Do immediate cytology and specialist radiologists improve the adequacy of ultrasound-guided fine-needle aspiration cytology?

OBJECTIVE: To assess whether a dedicated "1-stop" neck lump clinic has improved the percentage of adequate fine-needle aspiration cytology (FNAC) samples and reduced the need for repeat FNAC. STUDY DESIGN: Retrospective review. SETTING: District General Hospital in the United Kingdom. SUBJECTS AND METHODS: Patients attending for ultrasound-guided FNAC over a 6-month period from August 2012 to February 2013. Patients were placed in 4 groups: group 1, FNAC performed by any of the subspecialist radiologists with cytology support (n = 100); group 2, FNAC performed by general radiologists without cytology support (n = 112); group 3, FNAC performed by a particular subspecialist radiologist with cytology support (n = 61); and group 4, FNAC performed by the same subspecialist radiologist without cytology support (n = 125). RESULTS: There was a significantly higher rate of adequacy of FNAC in the presence of a subspecialist radiologist with immediate cytology (group 1) versus a general radiologist without cytology support (group 2; 87/100 vs 63/112, P = .0001), a significantly higher rate of adequacy of FNAC in the presence of cytology support with the same radiologist (group 3 vs group 4, 55/61 vs 97/125, P = .04), and a significantly higher rate of adequacy of FNAC in the presence of a subspecialist radiologist versus a general radiologist without cytology support (group 4 vs group 2, 97/125 vs 63/112, P = .0005). CONCLUSION: Immediate cytology and the presence of a subspecialist radiologist increase the adequacy of FNAC. The adequacy rate of non-cytology-supported FNAC or nonsubspecialist FNAC is below the adequate rate expected from the literature or as recommended in national guidelines.

No significant displacement of basal brain structures upon head movement: Kinematic MRI morphometry relevant to neuroendoscopy.

BACKGROUND: An appreciation of normal intracranial anatomy allows optimal planning of trajectories necessary for safe and effective neuroendoscopy. Little information exists on displacement of the caudal brain relative to the skull upon head movement; this could have important implications for planning and performance of neuroendoscopic procedures. We used kinematic magnetic resonance imaging (MRI) studies to examine the morphometric displacement and changing anatomical relationships between the clivus and basal brain structures, intracranial vessels, and subarachnoid spaces. PATIENTS: We retrospectively analyzed 15 patients undergoing sagittal T2 kinematic MRI of the head and neck in modest flexion and extension. The angle between a horizontal axial reference plane and a line between the opisthion and the hard palate defined the degree of flexion and extension. We then measured in flexion and extension (1) the cervicomedullary angle (CMA), (2) displacement of the ventral surface of the brainstem (i.e., depth of the prepontine and premedullary cisterns), (3) total sagittal area of the combined suprasellar and ventral brainstem cisterns, and (4) the basilar tip to tuber cinereum distance. RESULTS: Relative to neutral head position, a mean extension angle of -15.8 degrees was achieved in all 15 patients, and a mean flexion angle of +9.9 degrees was achieved in 6 patients. The mean CMA was 146 degrees in flexion and 158 degrees in extension. The mean reduction in prepontine and premedullary cistern depth was 0.7 mm and 0.5 mm, respectively, upon flexion from extension. The combined area of suprasellar and ventral brainstem cisterns was minimally reduced from 402 mm2 in flexion to 399 mm(2) in extension. The basilar tip did not move significantly from its position in flexion to extension, 5.3 mm to 5.2 mm respectively from the tuber cinereum. CONCLUSION: Kinematic MRI shows minimal brainstem-to-clivus displacement even within minor physiological changes in head flexion. Importantly, these movements are small and there is no significant shift in the position of the basilar tip in modest flexion or extension. These results should be useful for presurgical planning of optimal patient positioning during neuroendoscopic procedures such as third ventriculostomy and the expanded endonasal transsphenoidal approach to the retroclival space.

The aqueduct of Sylvius: applied 3-T magnetic resonance imaging anatomy and morphometry with neuroendoscopic relevance.

