[Prenatal chromosome findings in sonographically conspicuous fetuses]

A retrospective evaluation of 463 prenatal chromosome analyses in a total of 375 patients with suspicious ultrasound findings, revealed a high rate of severe chromosomal abnormalities (16%). The highest risk for an abnormal karyotype was found after sonographic detection of hygroma colli. Abnormal chromosome counts were also frequently found in fetuses with omphaloceles, duodenal atresia and hydrops fetalis, as well as in presence of intrauterine growth retardation and/or anomalies of the amniotic fluid volume. The anomalies mentioned above are, therefore, an urgent indication for a prenatal chromosome analysis. The technical improvements of ultrasound machines and growing experience of operators will lead to an increasing importance of sonography as a method for the identification of pregnancies, that are at high risk for chromosomal abnormalities.

The incidence of serious hemodynamic changes in physically-limited patients following oral dipyridamole challenge before thallium-201 scintigraphy

Dipyridamole has liberalized referrals for stress TI-201 chloride (thallium) studies at the Iowa City Veterans Administration Medical Center. Seventy-five percent of referrals now receive dipyridamole and, unlike patients who tolerate conventional exercise testing, these patients are often quite debilitated. Therefore, the hemodynamic consequences of dipyridamole were reviewed in 120 consecutive, physically-limited patients referred for thallium scintigraphy following an average oral dose of 5.4 mg/kg. Each patient's blood pressure was measured every 5 minutes for 1 hour after dipyridamole and compared with several clinical factors to determine if blood pressure change was predictable. In all patients, blood pressure changed from 136 +/- 21/83 +/- 15 (mean +/- 1 SD) to 117 +/- 25/72 +/- 15 following dipyridamole administration. One hundred nine of the 120 patients had a blood pressure decline from 137 +/- 21/82 +/- 12 to 113 +/- 21/70 +/- 13. Of the 109, 43% (N = 47) had a systolic blood pressure decline greater than 20 mmHg, 16% (n = 18) greater than 40 mmHg, and 13% (n = 14) greater than 50 mmHg. Thirteen percent (n = 14) required emergent reversal of the dipyridamole with aminophylline. Significant hypotension is relatively common but generally unpredictable after oral dipyridamole. Therefore, patient eligibility criteria should be carefully considered; strict hemodynamic monitoring must be routine in the usual patient undergoing thallium scintigraphy after oral dipyridamole challenge.

Progressive aphasia in a patient with Pick's disease: a neuropsychological, radiologic, and anatomic study

Although Pick's disease is generally considered as a dementia characterized by signs of frontal lobe dysfunction, it can present with selective language defects rather than with cognitive decline. In this study, we report prospective and serial clinical, neuropsychological, and neuroradiologic observations in a 59-year-old man whose prominent disturbance was in the retrieval and learning of names denoting concrete entities and actions. Postmortem study confirmed the diagnosis of Pick's disease and revealed that neuronal loss and gliosis were most prominent in left anterior temporal cortices. The findings are in keeping with evidence that the left anterior temporal cortices and interconnected hippocampal system are critically involved in the learning and retrieval of verbal lexical items. The evidence from this patient, along with similar evidence from the literature we reviewed, suggests that when patients present with a progressive aphasia characterized by anomia, Pick's disease should be considered as the probable diagnosis.

Patterns of regional diastolic function in the normal human left ventricle: an ultrafast computed tomographic study

The detailed evaluation of regional diastolic filling at multiple ventricular levels in the normal human left ventricle has not previously been reported. Ultrafast computed tomography was used to characterize global and regional early diastolic filling in the left ventricle of 11 normal male volunteers. Regional early diastolic filling data from six distinct ventricular levels (apex to base) were fit to a third-order polynomial curve, and the peak rate of diastolic filling and time of peak filling were determined. Peak filling rate was 259 +/- 17 ml/s (+/- SEM) as a global average, where peak filling rate referenced to end-diastolic volume and stroke volume across the levels examined was 3.78 +/- 0.17 s-1 and 4.83 +/- 0.20 s-1, respectively. Average filling fraction was 39 +/- 1%, and time to peak filling from end-systole was 145 +/- 5 ms. Regional (tomographic) peak filling rates, except for the most apical level examined, were not statistically different across the ventricle. Filling fraction and time to peak filling were remarkably constant from one level to another. However, reference of regional peak filling rate to regional end-diastolic volume demonstrated significant nonuniformity from apex (120% of average for all levels) to base (87% of average for all levels). Peak filling rate referenced to tomographic stroke volume was less variable and not statistically different across the ventricle as a whole.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteomyelitis of the foot in diabetic patients: evaluation with plain film, 99mTc-MDP bone scintigraphy, and MR imaging

Diagnosis of osteomyelitis of the foot in diabetic patients may be difficult because of the coexistence of chronic cellulitis, vascular insufficiency, and peripheral neuropathy. This study compared the diagnostic accuracies of plain films, bone scans, and MR imaging studies in diabetic patients with suspicion of osteomyelitis of the foot. Twenty-nine plain radiographs, 20 bone scans, and 30 MR studies were obtained in 24 patients. Twenty-nine bones from 14 patients were pathologically proved either positive (25 bones) or negative (four bones) for osteomyelitis. Another 15 bones (10 patients) studied with MR had no pathologic proof, but the bones healed with only local wound care and/or a short course of oral antibiotics. These patients had trauma, cellulitis, or unhealed ulcers. The sensitivity and specificity of plain films were both 75%. Bone scans had a very low specificity (100% false-positive rate). A negative bone scan should strongly exclude the probability of osteomyelitis. Unlike the findings in previous reports, MR had much higher sensitivity and specificity than bone scans in detecting osteomyelitis in diabetic patients. When the 10 patients without pathologic proof (those who presumably had neuroarthropathy, vascular insufficiency, and/or cellulitis) were included, the sensitivity and specificity of all three techniques decreased. Our experience with this small group of patients suggests that MR is a useful imaging technique for diagnosing osteomyelitis of the foot in diabetic patients.

