A phase I single-dose trial of gadolinium texaphyrin (Gd-Tex), a tumor selective radiation sensitizer detectable by magnetic resonance imaging.

Gadolinium Texaphyrin (Gd-Tex) is a radiation sensitizer with a novel mechanism of action that sensitizes both oxic and hypoxic cells, localizes selectively in tumors, and is detectable by magnetic resonance imaging (MRI). This Phase I single-dose trial of Gd-Tex administered concurrently with radiation therapy was carried out to determine the maximally tolerated dose (MTD), dose-limiting toxicities, pharmacokinetics, and biolocalization of Gd-Tex as determined by MRI. Adults with incurable cancers of any histology requiring radiation therapy were eligible. A single i.v. dose of Gd-Tex was followed at least 2 h later by radiation therapy. The Gd-Tex dose was escalated in cohorts of 3 to 5 patients. Thirty-eight patients (median age, 58 years; range, 35-77 years) with incurable cancers of the lung (26), cervix (3), or other solid tumors (9) received a total of 41 single administrations of Gd-Tex. The Gd-Tex dose was escalated from 0.6 to 29.6 mg/kg. Irradiated sites included the thorax, brain, pelvis, bone, soft tissue, and sites of nodal metastases. The MTD was 22.3 mg/kg, determined by reversible acute tubular necrosis as the dose-limiting toxicities. Gd-Tex selectively accumulated in primary and metastatic tumors as demonstrated by MRI. No increase in radiation toxicity to normal tissues was seen. The median half-life of Gd-Tex after single-dose administration is 7.4 h. This study demonstrates that Gd-Tex is well tolerated in doses below the MTD, and that there is selective biolocalization in tumors. The maximum recommended dose for single administrations is 16.7 mg/kg.

Primary leiomyosarcoma of the seminal vesicle.

A case of leiomyosarcoma of the seminal vesicle is described in a 68-year-old man. Digital rectal examination and pelvic computed tomography (CT) scan disclosed a large pelvic mass in the region of the prostate, whereas magnetic resonance imaging (MRI) suggested that the mass arose from the right seminal vesicle. Biopsy of the mass revealed a high-grade malignancy, thus a radical cystoprostatectomy was performed. Pathologic examination revealed a leiomyosarcoma arising from the right seminal vesicle. The patient is well and free of recurrent disease 13 months following surgery.

[Study of urethral anatomy and pelvic floor using MRI with surface and endorectal coil]. / Etude de l'anatomie urétrale et du plancher pelvien par IRM avec antenne de surface et antenne endorectale.

PURPOSE: Although high resolution MRI can play a critical role in the evaluation of diseases affecting the female urethra, normative values have not been established. In this retrospective study, the normal values for female urethral dimensions and its supportive structures were measured and compared using a body coil (BC) and endorectal coil (ERC), and correlated with age and menopause. MATERIAL AND METHODS: BC and/or ERC images of the pelvis in 20 patients (ages 27-82) with confined cervical cancer (stage IB or less) were reviewed. None of the patients had a history of urinary symptoms, pelvic prolapse, pelvic radiation, or prior bladder or urethral surgery. Images evaluated included axial and/or sagittal T2 weighted SE images of the lower pelvis before and/or after endorectal coil placement. Several measurements including urethral and bladder dimensions were obtained independently by two radiologists and compared statistically. Calculated urethral volume was correlated with the patients' age and menopausal status. The impact of calculated bladder volume on urethral dimensions was evaluated. Additional measurements of contiguous supporting structures were also correlated with age. RESULTS: Inter-rater reliability showed a strong intra-class correlation (95% CI) for urethral dimensions. A statistically significant difference between raters was only noted for the right pubovesical ligament measurement. Inter-technique reliability was also strong (95% CI) except for the distal transverse urethral dimension. Bladder volume did not effect measurement of urethral dimensions (p > .39). Lastly, calculated urethral volume utilizing the ERC technique showed an inverse correlation with age (p < 0.05) and with the BC a correlation with menopausal status (p < 0.05). CONCLUSIONS: Measurement of urethral dimensions by either ERC or BC MRI is reliably reproducible by independent radiologists. There is no need for standardization of bladder volumes during urethral MRI. Normative values for all measured angles and dimensions are presented. There is evidence of correlation of urethral volume with age and menopause, though a larger study is warranted.

Magnetic resonance imaging of musculoskeletal tumors.

Magnetic resonance (MR) has been shown to provide superior soft tissue contrast as well as superior anatomical definition when compared with other diagnostic modalities in the evaluation and staging of many bone and soft tissue tumors. MR signal patterns with various parameter weighting can provide information that aids in the tissue characterization of the lesion. Technical factors as well as the clinical role of MR in the evaluation of musculoskeletal tumors are discussed.

