Cone beam CT analysis of Haller cells: prevalence and clinical significance.

OBJECTIVES: Haller cells are anterior ethmoid air cells located in the medial orbital floor immediately lateral to the maxillary infundibulum. The purpose of this study was to demonstrate the prevalence and relationship between the existence and size of these cells with ipsilateral maxillary sinusitis and orbital floor dehiscence as visualized on cone beam CT (CBCT) images. METHODS: CBCT image volumes of 50 patients were retrieved and analysed. All CBCT images were acquired with a 9-inch field of view scan. χ(2) and Cochran-Mantel-Haenszel tests were used for statistical analysis of the obtained data, and p-values of <0.05 were considered to be statistically significant. RESULTS: There was no statistically significant association between the existence and size of Haller cells and maxillary sinusitis. There was a significant association between Haller cells and orbital floor dehiscence. CONCLUSIONS: The explanation of maxillary sinusitis on the basis of mechanical obstruction is unlikely. This study provides evidence for the usefulness of CBCT scan in delineation of the sinonasal anatomy.

Vitreous concentration of topically applied brimonidine tartrate 0.2%.

OBJECTIVE: To determine the vitreous concentration of brimonidine after topical administration of Alphagan. DESIGN: Prospective observational case series. PARTICIPANTS: Eighteen patients scheduled for elective pars plana vitrectomy. METHODS: Brimonidine tartrate, 0.2%, was topically administered twice or three times daily for 4 to 14 days preoperatively in 13 patients. Four patients served as controls, without application of brimonidine. A dry, undiluted vitrectomy specimen obtained intraoperatively was collected, frozen, and sent to an independent bioanalytical facility for quantitative determination of vitreous concentration of brimonidine using gas chromatography/mass spectrometry. MAIN OUTCOME MEASURES: The concentration of brimonidine in human vitreous. RESULTS: All patients treated with brimonidine measured above the lower limit of quantitation with a mean vitreous concentration of 185 +/- 500 nM. All patients not treated with brimonidine measured at or below the lower limit of quantitation of 0.05 nM. There was a trend toward higher concentration in patients who were either aphakic or pseudophakic compared with those that were phakic. CONCLUSIONS: Topically applied brimonidine results in vitreous levels at or above 2 nM, the concentration shown to activate alpha(2)-receptors.

Corticotropin- and thyrotropin-secreting pituitary microadenomas: detection by dynamic magnetic resonance imaging.

Hormone-secreting pituitary microadenomas are often not visible on magnetic resonance imaging (MRI). Diagnosis requires confirmatory endocrine test results and often an invasive procedure, inferior petrosal sinus sampling (IPSS). Improved pituitary imaging may eliminate the need for IPSS in some patients, as shown in the 2 women in this report. The first patient with hirsutism, weight gain, and hypertension had intermittent elevations of urinary free cortisol, abnormal results on a low-dose dexamethasone suppression test, and positive results on a dexamethasone-suppressed ovine corticotropin-releasing hormone test (corticotropin, increase of 122%; cortisol, increase of 118%). Gadolinium-enhanced MRI showed no focal lesion, but dynamic MRI (sequential images beginning immediately after contrast injection) revealed a right-sided 5-mm microadenoma, confirmed by transsphenoidal surgery. The second patient had a goiter, anxiety, increased free thyroxine and triiodothyronine levels, and a normal thyrotropin value with no response to thyrotropin-releasing hormone. Magnetic resonance imaging showed no lesion, but dynamic MRI detected an 8-mm microadenoma. Although about 8% to 10% of healthy persons have incidental pituitary lesions that are 3 mm or larger on MRI, identification of a distinct lesion and positive results on a dexamethasone-suppressed ovine corticotropin-releasing hormone test should decrease the probability of a false-positive result on an imaging study. We recommend that dynamic MRI be performed in any patient with a suspected microadenoma, before IPSS is performed.

Magnetic resonance imaging of cerebrospinal fluid leak and tamponade effect of blood patch in postdural puncture headache.

