Investigation of erectile dysfunction.

Erectile dysfunction (ED) represents a common and debilitating condition with a wide range of organic and non-organic causes. Physical aetiologies can be divided into disorders affecting arterial inflow, the venous occlusion mechanism or the penile structure itself. Various imaging modalities can be utilised to investigate the physical causes of ED, but penile Doppler sonography (PDS) is the most informative technique, indicated in those patients with ED who do not respond to oral pharmacological agents (e.g. phosphodiesterase type 5 inhibitors). This review will examine the anatomical and physiological basis of penile erection, the method for performing PDS and features of specific causes of ED, and will also consider the alternative imaging modalities available.

Priapism: pathophysiology and the role of the radiologist.

Priapism is defined as a penile erection that persists for 4 h or longer and is unrelated to sexual activity. Its identification is important as lack of timely treatment (particularly of the low flow/ischaemic subgroup) can result in persisting erectile dysfunction as a consequence of irreversible corporal fibrosis. This review describes the physiology and anatomy of the normal erection, the aetiology and pathophysiology of the different types of priapism, and the role of the radiologist in the management of the condition. The treatment of iatrogenic priapism following intracavernosal injection of pharmacostimulant is discussed.

A retrospective study examining thrombolysis for occluded femoro-popliteal grafts - is it worthwhile?

AIM: To assess the effectiveness of catheter directed thrombolysis (CDT) in the treatment of acute graft occlusion. METHODS: Tissue prothrombin activator (rt-PA) was the sole agent used for thrombolysis. This was infused through a 4F straight 65 cm catheter placed under ultrasound guidance. Following a pre-CDT angiogram, a catheter was placed just proximal to the distal anastomosis. An infusion of rt-PA was given over 24 h. An assessment of acute clinical success, limb salvage rates, patency rates and complication rates were made over a period of one year. RESULTS: 80% (20/25) of grafts were successfully reopened immediately. 4/5 (80%) of the unsuccessful CDT cases required amputation within a few weeks. 60% (12/20) of successful CDT cases had an underlying stenotic lesion which required angioplasty. Limb salvage rate was 72% (18/25) at 12 months. There was no CDT related mortality. Secondary patency rate at 9 months was 76% (13/17). CONCLUSION: CDT can achieve reasonable results in this group of challenging patients and may be seen as a useful accessory in the vascular toolkit. However, precise indications for its use need further clarification.

The repair of gamma-ray-induced chromosomal damage in human lymphocytes after exposure to extremely low frequency electromagnetic fields.

G(0) human blood lymphocytes were irradiated with 2.0 Gy gamma-rays and cultured to metaphase whilst held in a 50-Hz power frequency magnetic field of 0.23, 0.47 or 0.7 mT. No differences were found in the frequencies of gamma-induced chromosome aberrations observed in cells held in the EM fields compared with replicates held in a sham coil. Similar field conditions have been reported to increase the frequency of gamma-induced HPRT mutations, leading to a suggestion that the EM fields alter the fidelity of repair of genomic lesions. This was not confirmed by the chromosome aberration assay described here.

Possible associations between ELF electromagnetic fields, DNA damage response processes and childhood leukaemia.

Epidemiology has shown an association between exposure to extremely low frequency (ELF) electromagnetic fields (EMF) and childhood leukaemia. The causal nature and biological basis of this association are however questionable. Studies with aneuploid cell lines raised the hypothesis that ELF EMF may act as a coleukaemogen by compromising DNA damage response to genotoxic agents such as ionising radiation. We examined this hypothesis using gamma-ray-induced dicentric chromosome exchange in human lymphocytes. The results from 12 h post-gamma-ray exposure to fields of 0.23, 0.47 and 0.7 mT provide no support to the hypothesis. The power of the study was sufficient to exclude an ELF enhancement of chromosomal exchange of 10-15% (2SE).

Fluorescence scanning near-field optical microscopy of polyfluorene composites.

