MRI: incidence and evaluation of size and form criteria in hypophysis-healthy probands and in patients with detectable microadenomas

Magnetic resonance imaging (MRI) was performed in 42 patients with proven microadenomas and in 42 patients with normal pituitary hormone analysis. The normal MRI--anatomy of the pituitary gland and its possible variations with measurement of the volume and comparison of the anatomy with that of the gland after changes caused by microadenomas has to our knowledge not yet described. In this study we measured the height, coronary and sagittal diameter of the pituitary gland in both groups as well as other indirect signs of microadenomas (asymmetry of the gland, sella turcica, and the stalk). The pituitary volume indicates the expansion of microadenomas much better than the gland height (and the other diameters). Normal pituitary glands showed a significant lower volume (525 +/- 137 mm3 [R = 225-800 mm3]) than patients with proven microadenomas (734 +/- 393 mm3 [R = 335-2800 mm3], p < 0.001). The normal pituitary gland and sella turcica show a large variety of anatomic variations. These variations are less frequent in healthy subjects (10-21%) than in patients with microadenomas (48-71%). The described criteria are of some value in diagnosis of a suspected gland hypertrophy or microadenoma. In 75% of the patients with normal pituitary parameters and in 12% of the patients with microadenomas no indirect adenoma criteria was found in our study.     

A comparison of dialysers with low-flux membranes: significant differences in spite of many similarities

PURPOSE: To determine whether dynamic traditional spin-echo MR imaging, with the use of routine T1 parameters during contrast infusion, is superior to standard MR imaging after contrast administration for detecting microlesions of the pituitary gland. METHODS: Sixty-four patients with pituitary microlesions 3 to 10 mm in diameter were examined with a dynamic traditional spin-echo technique; that is, a typical T1 spin-echo sequence of 500-600/20-25/2 (repetition time/echo time/excitations), 3-mm-thick sections, 16-cm field of view, 256 x 128 matrix, and a scan time ranging from 2 minutes to 2 minutes 40 seconds during contrast infusion. In addition, standard imaging with unenhanced and contrast-enhanced spin-echo sequences were obtained. The three sequences were evaluated retrospectively and graded for gland-lesion contrast conspicuity, lesion homogeneity, and delineation of lesion margin. RESULTS: The dynamic sequence was judged to be better than the standard enhanced sequence for depicting microlesions in 42% to 47% of patients. Lesions were identified only on the dynamic study in an additional 1% to 14% of patients. Lesions were seen equally well on the standard and dynamic sequences only in 16% to 23% of cases. The standard postcontrast sequence was judged better in 12.5% to 17% of cases, with lesions identified only on the standard sequence in an additional 8% to 9%. CONCLUSION: Dynamic traditional spin-echo MR imaging improved lesion detection and provided increased clarity over standard sequences after contrast infusion. Both sequences are important, since lesions were detected only on the dynamic sequence in 11% to 14% of patients and only on the standard sequence in 8% to 9% of patients.     

Renal cell carcinoma: preoperative assessment for enucleative surgery with angiography, CT, and MRI

PURPOSE: Our purpose was to assess various imaging methods in detecting a pseudocapsule of renal cell carcinoma (RCC), which is critical for successful tumor enucleation. METHOD: In 42 patients with histopathologically proven RCC, images obtained at angiography (n = 42), CT (n = 30), and MRI (n = 19) were investigated retrospectively. All patients underwent treatment (enucleation: n = 15; nephrectomy: n = 27). The imaging criteria for the presence of a pseudocapsule were as follows: a surrounding radiolucent rim on angiography, a low or high density rim on CT, and a low intensity rim on MRI. All images were retrospectively reviewed by three radiologists without knowledge of the clinical and histological findings. RESULTS: Thirty-three of 42 RCCs showed a pseudocapsule on the surgical specimen. A pseudocapsule was detected in 67% of tumors (22/33) on angiography, 26% (6/23) on CT, 27% (4/15) on T1-weighted MRI, 93% (14/15) on T2-weighted MRI, 67% (8/12) on dynamic enhanced T1-weighted MRI, and 15% (2/13) on delayed enhanced T1-weighted MRI. CONCLUSION: T2-weighted MR images are superior for visualizing a pseudocapsule of RCC and for providing reliable selection criteria for tumor enucleation.     

