In and around the pineal gland: a neuroimaging review.

Lesions arising in or around the pineal gland comprise a heterogeneous group of pathologies ranging from benign non-neoplastic cysts to highly malignant neoplasms. Pineal cysts are frequently encountered as an incidental finding in daily radiology practice but there is no universal agreement on the criteria for, frequency of, and duration of follow-up imaging. Solid pineal neoplasms pose a diagnostic challenge owing to considerable overlap in their imaging characteristics, although a combination of radiological appearances, clinical findings, and tumour markers allows for narrowing of the differential diagnosis. In this review, we describe the radiological anatomy of the pineal region, clinical symptoms, imaging appearances, and differential diagnosis of lesions arising in this area, and highlight the clinical management of these conditions.

Use of optical coherence tomography for the diagnosis of preclinical lesions of circumscribed palmar hypokeratosis.

Circumscribed hypokeratosis of palms and soles is a rare dermatosis, usually affecting women. Diagnosis is mainly based on the clinical characteristics, including the clinical appearance and anatomical site of the skin lesions and on the demographic features of the affected patients, usually middle-aged to elderly women. Skin biopsy may be performed to confirm clinical diagnosis. Optical coherence tomography (OCT) is a technique that has been undergone substantial development in dermatology in recent years, and its use in clinical practice has been growing progressively. Several dermatological conditions have been studied with this tool, but to our knowledge, it has not been used to investigate this form of hypokeratosis. We report a case of circumscribed palmar hypokeratosis for which diagnosis was confirmed by OCT, which was performed as the patient was reluctant to undergo skin biopsy because of its invasiveness. We highlight the potential use of OCT in obtaining a virtual skin biopsy to confirm clinical diagnosis and identify preclinical skin lesions amenable to early treatment.

3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP.

This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work - (32)S, (12)C, (23)Na, (14)N, (31)P and (39)K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in (31)P, (39)K and (23)Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

Sensitivity analysis for liver iron measurement through neutron stimulated emission computed tomography: a Monte Carlo study in GEANT4.

Neutron stimulated emission computed tomography (NSECT) is being developed as a non-invasive imaging modality to detect and quantify iron overload in the human liver. NSECT uses gamma photons emitted by the inelastic interaction between monochromatic fast neutrons and iron nuclei in the body to detect and quantify the disease. Previous simulated and physical experiments with phantoms have shown that NSECT has the potential to accurately diagnose iron overload with reasonable levels of radiation dose. In this work, we describe the results of a simulation study conducted to determine the sensitivity of the NSECT system for hepatic iron quantification in patients of different sizes. A GEANT4 simulation of the NSECT system was developed with a human liver and two torso sizes corresponding to small and large patients. The iron concentration in the liver ranged between 0.5 and 20 mg g(-1), corresponding to clinically reported iron levels in iron-overloaded patients. High-purity germanium gamma detectors were simulated to detect the emitted gamma spectra, which were background corrected using suitable water phantoms and analyzed to determine the minimum detectable level (MDL) of iron and the sensitivity of the NSECT system. These analyses indicate that for a small patient (torso major axis = 30 cm) the MDL is 0.5 mg g(-1) and sensitivity is ∼13 ± 2 Fe counts/mg/mSv and for a large patient (torso major axis = 40 cm) the values are 1 mg g(-1) and ∼5 ± 1 Fe counts/mg/mSv, respectively. The results demonstrate that the MDL for both patient sizes lies within the clinically significant range for human iron overload.

SU-E-T-108: 3D Measurement of Neutron Dose from a Novel Neutron Imaging Technique.

