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A F Jacobson

Publications and source records attributed to A F Jacobson.

At least 37 records · Page 2Linked to original sources
PubMed1998

On the shoulders of a giant: a mentoring experience.

This article describes the development of a mentoring relationship between the author and Elizabeth Winslow since it began in 1990. It includes numerous examples of ways in which the mentor, Dr Winslow, provided inspiration, support, and encouragement during high and low points of the author's professional development. The process by which Dr Winslow became the author's mentor and the nature of the current mentor/mentee relationship challenge commonly held beliefs about how mentoring relationships begin and unfold.

Education, Nursing, Graduate↗
PubMed1998

The value and correlates of left ventricular cavity assessment in dipyridamole 201Tl SPET studies.

Left ventricular cavity (LVC) enlargement during SPET dipyridamole 201Tl myocardial perfusion imaging studies is a proven marker of severity of coronary artery disease. Nevertheless, the influence of the extent of myocardial infarct and ischaemia on the degree of LVC enlargement both at rest and with dipyridamole has not been clearly analysed. One hundred and one patients were studied by both dipyridamole myocardial perfusion imaging and radionuclide ventriculography within 1 week. The left ventricular ejection fraction (LVEF) was 57 +/- 9 in normal resting LVC patients (group I), 43 +/- 8 in mild LVC enlargement patients (group II) and 28 +/- 5 in moderate-to-severe LVC enlargement patients (group III). The number of fixed defects was increased in patients in group II and group III, but there was no significant differences in the number of ischaemic segments among groups. The number of ischaemic segments was much higher in patients with transient cavity dilatation than those without cavity change; nonetheless, both LVEF and the numbers of fixed segments were unchanged. The degree of LVC enlargement at rest strongly reflects the resting left ventricular systolic function as well as the extent of previous myocardial infarct. On the other hand, transient cavity dilatation during dipyridamole infusion can only reflect the extent of viable myocardium at risk.

Aged↗
PubMed1997

Musculoskeletal pain as an indicator of occult malignancy. Yield of bone scintigraphy.

BACKGROUND: When musculoskeletal pain is persistent or out of proportion to clinical findings, diagnostic imaging is often used to evaluate for the presence of occult pathologic conditions. OBJECTIVE: To examine the efficacy of bone scintigraphy for identifying occult malignancy in such patients. METHODS: Bone scans of 491 patients with new or recurrent complaints of musculoskeletal pain and no previously known malignancy were retrospectively reviewed. The findings of each scan were classified into 1 of the following categories: (A) no evidence of malignancy; (B) equivocal (1-3 lesions of uncertain significance); or (C) probable metastatic disease (> 3 lesions without trauma or other benign explanation). All diagnoses of malignancy established within 6 months of the bone scan were then determined from review of radiological and clinical records. RESULTS: The distribution of scan interpretations was as follows: category A, 386 (79%); category B, 84 (17%); and category C, 21 (4%). Among the 181 patients younger than 50 years, 161 (89%) had category A and 20 (11%) had category B scans. Of the 310 patients aged 50 years or older, 226 (73%) had scans in category A, 64 (21%) in category B, and 21 (7%) in category C. Thirty patients (6%) had malignancy involving bone, 29 among those aged 50 years or older. In patients aged 50 years or older, 10 (16%) of 64 with equivocal scan findings (category B) and 19 (90%) of 21 with widespread abnormalities (category C) had malignancy involving bone. Initial radiographs of symptomatic sites showed lytic or blastic bone abnormalities suggestive of malignancy in 16 (59%) of the 29 older patients in whom this diagnosis was confirmed. CONCLUSIONS: In patients aged 50 years or older, the yield of bone scintigraphy for identification of occult malignancy (29/310; 9%) is sufficient to justify its use in the investigation of the cause of problematic bone or musculoskeletal symptoms.

Adult↗
PubMed1997

Hemodynamic response and change in organ blood volume during spinal anesthesia in elderly men with cardiac disease.

