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Biomedical subjects

D M Achong

Publications and source records attributed to D M Achong.

At least 19 recordsLinked to original sources
PubMed2001

I-123 uptake by mediastinal goiter after recombinant human thyroid-stimulating hormone administration.

Radioiodine scintigraphy is useful to confirm the presence of mediastinal thyroid tissue. However, the degree of iodine avidity of mediastinal goiters varies. Recombinant human thyroid-stimulating hormone given to stimulate iodine uptake by thyroid remnants and thyroid cancer metastases can now replace thyroid hormone withdrawal scanning of selected patients who have well-differentiated thyroid carcinoma. A case of mediastinal goiter visualized with I-123 after the administration of recombinant human thyroid-stimulating hormone is reported.

Aged↗
PubMed1999

Normal gallbladder ejection fraction after morphine augmentation.

PURPOSE: Morphine sulfate causes spasm of the sphincter of Oddi. Conversely, the cholecystagogue sincalide produces relaxation of the sphincter and contraction of the gallbladder. This prospective study evaluated whether sincalide could produce normal gallbladder emptying after low-dose morphine sulfate (0.04 mg/kg). METHODS: Thirty to 120 minutes (mean, 51 minutes) after morphine sulfate-augmented gallbladder visualization, 25 gallbladder ejection fractions in 24 patients were measured. One patient was studied twice, 2 weeks apart. Gallbladder ejection fractions were calculated after controlled 30-minute infusions of sincalide (0.02 microg/kg). RESULTS: Fourteen gallbladder ejection fractions were normal (mean, 63%; range, 45% to 80%) and 11 gallbladder ejection fractions were abnormal (mean, 12%; range, 5% to 19%; P < 0.001). CONCLUSIONS: Normal gallbladder ejection fractions can be obtained as early as 30 minutes after administration of low-dose morphine sulfate. Potential applications of post-morphine sulfate sincalide challenge would include, for example, to support true-negative morphine sulfate-augmented gallbladder visualization in a patient with a high clinically indicated potential of having acute cholecystitis.

Adult↗
PubMed1996

Gallbladder nonvisualization with pericholecystic rim sign: morphine-augmentation optimizes diagnosis of acute cholecystitis.

UNLABELLED: This study investigated the value of morphine-augmentation in patients who demonstrated gallbladder nonvisualization with a pericholecystic rim sign at 1 hr, a cholescintigraphic pattern considered highly predictive of acute cholecystitis. METHODS: Retrospectively, 170 consecutive morphine-augmented cholescintigrams were analyzed for the presence of a pericholecystic rim sign, marked or mild, associated with gallbladder nonvisualization at 1 hr (before morphine); those with a pericholecystic rim sign were further evaluated for persistent gallbladder nonvisualization versus gallbladder visualization after morphine. Scintigraphic interpretations were correlated with surgical pathology or clinical diagnosis. RESULTS: Before morphine, 43/170 (25%) patients demonstrated gallbladder nonvisualization with a pericholecystic rim sign. Since only 31 had acute cholecystitis, a diagnosis based solely on that scintigraphic pattern would have resulted in 12 false-positives. After morphine, gallbladder visualization correctly excluded acute cholecystitis in seven; a single false-negative was encountered; five false-positives remained. Morphine-augmentation improved the positive predictive value from 72% (gallbladder nonvisualization with pericholecystic rim sign before morphine) to 86% (gallbladder nonvisualization after morphine). Of 24 patients with marked pericholecystic rim signs, 21 had acute cholecystitis. Of 31 with acute cholecystitis, however, 10 (32%) had a mild pericholecystic rim sign. CONCLUSION: Morphine-augmented cholescintigraphy optimizes the diagnosis of acute cholecystitis in patients with the suggestive, but not pathognomonic, cholescintigraphic pattern at 1 hr of gallbladder nonvisualization with a pericholecystic rim sign, regardless of its intensity.

Acute Disease↗
PubMed1995

Diffusely discordant In-111 WBC/Tc-99m SC bone marrow uptake. A possible chemotherapeutic effect.