PURPOSE: We have been developing a fast-neutron spectroscopic technique to quantitatively image the distribution of elements in the body using quasi-monochromatic neutron beams. Previously, we demonstrated the ability of the technique to quantify specific elements in the liver and breast while limiting radiation dose to clinically acceptable levels. Here we present the results of a physical dose measurement performed through neutron irradiation of 3D PRESAGE dosimetry phantoms. METHODS: Two PRESAGE optical-CT dosimeters were placed inside a physical phantom of the human torso and irradiated with 8 MeV neutrons produced via the 2H(d,n) reaction using a tandem Van-de-Graaff accelerator. The dosimeters, measuring 10 cm and 4 cm in diameter, were located in regions corresponding to the liver (10 cm), and the kidney (4 cm). Irradiation was performed with the neutron beam incident directly on the larger dosimeter. Cumulative neutron fluence incident upon each dosimeter was determined using an aluminum-foil activation technique. Following irradiation, the change in optical density in both dosimeters was measured to determine the relative irradiation and dose distribution in each volume. RESULTS: Both PRESAGE dosimeters exhibited detectable changes in optical density corresponding to the dose deposited in the volume. The two dosimeters registered doses of 8.5 Gy (direct incidence, 4.5 hour irradiation) and 0.25 Gy (off-axis, 20 hour irradiation), respectively. The larger dosimeter showed highest intensity at the entry point of the beam with exponential drop-off along the beam direction. The smaller dosimeter registered a more uniform change in intensity, consistent with the higher incidence of scattered neutrons at this location. CONCLUSION: The results demonstrate the utility of PRESAGE dosimeters in measuring dose from neutron irradiation and highlight the difference in relative doses between primary and proximal organs when exposed to neutron beams. This work was supported by the United States Department of Energy, Office of Nuclear Physics under Grant No. DE-FG02-97ER41033, the National Cancer Institute under grant R01CA100835, and by the Department of Defense under award W81XWH-09-1-0066.

Review: molecular pathogenesis of blood-brain barrier breakdown in acute brain injury.

Historically, the blood-brain barrier (BBB) was considered to be at the level of cerebral endothelium. Currently, the interaction of endothelium with other components of the vessel wall and with neurones and glial cells is considered to constitute a functional unit, termed the neurovascular unit that maintains cerebral homeostasis in steady states and brain injury. The emphasis of this review is on cerebral endothelium, the best-studied component of the neurovascular unit, and its permeability mechanisms in health and acute brain injury. Major advances have been made in unravelling the molecular structure of caveolae and tight junctions, both of which are components of the structural barrier to the entry of plasma proteins into brain. Time course studies suggest that caveolar changes precede junctional changes in acute brain injury. Additional factors modulating BBB permeability in acute brain injury are matrix metalloproteinases-2 and 9 and angiogenic factors, the most notable being vascular endothelial growth factor-A and angiopoietins (Ang) 1 and 2. Vascular endothelial growth factor-A and Ang2 have emerged as potent inducers of BBB breakdown while Ang1 is a potent anti-leakage factor. These factors have the potential to modulate permeability in acute brain injury and this is an area of ongoing research. Overall, a combination of haemodynamic, structural and molecular alterations affecting brain endothelium results in BBB breakdown in acute brain injury.

Experimental detection of iron overload in liver through neutron stimulated emission spectroscopy.

Iron overload disorders have been the focus of several quantification studies involving non-invasive imaging modalities. Neutron spectroscopic techniques have demonstrated great potential in detecting iron concentrations within biological tissue. We are developing a neutron spectroscopic technique called neutron stimulated emission computed tomography (NSECT), which has the potential to diagnose iron overload in the liver at clinically acceptable patient dose levels through a non-invasive scan. The technique uses inelastic scatter interactions between atomic nuclei in the sample and incoming fast neutrons to non-invasively determine the concentration of elements in the sample. This paper discusses a non-tomographic application of NSECT investigating the feasibility of detecting elevated iron concentrations in the liver. A model of iron overload in the human body was created using bovine liver tissue housed inside a human torso phantom and was scanned with a 5 MeV pulsed beam using single-position spectroscopy. Spectra were reconstructed and analyzed with algorithms designed specifically for NSECT. Results from spectroscopic quantification indicate that NSECT can currently detect liver iron concentrations of 6 mg g(-1) or higher and has the potential to detect lower concentrations by optimizing the acquisition geometry to scan a larger volume of tissue. The experiment described in this paper has two important outcomes: (i) it demonstrates that NSECT has the potential to detect clinically relevant concentrations of iron in the human body through a non-invasive scan and (ii) it provides a comparative standard to guide the design of iron overload phantoms for future NSECT liver iron quantification studies.

Examining the direct costs and effectiveness of syphilis detection by selective screening and partner notification.

