Biomedical subjects
A J Hilson
Publications and source records attributed to A J Hilson.
Bone scan appearance of a retroperitoneal cystic liposarcoma.
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Diagnostic value of radionuclide phallography with intravenous vasodilator stress in the evaluation of arteriogenic impotence.
Arteriogenic impotence is a major cause of organic erectile dysfunction. We evaluated the diagnostic value of quantitative radionuclide phallography with intravenous pharmacological stress in screening impotent patients for penile arterial inadequacy. Using technetium-99m labelled autologous erythrocytes, dynamic scintigraphy of the penile blood pool was performed. Penile haemodynamic changes following intravenous injection of the vasodilator isoxsuprine hydrochloride were assessed by quantitation of penile blood flow and volume. Forty-seven impotent patients (11 psychogenic, 24 arteriogenic, 10 venogenic, 2 endocrine) were studied. Arteriogenic impotent patients demonstrated a lesser degree of increase in penile blood flow and volume than impotent patients with uncompromised penile arterial inflow. Quantitation of penile blood flow and volume yielded a high diagnostic accuracy (> 90%). Radionuclide phallography with intravenous vasodilator stress forms a simple and accurate method for evaluating the functional integrity of penile arterial inflow.
99mTc-DMSA imaging with tomography in renal transplant recipients with abnormal lower urinary tracts.
This study examined whether renal parenchymal imaging using 99mTc DMSA scintigraphy with tomography is a sensitive measure of renal scarring in renal transplant recipients with an abnormal lower urinary tract and whether such scars correlate with impairment of renal function. Three groups of patients were compared: group 1, patients with an abnormal lower urinary tract and deteriorating renal function (n = 9); group 2, abnormal lower urinary tract and stable renal function (n = 5); and group 3, normal lower urinary tract and deteriorating renal function (n = 8). Eight of the nine patients in group 1 had multiple scars visible on 99mTc DMSA scans and this correlated with histology when a renal biopsy was performed; the only patient without scars had a transplant glomerulopathy. The presence of scars was associated with either raised intravesical pressures or recurrent urinary tract infections (UTIs). Only one patient in each of groups 2 and 3 had visible scars and both these patients had a history of recurrent UTIs. Patients in group 3 with deteriorating renal function due to chronic rejection documented by biopsy did not have cortical scars visible with 99mTc DMSA tomography. 99mTc DMSA scanning with tomography is a useful investigation in the management of renal transplant patients with declining renal function; multiple scars may indicate abnormal lower urinary tract function and are not seen in chronic rejection.
99Tcm-DMSA SPET: tool or toy?
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Scintigraphic evidence of abnormal ureteric peristalsis following urological surgery.
OBJECTIVE: To investigate the effect of urological surgery on ureteric peristaltic activity. SUBJECTS AND METHODS: Ureteric peristalsis was assessed in a sample urological population (n = 29 patients) and the findings compared with a control population (n = 14 patients). RESULTS: The incidence of disordered peristalsis was significantly increased (P < 0.05) following urological surgery and, in particular, the incidence of retrograde peristalsis was very significantly increased (P < 0.01) following ureteric division and re-anastomosis. CONCLUSION: The results of this study are consistent with a central role for myogenic activity in the conduction of ureteric peristalsis in man.
Selective radionuclide localisation in primary liver tumours (pilot study).
The therapeutic potential of 131I-Lipiodol was investigated in 8 patients with cholangiocarcinoma (CCA) and 15 patients with hepatocellular carcinoma (HCC). Patients received one or two doses of 131I-Lipiodol via hepatic arterial injection. The mean total administered activity was 668 (SD 325) MBq in CCA and 953 (SD 477) MBq in HCC. One patient with CCA retained 131I-Lipiodol. The cumulative radiation dose was 9.6 Gy to tumour, 6.4 Gy to liver and 1.5 Gy to lung. The patient remained asymptomatic with no evidence of tumour 30 months from the start of treatment, whereas the remaining 7 patients exhibited tumour progression. The mean survival in CCA was 11.6 (SD 14.5) months. All 15 patients with HCC retained 131I with tumour: liver ratios of up to 30:1. The mean cumulative radiation dose was 34.7 (SD 32.4) Gy to tumour, 3.3 (SD 1.5) Gy to liver and 4.4 (SD 2.3) Gy to lung. The mean dose per administered activity was 3.8 (SD 4.1) cGy/MBq. Partial response (reduction in tumour size > 50%) was observed in 6 patients (40%). The mean survival was 7.1 (SD 6.0) months. 131I-Lipiodol can deliver highly selective internal irradiation to foci of HCC with evidence of objective response and may be the treatment of choice for patients with cirrhosis and a small tumour.
