreted the results in terms of the edaphic characteristics of the A. australis-influenced ecosystem. Representatives of five families of Glomeromycota were identified via high-throughput pyrosequencing. Imaging studies showed that there is abundant, but not ubiquitous, colonisation of nodules, which suggests that nodules are mostly colonised by horizontal transmission. Roots were also found to harbour AMF. This study is the first to demonstrate the multiple Glomeromycota lineages associated with A. australis including some that may not have been previously detected.

Proton Density MRI Increases Detection of Cervical Spinal Cord Multiple Sclerosis Lesions Compared with T2-Weighted Fast Spin-Echo.

BACKGROUND AND PURPOSE: There is a paucity of literature that supports the Consortium of Multiple Sclerosis Centers guideline that proton density MR imaging is a core spinal cord sequence. We hypothesized that proton density fast spin-echo imaging is superior to T2 fast spin-echo MR imaging for the detection of cervical cord MS lesions. This study compared the detection rate and conspicuity of cervical cord MS lesions on sagittal 1.5T proton density fast spin-echo and T2 fast spin-echo MR imaging. MATERIALS AND METHODS: One hundred consecutive patients with MS imaged with 1.5T sagittal proton density fast spin-echo and T2 fast spin-echo cervical cord MR imaging between September 2012 and October 2013 were retrospectively included. The number of MS lesions detected on each sequence was recorded; conspicuity was assessed quantitatively with the lesion-to-cord contrast ratio and lesion-contrast-to-noise ratio. Statistical analysis was performed by using the Wilcoxon signed rank test. RESULTS: Seventy-eight patients had MS cord lesions detected. Proton density fast spin-echo imaging detected a greater number of lesions (n = 181) compared with T2 fast spin-echo imaging (n = 137, P < .001). Fifteen patients (19%) with abnormal findings on proton density fast spin-echo imaging had normal findings on T2 fast spin-echo imaging; no patient with abnormal T2 fast spin-echo imaging findings had normal proton density fast spin-echo imaging findings. Although proton density fast spin-echo and T2 fast spin-echo imaging had similar lesion-to-cord contrast ratios (proton density fast spin-echo, 0.32 ± 0.01, versus T2 fast spin-echo, 0.33 ± 0.01; P = .43), proton density fast spin-echo had greater lesion-contrast-to-noise ratio (proton density fast spin-echo, 82 ± 3.0, versus T2 fast spin-echo, 64 ± 2.6; P < .001). CONCLUSIONS: Proton density fast spin-echo imaging is superior to T2 fast spin-echo MR imaging for the detection of cervical cord MS lesions. Proton density fast spin-echo detects cord lesions in patients in whom T2 fast spin-echo findings appear normal. This study forms the evidentiary base for the current Consortium of Multiple Sclerosis Centers guideline that proton density imaging is a core spinal cord sequence.

Risedronate in adults with osteogenesis imperfecta type I: increased bone mineral density and decreased bone turnover, but high fracture rate persists.

UNLABELLED: Bisphosphonates can increase bone mineral density (BMD) in children with osteogenesis imperfecta (OI). In this study of adults with OI type I, risedronate increased BMD at lumbar spine (but not total hip) and decreased bone turnover. However, the fracture rate in these patients remained high. INTRODUCTION: Intravenous bisphosphonates given to children with OI can increase BMD and reduce fracture incidence. Oral and/or intravenous bisphosphonates may have similar effects in adults with OI. We completed an observational study of the effect of risedronate in adults with OI type I. METHODS: Thirty-two adults (mean age, 39 years) with OI type I were treated with risedronate (total dose, 35 mg weekly) for 24 months. Primary outcome measures were BMD changes at lumbar spine (LS) and total hip (TH). Secondary outcome measures were fracture incidence, bone pain, and change in bone turnover markers (serum procollagen type I aminopropeptide (P1NP) and bone ALP). A meta-analysis of published studies of oral bisphosphonates in adults and children with OI was performed. RESULTS: Twenty-seven participants (ten males and seventeen females) completed the study. BMD increased at LS by 3.9% (0.815 vs. 0.846 g/cm(2), p = 0.007; mean Z-score, -1.93 vs. -1.58, p = 0.002), with no significant change at TH. P1NP fell by 37% (p = 0.00041), with no significant change in bone ALP (p = 0.15). Bone pain did not change significantly (p = 0.6). Fracture incidence remained high, with 25 clinical fractures and 10 major fractures in fourteen participants (0.18 major fractures per person per year), with historical data of 0.12 fractures per person per year. The meta-analysis did not demonstrate a significant difference in fracture incidence in patients with OI treated with oral bisphosphonates. CONCLUSIONS: Risedronate in adults with OI type I results in modest but significant increases in BMD at LS, and decreased bone turnover. However, this may be insufficient to make a clinically significant difference to fracture incidence.

