Calcified Pseudoneoplasm of the Neuraxis

Calcified pseudoneoplasms of the neuraxis are extremely rare non-neoplastic lesions that can exist anywhere in the CNS. Although benign, the lesions can cause substantial neurologic symptoms, typically related to mass effect on adjacent structures. Calcified pseudoneoplasms of the neuraxis can also mimic other entities such as calcified oligodendrogliomas and meningiomas. Nevertheless, the lesions can usually be strongly suggested at the time of imaging due to a number of fairly unique imaging characteristics. Here, the clinical presentation of a patient with a posterior fossa calcified pseudoneoplasm of the neuraxis is described, along with its imaging and pathologic features.

Imaging Review of Paraneoplastic Neurologic Syndromes

Paraneoplastic syndromes are systemic reactions to neoplasms mediated by immunologic or hormonal mechanisms. The most well-recognized paraneoplastic neurologic syndrome, both clinically and on imaging, is limbic encephalitis. However, numerous additional clinically described syndromes affect the brain, spinal cord, and peripheral nerves. Many of these syndromes can have imaging findings that, though less well described, are important in making the correct diagnosis. Moreover, imaging in these syndromes frequently mimics more common pathology, which can be a diagnostic challenge for radiologists. Our goal is to review the imaging findings of paraneoplastic neurologic syndromes, including less well-known entities and atypical presentations of common entities. Specifically, we discuss limbic encephalitis, paraneoplastic cerebellar degeneration, paraneoplastic brain stem encephalitis, cranial neuropathy, myelitis, and polyneuropathy. We also demonstrate common diagnostic pitfalls that can be encountered when imaging these patients.

High-Throughput Phenotyping of Dynamic Canopy Traits Associated with Stay-Green in Grain Sorghum

Drought is a recurring phenomenon that puts crop yields at risk and threatens the livelihoods of many people around the globe. Stay-green is a drought adaption phenotype found in sorghum and other cereals. Plants expressing this phenotype show less drought-induced senescence and maintain functional green leaves for longer when water limitation occurs during grain fill, conferring benefits in both yield per se and harvestability. The physiological causes of the phenotype are postulated to be water saving through mechanisms such as reduced canopy size or access to extra water through mechanisms such as deeper roots. In sorghum breeding programs, stay-green has traditionally been assessed by comparing visual scores of leaf senescence either by identifying final leaf senescence or by estimating rate of leaf senescence. In this study, we compared measurements of canopy dynamics obtained from remote sensing on two sorghum breeding trials to stay-green values (breeding values) obtained from visual leaf senescence ratings in multienvironment breeding trials to determine which components of canopy development were most closely linked to the stay-green phenotype. Surprisingly, canopy size as estimated using preflowering canopy parameters was weakly correlated with stay-green values for leaf senescence while postflowering canopy parameters showed a much stronger association with leaf senescence. Our study suggests that factors other than canopy size have an important role in the expression of a stay-green phenotype in grain sorghum and further that the use of UAVs with multispectral sensors provides an excellent way of measuring canopy traits of hundreds of plots grown in large field trials.

Intramedullary spinal cord metastases: prognostic value of MRI and clinical features from a 13-year institutional case series

BACKGROUND AND PURPOSE

In patients with intramedullary spinal cord metastases, the impact of MR imaging and clinical characteristics on survival has not been elucidated. Our aim was to identify MR imaging and clinical features with prognostic value among patients with intramedullary spinal cord metastases from a large retrospective series.

MATERIALS AND METHODS

The relevant MR imaging examination and baseline clinical data for each patient from a consecutive group of patients with intramedullary spinal cord metastases had previously been reviewed by 2 neuroradiologists. Additional relevant clinical data were extracted. The influence of clinical and imaging characteristics on survival was assessed by Kaplan-Meier survival curves and log-rank tests for categoric characteristics.