Presaccadic omnidirectional burst activity in the basal interstitial nucleus in the monkey cerebellum

The endocrine function and pituitary imaging in Sheehan's syndrome more than 30 years after causative events were evaluated. Magnetic resonance imaging (MRI), a combined anterior pituitary test, plasma vasopressin-to-osmolality adaptation study, and antithyroid and antipituitary cell antibody measurement were performed in 6 women with Sheehan's syndrome. The interval from delivery to the onset of symptoms of hormonal deficiency ranged from 3 to 32 years. Since clinical onset, all had received glucocorticoid and thyroid replacement therapy. Cranial MRI examination showed an "empty sella" in 5 cases. Among these, 2 of 5 (40%) demonstrated panhypopituitarism and the other 3 (60%) maintained gonadotropin response. The pituitary gland was normally discernible but with a low-intensity lesion on T1-weighted images in a patient who maintained PRL and gonadotropin responses. Posterior pituitary function was abnormal in 3 of 6 (50%) despite the absence of polyuria. No antipituitary antibodies were detected in any of the cases. Thyroid peroxidase antibody was negative in all cases, but antithyroglobulin antibody was detected in 2 of 6 (33%). Thyroid-stimulating antibody was not detected, but one case had an anti-TSH antibody. Thirty years after the initial events, most patients with Sheehan's syndrome showed signs of an empty sella on MRI, all having noticeable suppression of anterior and/or posterior pituitary hormones with no related autoimmunity.     

Chordomas of the skull base: dynamic MRI

OBJECTIVE: To investigate the role of dynamic MRI in the diagnosis of chordomas at the skull base. MATERIALS AND METHODS: Six patients with surgically proven chordomas of the skull base were examined with spin-echo technique (repetition time/echo time 200 ms/15 ms). Serial imaging was performed every 30 s for 240 s after a rapid injection of gadopenetate dimeglumine (0.1 mmol/kg). The contrast material enhancement ratio (CER) was analyzed. The CER was obtained for each region of interest as follows (Sn - So) x 100/Smax - So, where Sn indicates signal intensity at each dynamic phase; So, signal intensity on the image obtained before administration of contrast material; and Smax, maximum signal intensity of all dynamic imaging. RESULTS: All chordomas showed very slow but steady increase of contrast enhancement with no peak within 240 s. The CERs of six cases at 30 s are 13 to 40 (mean value +/- standard deviation: 22.8 +/- 10.2). CONCLUSION: Dynamic MRI may be helpful in differentiating between chordomas and other tumors of the skull base.     

Uterine cervical carcinoma: comparison of standard and pharmacokinetic analysis of time-intensity curves for assessment of tumor angiogenesis and patient survival