Resistance and pulsatility Doppler indices: how accurately do they reflect changes in renal vascular resistance.
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Case report: localization of lipiodol-radioiodine in hepatic metastases from renal cell carcinoma.
Lipiodol, an iodinated derivative of poppyseed oil, is selectively retained in hepatocellular carcinoma and has been used as a vehicle to deliver localized doses of chemotherapeutic and radioactive agents to such tumours, thereby reducing the problems of external beam irradiation and the systemic toxicity of chemotherapy. We describe the first reported case where Lipiodol-targeted radiotherapy has been administered to a patient with secondary renal cell carcinoma in the liver. Localization was good and there were no complications. This case suggests that in future such patients may benefit from this therapy for unresectable lesions.
Iodine-131-Lipiodol for hepatocellular carcinoma: the benefits of targeting.
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Captopril radionuclide test in renovascular hypertension: a European multicentre study. European Multicentre Study Group.
The diagnostic work-up of renovascular hypertension is still controversial. The efficacy of renal scintigraphy with technetium-99m diethylene triamine pentaacetate (DTPA) before and after captopril (scintigraphic captopril test) was evaluated in a multicentre study. All 380 hypertensive patients in the study underwent renal arteriography; 125 had renal arterial stenosis > or = 70%, and 54 had a technically successful intervention to correct the stenosis. The post-captopril study had a sensitivity of 93% and a specificity of 100% for predicting blood pressure response to intervention, if renal function was normal and a combination of quantitative parameters was applied (individual kidney uptake index < 40%, time to peak activity < 2 min or > 10 min). In the entire population renal artery stenosis > or = 70% was detected with a sensitivity of 83% and a specificity of 93% if renal function was normal. In patients with abnormal renal function the performance of the test was worse, owing to a lower specificity which could be increased by using only time parameters. The performance of the test was optimal when the post-captopril findings were examined; no improvement was achieved by evaluation of the changes induced by captopril from the baseline. The test can thus be simplified by performing only a post-captopril study for routine use: a negative test would exclude a curable form of renovascular hypertension in > 80% and a positive test would predict it in > 90% of the patients selected for suspicion of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Penile radionuclide studies in impotence: an overview.
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A pilot study of flaccid penile blood flow patterns in normal subjects and patients with erectile dysfunction.
Dynamic penile scintigraphy was performed using 99Tcm-labelled autologous erythrocytes in five normally potent volunteers and 22 patients with erectile dysfunction including 11 patients with psychogenic and 11 patients with vasculogenic impotence (four arteriogenic, three venogenic, three arteriogenic and venogenic, one arteriogenic and neurogenic). Penile radioactivity changes in the flaccid state were monitored by a gamma camera for 60 min after injection of the radionuclide. The penile time-activity curves of the normal controls characteristically showed secondary pulses of increased activity of variable amplitude, duration and frequency, consistent with phasic increase in penile blood pool. This normal rhythmic pattern was impaired in patients with penile arterial insufficiency whereas a blunted pattern was seen in most patients with functional impotence as well as in patients with nonarteriogenic organic impotence with a psychological overlay. This study provides new insights into the flaccid penile circulatory physiology, which may contribute to our understanding of the pathophysiology of erectile dysfunction. In arteriogenic subjects, the impaired response may be attributable to an inadequacy of penile arterial inflow as well as secondarily due to the resultant sinusoidal dysfunction subsequent to penile ultrastructural damage due to an altered nutritive environment. Increased adrenergic activity in patients with psychogenic impotence may be responsible for the observed deviation from the normal pattern.
Ureteric peristalsis studies in loin pain and haematuria syndrome: another diagnostic disappointment.