RESULTS

Forty-nine patients had 70 intramedullary spinal cord metastases; 10 (20%) of these patients had multiple metastases. From the date of diagnosis, median survival for all patients was 104 days (95% CI, 48-156 days). One clinical feature was associated with decreased median survival: lung or breast primary malignancy (57 days) compared with all other malignancy types (308 days; P < .001). Three MR imaging features were associated with decreased median survival: multiple intramedullary spinal cord metastases (53 versus 121 days, P = .022), greater longitudinal extent of cord T2 hyperintensity (if ≥3 segments, 111 days; if ≤2, 184 days; P = .018), and ancillary visualization of the primary tumor and/or non-CNS metastases (96 versus 316 days, P = .012).

CONCLUSIONS

Spinal cord edema spanning multiple segments, the presence of multifocal intramedullary spinal cord metastases, and ancillary evidence for non-CNS metastases and/or the primary tumor are MR imaging features associated with decreased survival and should be specifically sought. Patients with either a lung or breast primary malignancy are expected to have decreased survival compared with other primary tumor types.

QTL analysis in multiple sorghum populations facilitates the dissection of the genetic and physiological control of tillering

A QTL model for the genetic control of tillering in sorghum is proposed, presenting new opportunities for sorghum breeders to select germplasm with tillering characteristics appropriate for their target environments. Tillering in sorghum can be associated with either the carbon supply-demand (S/D) balance of the plant or an intrinsic propensity to tiller (PTT). Knowledge of the genetic control of tillering could assist breeders in selecting germplasm with tillering characteristics appropriate for their target environments. The aims of this study were to identify QTL for tillering and component traits associated with the S/D balance or PTT, to develop a framework model for the genetic control of tillering in sorghum. Four mapping populations were grown in a number of experiments in south east Queensland, Australia. The QTL analysis suggested that the contribution of traits associated with either the S/D balance or PTT to the genotypic differences in tillering differed among populations. Thirty-four tillering QTL were identified across the populations, of which 15 were novel to this study. Additionally, half of the tillering QTL co-located with QTL for component traits. A comparison of tillering QTL and candidate gene locations identified numerous coincident QTL and gene locations across populations, including the identification of common non-synonymous SNPs in the parental genotypes of two mapping populations in a sorghum homologue of MAX1, a gene involved in the control of tiller bud outgrowth through the production of strigolactones. Combined with a framework for crop physiological processes that underpin genotypic differences in tillering, the co-location of QTL for tillering and component traits and candidate genes allowed the development of a framework QTL model for the genetic control of tillering in sorghum.

Association mapping of resistance to Puccinia hordei in Australian barley breeding germplasm

"To find stable resistance using association mapping tools, QTL with major and minor effects on leaf rust reactions were identified in barley breeding lines by assessing seedlings and adult plants." Three hundred and sixty (360) elite barley (Hordeum vulgare L.) breeding lines from the Northern Region Barley Breeding Program in Australia were genotyped with 3,244 polymorphic diversity arrays technology markers and the results used to map quantitative trait loci (QTL) conferring a reaction to leaf rust (Puccinia hordei Otth). The F3:5 (Stage 2) lines were derived or sourced from different geographic origins or hubs of international barley breeding ventures representing two breeding cycles (2009 and 2011 trials) and were evaluated across eight environments for infection type at both seedling and adult plant stages. Association mapping was performed using mean scores for disease reaction, accounting for family effects using the eigenvalues from a matrix of genotype correlations. In this study, 15 QTL were detected; 5 QTL co-located with catalogued leaf rust resistance genes (Rph1, Rph3/19, Rph8/14/15, Rph20, Rph21), 6 QTL aligned with previously reported genomic regions and 4 QTL (3 on chromosome 1H and 1 on 7H) were novel. The adult plant resistance gene Rph20 was identified across the majority of environments and pathotypes. The QTL detected in this study offer opportunities for breeding for more durable resistance to leaf rust through pyramiding multiple genomic regions via marker-assisted selection.