Dynamic studies of Gd-based contrast agents in magnetic resonance imaging (MRI) are increasingly being used for tumor characterization as well as for therapy response monitoring. Because detailed knowledge regarding the pathophysiological properties, which in turn are responsible for differences in contrast enhancement, remains fairly undetermined, it was the aim of this study to: (a) examine the association of standard and pharmacokinetic analysis of time-intensity curves in dynamic MRI with histomorphological markers of tumor angiogenesis [microvessel density (MVD) and vascular endothelial growth factor (VEGF)]; and (b) determine the ultimate value of a histomorphological and a dynamic MRI approach by the correlation of those data with disease outcome in patients with primary cancer of the uterine cervix. Pharmacokinetic parameters (amplitude, A; exchange rate constant, k21) and standard parameters [the maximum signal intensity increase over baseline (SI-I) and the steepest signal intensity-upslope per second (SI-U/s)] were calculated from a contrast-enhanced dynamic MRI series in 37 patients with biopsy-proven primary cervical cancer. On the surgical whole mount specimens, histomorphological markers of tumor angiogenesis (MVD and VEGF) were compared to MRI-derived parameters. For MRI and histomorphological data, Kaplan-Meier survival curves were calculated and compared using log-rank statistics. A significant association was found between MVD and A (P < 0.01) and SI-I (P < 0.05). No significant relationships were observed between VEGF expression and all dynamic MRI parameters. Kaplan-Meier curves based on k21 and SI-U/s showed that tumors with high k21 and SI-U/s values had a significantly (P < 0.05 and 0.001, respectively) worse disease outcome than did tumors with low k21 and SI-U/s values. None of the histomorphological gold standard markers for assessing tumor angiogenesis (MVD and VEGF) had any significant power to predict patient survival. It is concluded that in patients with uterine cervical cancer: (a) the pathophysiological basis for differences in dynamic MRI is MVD but not VEGF expression; (b) a functional, dynamic MRI approach (both standard and pharmacokinetic analysis) may be better suited to assess angiogenic activity in terms of patient survival than are the current histomorphological-based markers of tumor angiogenesis; and (c) compared with standard analysis, a simple pharmacokinetic analysis of time-intensity curves is not superior to assess MVD or patient survival.     

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.     

Triple dose of gadolinium-DTPA and delayed MRI in patients with benign multiple sclerosis

OBJECTIVES: To evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) or delayed MRI increase the number, size, and conspicuousness of enhancing lesions in patients with benign multiple sclerosis. METHODS: T1 weighted brain MRI was carried out on 20 patients with benign multiple sclerosis (expanded disability status scale < 3 with a disease duration > 10 years) in two sessions. In the first session, one scan was obtained before and two scans five to seven minutes and 20-30 minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, the same procedure was repeated with 0.3 mmol/kg Gd-DTPA (triple dose). RESULTS: Nine enhancing lesions were found in seven patients (35%) using the standard dose of Gd-DTPA. The numbers of enhancing lesions increased to 13 (P = 0.03) and the number of patients with such lesions to eight (40%) on the delayed standard dose scans. On the early triple dose scans, we found 19 enhancing lesions in 10 patients (50%). The number of enhancing lesions was significantly higher (P = 0.01) than that obtained with the early standard dose. The number of enhancing lesions was 18 and the number of "active" patients 11 (55%) on the delayed triple dose scans. The enhancing areas increased progressively from the early standard dose scans to the delayed triple dose scans. The contrast ratios of the lesions detected in early standard dose scans was lower than those of lesions present in the early (P = 0.01) and delayed (P = 0.04) triple dose scans. CONCLUSIONS: More enhancing lesions were detected in patients with benign multiple sclerosis with both delay of MRI and the use of triple dose of Gd-DTPA suggesting that the amount of inflammation in the lesions of such patients is mild and heterogeneous.     

MRI-demonstrable regression of a pituitary mass in a case of primary hypothyroidism after a week of acute thyroid hormone therapy

Although magnetic resonance imaging (MRI) characteristics of pituitary gland hyperplasia in primary hypothyroidism have been previously described, the time span necessary for the regression of the hyperplasia in response to acute thyroid hormone (TH) therapy has not been defined. A 26-yr-old woman underwent 131I ablation 11 yr before admission. Intermittent poor compliance to levothyroxine (LT4) therapy led to inappropriately high serum thyroid-stimulating hormone (TSH) for her triiodothyronine (T3) and thyroxine (T4) levels. The patient was investigated to rule out TSH-secreting pituitary adenoma or resistance to TH. On admission, the patient's clinical features and thyroid function tests, as well as thyrotropin-releasing hormone (TRH) and acute T3 suppression tests, were in favor of profound primary hypothyroidism. MRI revealed symmetrical enlargement of the pituitary gland with distinct morphological characteristics of a macroadenoma. The patient began high-dose TH therapy and was rescanned six days later. The follow-up scan revealed a dramatic shrinkage of the pituitary gland. Four weeks later, serum T4 and TSH were within the normal range, and repeat MRI scan of the pituitary at that time showed a normal gland. This case is the first to document dramatic shrinkage of pituitary hyperplasia in long-standing primary hypothyroidism within one week of acute TH therapy. MRI alone is unable to reliably differentiate between a TSH-secreting pituitary adenoma and hypothyroidism-induced pituitary hyperplasia. Dynamic endocrine testing as well as repeat pituitary MRI after a brief TH trial may provide a firm diagnosis in similar cases.     