Multicentric/multifocal cerebral lesions: can fluid-attenuated inversion recovery aid the differentiation between glioma and metastases?

The purpose of the study was to assess whether non-enhancing adjacent cortical signal intensity abnormality detected on fluid-attenuated inversion recovery (FLAIR) can differentiate between multicentric and/or multifocal glioma and non-glioma pathology in patients with multiple enhancing cerebral lesions. Nineteen MR studies were reviewed after a database search and exclusion criteria applied, to detect areas of FLAIR cortex involvement without enhancement. Statistical analysis was carried out using a 2 x 2 contingency table and Fischer's exact ratio. Non-enhancing adjacent cortical T2 signal abnormality was seen in eight of eight multicentric and/or multifocal gliomas and four of 11 of the non-glioma pathologies (10 metastatic disease and 1 lymphoma). The presence of non-enhancing adjacent cortical T2 signal abnormality had a sensitivity of 100% and specificity of 63% for glioma. The positive predictive value was 67% and negative predictive value 100%. Fischer's exact probability test was P = 0.01 when applied to the glioma versus non-glioma categories, indicating a significant difference. Non-enhancing adjacent cortical T2-weighted FLAIR signal appears to be more frequently seen in patients with glioma and multiple enhancing lesions compared with those with glioma and a solitary enhancing cerebral lesion. The absence of this sign favours metastatic disease and the presence suggests that multicentric and/or multifocal glioma should remain a consideration.

T1 hyperintense vertebral column melanoma metastases.

We report a case of T1 hyperintense vertebral column metastatic disease in a 24-year-old man with metastatic melanoma. Radiologic work-up revealed multiple lytic vertebral metastases on CT with corresponding T1 hyperintensity on MR imaging. Whereas T1 hyperintensity associated with melanoma has been well documented, to our knowledge, this is the first described case of widespread T1 hyperintense metastatic bone disease. T1 hyperintense bone lesions are virtually always benign. However, correlation with the lesion appearances on other MR imaging sequences and imaging modalities as well as with the clinical history may occasionally suggest otherwise.

Accuracy of MRI diagnosis of internal derangement of the knee in a non-specialized tertiary level referral teaching hospital.

This study was designed to assess the accuracy of knee MRI examinations carried out in a general tertiary referral hospital without a musculoskeletal fellowship trained radiologist. The study included all patients who had undergone a knee arthroscopy carried out within a 2-year period and who had had a prior MRI knee examination, where both were carried out at this institution. The accuracy of the MRI knee examination was determined by correlation to the arthroscopy report. The accuracy for diagnosis of meniscal and cartilage injuries, in this setting, was found to be similar to a published meta-analysis of previous studies correlating knee MRI and arthroscopy. The overall accuracy of this study was better than the previous similar study. However, the accuracy for diagnosing ACL injuries was lower than in the meta-analysis. The potential reasons for this and other sources of error are discussed.

Comparison of performance of computer display monitors for radiological diagnosis; "diagnostic" high brightness monochrome LCD, 3MP vs "clinical review" colour LCD, 2MP.

A study to compare performance of the following display monitors for application as PACS CR diagnostic workstations is described. 1. Diagnostic quality, 3 Mega Pixel, 21 inch monochrome LCD monitors--Planar C3i. 2. Clinical review quality, 2 Mega Pixel, 21 inch colour LCD monitors--Planar PX212. Two sets of seventy radiological studies were presented to four senior radiologists on two occasions, using different displays on each occasion. The clinical condition used for this investigation was to query for the presence of a solitary pulmonary nodule. Receiver Operating Characteristic (ROC) curves were constructed for diagnostic performance for each presentation. Areas under the ROC curves (AUC) for diagnosis using different monitors were compared and the following results obtained: Monochrome AUC = 0.813 +/- 0.02, Colour AUC = 0.801 +/- 0.021. These results indicate that there is no statistically significant difference in the performance of these monitor types at a 95% confidence level.

