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M Mesgarzadeh

Publications and source records attributed to M Mesgarzadeh.

34 records · Page 2Linked to original sources
PubMed1988

Computer tomography evaluation of Cotrel-Dubousset instrumentation in idiopathic scoliosis.

In 30 adolescent patients with 36 structural curves undergoing posterior spinal arthrodesis using Cotrel-Dubousset (CD) instrumentation, computer tomography (CT) was performed to evaluate the change in rotation and in the sagittal plane. The average preoperative Cobb angle was 51.7 degrees, and improved to 18.7 degrees postoperatively, or 64.9%. The angle of rotation of the apical vertebra relative to the anterior midline of the body (RAML) improved from 27.9 degrees preoperatively to 21.5 degrees postoperatively (23.9%). The angle of rotation relative to the sagittal plane (RAsag) improved from 15.2 degrees preoperatively to 13.4 degrees postoperatively (14.3%). The kyphotic angle increased an average of 10.6 degrees in the 14 patients whose preoperative angle was less than 25 degrees. As measured by CT, CD instrumentation improves both the rotational and sagittal plane deformities better than that reported for other systems.

Adolescent↗
PubMed1987

The role of magnetic resonance imaging in giant cell tumor of bone.

In six cases of giant cell tumor the magnetic resonance (MR) images obtained with various pulse sequences and field strengths were compared to the corresponding computed tomography (CT) scans and plain roentgenograms. MRI was superior to CT and plain films in demonstrating areas of tissue inhomogeneity within the tumor as well as soft tissue extension. CT was superior in demonstrating cortical thinning. Multiplanar imaging capability and visualization of articular cartilage may demonstrate intra-articular tumor spread. The characteristic MRI findings with short TR/TE (T1-weighting) and long TR/TE (T2-weighting) are described. We also describe one case where serial MR scans were used to assess response to therapy.

Adolescent↗
PubMed1987

Magnetic resonance imaging (MRI) in the evaluation of spinal cord injured children and adolescents.

In order to determine the indications and usefulness of MRI scanning in evaluating spinal cord trauma, MRIs on 43 subacute and chronic spinal cord injured children were compared with CT myelograms and other diagnostic tests. MRI scans were superior to CT myelograms in evaluating post-traumatic syrinx, disc pathology and the physiological status of the cord. CT myelogram remains an essential study before considering spinal cord decompression. The presence of internal fixation is not a contraindication to MRI scanning.

Adolescent↗
PubMed1987

Proximal femoral focal deficiency: radiologic analysis of 49 cases.

Proximal femoral focal deficiency, an uncommon congenital anomaly, necessitates early radiologic classification for surgical planning and treatment. Objective radiographic criteria, including femoral length index, acetabular depth index, acetabular angle index, and shape of the proximal femur were determined in 49 patients before cartilaginous ossification of the femoral capital epiphysis; final classification was based on follow-up radiographs or findings at arthrography or surgery. These parameters were analyzed to determine the accuracy and contributions of each in classification. Correct classification into one of three groups was possible in 86% of cases with use of three of the parameters: femoral length index, acetabular depth index, and shape of the proximal femur. The acetabular angle was found to contribute insignificantly to classification. Magnetic resonance imaging, used in only one case, depicted the nonossified cartilaginous femoral capital epiphysis, thus obviating the need for invasive diagnostic procedures and facilitating early classification.

Acetabulum↗
PubMed1987

Osteochondritis dissecans: analysis of mechanical stability with radiography, scintigraphy, and MR imaging.

Twenty-one joints with stable (n = 9) or loose (n = 12) osteochondritis dissecans (OCD) lesions were examined in 15 subjects with plain radiography, three-phase bone scintigraphy, and magnetic resonance (MR) imaging. The lesion size and the thickness of the sclerotic margin as measured on plain radiographs were good parameters for predicting loosening. However, bone scintigraphy was more sensitive and specific in determining the mechanical stability of OCD lesions. MR imaging permitted direct visualization of loosening and fragment displacement; the latter permits differentiation of in situ loosening from a grossly unstable lesion. The noninvasive nature of bone scintigraphy and MR imaging makes them potentially preferable diagnostic modalities to arthrography for evaluating the mechanical status of OCD lesions.

Adolescent↗
PubMed1986

Infection in diabetic osteoarthropathy: use of indium-labeled leukocytes for diagnosis.

Indium-111 labeled leukocyte imaging was compared with three-phase skeletal scintigraphy as a means of determining whether osteomyelitis was complicating diabetic osteoarthropathy. Three-phase scintigraphy demonstrated increased activity in both infected and noninfected osteopathic bone, with a sensitivity of 75% and a specificity of 56% for osteomyelitis. Leukocyte imaging had the same sensitivity but was most helpful for excluding infection (specificity, 89%) when three-phase imaging could not. Abnormal leukocyte localization was seen at the primary site of infection in all cases within 4 hours after injection. Disadvantages of leukocyte imaging included long preparation time, low count rates resulting in poor spatial resolution, and absence of bone landmarks, which made it difficult to differentiate soft tissue from bone infection.

Adult↗
PubMed1985

Subungual keratoacanthoma.