Aging and disease may make the elderly patient with cardiac disease particularly susceptible to hypotension during spinal anesthesia. We studied 15 men, 59-80 y old, with histories of prior myocardial infarction (n = 9), congestive heart failure (n = 2), and/or stable myocardial ischemia (n = 11) given spinal anesthesia with 50 mg lidocaine in dextrose. Technetium-99m-labeled red blood cell imaging estimated left ventricular ejection fraction (EF) and changes in blood volume in the abdominal organs and legs. Arterial and pulmonary artery catheters provided hemodynamic measurements. Sensory block averaged T4 (range T1-10). Mean arterial pressure decreased 33% +/- 15% (SD) (P < 0.001), secondary to decreases in vascular resistance (SVR), -26% +/- 13% (P < 0.001) and cardiac output, -10% +/- 16% (P = 0.03). EF increased from 53% +/- 11% to 58% +/- 14% (P < 0.001) while left ventricular end-diastolic volume (LVEDV) decreased (-19% +/- 9%, P < 0.001). Blood volume increased in the legs (6% +/- 6%, P = 0.006), kidneys (10% +/- 9%, P < 0.001), and mesentery (7% +/- 5%, P 0.001) but not in the liver or spleen. Cardiac function was well maintained. We concluded that the primary mechanism of hypotension was a decrease in SVR, not cardiac output, despite the decrease in LVEDV.

Aged↗
PubMed1997

Scintigraphy with indium-111-labeled homologous (donor) platelets in the platelet transfusion refractory bone marrow transplant patient.

Some bone marrow transplant patients who require multiple platelet transfusions as a consequence of post-transplant thrombocytopenia become refractory to these transfusions. As the spleen is the primary site of destruction for senescent and damaged platelets, splenectomy is a potential therapy for persistent thrombocytopenia. Scintigraphy with 111In-labeled platelets has been used to identify increased splenic sequestration and destruction in various platelet disorders, especially idiopathic thrombocytopenic purpura, before consideration of therapeutic splenectomy, but this technique has not been widely described in platelet transfusion refractory bone marrow transplant patients. We report on the results of 111In-labeled platelet scans in two such patients and review the pertinent literature in relation to the possible benefits and limitations of this scanning technique.

Adult↗
PubMed1997

Clinical outcome of patients with intermediate probability lung scans during six-month follow-up.

UNLABELLED: A retrospective review of a consecutive series of patients with intermediate probability (IP) ventilation/perfusion lung scans was performed to evaluate: the frequency of documented thromboembolic (TE) disease, either pulmonary embolism (PE) or deep-venous thrombosis (DVT), at time of presentation; the prevalence of new diagnoses of TE disease during 6-mo follow-up; and occurrence of mortality during the same follow-up interval. METHODS: Radiologic and clinical records for all patients who had ventilation/perfusion lung scans reported as IP or indeterminate during a 7-yr period were reviewed. TE disease at presentation or during follow-up was identified from results of pulmonary angiography, chest CT, lower extremity Doppler ultrasound and venography, and repeat lung scans. Occurrence of mortality and cause of death were determined by medical record review. RESULTS: Of 164 patients studied, 36 (22%) had TE disease confirmed at initial presentation (PE = 19; DVT only = 17), and four others (2%) developed evidence of TE disease during follow-up, two with PE and two with DVT. Prevalence of TE disease was significantly greater in patients with matching perfusion/chest radiographic abnormalities and ventilation/perfusion mismatches (0.5-1.5 segmental equivalents) than in those with various patterns of matching ventilation/perfusion defects (31% versus 14%, p < 0.01). Twenty-eight patients (18%) died during follow-up, but recurrent PE was implicated in only one death in a patient with angiographically-confirmed PE at initial presentation. Among the 116 patients who did not receive long-term anticoagulation after their initial lung scans, 22 (19%) died, none of whom had PE confirmed or suspected as a contributing cause. CONCLUSION: The prevalence of new or recurrent TE disease is low in patients with IP lung scans who are appropriately evaluated and managed after their initial presentation. No evidence of significant mortality secondary to untreated PE was found in the study group.

Female↗
PubMed1996

Should the presence of other diseases exclude subjects as controls in studies of gallbladder response to cholecystokinin octapeptide (sincalide)? Scintigraphic results in patients with malignancies but no known gallbladder disease.

