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Objectives: Chronic acalculous cholecystitis (CAC) increasingly is being diagnosed as a cause of recurring biliary symptoms in children, but its clinical diagnosis remains challenging. The primary objective was to evaluate the utility of hepatocholescintigraphy in pediatric patients with suspected CAC. A secondary objective was to describe their clinical follow-up after diagnosis., Methods: Medical records of patients (aged 9-20 years) who underwent hepatocholescintigraphy from February 2008 to January 2012 were reviewed. Patients with gallstones, and with ≤1 year of clinical follow-up, and studies without gallbladder (GB) stimulation were excluded. GB ejection fraction (GBEF) of <35% after sincalide or fatty meal (Lipomul) stimulation were considered abnormal. Diagnosis of CAC was based on histopathology after cholecystectomy. Patients with negative GB pathology, or complete resolution of symptoms without surgery, or alternative diagnoses for persistent symptoms were considered to not have CAC., Results: Eighty-three patients formed the study group (median age 14.9 years), of which 81.9% were girls. Median duration of symptoms and clinical follow-up were 6 months and 2.9 years, respectively. Fifty-two patients had at least 1 study with sincalide and 36 patients had at least 1 study with Lipomul. Initial cholescintigraphy was 95.0% sensitive and 73.0% specific in diagnosing CAC, with a negative predictive value of 97.9%. Of the 31 patients with abnormal GBEF, 22 underwent cholecystectomy with improvement in pain in 72.7%, whereas all of the 9 without surgery improved., Conclusions: Hepatocholescintigraphy is useful for excluding CAC, although the clinical implications of an abnormal GBEF need to be further defined.

Nuclear medicine has an important role in the care of newborns and children less than 1 y old. Patients in this age group present with a spectrum of diseases different from those of older children or adults. These patients can benefit from the full range of nuclear medicine studies. In these young children, nuclear medicine studies are more likely to be used to evaluate a wide range of congenital conditions but also can be helpful for evaluating acquired conditions such as infection, cancer, and trauma. This review first will cover the general aspects of nuclear medicine practice with these patients, including the special considerations that can help achieve successful diagnostic imaging. These topics will include clinical indications, imaging technology, instrumentation, software, positioning and immobilization, sedation, local and general anesthesia, radiopharmaceutical doses, radiation risk, and dose reduction. The review then will discuss the specific nuclear medicine studies that typically are obtained in patients in this age group. With extra care and attention to the special needs of this population, nuclear medicine departments can successfully study patients less than 1 y old.

Pinhole magnification imaging is an important technique for practitioners of pediatric nuclear medicine. This article reviews basic principles of pinhole magnification imaging and ways for optimizing image acquisition with this technique. Applications to skeletal scintigraphy, scrotal scintigraphy and renal cortical scintigraphy are discussed and illustrated.

Deconvolution has been used to correct first-pass radionuclide angiocardiography for the time course of the delivery of radiopharmaceutical into the cardiopulmonary system. The extreme sensitivity of deconvolution to random errors in the data may account for some of the problems encountered in practice. We implemented several deconvolution algorithms that were suitable for use with the unimodal and multimodal superior vena caval and pulmonary curves found in left-to-right shunt quantification. The sensitivity of the algorithms to random errors was assessed using mathematical test problems degraded with pseudorandom noise. An algorithm that constrained the deconvolved pulmonary curve to be expressable as the non-negative sum of a set of lagged normal curves was found to have the smallest maximum error on the curves tested. Comparison with results from a previously published test problem indicated an error reduction of greater than 50% over previously used algorithms. Use of this algorithm may permit more accurate deconvolution of pulmonary time-activity curves and thereby improve shunt quantification.

The case of a patient with massive, posttraumatic, subconjunctival cerebrospinal fluid collections is described in which diagnosis and postoperative management was simplified by serial radionuclide cisternography.