Selective screening and partner notification are two principal means of preventing and controlling syphilis in the United States, yet few studies have been undertaken to compare and evaluate the cost or effectiveness of detecting syphilis using either strategy. The objective of this paper is to assess from the perspective of a health department the cost-effectiveness of selective screening compared with the strategy of partner notification in the detection of early syphilis in Houston, Texas, in 1994 and 1995. The cost-effectiveness analysis was performed using the recurring direct costs associated with detecting syphilis by both strategies. The middle estimates for the total direct costs associated with selective screening and partner notification were $579,101 and $229,529, respectively, for the 1466 and the 567 cases of early syphilis detected. On a cost per case basis, selective screening was more cost-effective than partner notification in the detection of primary, secondary and maternal syphilis cases. However, when consideration was given to prophylactic treatment, partner notification was more cost-effective in the detection of all early stage disease. Our findings suggest that the relative benefit of partner notification over selective screening depends on prophylactic treatment and an increase in worker productivity.

Renal involvement in multiple myeloma.

The present study is a retrospective chart analysis of 33 patients who satisfied the diagnostic criteria of multiple myeloma. Sixteen (49.5%) of these 33 patients developed renal failure at some point in time. The mean age +/- 1SD of patients who developed renal failure was 59.2 +/- 13 years (range 34-85 years). There were 12 males and 4 females. The precipitating factors for renal failure were dehydration (12.5%), hypercalcemia (62.5%) and use of non-steroidal antiinflammatory drugs (6.2%). Hypercalcemia was observed in 10 of the 16 patients who developed renal failure while it was seen in only 4 of the 17 cases who did not develop renal failure (relative risk 5.4). In 11 (68.7%) patients, the renal function improved with hydration, treatment of hypercalcemia and chemotherapy. The 1 and 3 year actuarial survival of patients with renal failure and multiple myeloma was 87% and 74% respectively.

Reversible effects of mercuric chloride on reproductive organs of the male mouse.

Effects of oral administration of mercuric chloride (HgCl2, 1.25 mg/kg) daily for 30 d on the mouse testis, vas deferens, epididymis, and cauda epididymal sperm were investigated. Testis, vas deferens, and epididymis functions were evaluated with respect to sperm count, motility, and viability, and biochemical tests, including succinate dehydrogenase (SDH), adenosine triphosphatase, sialic acid, protein, cholesterol, and glycogen levels in these tissue. Sperm morphology and sperm nuclear integrity were evaluated with standard staining methods. Treatment did not affect whole body and tissue weights. Sperm parameters and fertility were reduced by HgCl2 and most of the biochemical parameters declined. Morphologic histologic alterations were also observed in the tissues studied. All parameters partially recovered after withdrawal of HgCl2 for 45 d.

Screening for diabetic retinopathy. The wide-angle retinal camera.

OBJECTIVE: To define the test characteristics of four methods of screening for diabetic retinopathy. RESEARCH DESIGN AND METHODS: Four screening methods (an exam by an ophthalmologist through dilated pupils using direct and indirect ophthalmoscopy, an exam by a physician's assistant through dilated pupils using direct ophthalmoscopy, a single 45 degrees retinal photograph without pharmacological dilation, and a set of three dilated 45 degrees retinal photographs) were compared with a reference standard of stereoscopic 30 degrees retinal photographs of seven standard fields read by a central reading center. Sensitivity, specificity, and positive and negative likelihood ratios were calculated after dichotomizing the retinopathy levels into none and mild nonproliferative versus moderate to severe nonproliferative and proliferative. Two sites were used. All patients with diabetes in a VA hospital outpatient clinic between June 1988 and May 1989 were asked to participate. Patients with diabetes identified from a laboratory list of elevated serum glucose values were recruited from a DOD medical center. RESULTS: The subjects (352) had complete exams excluding the exam by the physician's assistant that was added later. The sensitivities, specificities, and positive and negative likelihood ratios are as follows: ophthalmologist 0.33, 0.99, 72, 0.67; photographs without pharmacological dilation 0.61, 0.85, 4.1, 0.46; dilated photographs 0.81, 0.97, 24, 0.19; and physician's assistant 0.14, 0.99, 12, 0.87. CONCLUSIONS: Fundus photographs taken by the 45 degrees camera through pharmacologically dilated pupils and read by trained readers perform as well as ophthalmologists for detecting diabetic retinopathy. Physician extenders can effectively perform the photography with minimal training but would require more training to perform adequate eye exams. In this older population, many patients did not obtain adequate nonpharmacological dilation for use of the 45 degrees camera.

