Serial reduction of ventilation in lung with congenital absence of pulmonary artery

A 3-year-old boy with unilateral absence of the right pulmonary artery had a lung scan that demonstrated 46% of total ventilation on that side. This had fallen to 39% by 2 years later, and at 11 years after the first study the value was 30%. Ventilation lung imaging may be useful in demonstrating the degree of ventilatory dysfunction in a lung compromised by absence of the pulmonary artery. Possible causes of the pulmonary damage are discussed.

Induced right-to-left cardiac shunt during pulmonary perfusion imaging

Ventilation-perfusion lung scans are routinely performed using Tc-99m labeled MAA particles administered intravenously which are subsequently trapped in the pulmonary artery capillary bed. In the presence of a right-to-left shunt, activity may be seen in the systemic circulation. Right-to-left shunts may be worsened by inducing hypoxemia which causes pulmonary artery constriction, and also by increasing venous return to the heart. In this case, the authors used various maneuvers to increase right-to-left shunting and thereby demonstrated the presence of fixed pulmonary hypertension. These findings suggested that the patient's dyspnea on exertion was not primarily because of left ventricular dysfunction, and proposed coronary bypass surgery was deferred for medical management.

Transient regional osteoporosis of the ankle and foot. A report of four cases and review of the literature

Transient regional osteoporosis of the ankle and foot is an uncommon clinical entity characterized by local tenderness over the involved area. Plain radiographs demonstrate osteopenia of the involved bone and technetium diphosphonate bone imaging shows increased tracer uptake at the same location. This disorder is benign and self-limiting, and treatment is conservative.

Splenic and partial hepatic necrosis after vascular occlusion

A 74-year-old woman underwent two operations to correct an aortoduodenal fistula and to have an axillofemoral bypass graft inserted; these required temporary vascular occlusion. Her hepatic function test results began deteriorating. Initial and follow-up Tc-99m sulfur colloid studies revealed activity in the kidneys, consistent with disseminated intravascular coagulation. There was significant radiocolloid in the bone marrow and lungs, suggesting severe hepatic dysfunction. The spleen was not demonstrable on dynamic images or static views. In addition, there was a significant lateral hepatic defect, with a "lung overlap." The splenic lack of function and the hepatic lesion were due to necrosis (demonstrable on CT imaging), likely related to the prior vascular clamping.

Disassociation of splenic accumulation of Tc-99m MDP and radiocolloid

Two cases of splenic uptake of Tc-99m MDP are presented, in which there was preserved reticuloendothelial activity (Tc-99m sulfur colloid accumulation). In addition to the literature data, data from these cases were used to show the disassociation of uptake of bone agents and radiocolloid in the spleen. Prior reports, in which both agents concentrated in the spleen, were tabulated. An updated gamut on splenic accumulation of Tc-99m MDP or analogues was given.

Value of 111indium leukocyte scanning in febrile organ transplant patients

Immunosuppressed febrile organ transplant patients present a diagnostic and therapeutic dilemma since symptomatology is often altered by immunosuppression, which also masks the location of infection. Fifty 111indium leukocyte ( 111In WBC) scans were performed to determine their usefulness in the organ transplant patient. The results were compared with computerized tomography (CT) and gallium 67-citrate (Ga) scanning. Eleven patients received both 111In WBC and Ga scans; 22 received both 111In WBC and CT scans. Ten 111In WBC scans had subtraction of 99m Tc sulfur or albumin colloid for liver evaluation and four 111In WBC scans had subtraction of 99m Tc DMSA for kidney evaluation. The overall sensitivity and specificity for 111In WBC scans was 90% and 90%, respectively. Lung uptake was sensitive (89%) and specific (97%) for pulmonary infections, including bacterial, fungal and cytomegalovirus pneumonias. Renal graft uptake occurred in 15 cases (41%), all except 2 being due to rejection, pyelonephritis, urinary tract infections, or cytomegalovirus infections. Pyelonephritis and renal abscesses were diagnosed in 3 cases with 99m Tc DMSA subtraction. Perihepatic abscesses (2), and infected liver cysts (4) were diagnosed with 99m Tc sulfur or albumin colloid subtraction. There were five false-negative CT scans and three false-negative Ga scans. Therefore, when compared with 111In: sensitivity = 88% vs 64% (CT), specificity = 80% vs 86% (CT); and sensitivity = 111In 90% vs 67% (Ga), specificity = 100% for both 111In WBC and Ga scans.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosing osteomyelitis in Gaucher's disease. Observations on two cases

Bone scans in two patients with Gaucher's disease were reported as consistent with Gaucher's-associated osseous crises. A bone-radiogallium subtraction study was also initially negative in each individual (although it later became positive in one). At surgery both patients were seen to have osteomyelitis. These two cases point out the difficulty in attempting to diagnose osteomyelitis in the presence of Gaucher's bone disease. A possible role for MRI in such instances was mentioned. Also noted was clinical reluctance to accept a diagnosis of osteomyelitis (positive bone-radiogallium subtraction study) in an afebrile Gaucher's patient.