Cerebral infarction due to moyamoya disease in young adults

Moyamoya disease was diagnosed as the cause of cerebral infarction in eight young adults (seven women, one man), aged 17-40 (mean 33) years. All had angiographic abnormalities characteristic of moyamoya disease. Single-photon emission tomography showed bilateral carotid circulation hypoperfusion and posterior circulation hyperemia in all seven patients with regional cerebral blood flow studies. All seven women had used oral contraceptives before cerebral infarction. Four patients were treated medically; one died of a second cerebral infarction 9 months after diagnosis. Four patients underwent superficial temporal-to-middle cerebral artery anastomosis; they did well. Moyamoya disease should be included in the differential diagnosis of cerebral infarction as well as intracranial hemorrhage in young adults, particularly women. A possible relation between moyamoya disease and oral contraceptive use deserves investigation.

Pancreatic transplant imaging

Forty-four clinical episodes of suspected (pancreas) transplant rejection in 17 pancreatic transplantation patients were reviewed retrospectively. The clinical impression of acute graft rejection, chronic rejection, or nonrejection in each episode was correlated with the results of 19 nuclear medicine, 12 ultrasound (US), and 44 magnetic resonance (MR) imaging studies. US was found to be a moderately sensitive (82%) method of detecting graft rejection. US also was effective in identifying intra- and peripancreatic fluid accumulations. Nuclear medicine imaging was also a sensitive technique (86%) and the only modality that provided physiologic information regarding graft perfusion. MR imaging allowed correct prediction of the presence or absence of graft rejection in 39 of 44 cases (sensitivity, 100%; specificity, 76%) and was an effective means of detecting pathologic fluid collections. Nuclear medicine, US, and MR imaging are all believed to be sensitive methods of detecting graft rejection and are complementary adjuncts to the clinical evaluation of pancreatic transplants.

Validation studies for brain blood flow assessment by radioxenon tomography

A tomographic technique has been used recently for cerebral blood flow measurements with inhaled radioxenon. Based on experiments in a specially developed dynamic phantom and on studies in primates in vivo, we have analyzed the validity of this method for measurements of both regional and total blood flow in the brain. We have also examined the errors introduced into flow computations as a function of changes in such parameters as: rate of xenon input, size of region of interest, magnitude of regional flow rates, and inter-regional flow differences. Our findings indicate a reasonable degree of accuracy for flow measurements in gray matter regions that are 3 cm in diameter or larger, while white matter blood flow is generally overestimated. The accuracy for regional flow assessments degrades as a function of: diminishing region size, increasing inter-regional flow differences, and flow rates in excess of 100 ml/100 g/min. Measurements for brain regions 2 cm or smaller in diameter can be in error by 25-50% as a result of partial volume averaging. Although the technique is not ideal for accurate flow measurements in small regions of the brain, it nevertheless provides a convenient means of assessing perfusion in major vascular territories of the brain in routine clinical applications.

Regional cerebral blood flow in normal pressure hydrocephalus

Regional cerebral blood flow (rcbf) was studied preoperatively and at 2 and 6 months postoperatively in 22 normal pressure hydrocephalus patients using xenon-133 inhalation and single photon emission computed tomography. Sixteen of the 22 patients improved (improved group) and six did not (unimproved group). The following comparisons were made: (1) preoperative rcbf in the improved group, to 14 normal elderly volunteers and to that in 59 SDAT (senile dementia of the Alzheimer type) patients; (2) preoperative rcbf in the improved and unimproved groups to determine if rcbf could predict surgical outcome; (3) pre- to postoperative rcbf in the improved group to see if increased cbf accounted for clinical improvement. The findings were: (1) preoperative rcbf in the improved group was lower than that in normal controls but was the same as that in SDAT; however, the ratios of rcbf values in anterior and posterior brain regions were significantly different between improved group and SDAT (p = 0.02); (2) an anterior/posterior ratio of 1.05 correctly classified surgical outcome in 19/22 patients; five of six in the unimproved group were above this cut off while 14/16 in the improved group were below; (3) in the improved group rcbf increased at 2 but not at 6 months after surgery without a corresponding reduction of clinical signs, supporting the notion that increase in cbf probably does not account for clinical improvement in normal pressure hydrocephalus.

Determination of surface displacements by holographic electrooptical processing

This paper is concerned with the description of a new holographic electrooptical processing method for the determination of surface displacements of various materials. In particular, the automated procedure to achieve a large number of surface measurements with high accuracy by the use of a microcomputer is discussed in detail.