Biomedical subjects
Publications and source records attributed to S F Quinn.
A case of the rare occurrence of conventional GCT in a rib is presented. Due to its radiological aggressivity, the possibility of a MGCT was entertained clinically, and preoperative chemotherapy and radiation therapy were given. The literature on giant cell tumors of the ribs is reviewed, and their distinction from primary MGCT and other giant-cell-containing lesions is discussed.
Many hepatic hemangiomas are discovered incidentally during incremental dynamic bolus computed tomography (CT). To meet the established criteria for diagnosis with CT, however, a second CT examination with single-level dynamic bolus imaging is necessary. A prospective evaluation was performed to examine a simple sign that may be used to diagnose cavernous hemangiomas during incremental dynamic bolus CT. This sign is the visualization of foci of globular enhancement within the hemangioma, analogous to areas of puddling of contrast material seen at angiography. A total of 34 lesions in 21 patients demonstrated foci of globular enhancement. Of the 34 lesions, 32 (94%) proved to be hemangiomas. All 21 patients underwent confirmatory evaluation. Foci of globular enhancement seen during dynamic bolus CT are a strong indication that the lesion is a cavernous hemangioma. This diagnostic sign may obviate further, more expensive imaging studies.
During a 32-month period, 25 modified self-expandable endovascular stents were placed in 20 hemodialysis access sites to treat 21 stenoses and four occlusions in 19 patients. All stenoses were initially dilated with a high-pressure balloon. The initial success rate was 90% (18 of 20 access sites). The stents were patent from 0 to 960 days (mean duration of follow-up, 309 days). At 2 years follow-up, the patency rates were as follows: primary, 25%; secondary, 34%; and tertiary, 42%. The morbidity rate associated with this procedure was 15% (three of 20 sites); the mortality rate, 5% (one of 19 patients). All five complications (graft or native-vein thrombosis [n = 2], nerve deficits [n = 2], and death secondary to sepsis [n = 1]) occurred in three patients early in the study, before the use of prophylactic antibiotics and refinements in technique. The best results occurred in patients in whom the stenosis or occlusion affected a large vein that had no acute angle and was away from venous confluences such as the femoral and iliac regions.
Similar to arthrograms, radial plane magnetic resonance (MR) images of the knee provide cross-sectional images of the menisci that are perpendicular to the long axis of the meniscus. The authors evaluated 259 consecutive patients who underwent MR imaging of the knee and arthroscopy. Radial multiplanar gradient-recalled-echo imaging was performed--with repetition time of 700 msec, echo times of 12 and 31 msec (700/12, 31), and a flip angle of 20 degrees--as well as sagittal spin-echo imaging (2,500/20, 80). The radial and sagittal images were interpreted separately and then in combination, and findings were compared with arthroscopic reports. There was no statistical difference between the interpretations of the radial and sagittal images in the evaluation of the menisci. When the interpretations of the radial and sagittal images were combined, the sensitivity and specificity improved slightly. The radial images increased the conspicuity of meniscal tears but at the expense of anatomic detail. The sagittal images enabled better evaluation of the meniscocapsular attachment region and some flap tears of the meniscal free edge. The interpretive accuracies of the combination of sagittal and radial images were 92% and 93% for the medial and lateral menisci, respectively.
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The tendon of the long head of the biceps muscle (long bicipital tendon) has a complex course from its muscle belly to its insertion onto the supraglenoid tubercle/glenoid labrum. It is stabilized by numerous tendinous and ligamentous structures and is, in turn, partly responsible for maintenance of normal glenohumeral function. In this report we describe the anatomy of this tendon, correlating high-resolution MR images with cryomicrotome sections. We illustrate typical MR findings in pathologic conditions affecting the long bicipital tendon sheath, the substance of the tendon, and finally the tendon position.