Immunoglobulin G4-related disease of the orbit: imaging features in 27 patients

BACKGROUND AND PURPOSE

Immunoglobulin G4-related disease is a systemic fibroinflammatory process of unknown etiology, characterized by tissue infiltration by immunoglobulin G4 plasma cells. The purpose of this study was to retrospectively identify the spectrum of imaging features seen in immunoglobulin G4-related disease of the orbit.

MATERIALS AND METHODS

This study included 27 patients with biopsy-proved immunoglobulin G4-related disease of the orbit and either a CT or MR imaging of the orbits. These CT or MR imaging examinations were evaluated for the following: extraocular muscle size, extraocular muscle tendon enlargement, lacrimal gland enlargement, infiltrative process in the orbital fat (increased attenuation on CT or abnormal signal on MR imaging), infraorbital nerve enlargement, mucosal thickening in the paranasal sinuses, and extension of orbital findings intracranially.

RESULTS

Extraocular muscles were enlarged in 24 of 27 (89%) patients, 21 (88%) bilaterally. In 32 of 45 (71%) affected orbits, the lateral rectus was the most enlarged muscle. In 26 (96%) patients, the tendons of the extraocular muscles were spared. Nineteen (70%) patients had lacrimal gland enlargement. Twelve (44%) patients had an infiltrative process within the orbital fat. Infraorbital nerve enlargement was seen in 8 (30%) patients. Twenty-four (89%) patients had sinus disease. Cavernous sinus or Meckel cave extension was seen in 3 (11%) patients.

CONCLUSIONS

In patients with extraocular muscle enlargement, particularly when the tendons are spared and the lateral rectus is the most enlarged, and even more so when other noted findings are present, immunoglobulin G4-related disease should be a leading differential consideration, even over more commonly known etiologies of extraocular muscle enlargement.

Tympanic plate fractures in temporal bone trauma: prevalence and associated injuries

BACKGROUND AND PURPOSE

The prevalence of tympanic plate fractures, which are associated with an increased risk of external auditory canal stenosis following temporal bone trauma, is unknown. A review of posttraumatic high-resolution CT temporal bone examinations was performed to determine the prevalence of tympanic plate fractures and to identify any associated temporal bone injuries.

MATERIALS AND METHODS

A retrospective review was performed to evaluate patients with head trauma who underwent emergent high-resolution CT examinations of the temporal bone from July 2006 to March 2012. Fractures were identified and assessed for orientation; involvement of the tympanic plate, scutum, bony labyrinth, facial nerve canal, and temporomandibular joint; and ossicular chain disruption.

RESULTS

Thirty-nine patients (41.3 ± 17.2 years of age) had a total of 46 temporal bone fractures (7 bilateral). Tympanic plate fractures were identified in 27 (58.7%) of these 46 fractures. Ossicular disruption occurred in 17 (37.0%). Fractures involving the scutum occurred in 25 (54.4%). None of the 46 fractured temporal bones had a mandibular condyle dislocation or fracture. Of the 27 cases of tympanic plate fractures, 14 (51.8%) had ossicular disruption (P = .016) and 18 (66.6%) had a fracture of the scutum (P = .044). Temporomandibular joint gas was seen in 15 (33%) but was not statistically associated with tympanic plate fracture (P = .21).

CONCLUSIONS

Tympanic plate fractures are commonly seen on high-resolution CT performed for evaluation of temporal bone trauma. It is important to recognize these fractures to avoid the preventable complication of external auditory canal stenosis and the potential for conductive hearing loss due to a fracture involving the scutum or ossicular chain.

Intramedullary spinal cord metastases: visibility on PET and correlation with MRI features

BACKGROUND AND PURPOSE

Studies systematically evaluating the detection of intramedullary spinal cord metastasis with PET are lacking. Our purpose was to evaluate the visibility of intramedullary spinal cord metastasis on PET in a single institutional series and to correlate PET and MR imaging features.