Gastric pertechnetate contribution to blood pool images

During a cardiac blood pool study (Tc-99m erythrocytes), there was an apparent "cold" area in the left lobe of the liver. At one hour, the prior void appeared to have filled in, suggesting an intrahepatic hemangioma. However, the changing pattern of radioactivity, and its shape, indicated that this actually represented Tc-99m pertechnetate in the gastric wall and stomach cavity. In a second case, the interval between intravenous injection of stannous pyrophosphate and Tc-99m pertechnetate was prolonged. Changing activity, again in the gastric wall and cavity, obscured part of the liver. This cleared with time, allowing hepatic evaluation. Thus, gastric pertechnetate can contribute to blood pool images of the heart or liver and multiple images may be needed to separate this component from nearby tissues.

Nuclear medicine studies of aging--IX. Resting left ventricular ejection fraction-diastolic area relationship in the "oldest old"

We retrospectively investigated the relationship between left ventricular ejection fraction (EF) and end diastolic cross sectional area (DCS), by means of gated cardiac blood pool studies, in 62 individuals (68 studies) who were of age 85 y or older. In these "oldest old", a plot of log ejection fraction as a function of log cross sectional area revealed good correlation (r = 0.66). The graph demonstrated the increase in heart size with a falling ejection fraction. Of the "oldest old", 38% had EF values at or above 55%. By comparison, in a group of 100 patients of ages 55-75 y, 32% had EF values of or above 55%. In the "oldest old" 13/68 (19%) had "hyperdynamic" EF values over 65%; in the 55-75 y old group, this value was 16%. The log-log plot was divided into four quadrants by two lines (one at a DCS of 26 cm2 and the other at EF of 55%). Possible prognostic significance of each of these four categories will have to be determined by following the patients and sorting out the contributions of such factors as hypertension, coronary artery disease and medications.

The influence of various factors on the accuracy of gallium-67 imaging for occult infection

To examine whether the results and interpretation of gallium-67 citrate imaging may be adversely influenced by factors present in compromised patients, we reviewed our 1-year experience in 69 patients in intensive care units, renal transplants, and those on hemodialysis. Our results indicate that it is an inappropriate diagnostic procedure for acute pancreatitis since seven of nine had false-negative results. Using loglinear modeling and chi-square analysis we found that treatment with antiinflammatory steroids, severe liver disease, end-stage renal disease, and renal transplantation with immunosuppressive therapy did not interfere with gallium-67 uptake. Increased rate of true-negative results in patients with end-stage renal disease was due to a greater and earlier use of the test in the febrile transplant patient and in hemodialysis patients with infections not amenable to diagnosis with gallium-67 scan (transient bacteremia and bacteriuria). We conclude that gallium-67 imaging is a useful diagnostic tool that, with the exception of acute pancreatitis, has very few false-negative results.

Nuclear medicine studies of aging--I. Procedure utilization in the oldest old

Analyses of procedure utilization are of importance if accurate projections are to be made of local and national needs as the population ages. Nuclear Medicine records of a general hospital were analyzed for 1986, to determine utilization patterns in the oldest old (age 85 years and greater) as compared with younger patients. The most elderly comprised 1.3% of the population of this state, but "consumed" 3.9% of the studies carried out in Nuclear Medicine (or a rate 3 times greater than expected). The average number of procedures/patient during the year was 1.56 in the oldest old vs 1.57 in younger individuals. The sex ratio of procedure utilization was 65% female (slightly lower than state wide national estimates of the female portion of the population). A far lower percentage of studies were performed as outpatients in the oldest old (12.2%) than in the younger population (44.9%); contributing factors were discussed. Of the procedures, several had the same percentage utilization in the oldest old and younger groups (gated cardiac blood pool, liver plus hepatobiliary, and radiogallium imaging). Bone scans were slightly less common in the very elderly. However, thyroid studies and radiothallium cardiac imaging were performed significantly less frequently in the more elderly. Procedures carried out more frequently in the very elderly were gastrointestinal bleeding examinations and lung imaging. Possible reasons for this were pointed out.

Recovery of femoral head perfusion after drainage of septic joint

A 64-year-old woman was febrile and had pain near the right hip. Blood cultures grew beta hemolytic streptococci. A bone scan showed reduced activity in the right femoral head and neck compared with the left femoral head and neck. She was treated with intravenous antibiotics and surgical decompression of a tense and bulging right hip joint. Five days later, a repeat bone scan revealed much of the femoral head activity to have returned. By day 20 after the initial bone image, there was intense activity throughout the femoral head and neck. Prompt relief of a distended hip joint can result in reperfusion of the femoral head and neck.