99mTc-methylene diphosphonate, a bone-seeking radionuclide, accumulated in the spleen of a 16-year-old boy with sickle-cell anemia even though no splenic calcification was visible. This may be explained by the presence of microscopic calcium deposits in the spleen, which form at an early age in this disease. Bone-seeking radionuclides may accumulate in regions of recent splenic infarction, as has been demonstrated in cerebral and myocardial infarction. Such radionuclides may be the only means of demonstrating the spleen in such patients.

Radionuclide angiocardiography is a useful method in the evaluation of patients with congenital heart disease, safely and nontraumatically. Physiologic variables such as transit times, cardiac output, left ventricular ejection fraction, stroke volume, end-diastolic volume can be measured accurately with this technique. An important application of radionuclide angiocardiography in children with congenital heart disease is in the detection, localization and quantification (pulmonary to systemic flow ratio) of intracardiac shunts and shunts between the great vessels. This technique has been found useful in the evaluation of the newborn infant with cyanosis, the patient with a cardiac murmur and the patient who has had cardiovascular surgery. Newer mobile gamma camera-computer systems permit the performance of radionuclide angiocardiography in several ill premature and newborn infants and patients during the early postoperative period. Specially designed magnifying collimators and the development of ultrashort-lived radionuclides should result in an overall improvement in the diagnostic capabilities of this technique and in a further reduction in the radiation dose.

191mIr is a useful tracer for radionuclide angiocardiography and may be of particular value in the evaluation of heart disease in children. It has a short half-life, a suitable photon energy, and may be obtained as a generator product by decay of its long-lived parent 191Os. A 191Os-191mIr generator capable of providing at least 18 mCi of 191mIr in 1.5 ml of eluant is described. 191mIr is separated from 191Os by absorbing 191OsCl6(-2) on an ion exchange resin and eluting with a solution of 8.7% NaCl at a pH of 2.2. The generator employs an additional resin column which is replaced to minimize 191Os breakthrough.

Paraplegics whose range of motion is limited by para-osteo-arthropathy (POA) may have difficulty in becoming independent unless the heterotopic bone mass is removed. The recurrence rate is high if the bony mass is not mature at the time of surgery. Radiography and alkaline phosphatase correlations are not trustworthy. In 3 paraplegics with POA, radiolabeled osteotropic agents demonstrated a steady decrease in the uptake ratio (heterotopic/normal bone) followed by a steady-state plateau, reflecting the most useful index of maturation and allowing surgical removal of bone without recurrence.

The value of scintigraphy in the early detection of osteomyelitis is demonstrated in children who had signs and symptoms suggestive of bone infection. Nine patients between 2 and 13 years of age were evaluated with technetium Tc 99m diphosphonate bone scintigrams and roentgenograms. Blood cultures were performed in all patients, and bone biopsy or drainage was obtained in six patients. The diagnosis of osteomyelitis was made in seven patients; one patient had a subperiosteal abscess surrounded by osteomyelitis, and one patient had cellulitis. The seven children with osteomyelitis had focal increase of radiopharmaceutical uptake in the bone. The child with the subperiosteal abscess had an area of decreased uptake in the center of the abscess surrounded by a zone of increased uptake of the radioactive bone-seeker. The patient with cellulitis had soft tissue changes by X-ray and a normal bone scintigram. In the seven patients with osteomyelitis, the bone scintigram was performed during the early phase of the disease and no bony changes were present on the roentgenogram. In one patient with subacute osteomyelitis, soft tissue changes were seen radiologically. Only three of the seven children with osteomyelitis developed radiological bony changes. Since bone scintigraphy can detect early local bone derangement, it is recommended in the initial evaluation of children in whom osteomyelitis is suspected.

Nine examples, in seven patients, from a large cadaver renal allograft program, illustrate the value of radio-hippuran photoscans in differentiating causes of post-implant oliguria. Hippuran scans are shown to be more valuable than chlormerodrin scans when renal function is acutely depressed. Hippuran scans aided in the decision to remove kidneys in four cases of severe oliguria and to retain kidneys in two others. In two further examples, extravasation of urine was detected by scanning after radio-hippuran injection when other tests had failed to do so.The technique of radio-hippuran scanning has a place in the differentiation of acute and subacute renal dysfunction and has proved particularly valuable in the early oliguric complications of a cadaver renal transplant program.