Fluorescence scanning near-field optical microscopy (SNOM) is used to investigate binary polyfluorene-based composites of varying composition. The samples investigated contain blends of the polymer poly(9,9'-dioctylfluorene-cobenzothiadiazole), F8BT, with similar polyfluorenes of wider band gap. Images acquired from a film containing 50% by weight F8BT exhibit a high degree of correlation between the topography and fluorescence, with an F8BT-rich phase which protrudes from the surface of the film forming isolated regions with sizes from hundreds of nanometres to several micrometres. A film containing 10% by weight F8BT also has micrometre-size F8BT-rich regions, but also present are small and locally varying proportions of F8BT in the other polyfluorene component phase, indicating a hierarchy of phases within this sample. The fluorescence and topographic images of a third sample studied, containing 90% by weight F8BT, display no correlation, demonstrating that it is not always appropriate to use topographic information to determine the phase structure within polymer blends. The fluorescence SNOM images acquired from these samples are able to assist our understanding of the photovoltaic efficiency of devices fabricated from these films, which are governed by the extent of the interfacial area between these two constituent polymers.

The design, construction and calibration of a carefully controlled source for exposure of mammalian cells to extremely low-frequency electromagnetic fields.

Despite some epidemiological evidence for an association between increased risk of cancer and exposure to electromagnetic fields (EMFs), cancer causation by such exposure remains unproven. Furthermore, for reasons such as biological unresponsiveness of the chosen system, poor equipment design and experimental confounders, no reproducible effects on animals or mammalian cells in culture have been demonstrated following exposure to power frequency EMFs at levels normally encountered in residential settings (<10 to 1000 microT). The apparatus described here, designed specifically to perform large, well-controlled cell biology experiments, reduces extraneous variables to the absolute minimum, so that small effects cannot be ascribed to some cause unrelated to the experimental protocol. Our novel apparatus consists of two identical solenoids which, in use, only differ by whether the field-producing current is flowing or not; they do not influence one another in any way. They are supplied with conditioned air from a common tissue culture incubator, are completely screened from environmental a.c. fields with Mumetal shielding and can be operated under normal laboratory conditions. Furthermore, the arrangement is such that the investigator is unaware whether cells have, or have not, been exposed until after the results have been evaluated. We report the design, construction, calibration and potential uses of this source.

Explaining women's intentions and use of hormones with menopause.

The purposes of this theoretically-based study were (a) to examine the contributions of psychosocial variables (i.e., affect, beliefs, and norms), habit, and facilitating conditions to explaining women's intentions and use of hormones with menopause and (b) to assess whether clinical or demographic factors explained intentions and use, when controlling for psychosocial, habit, and facilitating conditions variables. In a cross-sectional design, 184 pre-, peri-, and postmenopausal women completed questionnaire measures. To explain intentions, data from 124 participants who were not using hormones were analyzed. To explain use, data from 125 peri- and postmenopausal participants were analyzed. In multivariate analyses, anxiety was associated inversely with use; norms were associated positively with intentions and use. Age was associated inversely with intentions; hot flashes were associated inversely with use. Future researchers can examine the combined influences of affect, beliefs, and norms on decisions about hormones. Clinicians can address anxieties and assess social influences about hormone use, as well as offer ways to deal with hot flashes.

Positron emission tomography: a financial and operational analysis.

Positron emission tomography (PET) is an emerging clinical imaging technique that is facing the challenges of expansion in a period of imminent health care contraction and reform. Although PET began showing utility in clinical medicine in the mid-1980s [1], its proliferation into mainstream medical practice has not matched that of other new imaging technologies such as MR imaging. Many factors have contributed to this, including the changing health care economy, the high cost of PET, the length of time it takes to develop a PET facility, and its inherent complexity. In part because of the proliferation of the use of other technologies and the general explosion of costs, insurance carriers are now holding diagnostic techniques, including PET, to stricter standards of efficacy. New techniques must show improvement in long-term outcome of patients, a difficult task for diagnostic tools. In addition to these issues, PET is an expensive technology that requires highly trained multidisciplinary personnel. Questions have also been raised about the most appropriate mechanism for regulation of PET isotope preparation, leading to speculation about future regulatory requirements. The current pioneers of PET must meet these challenges in order for it to become a routine imaging technique. Because of its clinical value, PET will probably survive despite the challenges. For many reasons, though, not every hospital should necessarily develop PET services. Conversely, many hospitals without this technology should consider acquiring PET. The purpose of this article is to identify the financial, operational, and clinical challenges facing PET centers today, describe potential organizational configurations that may enable PET to survive in an antitechnology environment, and delineate which institutions should consider this new technology.

