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Contrast-enhanced digital subtraction dynamic MR angiography has been applied to lower limb arteries, with accuracy comparable to that of conventional angiography. Application of this technique to hands has not been reported. A 2-year-old girl with a diffuse haemangioma of the right hand elegantly demonstrated by MR angiogram is presented. The feeding vessel and the relationship with surrounding palmar blood vessels were clearly identified. This provided essential preoperative information facilitating surgical resection, yet without the technical difficulties and morbidity associated with conventional angiography.

Acute suppurative thyroiditis is an uncommon condition. Most patients have preexisting oropharyngeal fistulae. Penetrating oropharyngeal injuries resulting from swallowed foreign bodies provide an acquired channel of infection spreading into the relatively resistant thyroid gland. The authors describe a patient with infective thyroiditis complicating retropharyngeal abscess caused by a chicken bone that perforated the upper esophagus. Transient thyrotoxicosis complicating acute suppurative thyroiditis is very rare. Pertechnetate and Ga-67 scans confirmed extensive inflammation of the thyroid gland and the release of hormones as the cause, as distinct from concurrent Graves' disease. Awareness of this unusual complication is important to avoid inappropriate treatment for hyperthyroid disease.

Through a mechanism similar to renal artery stenosis, patients with reninoma and page kidney also suffered from renin mediated hypertension. Captopril renograms performed on our patients with the latter two conditions, however, did not yield diagnostic findings. Therefore, equivocal or negative captopril renography cannot serve to rule out conditions with elevated renin other than renal artery stenosis.

Objective: To examine the utilization and contribution of cardiac perfusion scans to patients undergoing percutaneous transluminal coronary angioplasty., Methods: From July 1996 to January 1998, 34 patients underwent percutaneous transluminal coronary angioplasty and cardiac SPECT imaging was studied. Twenty-five patients had pre-procedure SPECT scans. The agreement between angioplasty strategies and SPECT findings of ischemia and hypokinesia was examined., Results: When radionuclide imaging was performed before revascularization procedures, 84% of the patients had intervention strategies guided by scan findings. Perfusion scan findings including extent and severity of ischemia, degree of hypokinesia directed the selection of target vessel for angioplasty in the patient subgroup with multi-vessel disease. Post-angioplasty radionuclide cardiac scans were performed only on symptomatic patients, demonstrating ischemia and hypokinesia in most of them, conceivably reflected the selection bias., Conclusion: We recommend routine pre- and post-angioplasty radionuclide imaging with multigated scans for wall motion assessment for all patients receiving coronary intervention.

Cerebral glucose utilization was higher during the first positron emission tomography (PET) session than during the second session, as assayed using the PET [18F]fluorodeoxyglucose method in male human volunteers. This difference was due largely to data from subjects with low-trait anxiety, since subjects with high anxiety showed similar metabolism in both PET sessions. High-anxiety subjects showed greater right/ left ratios of cerebral metabolism than low-anxiety subjects, particularly during the second PET session. These findings suggest that the level of anxiety may be an important variable to consider in PET studies using multiple sessions.

Regional cerebral glucose metabolism in subjects with histories of polysubstance abuse was compared to that in control subjects who were drawn from the same community. The substance abuse group showed lower absolute metabolic rates for glucose in lateral occipital gyrus and higher normalized metabolic rates in temporal and frontal areas, including orbitofrontal cortex. It is suggested that some patterns of brain function associated with polysubstance abuse may represent consequences of drug exposure, or they could reflect pre-existing differences that may be relevant to the etiology and maintenance of polysubstance abuse.

DTPA renography is commonly used for measuring relative renal function. However, in patients with bilateral renal disease or solitary kidneys, split function studies are of no value. Available techniques to quantify individual renal function are either time consuming or inaccurate. The authors validate the kidney-to-liver ratio at 3 minutes (K3/L3) as an index of renal function, showing excellent correlation with GFR. Normal K3/L3 ranges were then computed in 113 pediatric kidneys (age 2 days to 16 years) and 24 adults. Indicative of renal maturation, the K3/L3 rapidly rose from a value of 1.32 at birth to 2.02 at 6 months. Subsequently, it increased slowly to reach a peak of 2.34 at age 2, followed by gradual decline to adult values after age 5. This decrease is due likely to continued growth of the hepatic blood pool after renal maturation. GFR followed the same maturation pattern to reach a plateau around 2 years of age. K3/L3 reflects individual kidney function, and it requires no blood sampling or urine collection. By establishing normal values at different stages of maturity, this method provides identification and quantification of renal dysfunction in infants, children, and adults.