Hyperintensity of the precentral gyral subcortical white matter and hypointensity of the precentral gyrus on fluid-attenuated inversion recovery: variation with age and implications for the diagnosis of amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Hyperintensity of the subcortical white matter (SWM) of the precentral gyrus and hypointensity of the precentral gyrus gray matter (PGGM) on fluid-attenuated inversion recovery (FLAIR) are described as potentially useful diagnostic findings in amyotrophic lateral sclerosis (ALS). A detailed study of the prevalence of these findings in various age groups has not been described. METHODS: One hundred twenty-two patients underwent axial FLAIR brain examinations as part of either hearing loss or tinnitus evaluation. Examinations were randomly selected to reflect an even spread through the decades from ages 15 to 78 years and were reviewed by 2 readers, blinded to patient's age and sex, for the presence/absence of the above 2 signs. If SWM hyperintensity was present, it was graded as intense as caudate nucleus (grade 1) or insula (grade 2). RESULTS: We identified 32 cases of grade 1 and 5 cases of grade 2 SWM hyperintensity, and 28 cases of PGGM hypointensity. Both signs showed significant Spearman correlation with increasing age (r = 0.55, P < .001 for grade 1, r = 0.45, P < .001 for grade 2 SWM hyperintensity, r = 0.45, P < .001 for PGGM hypointensity). Analysis of variance showed there was a significant difference between the different age groups (P < .001) for both signs. Grading of the SWM and PGGM signals were highly reproducible with very good interobserver agreement (r = 0.88, P < .001, and r = 0.97, P < .001, respectively). CONCLUSION: This study suggests a statistically significant relationship between increasing age and the frequency of precentral gyrus SWM hyperintensity and PGGM hypointensity on FLAIR, and reinforces previous reports that these signs can be seen in patients who do not have ALS.

Hyperintensity of the middle cerebellar peduncles on fluid-attenuated inversion recovery imaging: variation with age and implications for the diagnosis of multiple system atrophy.

BACKGROUND AND PURPOSE: T2 hyperintensity of the middle cerebellar peduncle (MCP) is described in a number of diseases, including multiple system atrophy (MSA). We hypothesize that mild MCP hyperintensity on fluid-attenuated inversion recovery (FLAIR) imaging can be a normal finding. To our knowledge, a detailed study of the prevalence of this finding in various age groups with the FLAIR sequence has not been described. METHODS: One hundred twenty-two patients underwent an axial FLAIR examination of the brain as part of either a hearing loss or tinnitus work-up (ie, to exclude an acoustic neuroma or a retrocochlear cause). Subjects aged 15-78 years were included to reflect an even spread through the decades and were divided into 6 age groups. A radiologist and an MR imaging fellow graded the examinations subjectively, blinded to age: 0 for normal or 1 for the presence of MCP hyperintensity if the increased signal intensity was greater than that of adjacent pons and cerebellar white matter. Spearman rank correlation test of MCP hyperintensity with age and analysis of variance (ANOVA) were performed. RESULTS: Of 122 patients, we identified 17 with MCP FLAIR hyperintensity. None of these patients had a clinical condition that could cause MCP hyperintensity. MCP hyperintensity did not show a statistically significant correlation with age (r = 0.05, P = .62). Patients were divided into 6 age groups, and ANOVA showed no statistically significant difference in the incidence of MCP hyperintensity between different age groups (P = .95). However, results were highly reproducible with excellent interobserver correlation (r = 0.97, P < .001). CONCLUSIONS: Mild MCP FLAIR hyperintensity can occur normally, and this finding shows no relationship with age.

Metastatic choriocarcinoma: a rare cause of stroke in the young adult.