MATERIALS AND METHODS

Patients were included if pretreatment MR imaging identifying an intramedullary spinal cord metastasis and an [(18)F] FDG-PET examination near the time of MR imaging were available. PET examinations were retrospectively reviewed, with reviewers blinded and then unblinded to the PET report and MR imaging findings. PET intramedullary spinal cord metastasis features were compared with and correlated with previously analyzed MR imaging lesion characteristics. Original clinical PET reports were reviewed.

RESULTS

The final study sample was 10 PET examinations in 10 patients with 13 intramedullary spinal cord metastases. In 7 (70%) patients, retrospective blinded review demonstrated convincing evidence of 10 (77%) intramedullary spinal cord metastases. Three MR imaging features correlated with intramedullary spinal cord metastases being visible on PET compared with those nonvisible, respectively: larger lesion enhancement size: mean size: 32.1 mm versus 6.0 mm (P = .038); larger longitudinal extent of T2 signal abnormality: mean 5.6 versus 1.0 segments (P = .0081); and larger ratio of extent of T2 signal abnormality to contrast enhancement: 3.8 versus 1.0 (P = .0069). Intramedullary spinal cord metastasis was confidently reported clinically in 2 (20%) patients, accounting for 5 (38%) intramedullary spinal cord metastases.

CONCLUSIONS

Most intramedullary spinal cord metastases can be detected on PET when performed near the time of pretreatment MR imaging. However, intramedullary spinal cord metastases may not be clinically reported on PET. Larger lesions with more edema are more likely to be visible. The spinal cord should be specifically and carefully assessed on PET for evidence of intramedullary spinal cord metastases to provide timely diagnosis.

Intracranial imaging of uncommon diseases is more frequently reported in clinical publications than in radiology publications

BACKGROUND AND PURPOSE

Descriptions of uncommon diseases with intracranial imaging abnormalities are often difficult to find in the radiology literature. We hypothesized that reported imaging findings of such conditions in the recent literature were more frequent in clinical compared with radiology journals.

MATERIALS AND METHODS

PubMed searches from December 1, 2007 to December 1, 2012 were performed for 5 uncommon CNS diseases with intracranial imaging manifestations: 1) Susac syndrome; 2) amyloid β-related angiitis; 3) Parry-Romberg syndrome/en coup de sabre; 4) transient lesion of the splenium of the corpus callosum; and 5) reversible cerebral vasoconstriction syndrome. Articles were classified as a case report, case series, or original research. Journals were categorized as radiology or clinical. The 1- and 5-year Impact Factors of the journals were recorded.

RESULTS

Two hundred two articles were identified for the 5 diseases, including 151 (74%) case reports, 26 case series (13%), and 25 original research articles (13%); 179 (89%) were published in nonradiology journals, compared with 23 (11%) in radiology journals. There was no significant difference between the mean 1- and 5-year Impact Factors of the radiology and clinical journals.

CONCLUSIONS

Recent reports of the selected uncommon diseases with intracranial manifestations are more frequent in clinical journals when compared with dedicated radiology publications. Most publications are case reports. Radiologists should review both radiology and clinical journals when reviewing imaging features of uncommon diseases affecting the brain. Lack of reporting on such disease in the radiology literature may have significant practice, educational, and research implications for the radiology community.