Effect on prognosis of bone marrow infiltration detected by magnetic resonance imaging in small cell lung cancer

The staging system of limited disease (LD) and extensive disease (ED) is widely used and has been shown to provide useful prognostic information in cases of small cell lung cancer (SCLC). However, accurate examinations are necessary for correct staging. In this report, we evaluated the clinical usefulness of magnetic resonance imaging (MRI) of bone marrow in SCLC. 37 patients with LD by standard staging and 41 with ED were examined with bone marrow MRI. Results of bone marrow MRI did not influence the choice of treatment in patients with LD. For subsequent analysis, patients with LD were divided into two groups: patients in whom bone marrow infiltration was detected with MRI (MRI-positive LD group) and those in whom it was not (MRI-negative LD group). Focal or diffuse metastases to bone marrow were detected with MRI in 46% (36/78) of all patients and 35% (13/37) of LD patients. The response rates to treatment in patients with MRI-positive LD were lower than those in patients with MRI-negative LD (P = 0.006). The survival of patients with MRI-positive LD was worse than that of MRI-negative LD (generalised Wilcoxon test: P = 0.0157), and closer to that of ED. Multivariate analyses using a Cox model that included the result of bone marrow MRI, performance status, chemotherapy regimen, radiotherapy and serum lactose dehydrogenase (LDH) level showed that the result of bone marrow MRI remained a prognostic factor in SCLC patients with limited disease. Bone marrow examination with MRI is useful for better staging of SCLC. According to our analysis of response rates and survival, MRI-positive LD should be considered a type of ED.     

"Born from the flank"--discussion concerning "cesarean section" in animals in the Talmud

We determined growth hormone (GH) and insulin-like growth factor I (IGF-I) levels after a 3 h infusion of escalating doses of growth hormone-releasing hormone (GHRH(1-29)) followed by a bolus injection in hypopituitary patients with marked differences in pituitary features at magnetic resonance imaging (MRI) in order to evaluate further the contribution of MRI in the definition of pituitary GH reserve in GH-deficient patients. Twenty-nine patients (mean age 14.5 +/- 4.0 years) were studied. Group I comprised 13 patients: seven with isolated GH deficiency (IGHD) (group Ia) and six with multiple pituitary hormone deficiency (MPHD) (group Ib) who had anterior pituitary hypoplasia, unidentified pituitary stalk and ectopic posterior pituitary at MRI, Group II consisted of eight patients with IGHD and small anterior pituitary/empty sella, while in group III eight had IGHD and normal morphology of the pituitary gland. Growth hormone and IGF-I levels were measured during saline infusion at 08.30-09.00 h, as well as after infusion of GHRH (1-29) at escalating doses for 3h: 0.2 micrograms/kg at 09.00-10.00 h, 0.4 micrograms/kg at 10.00-11.00 h, 0.6 micrograms/kg at 11.00-12.00 h and an intravenous bolus of 2 micrograms/ kg at 12.00 h. In the group I patients, the peak GH response to GHRH(1-29) was delayed (135-180 min) and extremely low (median 2mU/l). In group II it was delayed (135-180 min), high (median 34.8 mU/l) and persistent (median 37.4 mU/l at 185-210 min). In group III the peak response was high (median 30.8 mU/l) and relatively early (75-120 min) but it declined rapidly (median 14.4 mU/l at 185-210 min). In one group I patient, GH response increased to 34.6 mU/l. The mean basal value of IGF-I levels was significantly lower in group I (0.23 +/- 0.05 U/ml) than in groups II (0.39 +/- 0.13U/ ml, p < 0.01) and III (1.54 +/- 0.46 U/ml, p < 0.001) and did not vary significantly during the GHRH(1-29) infusion. The present study demonstrates that the impaired GH response to 3 h of continuous infusion of escalating doses of GHRH(1-29) was strikingly indicative for pituitary stalk abnormality, strengthening the case for use of GHRH in the differential diagnosis of GH deficiency. The low GH response, more severe in MPHD patients, might be dependent on the residual somatotrope cells, while the better response (34.6 mU/l) in the group Ia patients might suggest that prolonged GHRH infusion could help in evaluating the amount of residual GH pituitary tissue. Pituitary GH reserve, given the GH response to GHRH infusion in GH-deficient patients with small anterior pituitary/empty sella, seems to be maintained.     

