Michael K. Wolverson

Magnetic resonance imaging of lesions of synovial origin

Three patients with histologically differing lesions of synovial origin and two with synovial cysts, one of which was a dissecting popliteal cyst, were examined by magnetic resonance imaging (MR) and computerized tomography (CT). The three histologically proven synovial lesions were synovial sarcoma, diffuse giant cell tumor of tendon sheath, and synovial chondromatosis. In two of the five patients MR provided better anatomic and morphologic appreciation than CT, while in the others they were of equal value. CT demonstrated calcification in two of the lesions while on MR calcification could be identified in only one patient where it outlined the mass. MR did not demonstrate calcification in the substance of the diffuse giant cell tumor of tendon sheath. Coronal, transverse, and sagittal images of magnetic resonance graphically demonstrated the extent of the soft tissue masses and their relationship to bone, vessels, and soft tissue structures. Synovial sarcoma had a shorter T1 than diffuse giant cell tumor of tendon sheath (these two lesions being of comparable size) and also had a uniformly longer T2. The dissecting popliteal cyst showed the most intense signals on the T1 weighted images, while the uncomplicated synovial cyst showed a long T1. On the T2 weighted images, each type of cyst showed a long T2. The variance and overlap of intensity of MR signals suggest limited specificity in predicting the histologic nature of the synovial lesion.

Is there a common SUV threshold in oncological FDG PET/CT, at least for some common indications? A retrospective study

Abstract Purpose. We retrospectively compared the maximum standard uptake value (SUVmax) of FDG PET in four different sites to evaluate whether a common diagnostic SUVmax threshold may exist in these tumor locations. We further postulate that the SUVmax thresholds are higher in thoracic lesions than in extrathoracic lesions. Material and methods. N = 143 patients in four subgroups underwent a FDG PET/CT: a) 42 patients for solitary pulmonary nodules (SPNs) characterization with b) respective mediastinal lymph nodes (LNs), c) 65 patients for LN staging of head and neck cancer, and d) 36 cancer patients diagnosed with adrenal lesions. Receiver operating characteristics of SUVmax values were evaluated. Results. The SUVmax were statistically significantly greater in malignant than in benign lesions. For SPNs and mediastinal LNs, a SUVmax > 3.6 each resulted in a sensitivity of 81% and 87%, and a specificity of 94% and 89%. For cervical LNs and adrenal glands, a SUVmax > 2.2 each showed a sensitivity of 98% and 100%, and a specificity of 83% and 93%. Conclusion. A common SUVmax threshold did not exist in the four studied subgroups. The variable FDG uptake in SPNs and mediastinal LNs are associated with the high prevalence of inflammation/infection within the chest. Similar SUVmax thresholds however may exist for extrathoracic regions where the prevalence of inflammation/infection is low.

Analysis of radiocontrast-induced nephropathy by dual-labeled radionuclide clearance

RATIONALE AND OBJECTIVES.This study was devised to develop a method of measuring the acute effects of radiocontrast media on renal function and assessing the relationship of the dose of radiocontrast media infused with the incidence of radiocontrast- induced renal failure. In addition, the drug adenosine phosphate-magnesium chloride (ATP-MgCl2) was evaluated as a renoprotective agent. METHODS.Eighteen patients with pre-existing renal impairment, (serum creatinine greater than 133 µmol/L) were randomized to receive a continuous infusion of ATP-MgCI2 or placebo before and during a radiocontrast procedure. Subjects were monitored with daily serum creatinine and with radionuclide renal clearance studies at baseline, during, and 24 hours after the radiocontrast procedure. RESULTS.There was an initial deterioration in renal clearance in the entire study group (from 44.2 ± 4.6 to 32.6 ± 3.9 mL/min, P = .001) which was independent of the dose of radiocontrast infused. There was a persistent deterioration in renal clearance only in those who received greater than 135 mL of contrast media (from 48.6 ± 7.8 to 37.1 ± 3.9 mL/min, P = .05). There also was an increase in serum creatinine that persisted only in those subjects who received greater than 135 mL of contrast media (230 ± 27 to 283 ± 44 ( µmol/L, P = .01). CONCLUSION.Persistent deterioration in renal function after radiocontrast administration appears to be dose-dependent and is not prevented by the use of ATP-MgCl2. Radionuclide techniques are useful in monitoring acute changes in renal function during radiocontrast procedures and may be of value in assessing renal impairment in future intervention studies.

The role of computed tomography in pelvic fractures.