A 20-year old woman presented with acute right hemiplegia 10 weeks after intrauterine fetal death at 34-weeks gestation (G1P0). A brain MRI showed a typical acute infarct in the left middle cerebral artery territory. A CT pulmonary angiography carried out 1 week later for sudden cardiopulmonary deterioration showed disseminated pulmonary metastases. The CT was extended to the abdomen and pelvis, which showed a uterine mass with bilateral theca lutein cysts. The radiological diagnosis of metastatic choriocarcinoma was made and was subsequently confirmed with the markedly increased serum beta-human chorionic gonadotrophin. A serum beta-human chorionic gonadotrophin is therefore considered worthwhile in any young female adult who presents with stroke.

The solitary enhancing cerebral lesion: can FLAIR aid the differentiation between glioma and metastasis?

BACKGROUND AND PURPOSE: The purpose of this study is to investigate the diagnostic utility of fluid-attenuated inversion recovery (FLAIR) in differentiating between glioma and metastasis by assessing for nonenhancing adjacent cortical signal intensity abnormality in patients who present with a solitary enhancing cerebral lesion. METHODS: After approval from the institutional ethics committee was obtained, the MR imaging studies of 70 patients with a solitary enhancing lesion, without previous surgery or treatment, were reviewed. The axial FLAIR studies were initially reviewed for cortical involvement. If cortex involvement was detected, comparison with the axial T1, with and without gadolinium enhancement, was made to determine whether the cortex involvement was in an area without enhancement. If this was the case, the study was considered positive for glioma. Statistical analysis consisted of binary logistic regression and a 2 x 2 contingency table. RESULTS: Involvement of the adjacent cortex with FLAIR signal intensity abnormality but without enhancement was seen in 19 of 70 patients; 16 were gliomas and 3 were solitary metastasis. The sensitivity and specificity of this finding were 44% and 91%, respectively. The positive predictive value for glioma was 84%. CONCLUSION: FLAIR, when interpreted in concert with pre- and postgadolinium T1-weighted images, may be useful in differentiating glioma from metastasis when a solitary enhancing cerebral lesion is present. The presence of nonenhancing adjacent cortical involvement in a solitary enhancing lesion is a frequent and relatively specific sign.

Macroscopic vascular invasion in synovial sarcoma evident on MRI.

We present a case of recurrent synovial sarcoma in the soft tissues of the calf, where MR imaging not only confirmed the diagnosis of tumour recurrence, but also demonstrated direct venous invasion and tumour thrombus within the popliteal vein and its tributaries. Venous invasion has particular relevance to synovial sarcoma prognostication and should be actively sought on MR imaging. To our knowledge this is the first reported case in the English literature of histologically proven macroscopic popliteal vein invasion from a synovial sarcoma demonstrated on MR imaging.

The management of scaphoid fractures.

Appropriate management of scaphoid fractures is important because of the risk of long-term complications such as delayed or non-union, pain and disability. Up to 25% of scaphoid fractures are not visible on the initial radiographs. Consequently, all clinically suspected scaphoid fractures are treated as fractures with cast immobilisation until cause of the symptoms is clarified. The diagnosis often utilises a number of second line investigations that are generally performed 10-14 days after the injury. Bone scintigraphy is currently the most commonly used of these as it rarely misses a fracture. However, it does not visualise anatomical structure and therefore alternative diagnoses are difficult. Magnetic resonance imaging (MRI) is at least as sensitive and more specific than bone scanning and has the advantages of being able to identify other lesions and not expose the patient to any radiation. Furthermore, the scan may be performed as early as 2.8 days following an injury rather than 10 days later in the case of a bone scan. Although the cost of MRI is higher than other imaging modalities, it may be cost-effective in the overall management of patients with occult scaphoid fractures since it may prevent unnecessary cast immobilisation in active people. The most appropriate method of cast immobilisation is presently unclear but evidence exists for improved clinical outcomes in those that have both the thumb and elbow immobilised for the first six weeks.

Perihepatitis associated with systemic lupus erythematosus: computed tomography findings.

The imaging findings of a 29-year-old woman with known systemic lupus erythematosus, and a clinical presentation and CT appearances consistent with perihepatitis are presented.

Cost effectiveness of adding magnetic resonance imaging to the usual management of suspected scaphoid fractures.