Supermodels: sorghum and maize provide mutual insight into the genetics of flowering time

Nested association mapping (NAM) offers power to dissect complex, quantitative traits. This study made use of a recently developed sorghum backcross (BC)-NAM population to dissect the genetic architecture of flowering time in sorghum; to compare the QTL identified with other genomic regions identified in previous sorghum and maize flowering time studies and to highlight the implications of our findings for plant breeding. A subset of the sorghum BC-NAM population consisting of over 1,300 individuals from 24 families was evaluated for flowering time across multiple environments. Two QTL analysis methodologies were used to identify 40 QTLs with predominately small, additive effects on flowering time; 24 of these co-located with previously identified QTL for flowering time in sorghum and 16 were novel in sorghum. Significant synteny was also detected with the QTL for flowering time detected in a comparable NAM resource recently developed for maize (Zea mays) by Buckler et al. (Science 325:714-718, 2009). The use of the sorghum BC-NAM population allowed us to catalogue allelic variants at a maximal number of QTL and understand their contribution to the flowering time phenotype and distribution across diverse germplasm. The successful demonstration of the power of the sorghum BC-NAM population is exemplified not only by correspondence of QTL previously identified in sorghum, but also by correspondence of QTL in different taxa, specifically maize in this case. The unification across taxa of the candidate genes influencing complex traits, such as flowering time can further facilitate the detailed dissection of the genetic control and causal genes.

Intramedullary spinal cord metastases: MRI and relevant clinical features from a 13-year institutional case series

BACKGROUND AND PURPOSE

Because intramedullary spinal cord metastasis is often a difficult diagnosis to make, our purpose was to perform a systematic review of the MR imaging and relevant baseline clinical features of intramedullary spinal cord metastases in a large series.

MATERIALS AND METHODS

Consecutive patients with intramedullary spinal cord metastasis with available pretreatment digital MR imaging examinations were identified. The MR imaging examination(s) for each patient was reviewed by 2 neuroradiologists for various imaging characteristics. Relevant clinical data were obtained.

RESULTS

Forty-nine patients had 70 intramedullary spinal cord metastases, with 10 (20%) having multiple intramedullary spinal cord metastases; 8% (4/49) were asymptomatic. Primary tumor diagnosis was preceded by intramedullary spinal cord metastasis presentation in 20% (10/49) and by intramedullary spinal cord metastasis diagnosis in 10% (5/49); 98% (63/64) of intramedullary spinal cord metastases enhanced. Cord edema was extensive: mean, 4.5 segments, 3.6-fold larger than enhancing lesion, and ≥3 segments in 54% (37/69). Intratumoral cystic change was seen in 3% (2/70) and hemorrhage in 1% (1/70); 59% (29/49) of reference MR imaging examinations displayed other CNS or spinal (non-spinal cord) metastases, and 59% (29/49) exhibited the primary tumor/non-CNS metastases, with 88% (43/49) displaying ≥1 finding and 31% (15/49) displaying both findings. Patients with solitary intramedullary spinal cord metastasis were less likely than those with multiple intramedullary spinal cord metastases to have other CNS or spinal (non-spinal cord) metastases on the reference MR imaging (20/39 [51%] versus 9/10 [90%], respectively; P = .0263).

CONCLUSIONS

Lack of known primary malignancy or spinal cord symptoms should not discourage consideration of intramedullary spinal cord metastasis. Enhancement and extensive edema for lesion size (often ≥3 segments) are typical for intramedullary spinal cord metastasis. Presence of cystic change/hemorrhage makes intramedullary spinal cord metastasis unlikely. Evidence for other CNS or spinal (non-spinal cord) metastases and the primary tumor/non-CNS metastases are common. The prevalence of other CNS or spinal (non-spinal cord) metastases in those with multiple intramedullary spinal cord metastases is especially high.

Retrospective review of rapid pediatric brain MR imaging at an academic institution including practice trends and factors affecting scan times

BACKGROUND AND PURPOSE

In an effort to reduce radiation exposure in children requiring regular follow up for shunted hydrocephalus, our institution implemented a rapid brain MR imaging protocol. The purpose of this study was to review an academic practice experience with pediatric rapid brain MR imaging without patient sedation in the evaluation of hydrocephalus and a limited group of other conditions.