Leiomyosarcoma of the vulva.

A case of Leiomyosarcoma of the vulva is presented. It is important to discuss diagnosis and treatment because of its rarity and usual presentation as a benign lesion. Radical vulvectomy with bilateral groin dissection was performed. Local recurrence occurred four years after surgery and was re-excised. At present, the patient is alive with no evidence of disease.

Radical cystectomy for invasive squamous cell bladder cancer in a renal transplant patient.

A rare case of invasive squamous cell carcinoma of the urinary bladder developing 5 years after cadaveric renal transplant is described. The technical precautions to be taken while performing a radical cystectomy in such a situation is highlighted. This patient required chemotherapy in the post-operative period, and the role of chemotherapy in the presence of immunosuppressive therapy is discussed.

Cost-effectiveness of alternative methods for diabetic retinopathy screening.

OBJECTIVE: To assess from the perspectives of a government delivery system and patients, the cost-effectiveness of the 45-degrees retinal camera compared to the standard ophthalmologist's exam and an ophthalmic exam by a physician's assistant or nurse practitioner technician, for detecting nonproliferative and proliferative diabetic retinopathy. RESEARCH DESIGN AND METHODS: Comparison of 45-degrees fundus photographs with and without pharmacological pupil dilation taken by technicians and interpreted by experts, direct and indirect ophthalmoscopy by ophthalmologists, and direct ophthalmoscopy by technicians with seven-field stereoscopic fundus photography (reference standard). Costs were estimated from market prices and actual resource use. The study included 352 patients attending outpatient diabetes and general-medicine clinics at VA and DOD facilities. RESULTS: Medical system costs per true positive were: 45-degrees photos with dilation, $295; 45-degrees photos without dilation, $378; ophthalmologist, $390; and technician, $794. Patient costs per true positive were: 45-degrees photos with dilation, $139; 45-degrees photos without dilation, $171; ophthalmologist, $306; and technician, $1009. Cost-effectiveness is sensitive to program size due to high fixed cost of the camera methods but not to prevalence. Cost-effectiveness of the technician exam is strongly affected by its sensitivity. CONCLUSIONS: Primary-care screening with retinal photographs through pharmacologically dilated pupils for diabetic retinopathy is an appropriate and cost-effective alternative to screening by an ophthalmologist in this setting. Ophthalmologists are scarce, primary-care physicians are extremely busy, and large clinics allow fixed equipment costs to be spread across many patients.

Retrospective evaluation of recurrence after radical abdominal hysterectomy in patients with cervical carcinoma.

Out of total 176 patients with cervical carcinoma treated with radical abdominal hysterectomy at GCRI, 27 developed recurrence. The results of this study (Study A) were compared with the study carried out by Figge & Tamini, 1981 (Study B) and Thomas W. Burke, 1987 (Study C) as the approaches in all the three studies were more or less similar. The recurrence rates were 15.3%, 11.8% and 11.3% respectively in three studies. In cervical stage IB carcinoma, which is usually treated with this line of treatment, the recurrence rates were 20%, 12.3% and 11.3% respectively in three studies. The highest recurrence rates were observed in adenocarcinoma/adenosquamous carcinoma i.e. 50% in Study A, 33.3% in Study B and 17.4% in Study C. The adverse effects of high risk factors such as lymph node metastases and CLS involvement were less in Study A as compared to B. The deep stromal invasion was equally responsible in both the studies. The mean and median time interval until observed recurrence with post-operative radiotherapy were better in Studies B and A. Nearly 86% developed recurrence within 24 months which is useful observation for predicting the prognosis in similar situations. The evaluation and comparison of studies stresses the importance of new approaches to treatment on the current modalities as the present approach seems to be less effective especially in the presence of high risk factors.