BACKGROUND: The aqueduct of Sylvius (AqSylv) is a structure of increasing importance in neuroendoscopic procedures. However, there is currently no clear and adequate description of the normal anatomy of the AqSylv. OBJECTIVE: To study in detail hitherto unavailable normal magnetic resonance imaging morphometry and anatomic variants of the AqSylv. METHODS: We retrospectively studied normal midsagittal T1-weighted 3-T magnetic resonance images in 100 patients. We measured widths of the AqSylv pars anterior, ampulla, and pars posterior; its narrowest point; and its length. We recorded angulation of the AqSylv relative to the third ventricle as multiple deviations of the long axis of the AqSylv from the Talairach bicommissural line. We statistically determined age- and sex-related changes in AqSylv morphometry using the Pearson correlation coefficient. We measured angulation of the AqSylv relative to the fourth ventricle and correlated this to the cervicomedullary angle (a surrogate for head position). RESULTS: Patients were 13 to 83 years of age (45% male, 55% female). Mean morphometrics were as follows: pars anterior width, 1.1 mm; ampulla width, 1.2 mm; pars posterior width, 1.4 mm; length, 14.1 mm; narrowest point, 0.9 mm; and angulation in relation to the third and fourth ventricles, 26° and 18°, respectively. Age correlated positively with width and negatively with length of the AqSylv. There was no correlation between AqSylv alignment relative to the foramen magnum and the cervicomedullary angle. CONCLUSION: Normative dimensions of the AqSylv in vivo are at variance with published cadaveric morphometrics. The AqSylv widens and shortens with cerebral involution. Awareness of these normal morphometrics is highly useful when stent placement is an option during aqueductoplasty. Reported data are valuable in guiding neuroendoscopic management of hydrocephalus and aqueductal stenosis.

Tuber cinereum proximity to critical major arteries: a morphometric imaging analysis relevant to endoscopic third ventriculostomy.

BACKGROUND: Arterial bleeding in the interpeduncular fossa is a dreaded complication of endoscopic third ventriculostomy (ETV). When the "safe zone" of the tuber cinereum (TC) is fenestrated, the basilar artery tip (BT) or its branches may be encountered below the third ventriclular floor. Major arterial injuries might be avoided by careful preoperative planning. We aimed to establish previously unavailable normal magnetic resonance imaging (MRI) and MR angiographic (MRA) morphometry and configuration of the BT and posterior cerebral artery P1 segments relative to the TC. METHODS: We analyzed images of 82 patients with non-dilated ventricles (mean Evans' index 0.26), and lying in a neutral head position (mean cervico-medullary angle 141°). We cross-referenced axial MRAs with sagittal MRIs to measure distances of BT and P1 segments from the TC, and to classify the location of the BT in the interpeduncular and suprasellar cisterns. We correlated the sagittal areas of these cisterns and patients' ages with the TC-to-artery distances using regression analysis. RESULTS: The BT, right P1 and left P1 segments were a mean 4.9 mm, 5.5 mm, and 5.7 mm respectively from the TC. Seventy-four percent of BTs were anterior to the mammillary bodies. These distances and locations did not correlate with age (mean 53 years) or size of basal cisterns. CONCLUSIONS: The normal BT and P1 segments are anatomically close to the TC and potentially at risk during ETV in adults of all ages. The new morphometric data presented, along with cross-referencing of preoperative multiplanar images, could help reduce vascular complications during ETV.

Lessons learned from unintended sublingual sialography: imaging anatomy, technical considerations, and diagnostic implications.

OBJECTIVE: Digital subtraction sialography of the sublingual glands has not been reported previously, to our knowledge. We present a case series in which unintended digital subtraction sialography of the sublingual glands occurred during attempts at submandibular digital subtraction sialography. In four of the six cases, a mistaken diagnosis of severe sublingual gland sialectasis was made. CONCLUSION: Because of the unique histologic characteristics of the sublingual glands, knowledge of the technical aspects of sublingual duct cannulation and the relevant imaging anatomy is necessary to avoid image misinterpretation and clinical mismanagement.

The salivary ducts of Wharton and Stenson: analysis of normal variant sialographic morphometry and a historical review.

Submandibular and parotid salivary glands acquire lengthy ducts as they migrate during development. No conclusive reports exist on clinically important anatomical normal variants and morphometry of the submandibular duct of Wharton and the parotid duct of Stenson. We retrospectively analyzed 67 normal digital subtraction sialograms on patients ranging from 16 to 85 years of age (M:F=15:52). In 43 sialograms, the mean parotid duct length was 50 mm. The mean width of the proximal, mid, and distal segments of the parotid duct were 1.8 mm, 1.1 mm, and 1.6 mm, respectively. An accessory parotid gland was present in 68% of patients, with a mean angle of confluence of its tributary duct with the parotid duct of 53°. In 24 sialograms the mean length of the submandibular duct was 58 mm. The mean width of the proximal, mid, and distal segments of the submandibular duct were 2.0 mm, 2.7 mm, and 2.1 mm, respectively. The submandibular duct genu had a mean angle of 115°. The effect of independent variables (age, gender, and side) was statistically tested on the dependent variables (length, mean calibre, and angle) using regression analysis. None of the independent variables affected variations in length, size and angulation. These reported comprehensive and detailed morphometrics are useful for therapeutic planning of luminal procedures on the salivary ducts, including sialography, sialoendoscopy, interventional therapies, and lithotripsy.