MATERIALS AND METHODS

We retrospectively analyzed limited-sequence, rapid brain MR imaging scans performed in nonsedated patients younger than 14 years between April 2009 and December 2011. So-called failed examinations were determined by consensus of 2 authors as insufficiently diagnostic for evaluation of ventricular size. CT and MR imaging quarterly volumes for hydrocephalus-related indications were determined from 2005-2012. Multivariable logistic regression analysis was performed to elucidate factors potentially affecting scan durations including examination indication and patient age, sex, inpatient status, and clinical conditions.

RESULTS

A total of 398 examinations were performed on 168 patients (103 boys, 65 girls; median age, 13 months). None were deemed to be failed examinations. Median scan duration was 4.43 minutes (interquartile range, 4.42 minutes-5.88 minutes; SD, 2.42 minutes). Examination indication of altered mental status was the only factor associated with increased scan duration (+1.77 minutes; P = .0021). Hydrocephalus-related imaging volumes approximately doubled in the 7 years reviewed, but rapid MR imaging introduced in 2009 is quickly replacing CT scanning for these indications, accounting for nearly 7 of every 8 examinations at the end of the study period.

CONCLUSIONS

In every case of initial work-up and follow-up, rapid brain MR imaging effectively evaluated ventricular size and/or intracranial fluid and represents a viable alternative to CT scanning, irrespective of a child's age or clinical condition. For this indication and patient group, MR imaging is now the predominant imaging method in our practice.

Position-related variability of CSF opening pressure measurements

BACKGROUND AND PURPOSE

Normative data for CSF OP have previously been established with patients in the LD position. During fluoroscopically guided LP procedures, radiologists frequently obtain these OP measurements with patients prone. In this prospective study, our goal was to determine the variability of OP measurements as a function of patient positioning and to assess whether there is a relationship with patient BMI.

MATERIALS AND METHODS

Consecutive patients reporting for fluoroscopically guided LP or myelography were enrolled. OP was measured with the patient in 3 positions, with the order of the technique randomized: prone with table flat, prone with table tilted until the hub of the needle was at the level of the right atrium, and LD with the needle hub at the level of the spinal canal. The BMI of each patient was calculated. The Wilcoxon signed-rank test and linear regression analysis with bivariate fit of difference were used for analysis.

RESULTS

OP measurements with the patient in the prone position were significantly elevated compared with those in the LD position, with mean differences of 2.7 (P<.001) and 1.6 cm H2O, (P=.017) for prone flat and prone tilted, respectively. There was no significant difference in OP measurements for the prone flat versus prone tilted positions (P=.20). There was no correlation between BMI and observed differences (LD-flat: R2=0.00028; LD-tilt: R2=0.00038; prone-tilt: R2=0.00000020).

CONCLUSIONS

Measuring OP with the patient in the prone position may result in overestimation of CSF pressure. Table tilt did not significantly impact mean prone OP. Radiologists should specify exact patient positioning when reporting OP measurements.

Facet joint signal change on MRI at levels of acute/subacute lumbar compression fractures

BACKGROUND AND PURPOSE

The prevalence of facet joint signal change in acute/subacute lumbar vertebral body compression fractures is unknown. We hypothesized that facet joint signal change on MR imaging is more common in facet joints associated with an acute/subacute lumbar compression fracture than those associated with normal vertebral bodies or ones that have a chronic compression fracture.

MATERIALS AND METHODS

Three neuroradiologists and a neuroradiology fellow retrospectively graded facet joint inflammatory change on MR imaging in 900 facet joints in 75 patients with at least 1 painful osteoporotic lumbar compression fracture. Facet joint signal change was assessed on T2-weighted images with chemical fat-saturation, STIR images, and/or gadolinium-enhanced T1-weighted images with chemical fat-saturation. Each facet joint from the T12/L1 to L5/S1 level was assessed individually. An overall facet joint signal-change score, which is a composite measure of the grade of signal change for all 4 facet joints associated with a given lumbar vertebral level, was devised, and statistical significance was assessed via Wilcoxon rank sum tests.