In-111 WBC scintigraphy in a woman with relapsed acute lymphoid leukemia demonstrated normal uptake of white blood cells by the liver and spleen, but virtually absent bone marrow activity. Tc-99m SC imaging confirmed normal marrow function and distribution. A bone marrow biopsy revealed mildly hypocellular, regenerating marrow without leukemic infiltration. The effects of systemic cytotoxic chemotherapy on marrow reticuloendothelial function may have been responsible for this discordant uptake.

Bone Marrow↗
PubMed1994

A reversed sequence of gallbladder and small bowel visualization during cholescintigraphy. Its relationship to chronic cholecystitis.

During the first hour of cholescintigraphy, both the gallbladder and small bowel are visualized in the majority of normal subjects and patients with chronic cholecystitis. Usually, radioactive bile flows initially into the gallbladder followed by passage into the small bowel. To determine whether a reversed sequence of bile flow (i.e., small bowel followed by gallbladder) could serve as an indicator of chronic cholecystitis, 141 hepatobiliary scans were reviewed retrospectively with attention to the relative order of gallbladder and small bowel appearance during the first hour. The scintigraphic findings were correlated with results from real-time gallbladder ultrasonography in all 141 patients and gallbladder histopathology in a subset of 35 (25%). The specificity of a reversed sequence for chronic cholecystitis was 79% using ultrasonography and 100% for histopathology. This phenomenon likely reflects altered biliary flow dynamics secondary to recurrent inflammation and fibrosis. In patients referred for possible biliary tract disease, visualization of the gallbladder after the small bowel appears to predict chronic cholecystitis.

Aniline Compounds↗
PubMed1994

Gallium-avid painless thyroiditis in a patient with AIDS.

Intense thyroidal Ga-67 accumulation was seen in a man with AIDS imaged for suspected Pneumocystis carinii pneumonia. Concurrent Tc-99m pertechnetate thyroid scanning demonstrated absent trapping, helping establish the diagnosis of painless thyroiditis. Occult hyperthyroidism, and not pulmonary infection, may have been responsible for the patient's original presenting symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Periprosthetic Clostridium difficile hip abscess imaged with In-111 WBCs.

During a prolonged hospital stay, left hip pain developed in a woman with sickle cell disease and bilateral hip prostheses. In-111 labeled WBC scintigraphy supplemented by Tc-99m SC bone marrow imaging demonstrated abnormal WBC accumulation surrounding the left greater trochanter. Results of surgical exploration showed an abscess involving the pseudocapsule, trochanteric bursa, and periprosthetic cement column. Cultures grew Clostridium difficile, an unusual pathogen in this site.

Abscess↗
PubMed1994

Hepatic hemangioma in cirrhotics with portal hypertension: evaluation with Tc-99m red blood cell SPECT.

PURPOSE: To determine whether extensive shunting associated with portal hypertension (PH) adversely affects the diagnostic accuracy of technetium-99m red blood cell (RBC) single photon emission computed tomography (SPECT) for hepatic hemangioma (HH). MATERIALS AND METHODS: Nineteen possible HHs (1.0-11.0 cm in diameter) in 15 cirrhotics with PH were studied with RBC SPECT. RESULTS: RBC SPECT allowed correct categorization of four HHs (1.5, 2.8, 4.0, and 4.0 cm in diameter) and 13 non-HHs (1.5-11.0 cm in diameter). Two small HHs (1.0 and 1.4 cm in diameter) were "missed." Sensitivity, specificity, and accuracy were 67%, 100%, and 89%, respectively. CONCLUSION: Despite abnormal liver blood flow dynamics due to portosystemic collateralization, RBC SPECT allows reliable identification of HH in cirrhotics with PH. As in noncirrhotics, its major limitation is small lesion size.

Adult↗
PubMed1994

The computer-generated bone marrow subtraction image: a valuable adjunct to combined In-111 WBC/Tc-99m in sulfur colloid scintigraphy for musculoskeletal infection.