Varied appearance of cardiac pseudoaneurysms on blood pool images

Three cases of cardiac pseudoaneurysms were presented, with findings at the time of gated blood pool imaging. In only one of three was there the finding of a small neck connecting the ventricular cavity with the pseudoaneurysm. In the other two patients, there was a considerably larger communication. The size of the pseudoaneurysm itself was also of little diagnostic assistance. In one case it was small, while in a second patient it was larger in size. The third case revealed a pseudoaneurysm of enormous size (larger than the ventricular cavity). Gated blood pool imaging apparently can be called upon to demonstrate the presence of an abnormality. It may not be able to definitely establish the diagnosis of pseudoaneurysm, but should suggest the use of cardiac angiography to distinguish these life threatening lesions from true aneurysms.

Evaluation of renal-skeleton ratio of technetium-99m phosphonate in multiple myeloma

The kidneys were evaluated on [99mTc]phosphonate bone scans using 35 studies from 23 individuals with multiple myeloma; these images were compared with those from 50 controls. In each case, the kidneys could be visualized and calculation was made of the renal:skeleton ratio. Two myeloma patients showed an elevated renal:skeleton ratio. One was due to reduced vertebral uptake of [99mTc]phosphonate following therapeutic radiation. In the second case, the elevated ratio was related to renal uptake of the tracer (independent of urinary retention), and was consistent with nephrocalcinosis. No significant correlation between the renal:skeleton ratio and the degree of hypercalcemia, proteinuria, or renal impairment was found. We conclude that bone scintigraphy represents a safe, simple means of demonstrating renal presence and activity in multiple myeloma patients. However, calculation of the renal:skeleton ratio is not directly helpful in clarifying the events of calcium metabolism.

Dual radionuclide subtraction imaging of the spleen

Dual radionuclide subtraction imaging of the spleen using 67Ga citrate and 99mTc is useful in further delineating lesions that are identified on either a routine radiogallium survey or on a conventional sulfur colloid liver-spleen image. Better anatomic localization of left subphrenic abscesses may be obtained. Differentiation of tumors and abscesses from less serious lesions such as cysts, infarcts, and hematomas is possible. We have found this technique to be generally applicable to any organ that can be selectively imaged using a technetium radiopharmaceutical, including the liver, bones, and kidneys. In addition, we are currently evaluating thallium-pertechnetate subtraction imaging in the evaluation of parathyroid adenomata.

Delayed splenic rupture: a suggestion for "predictive monitoring"

Two cases of delayed splenic rupture are presented. In one, splenic damage was demonstrated on Day 29 following trauma, and rupture of the organ occurred 2 days later. In the second patient, splenic trauma was documented 1 day after an accident, and rupture occurred on Day 26. Each case was marked by the fact that only one spleen scan had been performed (in the first case because of discovery only long after the trauma, and in the second case because of the patient's failure to return). That is, while damage to the spleen was evident, there was no follow-up to document healing. Based on this, it is suggested that spleen imaging be carried out soon after trauma. If a trauma-related defect is shown, then a repeat study may be mandatory to document healing. Lack of such healing, or failure to progress at a normal rate, may be an altering sign to impending splenic rupture. Hence, "predictive monitoring" by early and then repeat imaging at a later date, is proposed.

"Reactivation" of Tc-99m MDP uptake in heterotopic bone

Heterotopic bone in the left femoral head area showed progressive decrease in Tc-99m MDP uptake, only to reveal increased uptake at a later date.

Rapid response of intrasplenic lesions to steroids in non-Hodgkin's lymphoma

A 70 year old woman had a [99mTc]sulfur colloid liver/spleen scan that showed splenomegaly and multiple intrasplenic defects. The lesions failed to concentrate radiogallium. Thirteen days later, after being on steroid therapy, the spleen had decreased in size and the lesions were only barely apparent. The intrasplenic process, due to non-Hodgkin's lymphoma, was thus markedly sensitive to steroids. It is uncertain if such rapid regression can be employed as a prognostic indicator in non-Hodgkin's lymphoma and suggests the need for further monitoring. The differential diagnosis of the rapid response of intrasplenic lesions to steroids is a limited one, and likely includes sarcoidosis.

Scintigraphic appearance of axillofemoral and femorofemoral bypass grafts

The scintigraphic appearance of axillofemoral and femorofemoral bypass grafts was reviewed in three cases in which the grafts were patent and intravascular radiotracers defined their course. In a fourth case, the axillofemoral graft was occluded and an aberrant vessel was identified (probably acting as a physiological shunt).