The purpose of this study was to review the radiologic presentations and management of biliary complications related to laparoscopic cholecystectomies. Additionally, a computed tomography (CT) evaluation of asymptomatic postsurgical patients was performed to determine the uncomplicated appearance of the gallbladder fossa. Over a 24-month period 23 biliary complications were seen in patients who underwent laparoscopic cholecystectomies (group 1). Twenty asymptomatic patients were examined with unenhanced CT examinations after laparoscopic cholecystectomy (group 2). Twenty patients in group I had bilomas located in the gallbladder fossa (n = 9), subhepatic (n = 7) and subphrenic (n = 2) spaces, and diffusely distributed in the peritoneal cavity (n = 2). The bile leaks were presumed to have been proved to be from the cystic duct (n = 19), right hepatic duct (n = 1), and common bile duct n = 3) injuries and leaks. Fourteen drains were placed percutaneously using CT (n = 12) or sonographic (n = 2) guidance, and in two cases drains were placed surgically. The duration of catheter drainage average 11.3 days. Six patients underwent endoscopic retrograde cholangiopancreatography (ERCP) procedures, including sphincterotomy (n = 6) and stent placement (n = 3). Patients who were treated with a drain or ERCP procedures or who were managed conservatively all recovered without the need for additional surgery. In five cases, the bile cultures were positive for multiple organisms. Three patients underwent surgical repairs for disrupted common bile ducts. In group 2 CT examinations showed minimal fluid densities in all patients. No evidence of distinct, well-demarcated fluid collection was seen in any of the 20 patients. (ABSTRACT TRUNCATED AT 250 WORDS)
We report on 10 patients with spontaneous perinephric hemorrhage associated with underlying disease, including renal cell carcinoma (5), angiomyolipoma (2), malignant melanoma (1), periarteritis nodosa (1) and severe portal hypertension (1). The etiology could not be identified with computerized tomography (CT) in 5 cases (50%), including 2 renal cell carcinomas, 1 angiomyolipoma, 1 periarteritis nodosa and 1 portal hypertension. Arteriography demonstrated underlying lesions in 4 of these 5 cases (80%) including the case of vasculitis. CT combined with magnetic resonance imaging is accurate for the diagnosis of spontaneous perinephric hemorrhage but the underlying pathological condition is often undetectable in the acute phase due to the perinephric blood. CT should be the first study performed if this diagnosis is suspected. Arteriography is recommended if a renal mass is not detected. If a mass is not identified with these 2 imaging studies and the patient is clinically stable, followup thin slice CT should be performed.
Four patients had spinal canal stenosis associated with deposition of calcium pyrophosphate dihydrate within the ligamentum flavum. Radiologic evaluation was performed with magnetic resonance imaging or computed tomography, and surgery was performed on all four patients. Pathologic examination of the surgical specimens demonstrated deposits of calcium pyrophosphate crystals within the ligamentum flavum. Focal enlargement of the ligamentum flavum was present in the cervical spine (n = 1), while a more diffuse, bilateral enlargement was identified in the lumbar spine (n = 3). Enlargement of the ligament either caused or was a component of spinal stenosis that caused neurologic signs or symptoms. Three of the patients had evidence of calcium pyrophosphate deposition elsewhere. Deposition of calcium pyrophosphate dihydrate within the ligamentum flavum causing either focal or diffuse enlargement can be associated with significant spinal stenosis.
Arthroscopy of the menisci is considered the standard by which all noninvasive imaging procedures of the knee are measured. To better recognize the accuracy and relevance of arthroscopic correlation, a study was done in 254 consecutive patients who underwent both magnetic resonance (MR) imaging of the knee and arthroscopy. If interpretation of arthroscopic findings disagreed with MR findings, the arthroscopic videotapes were reviewed. Seventeen errors occurred in interpretation, resulting in false-positive MR images. Nine of these errors (53%) were associated with lines of high signal intensity that reached the articular surface of the posterior horn, an area incompletely seen on the arthroscopic videotapes. Two errors (12%) occurred in postmenisectomy abnormalities that the arthroscopist believed were not clinically significant; the six other errors (35%) occurred in high-signal-intensity alterations in either the free edge or the entire meniscal substance that did not correlate with clinically significant tears. Thirty-two errors occurred in interpretation, resulting in false-negative MR images. Fifteen of these errors (47%) occurred in small tears that did not require meniscectomy.
Fibromatoses are a diverse group of soft-tissue lesions that have been inconsistently categorized and treated. The purpose of our study was to establish the range of appearances of fibromatoses on MR images and perform a pathologic correlation to explain the variable signal-intensity patterns. During a 3-year period, 26 patients with deep fibromatoses were examined with MR. The MR images were evaluated for signal-intensity characteristics, and findings were correlated retrospectively with the pathologic diagnoses. The results showed that the MR appearance of fibromatoses is similar to that of other soft-tissue lesions, and the signal intensities vary greatly from lesion to lesion and within lesions themselves. The fibromatoses were either hyperintense, isointense, hypointense, or of mixed signal intensity relative to adjacent skeletal muscle. The hypointense areas appear to be zones of hypocellularity and dense collagen deposition. Microscopically all of the lesions invaded adjacent structures, but the MR appearances of the margins varied and were judged to be well demarcated (n = 14), intermediate (n = 5), or poorly demarcated (n = 6). Our experience shows that fibromatoses have a variable MR appearance no different from that of other soft-tissue lesions, and this variability reflects the composition and cellularity of the lesions.