Dynamic contrast-enhanced MRI with subtraction of aggressive soft tissue tumors after resection

OBJECTIVE: To report the application of dynamic contrast-enhanced subtraction MRI for detecting recurrences in aggressive or malignant soft tissue tumors. DESIGN: The imaging studies consisted of static (T1- and T2-weighted spin-echo) acquisitions, followed by dynamic conventional spin-echo short TR/TE images (at 45 s, 1 min 30 s and 5 min) after a bolus of intravenous contrast medium. Contrast images were subtracted from the precontrast scan on the console. PATIENTS: Ninety-eight patients were studied who had had aggressive or malignant soft tissue tumors treated by surgery, and were followed up to assess recurrences. RESULTS: Subtraction MRI characterized recurrences better than routine sequences in 10 patients (1 lesion was seen only with this technique, 6 were better delineated, and 3 inflammatory pseudotumors were identified), and less well in 4 cases. CONCLUSION: As the number of levels studied on dynamic images is limited, and all but one recurrence were detected on T2-weighted images, it remains logical to start the examination with T2-weighted spin-echo images, and to use the dynamic study only if contrast injection is required.     

Myotonic dystrophy--dynamic mutation and disease pathogenesis

Pituitary volume in humans has been reported to change size in response to experimental manipulations of photoperiod, and to be increased during an episode of non-seasonal major depression. We wanted to determine whether pituitary volume changes either across the seasons or during an episode of winter depression. Nineteen patients with winter-seasonal affective disorder and 19 sex-, age-, height-, and weight-matched controls underwent magnetic resonance imaging of the pituitary gland in both winter and summer. Images were obtained using 0.7-mm contiguous slices and the areas of all slices were summed to compute the final volume for each gland. We found no main effects or interactions involving either diagnosis or season in our primary analysis. In a post-hoc analysis, we found a trend towards a season x gender effect (P = 0.06), such that pituitary volume increased slightly (+4.0%) across seasons in women, whereas it decreased slightly (-4.3%) across seasons in men. The results suggest that neither winter depression nor the change of seasons is associated with a significant change in pituitary size.     

Specific G protein activation and mu-opioid receptor internalization caused by morphine, DAMGO and endomorphin I

PURPOSE: This study investigates the usefulness of Gadolinium (Gd)-infusion magnetic resonance angiogram (MRA) in the detection of impalpable undescended testes. METHODS: Magnetic resonance (MRI) examination was performed in 14 patients with 17 impalpable undescended testes (unilateral, n = 11; bilateral, n = 3). MRAwasthen performed as follows: Gadolinium-DTPA-BMA (Omniscan) at 0.3 mmol/kg body weight was injected intravenously, and dynamic coronal examination using fast spoiled gradient recalled sequences was obtained with images taken at early arterial and delay venous phases. The testis was located by detection of the enhanced pampiniform venous plexus. RESULTS: Of the 17 undescended testes, 11 canalicular hypoplastic testes and 3 intraabdominal testes were detected in both routine MRI and MRA. Three atrophic testes were found in the scrotum by MRA but not detected by routine MRI. The detection rates of impalpable testes by MRI and MRA were 82.4% and 100%, respectively. All imaging findings were confirmed by surgical exploration. There was no morbidity associated with MRA. CONCLUSION: Gd-infusion MRA is an accurate and sensitive method of preoperative localization of impalpable testes and is superior to conventional MRI in the detection of atrophic testes.     

