Biomedical subjects

W J Shih

Publications and source records attributed to W J Shih.

265 records · Page 15Linked to original sources

PubMedDate not supplied

Giant cell carcinoma of the lung exhibiting a large, well-circumscribed photon deficiency in ventilation/perfusion scintigrams.

Giant cell carcinoma is a specific clinicopathological entity because of its fulminating clinical behavior and peripheral location in the lung. We present two patients with rapidly fatal giant cell carcinoma; each 99mTcMAA and/or 133Xe ventilation scintigrams showed a large, discrete, photon-deficient area in the lung. This unique scintigraphic finding may result from the peripheral location and rapid grawth of the giant cell tumor. Since giant cell carcinoma is a specific clinicopathological entity and of definite significance in establishing the prognosis of patients with lung cancer, 99mTcMAA and/or 133Xe scintigraphic findings may be useful in revealing such a tumor.

Aged↗

PubMedDate not supplied

Diabetic Charcot joint mimicking acute osteomyelitis in radiography and three-phase radionuclide bone imaging study.

Three phase radionuclide bone imaging procedures are used to differentiate cellulitis and osteomyelitis. Acute cellulitis is shown only as increased radioactivity in the blood flow and blood pool images; a persistent area of high activity in a delayed image is usually diagnosed as acute osteomyelitis. We present a patient with Charcot's joint secondary to diabetes mellitus whose three-phase bone imaging as well as radiographic studies revealed a consistent picture of acute osteomyelitis. In the appropriate clinical setting, Charcot's joint, along with several other etiologies (including bone tumors, leukemia, trauma, recent surgery, Paget's disease, and malunion of fracture), should be included in the differential diagnosis.

Arthropathy, Neurogenic↗

PubMedDate not supplied

Tc-99m HMDP bone scintigraphic findings in association with concurrent serum osteocalcin measurements.

Osteocalcin is a noncollagenous bone protein produced by osteoblasts. Increase in serum osteocalcin level reflects osteoblast activity with acceleration of bone formation. To evaluate the correlation of Tc-HDP bone scintigraphic findings and concurrent serum osteocalcin, serum osteocalcin values of 40 consecutive patients were measured by radioimmunoassay at the time of initial referral for bone studies. These patients, all males aged 23-93, were studied for various disease entities, including prostate carcinoma. The results of the assay were categorized into three groups (gp) as follows: 17 at normal (1.8 to 6.6 ng/ml) level (gp 1), 21 low (gp 2), and two high (gp 3). Only one bronchogenic carcinoma patient with a high level had a right iliac lesion suggesting metastasis. The bone scans of nine patients with normal or low levels showed positive metastases. Two patients with stress fractures as shown on bone scans had normal levels. The images of patients with disparity between serum osteocalcin and positive bone lesions may be interpreted as follows: Instead of osteoblastic activity resulting in the synthesis and/or release of osteocalcin, area(s) of increased uptake in the bone scan may be predominantly reflecting increased regional blood flow and decreased sympathetic tone, resulting in an increase in bone-agent deposition.

Adult↗

PubMedDate not supplied

Extracardiac intrathoracic abnormalities demonstrated by Tc-99m RBC gated blood pool imaging.

In addition to intrathoracic great vessel abnormality, pericardial effusion, and splenomegaly, extracardiac intrathoracic abnormalities were found in 12 of 210 patients' 99mTc red blood cell (RBC) gated cardiac blood pool imagings. These abnormalities, including five cases of absent pulmonary perfusion due to tumor mass, four of pleural effusion, two of pneumothorax, and one of left lung mass attenuation, were confirmed with concurrent or subsequent chest radiography, chest CTs, or biopsy. Pulmonary blood pool activity is normally seen on both sides in both anterior and left anterior oblique views; decreased or absent perfusion on either side or in part of the lung may indicate chest/pulmonary pathologies. Although pulmonary and thoracic wall lesions are not frequently seen, such incidental findings during gated cardiac blood pool imagings can lead to further study for these clinically unsuspected lesions and may benefit the patient.

Aged↗

PubMedDate not supplied

Serial bone scintigrams demonstrating obstructive uropathy and nephropathy due to transitional cell carcinoma of the urinary bladder.

Serial 99mTc diphosphonate bone scintigraphic studies of two patients with transitional cell carcinoma of the urinary bladder demonstrated gradually progressive renal dysfunction. The abnormalities in the last bone scan of each patient were compatible with the findings of the concurrent 131I hippuran and 99mTc-DTPA studies, and were presumably secondary to obstruction of the ureteral orifices by tumor in the urinary bladder. Progressive renal dysfunction may be reliably demonstrated by serial 99mTc diphosphonate bone scintigraphy.

Aged↗

PubMedDate not supplied

Thoracic vertebral photopenia may predict fatty changes of the corresponding bone marrow following irradiation.

We present a patient with unresectable bronchogenic carcinoma who underwent irradiation, then had four consecutive bone imaging studies in a 26-month period. Apparent photopenia of the upper thoracic vertebrae developed within six months after irradiation and became more apparent in the images thereafter. At autopsy a section of the corresponding bone marrow showed extensive fatty changes with very few residual blood vessels. Radiation damage of the vascular networks may significantly reduce the blood supply, when integrity of the blood supply is essential for delivery of a normal bone image by the bone-imaging agent. Interruption of blood supply may cause photopenia, and this interruption plus irradiation to marrow elements may also affect the hematopoietic activity of the corresponding bone marrow. The occurrence of radiation-induced photopenia on a bone-imaging study may indicate fatty changes of the corresponding marrow.