Objective: The purpose of this study was to assess the functional significance of ventricle-brain ratio (VBR) in terms of how it might affect sensitivity to cocaine, an indirect dopamine agonist., Method: Relationships between VBR and subjective responses to acute intravenous cocaine hydrochloride were examined in 20 male polydrug abusers. Tests were performed in conjunction with positron emission tomography scans to measure cerebral glucose metabolism., Results: Subjective measures of effects of cocaine, including self-report ratings of intensity of the drug effect, scores on the morphine-benzedrine scale of the Addiction Research Center Inventory, and several items on visual analogue scales, correlated negatively with VBR. VBR also differed significantly among subjects who were grouped according to scores on items ("rush" and "crash") of the Cocaine-Sensitive Scale (larger VBR in subjects with weaker responses). VBR was not correlated with cocaine-induced changes in cerebral metabolic rates for glucose., Conclusions: Relative insensitivity to the subjective effects of cocaine in polydrug abusers with ventricle enlargement suggests that ventriculomegaly may reflect changes in periventricular brain regions that mediate these effects of cocaine.

Lag phase is considered an important parameter of solid gastric emptying studies. However, different methodologies with their own normal values and physiologic implications are advocated for lag phase measurements. We applied both physiologic and mathematic approaches to quantify lag phases from identical image data sets for direct comparison of these two approaches. Gastric emptying studies were performed on 22 patients using a standard solid meal to calculate the lag phase in each using three different methods: (1) visual analysis to determine time when activity first appeared in the duodenum (LagPh); (2) time-activity curves to determine time of 2% decrease from peak stomach activity (LagCu); and (3) a mathematical definition using the modified power exponential method (TLAG). In addition, time of peak antral activity (AntPk) was calculated. The values for LagPh and LagCu were very similar (mean: 14.6 versus 15.2 min) and correlated well with each other (r = 0.89). TLAG using the power exponential showed different values (mean: 34.7 min) and correlated well only with AntPk (mean: 35.1 min; r = 0.92). We conclude that LagPh and LagCu estimate the time of onset of gastric emptying; the time when the smaller particles in the meal (< 1-2 mm) begin to leave the stomach (onset of variable emptying phase). On the other hand, TLAG and AntPk estimate total trituration time (time for most of meal to be processed) and signal the beginning of the constant gastric emptying phase.

Although left anterior oblique (LAO) gastric emptying studies appear to be an adequate alternative to geometric mean (GM) measurements in patients with normal gastric anatomy, it is not clear whether they can be used after gastric or duodenal surgery. In this study, dual-phase gastric emptying studies with combined solid-liquid meal were performed in 54 patients who had undergone pancreaticoduodenectomy (Whipple procedure). Gastric emptying was studied with GM, LAO, and anterior (ANT) methods. T1/2 and percent gastric retention at 10, 30, 60, 90, and 120 minutes were calculated. Results from the three methods were compared using correlation analysis and the t test. The t test showed no significant difference in T1/2 and percent retention values between the GM and LAO or ANT views. The solid emptying T1/2 showed a better correlation between GM and LAO values (r = 0.824) than between GM and ANT (r = 0.589). For the liquid T1/2, the reverse was true. Correlation between GM and ANT (r = 0.939) was better than between GM and LAO (r = 0.839); however, both LAO and ANT views correlated well with GM liquid emptying. It is concluded that the LAO view can replace GM gastric emptying methods in postpancreaticoduodenectomy patients for evaluation of both solid and liquid emptying, although the ANT view appears completely adequate for the study of liquid emptying.

The success of diuretic renography in the evaluation of children with renal outflow tract obstruction has been hampered by a high incidence of false-positive and indeterminate results. The main causes of interpretative errors are collecting system dilatation and impaired renal function. In this prospective study, we introduce a parameter with the potential to overcome these two problems: the normalized slope ratio (SRn). This ratio is calculated from the division of the maximum renal clearance slope by the maximum renal uptake slope, both normalized to peak renal activity. Fifty-one children (94 renal units) were evaluated. Traditional parameters such as diuretic half-time and percentage of retention at 30 min showed specificities of 77% and 85%, respectively. However, the normalized clearance slope increased specificity to 94% and SRn further improved it to 98%. The SRn takes into account the renal uptake curve, whose slope is dependent on glomerular function, and thus may correct for renal dysfunction. It also differentiates obstructed from patent kidneys even in cases with significant collecting system dilatation. As shown by regression analysis, it is independent of collecting system size. We recommend the routine use of this parameter to reduce false-positive and indeterminate results of diuretic renograms.