PubMed HealthSearch

Biomedical subjects

P C Ram

Publications and source records attributed to P C Ram.

16 recordsLinked to original sources

Extracranial cribside sonography in infants.

In 29 real-time ultrasonic studies of infants in the intensive care nursery, the technique either accurately diagnosed or led directly to the correct diagnosis in 27 (93%). Twenty-four of these infants had suspected abnormality in the abdomen or pelvis, three had congestive heart failure and bruits, one had respiratory distress and an opacified hemithorax on chest roentgenogram, and one was a child with ambiguous genitalia in whom sonography identified a uterus. We suggest that portable, real-time ultrasonography is an ideal modality with which to study seriously ill infants whose medical condition precludes transport to the radiology department.

Arteriovenous Malformations

CT appearance of abdominal thorotrast deposition and Thorotrast-induced angiosarcoma of the liver.

Although the clinical and radiographic manifestations of Thorotrast and its complications have been described, the computed tomographic (CT) appearance of Thorotrast deposition in the abdomen is less well known. Thorotrast produces a characteristic opacification of the liver, spleen, and abdominal lymph nodes. We report two cases of patients with Thorotrast-induced angiosarcoma of the liver detected by CT. Computed tomography in both cases demonstrated space-occupying lesions in the liver, which were readily detectable because of distortion of the Thorotrast-produced opacification.

Aged

Computed tomography of pleural disease.

The computed tomography (CT) scans of 65 cases with histologic and clinical evidence of pleural disease were reviewed. The studies were analyzed according to the following CT features of the lesions: attenuation coefficient, contour, angle of interface with the adjacent pleura, and relationship to the adjacent lung, bone, and extrapleural tissues. The CT feature most helpful in detecting pleural involvement was the angle formed by the interface of the lesion with the adjacent pleura. An obtuse or tapering angle was seen in lesions involving the pleura. The other CT features are useful in identifying the site of origin and the specific nature of a lesion.

Humans

Age-related changes in the thymus gland: CT-pathologic correlation.

Recent reports suggest that computed tomography (CT) is useful for thymoma detection in patients with myasthenia gravis. However, that usefulness may be conditioned by the state of the normal thymus. To examine this concept, the CT findings in 64 consecutive patients with histologic confirmation of thymic status after thymectomy or thymic biopsy during mediastinal exploration were reviewed. The normal thymus has a bilobed, arrowhead-shaped cross section at all ages, with gradual focal or diffuse fatty infiltration of the parenchyma usually occurring between 20 and 40 years of age. A thymoma is usually a spherical or oval mass, often producing a focal, distinct bulge in the adjacent pleural reflection. The differentiation of thymoma from normal thymus should be possible in most patients if age-related changes in the normal gland are appreciated.

Adolescent

CT demonstration of subcutaneous venous collaterals.

Subcutaneous collateral veins were identified by computed tomography (CT) in 12 patients. These were seen as enhancing round or tubular structures surrounded by subcutaneous fat, and most were associated with occlusion of a major vein in the abdomen or thorax. The CT appearance of deep vein occlusions included an intraluminal thrombus with an enhancing rim, a mass replacing the nonvisualized vein and distortion of the vein by an adjacent mass. The subcutaneous fat was examined on the CT scans of 50 patients not suspected of having deep venous occlusions. The appearance of normal subcutaneous structures and the differential diagnosis are discussed.

Collateral Circulation

Thymoma detection by mediastinal CT: patient with myasthenia gravis.

The precise role of computed tomography (CT) in evaluating the mediastinum for thymomas in patients with myasthenia gravis is not defined. The only published CT accuracy assessment reports a false-positive rate of 90%. Mediastinal CT was performed in 23 consecutive unselected patients with myasthenia gravis who underwent thymectomy independent of their neurologic status or diagnostic imaging results. Four patients had discrete thymomas; all were detected by CT. Conventional chest radiography and tomography were positive in three and falsely negative in one. In the remaining 19 patients with a normal or atrophic thymus or microscopic hyperplasia, CT was falsely positive in two; conventional chest radiography and tomography were falsely positive in three. Mediastinal CT is an accurate technique for evaluation of thymoma in patients with myasthenia gravis.

Adolescent

Volume determinations using computed tomography.

