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Biomedical subjects

M Fernandez-Ulloa

Publications and source records attributed to M Fernandez-Ulloa.

At least 19 recordsLinked to original sources
PubMed1998

Orthopaedic nuclear medicine: the pelvis and hip.

Bone scintigraphy is a sensitive method useful in the diagnosis of specific skeletal problems encountered in orthopaedic and sports medicine. Often, in these situations, routine radiographic evaluation may provide negative or questionable information. Bone scintigraphy is also useful in the evaluation of patients with ill-defined or persistent bone pain not satisfactorily explained by positive radiologic evaluation. In these situations, because of its ability to image the whole body, bone scintigraphy may reveal additional unsuspected traumatic pathology, Finally, nuclear medicine physicians need to be prepared to properly interpret findings unrelated to trauma and to direct the evaluation of patients toward the correct diagnosis and subsequent management. These goals can be achieved by using optimal imaging technique, by becoming familiar with the patient's clinical presentation, by understanding the biomechanics and pathophysiology of the entities encountered, by proper use of alternative diagnostic procedures, and by establishing good rapport with referring physicians.

Athletic Injuries↗
PubMed1995

Scintigraphic evaluation of pancreatic transplants using technetium-99m-sestamibi.

UNLABELLED: The purpose of this study was to evaluate the feasibility of using 99mTc-sestamibi in the assessment of pancreatic transplant. METHODS: Ten transplant recipients with a history of insulin-dependent diabetes mellitus were studied. Fourteen 99mTc-sestamibi studies were performed. Each patient was injected intravenously with 10 mCi of 99mTc-sestamibi. Two-second frames were obtained for 1 min, followed by serial dynamic and static images every 5 min for 30 min. Technetium-99m sestamibi studies, read by two nuclear medicine physicians, were correlated with clinicopathologic findings and compared to the ten 201Tl studies obtained in seven of these patients. RESULTS: On 99mTc-sestamibi images, normally functioning grafts showed adequate perfusion on the angiogram and good uptake followed by clearance on static images. Time-activity curves showed an initial upslope followed by a downslope after the initial uptake peak. The quality of 99mTc-sestamibi images was superior to those of 201Tl in five, similar in four and marginally inferior in one paired study. Technetium-99m-sestamibi was used for both flow and static images, whereas a 99mTc radiotracer angiogram was needed to accompany the 201Tl study. CONCLUSION: Our preliminary experience indicates that 99mTc-sestamibi helps evaluate pancreatic transplants and provides high count statistics, which result in better image quality and diagnostic detail. Extensive quantitative studies are being performed to further evaluate this agent's role in the clinical management of pancreatic transplant patients.

Adult↗
PubMed1989

Detection of acute osteomyelitis with indium-111 labeled white blood cells in a patient with sickle cell disease.

A young patient with sickle cell disease (SCD) and multiple hospitalizations for crisis was admitted because of suspected osteomyelitis. Initial laboratory work, radiographs, and bone images were not contributory. An In-111 white blood cell (WBC) study demonstrated two areas of increased radionuclide uptake consistent with osteomyelitis. One of these had associated soft tissue infection. No other areas of active osteomyelitis were visualized, in spite of the presence of several additional infection sites. Imaging with In-111 WBC is probably not justified for routine diagnosis of acute osteomyelitis in areas free of previous disease, where conventional bone images are highly efficient. In-111 WBC imaging, however, may be helpful in detecting osteomyelitis in selected patients with SCD in whom Tc-99m bone images and radiographs are usually abnormal and difficult to interpret due to previous bone infarcts. Localization of the infection focus is very important in choosing the aspiration site for bacteriologic studies. A negative study, however, should be interpreted cautiously.

Adolescent↗
PubMed1989

Solitary defect on liver sulfur colloid imaging secondary to focal fatty infiltration.

Radionuclide liver-spleen imaging using Tc-99m SC may identify focal defects on routine examinations. Fatty infiltration has generally been described as a diffuse process in the liver that may be manifested on Tc-99m SC liver imaging as a nonhomogeneous pattern of radiopharmaceutical distribution or multiple small defects. This case demonstrates a focal defect on radionuclide imaging, simulating a space-occupying lesion that ultimately proved to be focal fatty infiltration. Although not an uncommon finding on CT, to the authors' knowledge this has not been reported in the nuclear medicine literature to date.

Adipose Tissue↗
PubMed1988

Anatomic and position-induced increased radiopharmaceutical uptake in the cervical spine on bone imaging.

The finding of increased radiopharmaceutical (RP) in the cervical spine was noted in a patient when placed in the full forward flexion position. When imaged in the neutral position, this finding was not noted. A series of 10 consecutive patients demonstrated this finding. The positioning of the cervical spine erroneously manifested increased RP uptake, which may mimic disease and should be taken into account when positioning the cervical spine for routine imaging.

Adult↗
PubMed1988

Intra-abdominal abscess demonstrating an unusually large intra-abdominal pattern on an indium-111 leukocyte scan.