Is higher choroid plexus 'load' an aetiologic factor in idiopathic intracranial hypertension? A clinico-imaging morphometric correlative study.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition of raised cerebrospinal fluid (CSF) pressure with normal ventricular size. Although the pathogenesis of IIH remains controversial, increased CSF formation may be important. We hypothesised that if increased CSF formation was an aetiologic factor, it might result in a macroscopic increase in size of the choroid plexus (CP). METHOD: We retrospectively studied 50 patients with IIH. Total size of the CP was estimated on computed tomography (CT) venograms from the sum of axial areas measured at three locations. Results were compared with the CP load of 50 matched controls on post-contrast head CTs. Evans Index was measured to exclude ventriculomegaly. Results were analysed using a Student's t test for independent samples (p < 0.05), and the effect of ICP was tested on the dependent variable (area of CP) using regression analysis. RESULTS: There was no significant difference in the size of the CP glomus, total axial areas of the CP between IIH patients (183 mm(2)) and controls (178 mm(2)) and no correlation between the 'load' of CP and the degree of intracranial pressure (ICP) (R (2)< 0.02). CONCLUSION: If increased CSF formation is an aetiologic factor in IIH, this is not reflected in a corresponding raised 'load' of CP.

The circumventricular organs of the brain: conspicuity on clinical 3T MRI and a review of functional anatomy.

PURPOSE: The circumventricular organs (CVOs) occupy seven midline locations around the ventricles. They contain specialized ependymal cells called tanycytes and have an incomplete blood-brain barrier (BBB). We hypothesized that appearances of the lesser known CVOs on contrast-enhanced MRI might lead to confusion in image interpretation whereby they might be mistaken for pathology-related abnormal contrast enhancement. We therefore assessed the normal appearances and prevalence of contrast enhancement of the CVOs on routine clinical brain MRI and reviewed the functional anatomy of the CVOs. METHODS: We retrospectively reviewed sagittal and coronal pre- and post-contrast T1-weighted brain 3T MR images in 100 adult patients with normal findings. We assessed the presence of the median eminence (ME), neurohypophysis (NH), pineal gland (PG), subforniceal organ (SFO), organum vasculosum of the lamina terminalis (OVLT), subcommissural organ (SCO), and the area postrema (AP). RESULTS: The frequency of contrast enhancement of the seven CVOs was as follows: ME in 100 %, NH in 96 %, PG in 84 %, SFO in 1 %, OVLT in 34 %, SCO in 0 %, and AP in 2 %. CONCLUSIONS: The main CVOs (ME, NH, and PG) are well known and appreciated on brain imaging. However, there is a little awareness of the minor CVOs among neuroimagers. This is the first study of contrast enhancement prevalence of the SF, OV, SC, and AP on brain MRI. All the latter are small, faint, rarely visualized, and therefore not likely to cause misinterpretation with significant sources of pathology that cause breakdown of the BBB, such as tumor or inflammation.

Bochdalek's flower basket: applied neuroimaging morphometry and variants of choroid plexus in the cerebellopontine angles.

INTRODUCTION: Protrusions of fourth ventricular choroid plexus through the foramina of Luschka are called 'Bochdalek's flower basket' (BochFB). The bulbous terminal expansions (cornucopiae) extend into the cerebellopontine angle (CPA) cisterns. We studied and reviewed the normal imaging anatomy, morphometry and anatomical variants of BochFB. METHODS: We retrospectively analysed normal brain imaging findings on axial pre- and post-contrast CT scans and enhanced axial T1-weighted MRIs of 200 patients. We assessed BochFB for: (a) calcification, (b) lateral extension, (c) enhancement pattern, (d) cornucopiae shape, (e) symmetry and (f) proximity to tortuous vertebral arteries and morphometry of cornucopiae size and length of BochFB limbs. RESULTS: BochFB calcification was found in 38 % of patients aged over 51 years. Lateral extension of BochFB into the CPA cistern was prominent in 75 % on CT and 96 % on MRI. The mean length of these extensions was 23.6 mm. BochFB enhanced strongly in 47 % on CT and 66 % on MRI. The BochFB cornucopiae were bulbous in 51 % on CT and 54 % on MRI. The mean width of bulbous cornucopiae was 3.5 mm. Bilateral BochFB symmetry was found in 71 % on CT and 80 % on MRI. Six to 8 % of tortuous left vertebral arteries were close to BochFB. CONCLUSION: The cornucopiae are particularly well demonstrated on post-contrast MRI. However several sources of error in image interpretation may arise when imaging the normal BochFB on routine head CT and MRI. Difficulties in analysis arise especially on CT because of physiologic calcification, asymmetry, and the bulbous cornucopiae being mistaken for aneurysms.