The results of a pilot study employing the administration of intraarterial chemotherapy and accelerated fractionation radiotherapy for advanced gynecologic malignancies are reported. The protocol consisted of three treatment sessions every 3 to 4 weeks. Each session consisted of bilateral or unilateral catheterization of the hypogastric artery with the infusion of cisplatin 100 mg/m2 on Day 1 and 2-deoxy-5-fluorouridine (FUDR) 300 mg/m2 on Day 2. An accelerated fractionation schedule of external-beam radiation was begun on Day 1 consisting of 200 rads twice daily for 4 days (1600 rads per session). Eight patients entered the protocol, and seven completed external-beam radiotherapy. Five completed three intraarterial sessions, and three, two sessions. Five of seven evaluable patients had a complete local response. Local control was sustained fom 6 to 24 months in four patients. Complications included three sensorimotor neuropathies, one clinically insignificant catheter-related thrombosis, and three clinically significant radiation injuries. This multimodality treatment for locally advanced gynecologic tumors appears feasible with modification, and continued work exploring this approach is encouraged.
The most accurate prognostic indicator in patients with musculoskeletal sarcomas is the percentage of tumor necrosis after intraarterial chemotherapy. Magnetic resonance (MR) imaging was evaluated to determine its ability to indicate the percentage of necrosis in musculoskeletal neoplasms after treatment. Fourteen patients with musculoskeletal neoplasms underwent treatment protocols including intraarterial chemotherapy (n = 14), radiation therapy (n = 6), and systemic chemotherapy (n = 14). All patients underwent MR imaging before and after treatment, and all underwent either limb salvage surgery (n = 8) or amputation (n = 6) within 1 week of the last MR examination. Standard unehanced spin-echo T1-, spin-density-, and T2-weighted MR sequences were used. The MR images were compared with the pathologic specimens. On T2-weighted images, the signal intensities of viable tumor, tumor necrosis, edema, hemorrhage, and necrosis overlapped. With the unenhanced spin-echo technique, MR imaging cannot be used to predict the percentage of tumor necrosis in musculoskeletal neoplasms after intraarterial chemotherapy.
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The tarsal tunnel syndrome may be caused by extrinsic or intrinsic pressure on the posterior tibial nerve or its terminal branches. The specific symptoms depend on the extent of nerve involvement, and compression distal or proximal to the tarsal tunnel may result in variants of the syndrome. To define better the capability of MR imaging for evaluating this entity, we performed MR imaging on three normal subjects and correlated the images with cryomicrotome sections. Six patients with symptoms suggestive of tarsal tunnel syndrome also were studied with MR. In all normal subjects, MR images showed the flexor retinaculum and the structures passing deep to the retinaculum: the tibialis posterior tendon, flexor digitorum longus tendon, flexor hallucis longus tendon, and the posterior tibial neurovascular bundle. The medial calcaneal sensory branch(es) and the medial and lateral plantar nerves also were delineated. Mechanical causes of compression were shown in all six symptomatic patients. The pathologic entities included two neurilemomas, tenosynovitis involving all three tendons, a ganglion cyst arising from the flexor hallucis longus tendon sheath, posttraumatic fibrosis, and post-traumatic fibrosis with associated posttraumatic neuroma. The MR findings were confirmed surgically in five cases. MR imaging can accurately depict the contents of the tarsal tunnel and the courses of the terminal branches of the posterior tibial nerve. In our small series, MR imaging accurately showed the lesions responsible for tarsal tunnel syndrome.
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Digital subtraction arthrography of the wrist was used to identify abnormalities in eighty-six (60 per cent) of 139 patients during a fifteen-month period. Multiple abnormalities were noted in thirty-four (25 per cent) of the wrists. The clinical signs and symptoms in the eighty-six wrists did not always correlate with the defects that were seen on the arthrograms. Three of five patients who had an isolated tear of the scapholunate ligament, six of thirteen who had an isolated tear of the lunotriquetral ligament, and seven of nineteen who had an isolated tear of the triangular fibrocartilage complex also had signs and symptoms on the opposite side of the wrist. Many of the lesions that were seen on arthrography may have been serendipitous, degenerative, or unrelated to a specific injury. There was a high prevalence of positive ulnar variance in patients who had at least one ulnar abnormality. Capsular tears, most often seen on the radiovolar aspect of the wrist, were best outlined by contrast medium injected into the radiocarpal joint. The arthroscopic findings differed from the arthrographic findings in five of the twenty patients in whom both studies were done. The three-compartment technique of injection is a valuable diagnostic tool. Injections of contrast medium into the distal radio-ulnar joint outlined five of thirteen tears of the triangular fibrocartilage complex that were not seen after injection into the radiocarpal joint. Of the eleven tears that were seen after injection into the radiocarpal joint, five were not seen when contrast medium was injected into the distal radio-ulnar joint.
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