Computed tomography potentially offers the most accurate noninvasive means of estimating in vivo volumes. Contiguous 1-cm-thick CT scans were obtained through phantoms, dog kidneys in vivo, and human spleens before splenectomy. Cross-sectional areas were calculated for each individual scan and volumes then determined with each of four mathematical integration techniques. Volume estimations were compared to volumes determined by water displacement. The simplest, most practical means of calculating volumes, using the summation-of-areas technique with scans obtained at 2 cm intervals, was similar in accuracy to more complex methods. The mean percentage error of volume calculations using the sum-of-areas technique was 4.95% for five immobile phantoms, 3.86% for eight dog kidneys, 3.59% for eight human spleens in vivo at 1 cm scan spacing, and 3.65% for the same human spleens at 2 cm scan spacings. Difficulties in visual recognition and manual tracking of object boundaries seem to be more significant sources of error than patient-related factors.

Animals

Parapelvic cysts: appearance on CT and sonography.

The computed tomographic (CT) and sonographic appearance of 16 patients with parapelvic cysts were retrospectively reviewed. CT revealed a water-density renal hilar mass that did not fill with contrast material after intravenous injection. Sonography demonstrated a cystic renal hilar mass with echogenic walls that did not communicate with the collecting system. The differential diagnosis of renal hilar masses as seen by CT and sonography is discussed.

Adult

Review. In utero sonographic diagnosis of fetal cerebral anomalies.

Obstetric sonography can be used to diagnose anomalies in the fetal brain. Cystic masses in the fetal brain may be due to hydrocephalus, hydranencephaly, holoprosencephaly, or arachnoid cysts. The relations of the falx cerebrum, ventricular system, and cerebral convexities are essential in distinguishing among these anomalies. Anencephaly and encephaloceles can also be detected by sonography. A review of the literature and experience with 10 cases is discussed.

Anencephaly

CT appearance of focal fatty infiltration of the liver.

Focal fatty infiltration of the liver is an entity that may be confused with liver metastasis on computed tomography (CT). The imaging results and medical records of 16 patients with CT appearance suggestive of focal fatty liver were reviewed, three of whom had the simultaneous presence of metastatic liver disease. Focal fatty liver often has a distinctive appearance with CT, usually with a nonspherical shape, absence of mass effect, and a density close to water. Liver metastases are usually round or oval, and unless cystic or necrotic, they have CT attenuation values closer to normal liver parenchyma than water. A radionuclide liver scan almost always resolves any confusion about the differential diagnosis of focal fatty liver: a well defined focus of photon deficiency is due to neoplasm rather than focal fatty infiltration. Sonography sometimes helps to confirm the CT impression, but may be misleading if the diagnosis of focal or diffuse fatty infiltration is not suspected before the examination.

Adult

CT detection of intraosseous gas: a new sign of osteomyelitis.

In three patients the diagnosis of osteomyelitis was made when computed tomography (CT) demonstrated gas within the medullary cavity of the involved bone. The diagnosis was clinically unsuspected in two of the patients before the CT examination, and none showed bone abnormalities on plain radiographs. Two patients had evidence of infection of the deep soft tissues adjacent to bone, and the third developed the lesion in an allograft. In all three patients CT detection of intraosseous gas resulted in significant alteration of patient management.

Adult

Comparison of real-time and static-mode gray-scale ultrasonography in the diagnosis of cholelithiasis.

Real-time and conventional articulated-arm gray-scale static-mode scanning were performed on 100 patients in a prospective study to determine the complementary or duplicative roles of these two ultrasound modalities in the confirmation of clinically suspected cholelithiasis. Twenty-five abnormal findings were documented ultrasonographically, including 21 cases of cholelithiasis (12 confirmed by oral cholecystography and/or surgery), two cases of biliary sludge, one case of a gallbladder polyp, and one case of a probable blood clot. There was no instance of gallbladder lumen nonvisualization. Except in one case (that of a 420-pound patient), real-time ultrasonography documented all the gallbladder abnormalities shown by the articulated-arm static scans. In two cases, one corroborated by oral cholecystography, cholelithiasis was documented by real-time and not by static-mode ultrasonography. In most cases, real-time ultrasonography can be used to document the presence of cholelithiasis and obviate the need for conventional articulated-arm static-mode scanning.

Cholecystography