Altered muscle metabolism shown by magnetic resonance spectroscopy in sickle cell disease with leg ulcers.

We performed 31P magnetic resonance spectroscopy of gastrocnemius muscle at rest in 7 normal volunteers and 12 patients with sickle cell disease (7 with leg ulcers and 5 without leg ulcers but with painful crises). We measured intracellular pH and ratios of Pi to ATP, PCr to ATP and PCr to Pi (Pi = inorganic phosphate, ATP = adenosine triphosphate, and PCr = phosphocreatine). Magnetic resonance arteriograms were also performed. Significant differences were found for PCr/Pi ratios between normals and sickle cell disease patients with leg ulcers (p < 0.008). Magnetic resonance arteriograms were normal in volunteers and patients with sickle cell disease. The altered high energy phosphate metabolism in sickle cell disease with leg ulcers is consistent with muscle ischemia or hypoxia.

Budd-Chiari syndrome: detection with color Doppler sonography.

The value of color Doppler sonography in evaluating newly diagnosed Budd-Chiari syndrome in five patients was studied. Hepatic venous findings included absence of vessels (one patient), flow reversal (two patients), narrowing (four patients), and tortuosity (three patients). Detected collaterals included hepatic venous to hepatic venous (four patients), hepatic venous to subcapsular systemic venous (two patients), and portosystemic (three patients). Hepatic venous spectral Doppler waveforms were flat and essentially aphasic in four patients, indicative of distal hepatic venous compression. The inferior vena cava was markedly compressed in two patients and slightly compressed in one. Color Doppler sonography allowed more reliable and confident identification of irregular, compressed, or otherwise abnormal hepatic veins than did conventional sonography. Color Doppler sonography also showed collateral vessels that were undetected with conventional sonography or other imaging techniques. Our results suggest that color Doppler sonography may be a valuable tool in the initial diagnosis and evaluation of suspected Budd-Chiari syndrome.

Radionuclide ventriculography in severely underweight anorexia nervosa patients before and during refeeding therapy.

Congestive heart failure is a well-recognized complication of refeeding therapy in underweight patients with anorexia nervosa but there are few data describing cardiac function during the critical refeeding period. This prospective study examined left ventricular function with conventional electrocardiographic-gated radionuclide ventriculography (RVG) in severely underweight anorexia nervosa patients both before and during refeeding therapy. Eight patients underwent rest and exercise RVG at admission and after regaining approximately 5% to 10% of their ideal body weight. With the admission study serving as a control, the left ventricular ejection fraction and regional wall motion analysis were analyzed before and after refeeding and weight gain. Resting left ventricular ejection fractions were not significantly different between the first and second RVGs (64 +/- 11% vs. 62 +/- 8%, respectively; P greater than .05). Likewise, the left ventricular ejection fraction with maximal exercise did not significantly differ when comparing the first or the second RVG (74 +/- 10% vs. 72 +/- 8%, P greater than .05). During the baseline RVG, the left ventricular ejection fraction increased from 64 +/- 11% (rest) to 74 +/- 10% (maximal exercise) (P less than .001). During the second RVG, the ejection fraction increased from 62 +/- 8% (rest) to 72 +/- 8% (maximal exercise) (P = .003). However, the left ventricular exercise ejection fraction in the second RVG in one patient increased only by one absolute percentage point. Four of the eight patients had regional wall motion abnormalities detected during resting and/or exercise RVG. Abnormal cardiac function occurs in asymptomatic patients with anorexia nervosa undergoing refeeding therapy.

Color Doppler sonography in hepatocellular carcinoma.