Adequate radiologic demonstration of the extent of pelvic fractures facilitates planning of their treatment by the orthopedic surgeon. Traditionally, this evaluation has been by conventional radiology. This report details results of computed tomography (CT) in the evaluation of pelvic fractures in 34 patients. In most cases. CT was able to identify and delineate the extent of fractures, demonstrate displacement of the involved bones, localize bone fragments and characterize joint derangements. Many of these features were better demonstrated at CT compared with conventional radiographs. In particular, in 10 patients loose bodies were seen at CT that were not evident on conventional radiography. The extent of associated soft tissue injury is also well shown by CT and demonstrated peripelvic or intraarticular fluid collections can be aspirated under CT guidance to rule out sepsis. This study suggests that CT is useful in the assessment of major pelvic fractures.

Body computed tomography findings in systemic lupus erythematosus

Fifty-five computed tomography scans in 27 patients with systemic lupus erythematosus were reviewed. The most frequent indication for scanning was suspected intraabdominal sepsis, and the most frequent finding was mild lymphadenopathy. Renal abnormalities were: subcapsular hematoma, focal defects, overall enlargement, and diminution of size. Other findings included serositis, bowel wall thickening with pneumatosis intestinalis, pancreatic pseudocyst, and hepatic and splenic enlargement. Five abscesses were found that were indistinguishable from other fluid collections. Computed tomography was helpful in clinical evaluation and in some cases changed management.

Role of sonography in trichobezoars.

Three cases of trichobezoar (12/F, 5/F, and 35/M) are reported. All patients presented with an epigastric mass and the diagnosis was not suspected clinically. They were referred for sonography which revealed a hyperechoic curvilinear dense strip at the anterior margin of the lesion associated with marked acoustic shadowing and no through transmission. Similar findings were noted in all three cases. In vitro ultrasound scans performed on the operated specimen in one case confirmed that the sonographic findings were the result of the trichobezoar mass. Diagnosis was confirmed in all the cases by barium meal and surgery.

Ipsilateral decubitus position for percutaneous CT-guided adrenal biopsy.

Positioning the patient on the side to be biopsied elevates and relatively immobilizes the diaphragmatic leaf on the dependent side, allowing percutaneous adrenal needle biopsy by a direct posterior approach without traversing lung tissue. The ipsilateral decubitus position was used successfully for biopsy of four small adrenal lesions in which lung precluded a direct posterior approach in the prone position. In addition, the relative stability of the diaphragmatic leaf further facilitated accurate needle placement.

Ungual tufts in the follow-up of patients on maintenance hemodialysis

A recent publication showed the earliest signs of renal osteodystrophy in patients on maintenance hemodialysis (MHD) to occur in the tufts [1]. We present three patients on MHD, in two of whom the earliest unequivocal radiographic improvement was seen in the tufts. The third patient had been on MHD and, following subtotal parathyroidectomy, showed significant osseous improvement in the hands with relatively equal improvement in the tufts and middle phalanges. It appears that, with the use of routine primary or secondary magnification, the tufts are radiographically a highly sensitive site for both the early occurrence and improvement of osteodystrophy in patients on MHD. We are not aware of any previous publication pointing out exclusive improvement in the tufts in patients on MHD with virtually no change in the mid-phalanges. Two of these three cases illustrate that renal osteodystrophy is reversible by maintenance hemodialysis alone.

Computed tomography in the pretreatment assessment of carcinoma of the cervix

Fifty-nine patients with primary or recurrent carcinoma of the cervix were evaluated by computed tomography as part of their presurgical evaluation. The computed tomography staging results were compared with the surgical staging. Computed tomography staging was accurate in 71% (42 of 59), whereas clinical staging was accurate in 66% (39 of 59). In assessing paraaortic nodes by CT, there were 10 true-positive, 20 true-negative, 1 false-positive, and 2 false-negative results (sensitivity, 83%; specificity, 95%), for an overall accuracy of 91%. For pelvic nodes, there were 10 true-positive, 11 true-negative, 3 false-positive, and 6 false-negative results (sensitivity, 62.5% specificity, 78%), for an overall accuracy of 70%. Excretory urograms and barium enemas provided no information not obtained by computed tomography and are probably unnecessary if computed tomography is used as a routine staging examination. At present, computed tomography should not replace clinical assessment of extent of the disease. Its chief advantage over clinical staging is its ability to detect metastases beyond the true pelvis.

Superior gluteal artery haemorrhage following pelvic fractures controlled by embolisation

Successful embolisation of active bleeding from the superior gluteal artery seen in two patients within the last 12 months is described. Both patients had extensive abdominal and pelvic injuries. One patient eventually died from renal failure and a perforated colon. The other patient is mobile and has been periodically seen in the out-patient department over the past nine months. In both instances, haemorrhage was at the sacrosciatic notch. Early angiography, in patients with extensive pelvic trauma and major blood requirements, with intent to embolise any identifiable bleeding source would appear to be the best initial manoeuvre to prevent exsanguination.