OBJECTIVE: To determine the cost effectiveness of a magnetic resonance imaging scan (MRI) within 5 days of injury compared with the usual management of occult scaphoid fracture. METHODS: All patients with suspected scaphoid fractures in five hospitals were invited to participate in a randomised controlled trial of usual treatment with or without an MRI scan. Healthcare costs were compared, and a cost effectiveness analysis of the use of MRI in this scenario was performed. RESULTS: Twenty eight of the 37 patients identified were randomised: 17 in the control group, 11 in the MRI group. The groups were similar at baseline and follow up in terms of number of scaphoid fractures, other injuries, pain, and function. Of the patients without fracture, the MRI group had significantly fewer days immobilised: a median of 3.0 (interquartile range 3.0-3.0) v 10.0 (7-12) in the control group (p = 0.006). The MRI group used fewer healthcare units (median 3.0, interquartile range 2.0-4.25) than the control group (5.0, 3.0-6.5) (p = 0.03 for the difference). However, the median cost of health care in the MRI group (594.35 dollars AUD, 551.35-667.23 dollars) was slightly higher than in the control group (428.15 dollars, 124.40-702.65 dollars) (p = 0.19 for the difference). The mean incremental cost effectiveness ratio derived from this simulation was that MRI costs 44.37 dollars per day saved from unnecessary immobilisation (95% confidence interval 4.29 dollars to 101.02 dollars). An illustrative willingness to pay was calculated using a combination of the trials measure of the subjects' individual productivity losses and the average daily earnings. CONCLUSIONS: Use of MRI in the management of occult scaphoid fracture reduces the number of days of unnecessary immobilisation and use of healthcare units. Healthcare costs increased non-significantly in relation to the use of MRI in this setting. However, when productivity losses are considered, MRI may be considered cost effective, depending on the individual case.

Relationship between the area of cartilage shown on the magnetic resonance imaging middle-slice image of the medial and lateral tibial cartilages with cartilage volume and grade of osteoarthritis over time.

OBJECTIVE: Knee cartilage volume measurement requires significant time and training. Simplifying the measurement may improve feasibility. We investigated whether the area of cartilage shown on the middle slice of the medial and lateral tibial cartilages on sagittal MRI correlates with radiological features of osteoarthritis (OA), cartilage volume, and longitudinal change in cartilage volume. METHODS: One hundred and seventy-three subjects (normal and osteoarthritic), who had serial magnetic resonance imaging (cartilage volume measured) and baseline weight-bearing antero-posterior radiographs of the same knee were examined. RESULTS: In the lateral compartment, with increasing grade of OA there was a significant reduction in cartilage area. In the medial compartment, this was true for medial joint-space narrowing (after adjusting for gender). There was a moderate to strong association between cartilage area and volume, especially in those with early or no OA. However, when change over time was examined, the strength of these relationships was weak. CONCLUSION: Our data suggests that cartilage area may provide a simple surrogate measure of cartilage volume, in cross-sectional studies, after adjustment for gender: especially in subjects with early disease. However, before it can be widely used, further investigation will be required.

Tibial cartilage volume change in healthy postmenopausal women: a longitudinal study.

OBJECTIVE: To determine whether the amount of joint cartilage in healthy postmenopausal women is stable or changes over time, and whether oestrogen replacement therapy (ERT) influences this. DESIGN: A cohort study in healthy postmenopausal women without knee pain, initially selected on the basis of having either used ERT long term (more than five years) or never having used ERT. METHODS: 81 women (42 taking ERT and 39 non-users) had baseline knee radiographs and magnetic resonance imaging (MRI) on the dominant knee; 57 of these (70%) were followed with repeat MRI approximately 2.5 years later. Knee cartilage volume was measured at baseline and at follow up. Risk factors assessed at baseline, including ERT use, were tested for their association with change in knee cartilage volume over time. RESULTS: 29 subjects who were initially taking ERT and 28 non-users at baseline completed the study. Total tibial articular cartilage decreased, on average, by (mean (SD)) 2.4 (3.2)% per year (95% confidence interval for mean, 1.5% to 3.2%). Average annual reduction in medial and lateral tibial cartilage was 2.4 (3.6)% (1.4% to 3.3%) and 2.3 (4.2)% (1.2% to 3.4%), respectively. No association between ERT and the rate of reduction in cartilage volume was shown. CONCLUSIONS: Mean tibial cartilage volume loss in healthy postmenopausal women is between 1.5% and 3.2% a year. Whether this rate of change is similar throughout adult life or in men will require further investigation.