This prospective study examined the efficacy of magnetic resonance imaging (MRI) in visualizing cerebrospinal fluid (CSF) leak in patients with postdural puncture headache (PDPH) and determining the spread of the blood patch in the epidural space and the extent of tamponade on the thecal sac. After obtaining institutional review board approval, five patients with symptomatic PDPH after 3 days of failed conservative treatment were included in this study. MRI using proton density (PD) and T2-weighted imaging was performed on all patients and CSF flow studies were done on one patient. All patients received 20 mL of blood in the epidural space. They remained supine for 45 min, and repeat MRI studies were performed. Extent of the spread of blood in the epidural space was measured. A visual analog scale of 0-10 was used to evaluate the headache. All patients had severe postural headache with nausea/vomiting. Preblood patch MRI showed extrathecal CSF and hemosiderosis indicating the site of dural puncture in four patients. The postprocedure MRI demonstrated the blood patch as a large extradural collection with anterior displacement of the thecal sac, the mean spread being 4.6 intervertebral spaces. The tamponade effect of the blood patch was observed on PD, T2-weighted, and CSF flow images. All patients experienced immediate resolution of their symptoms. This study suggests that using MRI, the site of the CSF leak, the tamponade effect of the blood patch, and its spread in the epidural space can be documented.

Pancreatic metastasis from Ewing's sarcoma.

A 26-year-old man with Ewing's sarcoma of the femur was found to have a solitary visceral metastatic focus in the pancreas. This very unusual occurrence and the topic of metastases to the pancreas in general are discussed.

Craniofacial growth in rabbits after rigid or semi-rigid fixation of the frontonasal suture.

Treatment of craniofacial dysostosis involves complex remodeling of the cranium and facial bones. Maintenance of the newly positioned segments may be achieved by rigid fixation using plates; however, there is concern that, over time, these plates may interfere with normal growth. The purpose of this study was to test a method of "semi-rigid" fixation of an osteotomy of the frontonasal suture in juvenile rabbits by comparing standardized parameters of craniofacial growth after conventional suture plating with the experimental plating method and with growth after sham operation. Forty-five, 6-week-old, weanling rabbits were divided into three groups of 15 each (12 for cephalometry, 3 for histological examination): (group 1) control, sham operated; (group 2) rigid fixation; (group 3) semi-rigid fixation. Rabbits were maintained for 14 weeks. Craniofacial growth was assessed using three-dimensional image analysis techniques. Measurements were subjected to statistical analysis (one-way analysis of variance) to compare the three treatment groups. Pairwise comparison of means between the treatment groups was done using Bonferroni's method at the 0.05 significance level. Semi-rigid fixation permitted significantly more normal growth of the developing rabbit head than rigid fixation in total snout length, total vault length, left and right midface height, and left orbital length. Both semi-rigid and rigid fixation significantly restricted growth compared with sham operated animals in left and right posterior midface height, right orbital length, right and left nasal bone length, and left parietal width. There were no significant differences in the growth of all other parameters measured.

In vitro evaluation of MR hypointensity in Aspergillus colonies.

PURPOSE: To demonstrate that paramagnetic elements in fungal colonies can cause hypointensity in MR images. METHODS: Aspergillus fumigatus grown in vitro was imaged with CT and MR at the time of initial inoculation and 5 days later. CT and MR images, T2 values, scanning electron microscopy, energy-dispersive analysis, and furnace atomic absorption spectrometry were performed. RESULTS: After 5 days of growth, MR images of A fumigatus revealed curvilinear hypointensities on T2-weighted images corresponding to the fungal growth. Gradient-echo images revealed two distinct components of hypointensity with different calculated T2 values. Phase-angle-difference images revealed a phase shift characteristic of magnetic-susceptibility paramagnetic effects, which corresponded to the hypointense regions on gradient-echo images. Energy-dispersive analysis and furnace atomic absorption spectrometry confirmed the presence of paramagnetic elements. CONCLUSION: It was shown that in vitro A fumigatus concentrates metal elements contained within the nutrient broth. These focal collections of calculated T2 values are caused at least partly by magnetic susceptibility effects.

Inverted papilloma: evaluation with MR imaging.