Findings of hepatobiliary scintigraphy with intravenous cholecystokinin octapeptide (sincalide) were examined in 26 asymptomatic patients with various malignancies but no known pre-existing gallbladder disease, and normal hepatobiliary and gallbladder morphology on sonography. The maximum gallbladder ejection fraction (GBEF) following a 30 min infusion of 0.04 of micrograms kg-1 sincalide ranged from 2 to 100%, with a mean of 68%, a median of 78% and GBEF < 35% in five patients (19%), findings similar to those reported in 'normal' subjects. There was no correlation between decreased GBEF and the previous chemotherapy agents received, as well as with gallbladder wall thickness, volume, and whether the gallbladder or small bowel was seen first on scintigraphy. These results suggest that despite the presence of other diseases and histories which include extensive chemotherapy, asymptomatic patients with normal hepatobiliary sonography can serve as controls in studies of gallbladder contractility using sincalide.

Adult↗
PubMed1995

False-negative morphine-augmented hepatobiliary scintigraphy with a rim sign.

A patient with cholelithiasis and clinically suspected of acute cholecystitis underwent hepatobiliary scintigraphy that demonstrated initial nonvisualization of the gallbladder in association with a subtle rim sign, but subsequent gallbladder visualization after administration of intravenous morphine. After an 8-day period of medical management, an elective cholecystectomy was performed, which revealed a gangrenous gallbladder with a gallstone in the neck and full thickness necrosis. These results suggest that gallbladder visualization on morphine-augmented hepatobiliary scintigraphy should be interpreted cautiously in the presence of a rim sign because acute cholecystitis remains a possibility.

Biliary Tract↗
PubMed1995

Relief of common bile duct obstruction during the course of hepatobiliary scintigraphy.

Hepatobiliary scintigraphy performed in a patient suspected of having common bile duct obstruction showed persistence of the hepatic parenchymal phase and no bile duct or gallbladder activity during the first hour of imaging. On endoscopic retrograde cholangiopancreatography examination several hours later, an obstructing gallstone was identified in the common bile duct, and the stone was extracted in conjunction with a papillotomy. Delayed scintigraphic images at 6 hours were unchanged from the earlier views, but imaging at 24 hours showed tracer activity in the small bowel and colon along with persistent hepatic parenchymal activity. These results demonstrate that hepatobiliary radiopharmaceuticals remain in an excretable form in the liver in patients with complete common duct obstruction, but that resumption of bile flow and tracer excretion does not occur until a number of hours after relief of the obstruction.

Aged↗
PubMed1995

Scintigraphic detection of sequential symmetrical metatarsal stress fractures.

A patient with complaints of right foot pain and previous normal radiographs had an abnormal three-phase bone scan consistent with a second metatarsal stress fracture. Subsequent radiographs confirmed this diagnosis. Two months later, the patient developed pain in his left foot, and again initial radiographs were noncontributory. A later bone scan revealed a left second metatarsal stress fracture. The results in this case reemphasize the value of bone scintigraphy in patients with foot pain and no bone abnormalities on plain radiographs.

Fractures, Stress↗
PubMed1995

Diffuse renal retention on bone scintigraphy in localized clear-cell renal epithelial neoplasm.

Bone scintigraphy performed to assess the significance of an incidental finding of a small sclerotic rib lesion on a chest radiograph of a patient with no known malignancy demonstrated no evidence of metastatic disease, but there was moderate diffuse parenchymal retention in the left kidney. Renal ultrasound revealed an ovoid, slightly hyperechoic mass in the inferior pole of the left kidney, and subsequent contrast CT demonstrated a well-circumscribed hypervascular mass in that location. At nephrectomy, a localized 1.5-cm diameter clear-cell epithelial neoplasm, not definitely malignant, was found. No other abnormalities were noted in the remainder of the left kidney or in the surrounding soft tissues. No calcifications or other parenchymal changes in the kidney were identified to explain the retention of the bone agent, which was possibly related to the hyperemia associated with the neoplasm and undefined parenchymal factors.

Aged↗
PubMed1994

Serum caffeine levels after 24 hours of caffeine abstention: observations on clinical patients undergoing myocardial perfusion imaging with dipyridamole or adenosine.