Hyperthyroidism with metastatic follicular thyroid carcinoma

A 70-yr-old woman presented with hyperthyroidism and metastatic follicular carcinoma of the thyroid. The blood level of thyroid stimulating immunoglobulin (TSIg) was elevated. A total thyroidectomy was performed. One month later she remained hyperthyroid. Three weeks after therapy with 218 mCi of I-131 sodium iodide, the patient was euthyroid. Six months after the initial radioiodide therapy, she was again hyperthyroid and was given a second oral treatment dose of I-131 (220 mCi). Five months later, the patient had again become euthyroid. It is likely that initially the woman's metastases were producing sufficient hormone to render her hyperthyroid. After thyroidectomy and two large doses of radioiodide, she has remained euthyroid without having to take exogenous hormone. The blood level of TSIg had become undetectable. Based on this finding, we offer a tentative classification of the causes of hyperthyroidism in patients with thyroid carcinoma.

Pulmonary perfusion "without ventilation"

An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a "reversed ventilation/perfusion mismatch."

Radionuclide study of functional resolution of unilateral renal vein thrombosis

The diagnosis of unilateral renal vein thrombosis was established in a 50-year-old woman. A functional evaluation, by means of Tc-99m DTPA, was performed almost immediately, and at intervals up to nearly eight months later. Functional return of the involved kidney could be documented by plotting the ratio of affected kidney/total kidney activity. Conservative therapy was accompanied by a return of function of the kidney to 45% of total renal activity.

Splenic avulsion and bleeding shown on radiocolloid images

A case is discussed of a man who presented with trauma to the chest and abdomen. A radiocolloid image showed uptake by the liver. However, the spleen was not identified. Areas of activity outside of the spleen were noted. The patient had splenic avulsion; extra sites of activity likely represented bleeding sites in the abdomen. Failure to identify the spleen on a radiocolloid image, after trauma, should be an alerting sign to possible splenic avulsion (especially when there are also ectopic sites of accumulation of the radiocolloid).

Failure of uptake of radiocolloid by the femoral heads: a diagnostic problem: concise communication

One hundred six patients had the area of the femoral head scintigraphed after completion of a Tc-99m sulfur colloid liver scan. In 47 (45%), there was no visible activity in the femoral heads. This was somewhat age-related. All six individuals in the 11- to 19-yr age group showed femoral-head uptake of radiocolloid, but only 37% of those 70 to 79 yr old revealed such accumulation. The finding that less than one half of adults had uptake of radiocolloid in the femoral heads was consistent with results of three smaller series of patients (larger dose of radiocolloid, use of a different preparation of sulfur colloid, and use of In-III chloride). We conclude that not all adults take up radiocolloid in the femoral heads, and that lack of such uptake is not necessarily abnormal. Use of radiocolloid accumulation to gauge femoral-head vascularity may be more limited than previously appreciated, although right-left asymmetry might be of some diagnostic assistance.

Incidence of a pyramidal lobe on thyroid scans

Gamma camera pertechnetate and radioiodine thyroid scans were reviewed to determine the incidence of recognition of a pyramidal lobe. Ten to 17% of "normals" and of patients with various thyroid disease states had a pyramidal lobe on their scans. However, in patients with diffuse toxic goiter, 43% had a pyramidal lobe on the thyroid images. There appears to be a correlation between elevated thyroid function studies (likely in thyroid mass) and the incidence of a pyramidal lobe on thyroid scans in diffuse toxic goiter.

Radiocolloid studies of the regression of intrasplenic lesions

Five cases are presented in which intrasplenic defects, noted on Tc-99m sulfur colloid imaging, had at least partially regressed on follow-up studies. One, representing splenic trauma, reinforced the concept of the ability of the spleen to "heal" itself. A second case involved splenic invasion by direct extension of a soft tissue sarcoma. Improvement was noted after the patient was treated with chemotherapy. Three cases were related to splenic manifestations of lymphoma. Of these three patients (one each with lymphocytic, histiocytic, and mixed diffuse histiocytic lymphoma plus nodular), two showed improvement after treatment with chemotherapy alone and the third after combined chemotherapy and external radiation treatment. Return of splenic reticuloendothelial function to previously involved regions within the spleen occurred for all five patients. Comments were made as to the apparent rate of return of function.

Hemivertebral "disappearance" on bone scan

Two cases are described in which there was absence of uptake in hemivertebra on a Tc-99m methylene diphosphonate bone scan. In one of these patients, the bone image had been normal 56 days previously. Radiographs of the vertebrae were normal in both cases. Data are presented suggesting that the findings can most probably be explained in terms of compromise of blood supply to the hemivertebra; each half of a vertebra usually has a separate arterial contribution.