In-111 WBC scintigraphy supplemented by visual comparison with concurrent Tc-99m SC bone marrow imaging is used to identify infection within the marrow-containing skeleton. This retrospective study demonstrates the value of the computer-generated WBC/SC bone marrow subtraction image. Thirty-one patients with various conditions (postsurgery with or without orthopedic hardware, bacteremia with persistent fever, joint arthroplasty, and miscellaneous) underwent combined WBC/SC with bone marrow subtraction imaging. Infection was present in 21 of 36 possible sites (14 osseous, 7 soft tissue; 8 acute, 13 chronic). The bone marrow subtraction image identified two of these sites, which were not appreciated by visual inspection. The sensitivity, specificity, and accuracy for bone marrow subtraction were 95%, 93%, and 94%, respectively, as compared to 86%, 93%, and 89%, respectively, for the visual assessment of WBC and SC images. Computer-assisted subtraction imaging improves overall accuracy and enhances diagnostic certainty of combined WBC/SC scintigraphy for infection in the marrow-containing skeleton.

Adult↗
PubMed1993

Mesenteric lymphadenitis depicted by indium 111-labeled white blood cell imaging.

An acutely ill child with abdominal pain and concomitant pharyngitis often presents a diagnostic challenge. This report describes how indium 111-labeled white blood cell imaging helped to clarify the confusing case of a 4-year-old boy with fever, pharyngitis, and abdominal pain. The triad of abnormal white cell localization in the nasopharynx, cervical lymph nodes, and right lower abdominal quadrant supported the diagnosis of a systemic infection rather than appendicitis, abscess, or another surgical condition. Mesenteric lymphadenitis associated with systemic infection should be included in the differential diagnosis of abdominal pain in a child with this clinical presentation.

Abdominal Pain↗
PubMed1993

Septic pulmonary emboli from pulmonic valvular endocarditis demonstrated by serial ventilation-perfusion lung imaging.

The evolution of multiple ventilation-perfusion mismatches on serial lung scintigraphy in a fully anticoagulated, bacteremic patient with small pulmonary infiltrates and repeatedly negative Doppler ultrasonography of the lower extremities suggested pulmonary emboli from right-sided valvular endocarditis. The demonstration of pulmonic valvular vegetations on follow-up transesophageal echocardiography supported this diagnosis. In the proper clinical setting, septic pulmonary emboli should be included in the differential diagnosis of high-probability ventilation-perfusion lung imaging.

Diagnosis, Differential↗
PubMed1992

Early gallbladder visualization during Tc-99m RBC scintigraphy.

Gallbladder visualization has been described during delayed Tc-99m RBC blood pool imaging in patients with some combination of anemia, renal disease, and multiple recent blood transfusions. The authors present two cases of gallbladder activity that appeared 1 hour after the injection of Tc-99m RBCs in patients without renal or hematologic abnormalities.

Erythrocytes↗
PubMed1992

Incidence and significance of enterogastric reflux during morphine-augmented cholescintigraphy.

One hundred fourteen patients with suspected acute cholecystitis underwent morphine-augmented cholescintigraphy. The 115 studies were reviewed first to determine the incidence of enterogastric reflux under these conditions. Overall, enterogastric reflux was observed in 85/115 (74%), occurring only after intravenous morphine sulfate in the majority (59%, 50/85). Noted prior to morphine in 41% (35/85), the degree of enterogastric reflux increased noticeably directly following drug administration in over half of these cases. Surgical diagnoses were established in 73/114 (64%) patients as follows: 56 (77%) acute cholecystitis, 15 (20%) chronic cholecystitis, and 2 (3%) another entity (normal gallbladder and tumor encasement). These pathologically proven cases were examined more closely to address the diagnostic significance of enterogastric reflux during morphine-augmented cholescintigraphy. Enterogastric reflux was demonstrated in the majority of not only those with acute cholecystitis (48/56, 86%), but also those with chronic cholecystitis (12/15, 80%). A frequent but nonspecific finding, enterogastric reflux appears to be a pathophysiologic phenomenon that may be enhanced synergistically, at least to some degree, in patients requiring morphine-augmented cholescintigraphy.

Aniline Compounds↗