Sixteen patients with hepatocellular carcinoma (HCC) were assessed with color Doppler sonography (CDS) for flow compared to normal hepatic parenchyma. Nine showed moderate increased flow, and two revealed marked increased flow. In most instances, the increased flow was peripheral. Color Doppler was also useful in assessing seven patients with portal vein invasion. In two instances, venous invasion was not detected on preliminary grayscale images. In another patient, hepatic venous invasion was suspected on grayscale images, but was shown to represent extrinsic compression only by color Doppler.

Effects of isosorbide dinitrate on the pattern of arterial blood flow in healthy human subjects.

1. Blood velocity measurements have been made in the superficial femoral artery, 10 cm downstream of the common femoral artery bifurcation, in healthy human subjects, using a multi-channel Doppler ultrasound device. 2. In a randomized double-blind protocol, the effects of isosorbide dinitrate were examined during a 2 h period. 3. The changes induced by isosorbide dinitrate include: (i) an increase in the width of the artery and a reduction in brachial arterial blood pressure, implying relaxation of arterial smooth muscle; (ii) an increase in reverse flow and a decrease in time-averaged mean velocity associated with a relatively small decrease of the velocity excursion during the cardiac cycle, implying an increase in flow pulsatility; and (iii) an alteration of the flow pattern both in the core and near the vessel walls.

Color Doppler sonography of portocaval shunts.

Nine patients who had undergone end-to-side portocaval shunts were assessed using a sector real-time color Doppler sonography system. Shunt patency was demonstrated in 8 of 9 patients by detection of color-coded flow within the portal vein, in the anastomotic region, and in the inferior vena cava adjacent to the shunt. Color flow could not be detected in 1 patient. This patient had no evidence of shunt compromise. Spectral Doppler studies were also performed in these patients and flow was demonstrated in all 8. In these instances, information available with color Doppler imaging allowed visualization of the shunt even when it had not been apparent on preliminary real-time grey-scale imaging. This study, which does not assess accuracy, nevertheless suggests that color flow Doppler sonography may prove useful in assessing patients with portocaval shunts.

Color Doppler sonography in acute epididymitis and orchitis.

Clinical diagnosis of patients with acute scrotal pain is frequently imperfect. Imaging, using nuclear medicine scintigraphy and hand-held continuous-wave Doppler ultrasound devices, has been used in these patients. We retrospectively analyzed 28 consecutive patients referred for scrotal sonography, all of whom had been imaged using color Doppler sonography. Of 22 patients with confirmed diagnoses, 11 had acute epididymitis/orchitis and 11 had another diagnosis. Ten of 11 patients with acute epididymitis/orchitis had increased epididymal flow. Eight also had increased testicular flow. None of the 11 patients without acute epididymitis/orchitis had increased flow. Our data suggest that color Doppler sonography may be useful in establishing the diagnosis of acute epididymitis/orchitis. This might decrease the need for scrotal exploration. No distinction could be made among scrotal lesions in the nonacute epididymitis/orchitis group. Sensitivity was inadequate to reliably detect flow in normal testicles, a prerequisite to accurately diagnose torsion. Newly improved sensitivity may enhance the utility of color Doppler sonography in assessing patients with acute scrotal pathology.

Sonographically guided arthrocentesis of the hip.

High-resolution real-time sonography not only provides a noninvasive means of diagnosing hip effusions, but also provides easy access for arthrocentesis. Nineteen sonographically guided hip arthrocentesis were performed in 18 patients. In 13 of 19 patients aspirated, capsular distension was present. In 10 of 19 patients, fluid could be aspirated from the joint space (volume varying from 1 to 9 mL). Saline lavage was performed in 12 of the 19 joints needled. Intra-articular location was confirmed by observation during distension on real-time images or by successful aspiration. Sonographically guided arthrocentesis has potential advantages over conventional fluoroscopic techniques. These include a lack of ionizing radiation, superior visualization of needle location within the joint capsule, and the ability to diagnose soft tissue and periarticular abnormalities generally not seen fluoroscopically.