The subungual keratoacanthoma is a benign neoplasm which simulates and must be differentiated from squamous cell carcinoma. Subungual keratoacanthomas are rapidly growing tumors, causing bone destruction which usually heal spontaneously. The lesion most often presents as a painful, enlarging mass in middle-aged Caucasian patients. Radiographic examination demonstrates a lytic cup-shaped erosion of the underlying distal phalanx. It is essential to recognize keratoacanthoma and separate it from squamous cell carcinoma, both for prognostic and therapeutic reasons. We present two cases of proven subungual keratoacanthoma and discuss their radiographic and histologic characteristics, as well as the current treatment alternatives for this entity.

Aged↗
PubMed1985

The effect on medical metal implants by magnetic fields of magnetic resonance imaging.

Forces and torques, due to a 0.3 Tesla magnetic field were evaluated on ten hip prostheses and ten hemostat clips. Measurements were performed with an instrument utilizing the movement of a laser beam caused by the deflection of a cantilever. The results indicate effects, if any, to be smaller than the instrument's sensitivity which, at its highest, was 7 mg of force and 125 mg.cm of torque.

Alloys↗
PubMed1983

Filling, postcholecystokinin emptying, and refilling of normal gallbladder: effects of two different doses of CCK on refilling: concise communication.

A study of 18 normal subjects was undertaken to evaluate the rapidity of gallbladder filling with Tc-99m IDA during fast, and the degree of emptying and incidence of refilling after intravenous infusion of either 20 or 40 ng/kg of octapeptide of cholecystokinin (CCK-8). During fast, the frequency of onset of gallbladder filling with Tc-99m IDA at 20, 30, 40, and 42 min was 68%, 84%, 95%, and 100%, respectively. Following CCK-8 infusion, the gallbladder mean ejection period of 11 +/- 4 (s.d.) min and ejection fraction of 40% +/- 23 were similar in subjects given either a 20 ng/kg or a 40 ng/kg dose. The frequency of onset of refilling at 20, 30, 40, and 50 min after CCK-8 was 33%, 63%, 71%, and 79%, respectively for the combined groups. At 50 min after CCK-8, all subjects given 20 ng/kg refilled, whereas only 63% of the 40-ng/kg group did so. There was no correlation between the degree of emptying (ejection fraction) and onset of refilling. We conclude that the frequency of post CCK-8 onset of gallbladder refilling, which reflects sphincter tone recovery, is widely variable, depending upon both the dose and the duration from the time of infusion of CCK-8 and should be taken into consideration if a pre-emptying procedure is adopted during hepatobiliary imaging with Tc-99m IDA agents.

Adult↗
PubMed1983

Diagnosis of clinically unsuspected gallbladder perforation in an obese patient, by Tc-99m IDA cholescintigraphy.

A male Pickwickian syndrome patient was admitted to the hospital with sudden onset of abdominal pain. Physical examination was equivocal. Due to patient's ileus and morbid obesity (weight 450 lb), neither TCT scan nor ultrasound was possible. A Tc-99m PIPIDA hepatobiliary imaging study revealed intraperitoneal leakage of radioactive bile with collection of the activity in both abdominal gutters, indicating gallbladder rupture. Prompt surgery confirmed the diagnosis.

Adult↗
PubMed1983

Quantitative biliary dynamics: introduction of a new noninvasive scintigraphic technique.

We used a Tc-99m-labeled hepatobiliary agent to measure the partition of hepatic bile between gallbladder and intestine in sixteen normal patients and nine patients with cholelithiasis. In normal subjects, the fractions of the hepatic bile that flow into the gallbladder and the small intestine were widely variable, with mean values of 69 +/- 7% (s.e.) and 31 +/- 7% respectively. Bile reflux into the common hepatic duct was rare, occurring during the first 2/3 of the gallbladder ejection period and only when the ejection fraction was greater than 59%. The gallbladder's mean latent period, ejection period, ejection fraction, and ejection rate were 2 +/- 1 min, 11 +/- 1 min, 59 +/- 4%, and 5.9%/min respectively. In patients with cholelithiasis, the fraction of hepatic bile flowing into the gallbladder was normal, but the ejection fraction was significantly reduced (p less than 0.005). For an equivalent dose of cholecystokinin, the gallbladder in cholelithiasis is less responsive than in normal subjects.

Adult↗
PubMedDate not supplied

Femoral neck torsion angle measurement by computed tomography.

To establish the accuracy and reproducibility of measuring femoral neck torsion angles (FNTA) on CT images, this angle was measured on 12 dry femora directly on the gross specimens, on plain radiographs, and on CT images. The selection of the CT level, both at the femoral neck and the condyles, that may affect the measurement of FNTA was analyzed. The CT measurements of FNTA were found to have a reproducibility of 2.5 and 0 degrees mean offset error when compared with readings on plain radiographs. A new CT method was developed to measure this angle particularly in patients with coxa valga in whom this measurement is difficult if not impossible to accomplish by current methods. For this purpose composite CT images were made of the femoral head and the femoral shaft, immediately below the lesser trochanter. On these images the line connecting the centers of the femoral head and shaft were inferred to represent the cervical plane. In comparison with the standard CT method, this new method had the same reproducibility, although it slightly overestimated this angle by 2 degrees. This degree of error is negligible when compared with the normal variations of this angle, which ranges from -20 to +38 degrees. Furthermore, it compares favorably with the limited accuracy of derotational osteotomy surgery.

Adult↗