RESULTS

The overall facet joint signal-change scores were significantly higher at vertebral body levels affected by an acute/subacute compression fracture compared with control levels, which were associated with either normal bodies or chronic compression fractures.

CONCLUSIONS

Our findings suggest an association between facet joint signal change on MR imaging and acute/subacute lumbar vertebral body compression fractures.

Rim and flame signs: postgadolinium MRI findings specific for non-CNS intramedullary spinal cord metastases

BACKGROUND AND PURPOSE

No highly specific MR imaging features distinguishing ISCMs from primary cord masses have been described. Our purpose was to retrospectively compare peripheral enhancement features on postgadolinium MR imaging of ISCMs with primary intramedullary cord masses.

MATERIALS AND METHODS

A consecutive group of patients with firmly diagnosed ISCM (45 patients with 64 ISCMs) and a comparison group with consecutive pathologically proved primary intramedullary spinal cord masses (64 patients with 64 primary spinal cord masses: ependymoma, astrocytoma, hemangioblastoma, ganglioglioma, and cavernous malformation) were included. MR images were evaluated for 2 specific signs on postgadolinium images: a "rim" sign (more intense thin rim of peripheral enhancement around an enhancing lesion) and "flame" sign (ill-defined flame-shaped region of enhancement at the superior/inferior lesion margins). The frequency of rim and/or flame signs in ISCMs and primary cord masses was compared (χ2 test). For ISCMs, the maximal dimension of the enhancing lesion was correlated with the presence of rim or flame signs (t test).

RESULTS

Rim and flame signs, alone and in combination, were seen more frequently in ISCMs than in primary cord masses (P<.0001 for each). Specificity and sensitivity, respectively, for diagnosing ISCMs among spinal cord masses on a per-patient basis were the following: rim sign, 97%, 47%; flame sign, 97%, 40%; at least 1 sign, 94%, 60%; and both signs concurrently, 100%, 27%. In the ISCM group, the presence of either a rim or flame sign correlated with a larger measured maximum enhancing lesion size (P=.0065 and P=.0012, respectively).

CONCLUSIONS

The rim and flame signs are common in and specific for ISCM and are rare in primary spinal cord masses.

Irrigation nose: CT findings of paranasal sinus exostoses

We report the case of a 57-year-old male who presented with recurrent sinus infections and frequent nasal irrigation. He was found at nasal endoscopy to have multiple outgrowths along his ethmoid and maxillary sinuses. Computed tomography (CT) showed multiple bony exostoses along these sinuses. We report the imaging findings of exostoses associated with sinonasal irrigation.

QTL for nodal root angle in sorghum (Sorghum bicolor L. Moench) co-locate with QTL for traits associated with drought adaptation

Nodal root angle in sorghum influences vertical and horizontal root distribution in the soil profile and is thus relevant to drought adaptation. In this study, we report for the first time on the mapping of four QTL for nodal root angle (qRA) in sorghum, in addition to three QTL for root dry weight, two for shoot dry weight, and three for plant leaf area. Phenotyping was done at the six leaf stage for a mapping population (n = 141) developed by crossing two inbred sorghum lines with contrasting root angle. Nodal root angle QTL explained 58.2% of the phenotypic variance and were validated across a range of diverse inbred lines. Three of the four nodal root angle QTL showed homology to previously identified root angle QTL in rice and maize, whereas all four QTL co-located with previously identified QTL for stay-green in sorghum. A putative association between nodal root angle QTL and grain yield was identified through single marker analysis on field testing data from a subset of the mapping population grown in hybrid combination with three different tester lines. Furthermore, a putative association between nodal root angle QTL and stay-green was identified using data sets from selected sorghum nested association mapping populations segregating for root angle. The identification of nodal root angle QTL presents new opportunities for improving drought adaptation mechanisms via molecular breeding to manipulate a trait for which selection has previously been very difficult.

