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Biomedical subjects

M H Pui

Publications and source records attributed to M H Pui.

26 records · Page 2Linked to original sources
PubMed1995

Musculoskeletal melioidosis: clinical and imaging features.

OBJECTIVE: Melioidosis is a tropical infection caused by a gram-negative bacillus, Pseudomonas pseudomallei. The disease manifests initially as localized suppurative lesions and can progress to acute disseminated septicemia with 65-90% mortality if inadequately treated. Musculoskeletal involvement is common. The purpose of this study was to describe the clinical features and imaging appearances of musculoskeletal melioidosis. DESIGN: We retrospectively analyzed the clinical profiles and images of 26 patients diagnosed over a 6-year period as suffering from melioidosis. PATIENTS: The study group comprised 11 patients with musculoskeletal melioidosis and 15 patients with nonmusculoskeletal melioidosis. RESULTS AND CONCLUSIONS: We found that musculoskeletal melioidosis mimicks other infections both clinically and radiologically. Clinical awareness is therefore crucial, as diagnosis can only be established by bacteriological and immunological studies. Prompt treatment with long-term combination antibiotics in high dosages and surgical drainage of abscesses improves survival.

Adult↗
PubMed1995

Imaging patterns in melioidosis.

Melioidosis is an infectious disease caused by Pseudomonas pseudomallei. It is seldom diagnosed promptly and, if untreated, can lead to an 80-100% mortality rate. Twenty-eight patients with melioidosis were identified over a 6 year period, and their imaging patterns were analysed. Respiratory infections were the commonest form of presentation, frequently shown as diffuse airspace consolidation, and accounted for the highest mortality. Visceral and musculoskeletal infections were associated with chronicity and a high relapse rate. Multifocal splenic abscesses were a common occurrence. Septic arthritis of the knee was frequently seen. The majority of patients had diabetes mellitus and chronic ill-health. An increased awareness of the disease can contribute to its early detection and appropriate treatment.

Abscess↗
PubMed1995

MR imaging of the brain: comparison of gradient-echo and spin-echo pulse sequences.

OBJECTIVE: Gradient-echo pulse sequences can reduce imaging time and decrease motion artifacts. If gradient-echo pulse sequences are shown to be comparable to spin-echo sequences in MR imaging of the brain, then gradient-echo imaging can be valuable for examining critically ill, anxious, or uncooperative patients and can increase patient throughput. The purpose of this study was to prospectively compare one fast multiplanar spoiled gradient-recalled acquisition in the steady state (GRASS) (FMPSPGR) sequence with one conventional T1-weighted spin-echo sequence to determine the reliability of the FMPSPGR sequence for detecting cerebral lesions. SUBJECTS AND METHODS: Fifty-one patients with 142 cranial lesions, including brain tumors, infarction, infection, and noninflammatory lesions, were examined. Forty-two unenhanced and 39 contrast-enhanced FMPSPGR (113-240/2.6-3.6/90 degrees/4 [TR/TE/flip angle/acquisitions]) and spin-echo T1-weighted (400-579/11-12/90 degrees/2) MR images of the head were obtained with a 1.5-T system. The visibility, margination, and extent of the lesions; image quality; contrast; and artifacts were qualitatively and quantitatively compared. RESULTS: Supratentorial lesions were more conspicuous on the unenhanced FMPSPGR images because of the higher signal-to-noise ratio of the normal brain resulting in higher lesion contrast. The higher contrast-to-noise ratio of neoplasms on the contrast-enhanced spin-echo images was not found to be significant in the independent qualitative analysis. The conspicuity and extent of other lesions evaluated with the two pulse sequences were not significantly different for either the unenhanced or the contrast-enhanced studies. Vascular pulsation artifacts were significantly reduced on the contrast-enhanced FMPSPGR images. Susceptibility and chemical-shift phase-cancellation artifacts were more pronounced on the FMPSPGR images. CONCLUSION: The FMPSPGR sequence provides high-quality images with fewer vascular pulsation artifacts three to four times faster than the spin-echo sequence. The FMPSPGR sequence can reliably show intracranial lesions and can substitute for the T1-weighted spin-echo sequence in routine brain imaging.

Adolescent↗
PubMed1994

Granulocytic sarcoma in childhood leukemia: imaging features.

PURPOSE: To assess imaging features of granulocytic sarcoma (GS) in children with myelogenous leukemia. MATERIALS AND METHODS: Retrospectively analyzed were radiographs, bone scintigrams, ultrasound (US) scans, computed tomography (CT) scans, and magnetic resonance (MR) images obtained in 30 patients with acute and one with chronic myelogenous leukemia. RESULTS: With one exception in which GS antedated leukemia, GS was present concurrently with onset of leukemia or during remission or relapse. Radiographs, nuclear studies, and US findings were nonspecific. One parascapular GS was hyperintense on T2-weighted MR images, but in all eight central nervous system studies, tumors were isointense to gray matter, muscle, or marrow on T1-weighted images and to white matter or muscle, marrow, or both on T2-weighted images. Contrast enhancement of GS was homogenous on cranial CT scans and all MR studies. CONCLUSION: CT and MR imaging features may allow distinction of GS from hematomas and abscesses, which are also complications of leukemia. Thus, biopsy may be avoided in some patients.

Child↗
PubMed1994

Magnetic resonance imaging of splenic hemangiomatosis.

The authors report a case of splenic hemangiomatosis evaluated by magnetic resonance imaging (MRI). Typical areas of hyperintensity were observed in T2-weighted images. Because it is noninvasive and highly sensitive, MRI proved valuable in suggesting the diagnosis in this patient.

Aged↗
PubMed1986

False-normal bone imaging in spinal tuberculosis.

Tc-99m MDP bone imaging in spinal tuberculosis usually shows increased radioactivity at the sites of involvement. Uncommonly, the bone scan can be normal if the infection is low grade, indolent, or severely destructive. Two cases of spinal tuberculosis with normal bone imaging are reported. A normal bone image does not exclude tuberculous spondylitis. If there is clinical suspicion of this disease, further investigations, including tissue specimens, should be obtained.

Aged↗
PubMedDate not supplied

Gd-DTPA enhancement of CSF in meningeal carcinomatosis.

OBJECTIVE: We report four cases of CSF enhancement secondary to meningeal carcinomatosis observed during MRI. Only one case has been reported previously. MATERIALS AND METHODS: Four patients ranging from 4 to 20 years of age, and all having primary or secondary CNS neoplasms, were examined by cranial and/or spinal MRI before and after Gd-DTPA administration. Three of the patients had additional delayed imaging, and subtraction was used in one case. RESULTS: All four patients demonstrated CSF enhancement after Gd-DTPA administration, which increased on delayed imaging and was more apparent following subtraction. Three of the four patients died within 5 months of the MRI examination. CONCLUSION: CSF enhancement is uncommon, but when seen indicates massive tumor that coats the surface of the CNS. Detection of CNS enhancement may alter therapy; however prognosis may be poor when CSF enhancement is present. Delayed imaging and subtraction may improve detection of CSF enhancement.

Adult↗