Scintigraphy with Gallium 67 is frequently used in the evaluation of children with fever of unknown origin (FUO). Its usefulness in this setting, however, has not been definitely established. We reviewed the clinical records and imaging studies of 30 children with FUO who had Gallium scans. We defined FUO as a febrile illness of greater than two weeks duration which remained undiagnosed after initial clinical, laboratory and radiographic evaluation. 4 of 30 children had positive Gallium scans. Of 25 children with only systemic signs and symptoms in addition to fever, 1 had a positive scan. Of 5 children with more focal complaints, 3 had positive studies: all had localized infections which had remained occult despite imaging with other modalities. We conclude that in most children with FUO, who have only systemic complaints, Gallium scanning is rarely useful. It may be very helpful, however, when there is a suspicion of localized infection, even if other imaging studies are negative. [ABSTRACT FROM AUTHOR]

Few studies have been published that describe the role of scintigraphy in the evaluation of the spectrum of pediatric thyroid disorders. Between 1978 and 1987, we studied 280 children with iodine-123 (123I) scintigraphy. Clinical information and follow-up were available in 246. We analyzed the indications for referral and determined whether the information obtained with this technique was useful in subsequent management. Indications for scintigraphy included hypothyroidism, neck masses, hyperthyroidism, and miscellaneous reasons. Scintigraphy was helpful in distinguishing anatomic from functional causes of hypothyroidism. It reliably identified the location of the thyroid gland in patients with neck masses. The functional status of thyroid nodules was readily assessed and was important in directing further treatment. Scintigraphy added little to the management of children with post-irradiation hypothyroidism without a palpable nodule, patients with Hashimoto thyroiditis or Graves disease when the clinical diagnosis was straightforward. [ABSTRACT FROM AUTHOR]

Measurements were made on sulfur colloid scintigrams of normal pediatric livers and spleens by analyzing 131 scans from 116 patients referred for liver or spleen trauma. Studies were used only if scans were normal, there was no history of malignancy or hepatic or splenic disease either prior to of after the study. Linear correlation was made with age, weight and both age and weight. All measured parameters correlated better with weight than with age, with vertical liver dimension exhibiting the best correlation (r = 0.848). Multivariate analysis demonstrated uniformly better correlation of all measurements with both age and weight. Spleen and liver volumes were calculated assuming simple geometry, and showed excellent correlations. Graphical presentation of data will be useful in the clinical determination of hepatomegaly or splenomegaly in routine scintigraphy. [ABSTRACT FROM AUTHOR]

Purpose: To determine if the minimum administered radiopharmaceutical activity for hepatobiliary scintigraphy can be reduced while preserving diagnostic image quality using enhanced planar processing (EPP). Methods: A total of 40 infants between 10 and 270 days old (body mass 2.2 - 6.5 kg) had hepatobiliary scintigraphy during the period 2004 - 2010 following the intravenous administration of either Tc-mebrofenin (18 patients) or Tc-disofenin (22 patients). Due to the small size of these patients, they all received the minimum administered activity of 18.5 MBq consistent with the North American Consensus Guidelines. Six nuclear medicine physicians subjectively graded the acceptability of the image quality for clinical interpretation using a four-point scale (not acceptable, fair, good, excellent). Each physician independently graded seven image sets including the original study (full activity) and simulated reduced activity studies using binomial subsampling (50 % of full activity, 25 % of full activity and activity reduced by weight), with and without EPP. Results: For full-activity studies, 98 % were deemed acceptable by the six physicians for clinical interpretation. The percentages of acceptable 50 % reduced activity studies with and without EPP were not significantly different from the percentage of acceptable full-activity studies ( P = 0.193 and P = 0.998, respectively). The percentage of acceptable 25 % reduced activity studies without EPP was significantly different from the percentage of acceptable full-activity studies ( P < 0.001); however, this difference vanished when EPP was applied ( P = 0.482). The activity reduced by weight ranged from 1.85 to 4.81 MBq (10 % to 26 % of full dose) and the percentages of acceptable studies with and without EPP were significantly different from the percentage of acceptable full-activity studies ( P < 0.001 and P = 0.02, respectively). Conclusion: Clinically interpretable hepatobiliary scintigraphy images can be obtained in infants when the minimum administered activity is substantially reduced. Without EPP, clinically acceptable images may be produced with a reduction of 50 %, and with EPP, a reduction of 75 % or more may be possible. [ABSTRACT FROM AUTHOR]