When should I do dynamic CT myelography? Predicting fast spinal CSF leaks in patients with spontaneous intracranial hypotension

BACKGROUND AND PURPOSE

Some patients with SIH have fast CSF leaks requiring dynamic CTM for localization; however, patients generally undergo conventional CTM before a dynamic study. Our aim was to determine whether findings on head MR imaging, spine MR imaging, or opening pressure measurements can predict fast spinal CSF leaks.

MATERIALS AND METHODS

A retrospective review was performed on 151 consecutive patients referred for CTM to evaluate for spinal CSF leak. Head MR imaging was evaluated for diffuse dural enhancement and "brain sag," and spine MR imaging for presence of an extradural fluid collection. The opening pressure was recorded. The CTM was scored as no leak, slow leak localized on conventional CTM, or fast leak that required dynamic CTM.

RESULTS

Fast CSF leaks were identified in 32 (21%), slow leaks in 36 (24%), and no leak in 83 (55%) of 151 patients on initial CTM. There was significant association between spinal extra-arachnoid fluid on MR imaging and the presence of a fast leak (sensitivity 85%, specificity 79%, P < .0001). There was not significant association between fast leak and findings on head MR imaging (P = .27) or opening pressure (P = .30).

CONCLUSIONS

If all patients with spinal extra-arachnoid CSF on MR imaging had been sent directly to dynamic CTM, repeat myelography would have been avoided in most patients with fast leaks (23 of 27; 85%). However, a minority of patients with slow or no leaks would have been converted from conventional to dynamic CTM (16 of 77; 21%). Spinal MR imaging is helpful in premyelographic evaluation of SIH.

The role of MR myelography with intrathecal gadolinium in localization of spinal CSF leaks in patients with spontaneous intracranial hypotension

BACKGROUND AND PURPOSE

Localization of spinal CSF leaks in CSF hypovolemia is critical in directing focal therapy. In this retrospective review, our aim was to determine whether GdM was helpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on a prior CTM.

MATERIALS AND METHODS

Forty-one symptomatic patients with clinical suspicion of SIH were referred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. A retrospective review of the imaging and electronic medical records was performed on each patient.

RESULTS

In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously documented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for a suspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients (21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MR imaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previously identified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%).

CONCLUSIONS

GdM is a useful technique in the highly select group of patients who have debilitating symptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak on conventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should be reserved for those patients who fail conventional CTM.

Effect of Field Crops on Population Densities of Pratylenchus neglectus and P. thornei in Southeastern Australia; Part 1: P. neglectus

Eighty-one cultivars from 12 field crop species were assessed for suitability as hosts to the root lesion nematode, Pratylenchus neglectus, in two field trials. Host status was assessed on the basis of either final P. neglectus densities in soil or multiplication rate under different crops. Both techniques gave consistent results for crop and cultivar ranking, and it was therefore concluded that, in these trials, final population density could be used for screening cultivars for resistance to P. neglectus. Differences were observed among crops and cultivars for host suitability to P. neglectus. Chickpea, wheat, and canola were good hosts, while barley, oat, durum wheat, medic, and vetch were moderate hosts. Field pea, faba bean, and triticale were poor hosts. A range in host suitability was observed for wheat, barley, and oat cultivars.

Effect of Field Crops on Density of Pratylenchus in SouthEastern Australia; Part 2: P. thornei

The effect of 93 field crop and pasture cultivars on the end-of-season population densities of Pratylenchus thornei in soil was determined in the field in southeastern Australia. Wheat and barley cultivars had different effects on the population densities of P. thornei. Most commercial wheat cultivars that are grown in southeastern Australia were susceptible, while the barley cultivars were resistant or moderately resistant. Lentil, field pea, fenugreek, linseed, and medic were found to be resistant to P. thornei, while faba bean and canola were moderately resistant and narbon bean, subterranean clover, and vetch were susceptible. This study will enable growers to select rotational crops to reduce the population densities of these nematodes and therefore minimize the yield loss they cause.