Indium-111 WBC imaging of a patient with occult septicemia revealed a large focal pattern of radiopharmaceutical distribution within the abdominal cavity at 24 hours post radiopharmaceutical administration. This finding was felt to represent a large intra-abdominal abscess. A five liter peritoneal abscess was found at surgery. This case illustrates an unusual presentation of an intra-abdominal abscess.

Abdomen↗
PubMed1987

Variations in serum thyroxine concentrations with time after an oral replacement dose.

Serum thyroxine concentrations were measured sequentially in eight healthy male volunteers after the oral administration of one of two brand name, commercially available thyroxine tablets. In all cases, levels peaked at 2 hours and did not return to baseline values until 24 hours after dosing. From 2 through 10 hours, statistically significant elevations in serum thyroxine concentrations were observed. Such fluctuations may be important in evaluating laboratory results in patients receiving replacement doses of thyroxine.

Administration, Oral↗
PubMed1987

Esophageal motility studies in patients with Raynaud's phenomenon.

Esophageal motility was assessed in 40 patients with Raynaud's phenomenon by barium cineesophagram and radionuclide transit. Nineteen were further evaluated by esophageal manometry. Barium cineesophagram and radionuclide transit findings were discordant in 33%. A 20% intraobserver reading variation in barium cineesophagrams was noted. Results of esophageal manometry correlated with radionuclide transit (p = 0.06) but not with barium cineesophagram. Radionuclide transit studies appear useful in the evaluation of esophageal dysfunction in early connective tissue disease.

Adult↗
PubMed1985

Pseudo-vascular tumor in a renal flow study.

A case in which, for the first time, the superior mesenteric artery caused an appearance mimicking vascular tumor on a kidney radionuclide angiogram (RNA) obtained posteriorly, is reported. A subsequent contrast arteriogram showed that the superior mesenteric artery caused that appearance and confusion with possible vascular tumor on RNA. No similar cases with mesenteric blush simulating vascular tumor have been found in the literature. Mesenteric blushes on RNAs obtained posteriorly have been described only in cases of kidney agenesis and post-nephrectomy. This pattern should be kept in mind when interpreting RNAs to avoid subjecting patients to invasive diagnostic procedures.

Humans↗
PubMed1985

Gallium-67 lung uptake: conjugate-view technique.

A conjugate-view technique is derived for calculation of absolute gallium-67 (Ga-67) uptake from scintillation-camera images. The technique combines counts of posterior and anterior images of the lung with an attenuation correction obtained from cobalt-57 (Co-57) transmission imaging. The formulation is such that the effects of Compton scatter build-up are accounted for. Studies utilizing a canine model indicated that, normally, more activity is located in the chest wall than in the lungs. The quantitative technique must therefore accurately account for a variety of Ga-67 distributions, including that in the chest wall. Calculations were performed using a three-component model comparing results obtained with the conjugate-view approach to the actual uptake. These calculations suggest that an assumption of uniform activity distribution allows an accuracy of approximately +/- 10% over a broad range of body-part thicknesses and uptake by the lungs. It was concluded that the conjugate-view technique is necessarily approximate but can provide clinically useful results.

Animals↗
PubMed1985

Radioaerosol lung clearance in patients with active pulmonary sarcoidosis.

Pulmonary radioaerosol clearance rate of 99mTc diethylenetriamine pentacetate (DTPA) in 14 patients with untreated sarcoidosis was compared with 67Ga lung scan and increased lymphocytes in the bronchoalveolar lavage (BAL) fluid. Nine healthy nonsmoking subjects had a mean DTPA clearance rate of 1.18%/min (range, 0.54 to 1.60%/min). Eight of 14 patients with sarcoidosis had clearance rates greater than 1.60%/min. Of those 8 patients with abnormal DTPA clearance, 4 had positive gallium scans, 4 had more than 17% lymphocytes in the BAL fluid, and 3 had both tests positive. To study the cause of abnormal DTPA clearance, 23 subjects (including 3 normal controls, all 14 patients with sarcoidosis, and 6 patients with localized disease on chest roentgenogram) underwent both DTPA clearance studies and BAL for quantitation of the amount of albumin in lung fluid. There was a positive correlation between the rate of DTPA clearance and the albumin concentration in lung fluid (r = 0.87, p less than 0.01).

Aerosols↗
PubMed1985

Diagnosis of vertebral osteomyelitis: clinical, radiological and scintigraphic features.

Incidence of non-tuberculous vertebral osteomyelitis has been increasing significantly over the past 15 years. Its prompt diagnosis remains difficult. Presented here are five cases of vertebral osteomyelitis studied clinically, with laboratory studies, radiographically, and with Tc-99m bone and In-111 labeled white blood cells (In-111 WBC) scintigrams. Three of the cases are described in detail. The In-111 WBC studies were not found useful in detecting the infection in four out of the five patients. Reasons for these false negative results are discussed. Clinical, etiopathogenic and radiographic characteristics of vertebral osteomyelitis are also presented.

Adult↗