The rationale of this study was to investigate the feasibility of three-dimensional (3D) methods to analyze 18F-fluoro-deoxy-glucose (FDG) uptake in children with anaplastic astrocytoma (AA) in a multi-institutional trial, to compare 3D and two-dimensional (2D) methods and explore data associations with progression-free survival (PFS). 3D tumor volumes from pretreatment MR images (fluid attenuation inversion recovery and postgadolinium) of children with recurrent AA on a phase I trial of imatinib mesylate were coregistered to FDG positron emission tomography (PET) images. PET data were normalized. Four metrics were defined: the maximum ratio (maximum pixel value within the 3D tumor volume, normalized), the total ratio (cumulative pixel values within the tumor volume, normalized) and tumor mean ratio (total pixel value divided by volume, normalized). 2D analysis methods were compared. Cox proportional hazards models were used to estimate the association between these methods and PFS. Strongest correlations between 2D and 3D methods were with analyses using postcontrast T1 images for volume of interest (VOI). The analyses suggest 3D maximum tumor and mean tumor ratios, whether normalized by gray matter or white matter, were associated with PFS. This study of a series of pretreatment AA patients suggests that 3D PET methods using VOIs based on postcontrast T1 correlate with 2D methods and are related to PFS. These methods yield an estimate of metabolically active tumor burden and may add prognostic information after tumor grade is determined. Future rigorous multi-institutional protocols with larger numbers of patients will be required for validation. [ABSTRACT FROM AUTHOR]

Gallium-67 has been extensively used to diagnose and localize adult and pediatric inflammatory, infectious and malignant disease. Its mechanism of localizing in pathologic foci, although the subject of numerous studies both in vitro and in vivo, has not been clearly understood yet. The presence of normal polymorphonuclear leukocytes has been reported to be important in the accumulation of the tracer in inflammatory sites. We reviewed our experience with Gallium scintigraphy in three children with chronic granulomatous disease, an entity characterized by defective neutrophils and recurrent infection. Radiogallium was found to localize in inflammation in these patients. Hematologic disorders with specific structural or biochemical defects in their polymorphonuclear leukocytes may provide important information as to how these cells contribute to the accumulation of Gallium-67 in inflammation. [ABSTRACT FROM AUTHOR]

Twenty-eight infants with jaundice were evaluated with ultrasound and radionuclide scans. Comparison of these studies with pathologic, surgical and clinical examinations demonstrated good correlation between ultrasonic and radionuclide studies. Ultrasound is an important preliminary study in the workup of such patients. Combined imaging provides the most information in a patient with suspected biliary atresia. [ABSTRACT FROM AUTHOR]

Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy. 99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than 99mTc DTPA. We reviewed the ultrasound studies and 99mTc DMSA scintigrams of 42 infants (age range 1-12 months) with known or suspected MCDK. Overall, uptake on 99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition. [ABSTRACT FROM AUTHOR]

Presents the results of a case study which tested the use of iodine in the diagnosis of diseases in children. Assessment on the safety of iodine 131 thyroid uptake; Limitations on the use of radioactive iodine in children; Indications for thyroid scanning in children.