Although caffeine attenuates the vasodilatation produced by dipyridamole and adenosine, and is therefore contraindicated when these agents are used for myocardial perfusion scintigraphy, caffeine levels in clinical patients undergoing standard imaging protocols have not been studied. Eight-six patients undergoing clinically indicated intravenous dipyridamole (n = 75) or adenosine (n = 11) thallium-201 myocardial perfusion scintigraphy, all of whom reported abstention from products containing caffeine for 24 h, were studied prospectively. Blood samples were drawn prior to initiation of the pharmacologic infusion, and serum caffeine levels were determined using an enzyme immunoassay technique. Results of these determinations were correlated with maximum pulse and blood pressure changes measured during and immediately after the stressor infusion, and thallium imaging findings. Detectable caffeine levels were found in 34 patients (40%), ranging from 0.1 to 5.0 mg/l. There was no significant difference in mean systolic blood pressure decrease or mean pulse increase between patients with caffeine levels > 1.0 mg/l (20.4 +/- 18.2 mmHg, 11.0 +/- 8.9 BPM; n = 5) and those with lower (0.1 to 0.9 mg/l) (15.4 +/- 9.5 mmHg, 14.4 +/- 8.2 BPM; n = 29) or no detectable caffeine levels (18.0 +/- 11.5 mmHg, 16.6 +/- 10.1 BPM; n = 52). Redistribution on thallium imaging was also identified with a similar frequency in these three groups (2/5, 40%; 8/29, 28%; 22/52, 42% respectively).

Adenosine↗
PubMed1994

Nuclear medicine and other radiologic imaging techniques: competitors or collaborators?

In summary, there will continue to be competition between scintigraphy and the various other modalities used in Radiology, with Nuclear Medicine having to periodically reconfirm its value as current methods are refined and newer techniques are introduced. Compared to the revolutionary changes in radiologic imaging which have occurred over the past two decades. Nuclear Medicine and radiopharmaceutical technology have advanced at a slower, more evolutionary pace. It is essential that the nuclear medicine profession continue to provide solid data to demonstrate the validity and utility of radionuclide imaging results. We must be prepared to demonstrate to an often skeptical medical public that the "shinier" new methods in Radiology do not necessarily hold all the advantages when it comes to diagnostic evaluation of patients. There are many situations where the Nuclear Medicine procedure remains the most cost-effective and appropriate test for a particular patient evaluation, and those of us working in this field must not be shy about informing our clinical colleagues when our method has a demonstrated advantage over a competing imaging modality.

Cost-Benefit Analysis↗
PubMed1994

Relation of changes in radionuclide measures of effective renal plasma flow and glomerular filtration rate in spinal cord injury patients.

The association of changes in radionuclide measures of effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) in relation to the time since spinal cord injury (SCI) was investigated in 30 male SCI patients ages 28-72 (mean 49), with intervals from injury ranging from two to 48 years. ERPF and GFR were determined from plasma clearance curves following bolus injections of I-131 orthoiodohippurate (OIH) and Tc-99m diethylenetriaminepentaacetic acid (DTPA) respectively, and were compared with published age-adjusted normal values. Fifteen patients had decreased ERPF and 13 had decreased GFR, with decline in ERPF tending to precede a similar change in GFR. Among 18 patients < or = 20 years post-SCI, GFR was abnormal in six (33 percent), while ERPF was decreased in 10 (56 percent). In twenty-four patients (80 percent), GFR and ERPF were either both normal (n = 13) or both abnormal (n = 11), but filtration fraction (FF = GFR/ERPF) was increased to > 0.23 in 18 patients, including nine with normal GFR. Only 2 patients had normal ERPF/abnormal GFR, both of whom were > 35 years post-SCI and had FF < 0.20. In the SCI population, decreases in ERPF tend to precede similar changes in GFR, with resultant increase in FF in the majority of patients.

Adult↗
PubMed1994

Cavernous hemangiomas of the liver. Association of sonographic appearance and results of Tc-99m labeled red blood cell SPECT.