Role of MR imaging with transrectal coil in the evaluation of complex urethral abnormalities.

OBJECTIVE: The purpose of this study was to show the usefulness of MR imaging with a transrectal coil (TRC) in the management of various urethral abnormalities. This report also reveals the appearance of various postsurgical changes relating to the therapy of urethral abnormality. CONCLUSION: The high-resolution images obtained with TRC MR imaging were useful in evaluating urethral abnormalities. The imaging guided therapy in most cases. In two patients, TRC MR imaging more accurately depicted abnormality than did voiding cystourethrography and transvaginal sonography. In one case, TRC MR imaging was the only imaging technique that revealed the abnormality of periurethral scarring.

Acquired tracheomegaly in adults as a complication of diffuse pulmonary fibrosis.

We studied the chest radiographs of 34 consecutive patients with diffuse pulmonary fibrosis to determine the presence of tracheomegaly and to follow its progression with time. Patients had been identified by a computer search of medical records. We measured the internal transverse diameter of the trachea 2 cm above the top of the aortic arch on erect posteroanterior chest radiographs. Transverse diameters greater than 25 mm in men and 21 mm in women were considered indicative of tracheomegaly. Pulmonary-function tests, available in 30 of the 34 patients, showed restrictive lung disease. The transverse tracheal measurements were compared with the cause of fibrosis, severity of restriction, duration of illness, and other clinical variables. Tracheomegaly was present in 10 (29%) of the patients, including four with fibrosing alveolitis, four with sarcoidosis, and two with chronic progressive histoplasmosis. In seven of these patients, serial radiographs showed that the tracheal dilatation had progressed with time. Nine of 24 patients without tracheomegaly also had progressive increase in transverse tracheal diameter over time. Of the 10 patients with tracheomegaly, pulmonary-function tests were available in eight and showed moderate restrictive lung disease in six and severe restrictive lung disease in two. The duration of illness was 3-6 months in two patients, 10-22 years in five patients, and not recorded in three patients. Chronic cough and repeated respiratory infections were slightly more common in those patients with tracheomegaly than in those without. These data suggest that tracheomegaly develops as a complication of diffuse pulmonary fibrosis in patients who have at least moderate restrictive lung disease and prolonged illness, and it may have some association with chronic cough and repeated respiratory infection.

MR imaging-guided muscle biopsy for correlation of increased signal intensity with ultrastructural change and delayed-onset muscle soreness after exercise.

To determine if there is a correlation between the degree of delayed increase in signal intensity (SI) of muscle after exercise on magnetic resonance (MR) images and the amount of ultrastructural (ULS) injury and delayed-onset muscle soreness (DOMS), MR imaging-guided muscle biopsy was performed to obtain tissue from the legs of nine sedentary subjects 48 hours after downhill running on a treadmill. The degree of soreness was subjectively graded. T1-weighted, spin-density, T2-weighted, and short inversion time inversion-recovery images were obtained before and after biopsy, at 48 and 96 hours after exercise, respectively. The delayed SI increase of muscle on images obtained before biopsy was subjectively graded and measured. The degree of ULS injury was determined with electron micrographs. Serum creatine kinase levels were obtained before and up to 144 hours after exercise at 24-hour intervals. The measured SI, SI grades, and DOMS grades were correlated with the degree of ULS injury. Linear regression analysis revealed poor correlation between the DOMS grades and the degree of ULS injury and good correlation between the SI grade and the degree of ULS injury.

Muscle recruitment variations during wrist flexion exercise: MR evaluation.

OBJECTIVE: Many exercise protocols used in physiological studies assume homogeneous and diffuse muscle recruitment. To test this assumption during a "standard" wrist flexion protocol, variations in muscle recruitment were assessed using MRI in eight healthy subjects. MATERIALS AND METHODS: Variations were assessed by comparing the right to the left forearms and the effect of slight (15 degrees) pronation or supination at the wrist. RESULTS: Postexercise imaging showed focal regions of increased signal intensity (SI), indicating relatively strong recruitment, most often in entire muscles, although occasionally only in subvolumes of muscles. In 15 of 26 studies, flexor carpi radialis (FCR) showed more SI than flexor carpi ulnaris, while in 11 studies SI in these muscles increased equivalently. Relatively greater FCR recruitment was seen during pronation and/or use of the nondominant side. Palmaris longus, a wrist flexor, did not appear recruited in 4 of 11 forearms in which it was present. A portion of the superficial finger flexor became hyperintense in 89% of studies, while recruitment of the deep finger flexor was seen only in 43%. CONCLUSION: Inter- and intraindividual variations in forearm muscle recruitment should be anticipated in physiological studies of standard wrist flexion exercise protocols.