Bone Marrow↗

PubMedDate not supplied

Hepatic visualization with a "hot" spot adjacent to the porta hepatis in Tc-99m MAA venography of the lower extremity: a sign of IVC obstruction.

A patient with suspected leg vein occlusion underwent 99mTc-MAA and 99mTc-pertechnetate venographies. The former study showed faint visualization of the liver associated with a large "hot" spot near the porta hepatis, a secondary sign of inferior vena cava obstruction, whereas the latter study did not demonstrate such findings. It is emphasized that the usage of 99mTc-MAA for venography, in addition to allowing detection of pulmonary embolism, has the advantage of visualization of the liver to strengthen the diagnosis of inferior vena cava obstruction.

Humans↗

PubMedDate not supplied

Disappearance of Tc-99m HMDP tumor uptake in oat cell carcinoma after irradiation and chemotherapy.

Extraosseous localization of bone-seeking radiopharmaceuticals has been reported in various tumors, presumably on the basis of active calcium deposition in the tumors. We report a case of oat cell carcinoma in which the initial localization of Tc-99m-HMDP in the tumor disappeared after irradiation and chemotherapy. The disappearance of tracer uptake coincided with regression of the mass as seen in the chest radiograph. This finding may have potential application in determining tumor response to anticancer therapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Additional extrarenal abnormalities seen in Tc-99m DTPA renal flow study.

During 99mTc-DTPA renal flow studies, extrarenal abnormalities have been found to include aortic abnormalities (aneurysm, ectasia, thrombosis, and abruptly decreased flow), splenic abnormalities (enlarged, small, or absent spleen), hepatic arterialization, and very slow circulation. In addition to the above abnormal findings, we add three more extrarenal pathologies that may be concomitantly found with renal flow study: pleural effusion(s), malignancy of the abdomen, and anemia and/or skeletal metastases.

Abdominal Neoplasms↗

PubMedDate not supplied

Extrarenal pelvis mimicking obstructive uropathy in nine years of serial bone scintigraphies.

A woman who underwent mastectomy for left breast carcinoma has been followed-up yearly with bone scintigraphy using Tc-99m diphosphonate compounds for nine years. In the bone images of the initial three years (first, second, and third years postmastectomy), radiotracer accumulation in the right renal upper collecting system had been interpreted as obstructive uropathy. Then the patient underwent initial (third year postmastectomy) and repeat (fifth year postmastectomy) intravenous contrast pyelography (IVP), which revealed an extrarenal pelvis with no significant interval changes. The fourth and fifth bone scintigraphs and the subsequent four consecutive bone scintigraphs showed the same pattern radiotracer retention in the right renal collecting system. Thus, while interpretation of an accumulation of radiotracer in the upper renal collecting systems on a single bone scintigraphy may provide difficulty in making a differential diagnosis between obstructive uropathy and extrarenal pelvis, IVP is important for definitive diagnosis. Alternatively, a review of the previous consecutive bone studies, if available, may also aid in this differentiation, since obstructive uropathy may manifest as progressive renal dysfunction, while extrarenal pelvis may have the same pattern of radiotracer accumulation in the collecting system persistently.

Bone and Bones↗

PubMedDate not supplied

99m-Tc HMDP bone scintigraphic findings of gouty arthropathy of both hands: extending soft tissue uptake adjacent to the joints.

The 99mTc hydroxy methylene diphosphonate scintigraphic findings of both hands are correlated to the radiographic findings in a patient with a 30-year history of gouty arthropathy. Scintigraphic differentiation of the type of arthritis on the basis of uptake pattern is difficult. However, the findings of rheumatoid arthritis are confined to the joints and usually the involvement is symmetrical. With gout there is a tendency toward asymmetrical, bilateral, multifocal joint involvement with areas of intense abnormal uptake; because of the associated soft tissue swelling, the intense uptake usually extends beyond the involved joints.

Arthritis↗

PubMedDate not supplied

Massive splenic metastases with localization of a skeletal imaging agent.

A 70 year old man with squamous cell carcinoma of the lung underwent Tc-99m sulfur colloid liver-spleen scintigraphy and abdominal CT studies; both studies showed multiple large lesions in the massively enlarged spleen, with a cystic appearance being noted on the CT examination. Two consecutive Tc-99m HMDP bone scintigrams demonstrated mild, diffuse radioactivity in the region of the spleen, indicating extraosseous localization of the bone imaging agent in the spleen and suggesting solid tumor masses rather than cysts. At autopsy, the huge spleen weighing 2,200 gm contained multiple, large, metastatic masses. Some of the masses were undergoing necrosis/liquification which would explain the cystic appearance on CT. While bone scintigraphy plays an important role in the detection of skeletal metastatic lesions, extraosseous localization of the imaging agent can provide additional diagnostic information.

Aged↗

PubMedDate not supplied

Tc-99m HM-PAO pulmonary imaging of large cell carcinoma in the lung of a smoker showing a rounded photon deficient area.

Tc-99m HM-PAO has been used as a tumor-imaging agent because this radiopharmaceutical localizes in tumor masses, including lung carcinoma. We present a smoker with giant-cell-carcinoma of the lung whose Tc-99m MAA and Tc-99m HM-PAO lung images showed a photon-deficient area corresponding to the tumor mass. Rapid growth of large cell carcinoma leading to tumor necrosis and interruption of blood flow resulted in a localized photon deficient area in diffuse lung uptake secondary to a long smoking history on a Tc-99m HM-PAO lung images.

Carcinoma, Non-Small-Cell Lung↗