Although not a cause of progressive renal damage, loin pain and haematuria syndrome is nevertheless associated with significant morbidity. The management of pain often presents a formidable problem to urologists, physicians and general practitioners. An earlier study noted hold-up of urine in the renal pelvis and implicated this in the pathogenesis of pain. In this study we have failed to demonstrate an excess incidence of disordered urinary peristalsis in loin pain and haematuria syndrome.
Reduction of mismatch of global ventilation and perfusion on exercise is related to exercise capacity in chronic heart failure.
BACKGROUND: The inability to match lung perfusion to ventilation because of a reduced cardiac output on exercise contributes to reduced exercise capacity in chronic heart failure. OBJECTIVE: To quantify ventilation to perfusion matching at rest and at peak exercise in patients with chronic heart failure and relate this to haemodynamic and ventilatory variables of exercise capacity. DESIGN: Eight men in New York Heart Association class II underwent maximal bicycle ergometry with expired gas analysis. MAIN OUTCOME MEASURES: On separate days, ventilation and perfusion gamma camera imaging was performed at rest, and at 80% of previous peak exercise heart rate during bicycle ergometry. The vertical distribution of mismatch between ventilation and perfusion (V/Q) was estimated from subtracted profiles of activity (ventilation and perfusion) to derive a numerical index of global mismatch. RESULTS: Maximal mean (SD) oxygen consumption on bicycle ergometry was 16.0 (4.5) ml min-1 kg-1. There was a reduction in the global V/Q mismatch index from 23.96 (5.90) to 14.88 (7.90) units (p < 0.01) at rest and at peak exercise. Global V/Q mismatch index at peak exercise correlated negatively with maximal minute ventilation (R = -0.90, p < 0.01) and with maximal mean arterial pressure (R = -0.79, p < 0.05), although no relation was seen with maximal oxygen consumption. The reduction in global V/Q mismatch index from rest to peak exercise correlated with maximal oxygen consumption (R = 0.88, p < 0.01), and with maximal minute ventilation (R = 0.87, p < 0.01). CONCLUSIONS: During exercise in patients with chronic heart failure, there is a reduction in the global V/Q mismatch index. A lower global V/Q mismatch index at peak exercise is associated with higher maximal ventilation. The reduction in global V/Q mismatch index on exercise correlates well with maximal exercise capacity. This may imply that the inability to perfuse adequately all regions of lung on exercise and match this to ventilation is a factor determining exercise capacity in chronic heart failure.
Liver/spleen scintigraphy for diagnosis of splenic infarction in cirrhotic patients.
Splenic infarction is rare in cirrhotic patients. The diagnosis of the condition is based on clinical findings and splenic imaging. In recent years, ultrasonography and computed tomographic scan have gained popularity over the more classical scintigraphy as the preferred investigations for the diagnosis of splenic infarction. We report three cases of splenic infarction in patients with cirrhosis and portal hypertension. Computed tomographic scan, angiography and ultrasonography failed to identify the lesions and the diagnoses were finally made with the aid of liver--spleen scintigraphy. We suggest that scintigraphy is the investigation of choice if splenic infarction is suspected in patients with congestive splenomegaly secondary to liver cirrhosis.
Renal scintigraphy in acute scleroderma: report of three cases.
Scintigraphic findings in acute renal failure secondary to scleroderma are reported. In three patients, we have demonstrated severe reduction of renal perfusion with little or no parenchymal uptake of tracer and absent excretion. These findings are compatible with the known histological process of occlusive vasculopathy, and such scintigraphic findings at presentation may reflect a poor prognosis for renal recovery.
Volume-dependent intracavernous hemodilution during pharmacologically induced penile erections.
The change in the cavernous hematocrit following induction of pharmacological erection by an intracavernous injection of papaverine hydrochloride was documented in normal controls and patients with impotence. Blood samples taken from the penile cavernosa showed a significantly lower hematocrit compared to the systemic venous blood in all normal subjects. The decrease in the cavernous hematocrit was attributable to dilution of the cavernous blood pool by the injected volume of the drug, since this was not observed in erections produced by visual sexual stimulation. It appears that a restriction of the cavernous venous outflow in response to papaverine injection causes sequestration of the diluted blood in the cavernous compartment. The degree of cavernous hemodilution was found to aid in the differential diagnosis and was especially valuable in differentiating patients with arteriogenic impotence from those with venous leakage.