To determine if the sonographic appearance of cavernous hemangiomas of the liver correlated with their detectability on Tc-99m labeled red blood cell (RBC) SPECT scintigraphy, studies of 30 cavernous hemangiomas, 14 with typical and 16 with atypical sonographic appearance, were retrospectively reviewed. The 14 typical hemangiomas had uniform hyperechoic sonographic appearance, and ranged in size from 0.8-3.9 cm (mean 2.0 cm). The 16 atypical hemangiomas ranged in size from 1.0-9.0 cm (mean 3.4 cm) and sonographic appearance was hypoechoic (n = 9), echogenic (with hypoechoic or cystic center [n = 3] or with irregular margins or shape [n = 2]); or heterogeneous (n = 2). Nine of 14 (64%) typical cavernous hemangiomas were identified on SPECT, compared with 15 of 16 (94%) atypical cavernous hemangiomas (P = 0.07). All 18 lesions > or = 2 cm (6 typical, 12 atypical) were identified on SPECT. Sensitivity of SPECT for hemangiomas of smaller than 2 cm was 38% (3 of 8) for those with typical and 75% (3 of 4) for those with atypical sonographic appearance. Four of the five typical hemangiomas not seen on SPECT were < or = 1 cm in at least one dimension. Detection of cavernous hemangiomas on RBC liver SPECT is primarily dependent on lesion size, with the influence of the sonographic appearance of these lesions mostly associated with the smaller size of those with typical characteristics.

Aged↗
PubMed1993

Congenital or early developmental versus later acquired renal function asymmetry. Scintigraphic characteristics.

A congenitally or developmentally small right kidney in an adult spinal cord injury patient had only 12% of total uptake on radioiodine-labeled orthoiodohippurate renography but nevertheless had a normal-shaped time-activity curve. In a subsequent retrospective review of 175 consecutive radioiodine-labeled orthoiodohippurate renograms performed on adult patients over a 3-year period, 35 other patients with studies showing greater than 2:1 asymmetry in renal function were identified. Uptake, clearance, or both were abnormal in all 35 kidneys with less than 33.3% of function, with the left kidney more commonly affected (n = 24). Correlation from ultrasound, computerized tomography, intravenous pyelography, and angiography demonstrated acquired abnormalities associated with all 35 of these kidneys, including urinary obstruction (n = 20), renal artery stenosis (n = 9), and cortical scarring/infection and/or reflux (n = 15) (some patients had more than one diagnosis). While acquired renal function asymmetry almost always results in a smaller kidney with abnormal uptake or clearance characteristics, a congenitally small kidney may have overall reduced blood flow but still display a normal-shaped time-activity curve on radionuclide renography.

Adult↗
PubMed1993

Increased lung uptake of 99Tcm-sulphur colloid as an early indicator of the development of hepatic veno-occlusive disease in bone marrow transplant patients.

Nineteen bone marrow transplant (BMT) patients were studied prospectively with serial 99Tcm-sulphur colloid liver/spleen scintigraphy to determine if quantification of lung uptake aided in early identification of hepatic veno-occlusive disease (VOD). Anterior lung/liver (L/L) and geometric mean spleen/liver (S/L) ratios were determined prior to BMT conditioning chemotherapy/total body irradiation, and at 1-4 days (n = 17), 11-14 days (n = 18) and 27-33 days (n = 15) post-BMT, and correlated with the presence of VOD post-BMT employing standard clinical criteria. Veno-occlusive disease developed in nine patients (47%): mild 5; moderate 1; severe 3. Of 17 patients studied 1-4 days post-BMT, at which time no patient had objective evidence of VOD, an L/L ratio > or = 0.075 predicted subsequent development of moderate or severe VOD with a sensitivity of 100% (4/4) and a specificity of 85% (11/13). An L/L ratio > or = 0.075 on any post-BMT study had a sensitivity of 100% (9/9) and specificity of 70% (7/10) for the diagnosis of VOD of any severity. Increase in lung uptake at 4 weeks post-BMT was associated with a poor prognosis in patients with VOD, as the four with L/L ratios of 0.085-0.115 died during the first year, while the two patients with L/L ratios of 0.032 and 0.078 survived. Increased lung uptake on liver/spleen scintigraphy early post-BMT may be useful for identifying patients likely to develop significant VOD and for assessing their prognosis.

Adult↗