The authors examined the magnetic resonance (MR) appearance of inverted papillomas to determine if this histologically benign lesion could be distinguished from malignancies of the sinonasal cavity. MR images in 10 patients with histologically proved inverted papilloma were retrospectively reviewed. The signal intensity of inverted papillomas on short repetition time (TR) images was iso- to slightly hypertintense to muscle in all 10 patients. Inverted papillomas had intermediate signal intensity on the long TR/echo time (TE) images. The tumors were iso- or slightly hypointense to fat on long TR/short TE images. In the seven patients who received gadopentetate dimeglumine, all inverted papillomas showed solid inhomogeneous enhancement. A review of eight sinonasal malignancies showed no distinctive signal intensity or enhancement characteristics to help differentiate inverted papillomas from various malignant tumors. The authors conclude that there is no signature MR appearance for the benign inverted papilloma. The main utility of MR imaging is in defining the extent of the lesion.

Sensitivity of hysterosalpingography after tubal surgery.

Hysterosalpingography (HSG) to assess tubal patency in the postoperative evaluation of the infertile patient has been well described. However, the sensitivity and specificity of HSG after tubal surgery has not been reported. We correlated HSG and laparoscopic findings in 25 patients who had tubal surgery (microsurgical tubal reanastomoses [11] and distal salpingostomies [14]). HSG provided a more reliable means of assessing tubal patency (sensitivity and specificity of 96% and 61% respectively) than in detecting pelvic adhesive disease (PAD) (sensitivity and specificity of 12% and 75% respectively) regardless of tubal surgical procedure. HSG was associated with a high false negative rate (60%) due primarily to the inability to detect PAD. Complete agreement between HSG and laparoscopy was noted in only 15% of cases. These data suggest that HSG is a sensitive means to determine tubal patency, but was not sufficiently sensitive or specific to detect PAD after tubal surgery. These limitations should be noted in the interpretation of HSG in any infertile patient with a history of tubal surgery, and severely limits the application of HSG to the management of the post-operative infertile patient.

PIP: Researchers analyzed data on 25 women who underwent either tubal reanastomosis or distal salpingostomy at least 12 months earlier and came to the Tripler Army Medical Center in Honolulu, Hawaii, for hysterosalpingography (HSG) to compare HSD findings with those of laparoscopy, thereby determining HSG's sensitivity and specificity after tubal repair. They were only able to evaluate 42 tubes, since 2 patients had severe pelvic adhesive disease. HSG was more reliable in determining tubal patency (sensitivity of 96% and specificity of 61%) than in detecting pelvic adhesive disease (12% and 75%, respectively). HSG and laparoscopy findings agreed in just 15% of cases. HSG's inability to detect pelvic adhesions was responsible for this low agreement rate. Specifically, HSG found adhesions in only 6% of patients compared to 65% for laparoscopy (false negative rate = 60%). The adhesions completely covered all pelvic structures in 8% of cases at the same frequency for both reanastomosis and salpingostomy, thereby making it impossible to evaluate the anatomy. Further, HSG did not detect other pelvic pathologies (mild endometriosis, uterine fibroids, and ampullary fistulae) in 10% of cases. These findings suggest that HSG is sensitive and specific enough to assess tubal patency following reanastomosis, but is basically not specific enough to do so after distal salpingostomy. Therefore, clinicians should be aware of HSG's limitations when interpreting any HSG findings in infertile patients who had tubal surgery. Further, it limits their ability to manage postoperative infertile patients.

Carcinosarcoma of the lung with hypertrophic pulmonary osteoarthropathy.

Carcinosarcoma of the lung is a rare malignancy. Endobronchial and parenchymal variants are classically described. Clinicopathological features are often related to anatomical location, as is the case for most lung neoplasms. This case report details the surgical management of a carcinosarcoma in a patient seen with pulmonary osteoarthropathy.

Enteroliths causing intermittent obstruction in a patient with Crohn's disease.

Calcified enteroliths as a cause of intermittent small bowel obstruction is an uncommon clinical entity. The pathophysiological mechanism involves stasis of intestinal contents and has been associated with Meckel's diverticulum, tuberculosis, and regional enteritis. This case describes prophylactic operative intervention in a symptomatic patient with enteroliths as a result of Crohn's disease.

Tunneling leaky modes in a parabolic index fiber.

Single or close to single tunneling leaky modes have been prism coupled into nominally parabolic index SEL-FOC fibers with effective efficiencies on the order of 10%. The mode parameters fit fairly well to an analytical continuation of the solutions to Gloge and Marcatili's equations for parabolic index fibers. The data can also be used in conjunction with the Gloge and Marcatili equations to obtain information about the index profile.