Lymphocutaneous infection due to Scedosporium apiospermum

Lymphocytic hypophysitis is a rare disorder predominantly affecting females during the antepartum or postpartum period. It is characterized by destruction and lymphocytic infiltration of the pituitary gland, probably by an autoimmune process, leading to a pituitary mass lesion and/or various degrees of hypopituitarism. The lesion is usually confined to the adenohypophysis. Posterior pituitary gland or stalk involvement is rare, although patients presenting with diabetes insipidus have been reported. We describe a girl aged 13 years 9 months with lymphocytic hypophysitis who presented with diabetes insipidus and secondary amenorrhea. MRI of the brain revealed a 1 cm enhancing mass in the pituitary stalk. A biopsy of the mass by right pterional craniotomy showed lymphocytic infiltration without neoplastic cells or granuloma formation. To our knowledge, this is the youngest reported patient with a diagnosis of lymphocytic hypophysitis. In this case report, her clinical presentation is discussed along with a review of the literature. CONCLUSION: We present the first childhood case of lymphocytic hypophysitis which is an autoimmune inflammatory disorder of the pituitary gland. Although this is a rare condition in adults, it also needs to be considered in the pediatric population. Conservative management is preferred unless there are signs of increased intracranial pressure. Most importantly, close monitoring for multiple hormone deficiencies is indicated in this condition.     

Analysis of loss of heterozygosity on chromosome 11 and infrequent inactivation of the MEN1 gene in sporadic pituitary adenomas

To investigate the role of tumor suppressor genes in sporadic pituitary adenomas, we first analyzed loss of heterozygosity on 11q13 with microsatellite analysis in 31 tumors. Loss of heterozygosity on 11q13 was detected in 1 mixed GH/PRL adenoma, and the somatic 22-bp deletion of the multiple endocrine neoplasia type 1 (MEN1) gene encoding menin was detected in this tumor. Trisomy 11 suggested by the decreased mean allelic ratios of 66% or 65% for 16 or 13 microsatellite markers, respectively, in 2 of 31 pituitary adenomas was confirmed by interphase fluorescence in situ hybridization. Screening for mutations of the MEN1 gene did not find mutations with PCR-single strand conformation polymorphism analysis in other pituitary adenomas retaining heterozygosity on 11q13. Based on these, it is concluded that inactivation of the MEN1 gene comprises a rare etiology for tumorigenesis of the pituitary gland, and that trisomy 11 or another gene(s) may contribute to the pathogenesis of sporadic pituitary adenomas.     

Caregiving for children and adults with chronic conditions: introduction to the special issue

The purpose of this study was to compare the value of dynamic magnetic resonance imaging (MRI) and fat suppression in detecting a pancreatic tumor. The subjects were 19 patients with invasive ductal adenocarcinoma and six patients with islet cell tumor where diagnosis was established pathologically. Breath-hold gradient echo images, breath-hold gradient echo images with fat suppression and breath-hold gradient echo images with dynamic enhancement at 1.5 T were obtained for all patients. The efficacies of these three imaging techniques were compared by calculating the contrast-to-noise ratio, as indicative of conspicuousness between a tumor-affected and a normal pancreas. As for adenocarcinoma, our results indicated that the usefulness in detecting the tumor was high, decreasing in the order dynamic contrast images > fat suppression images > plain images, and that the difference between any two of these three types of image was statistically significant. On the other hand, these imaging techniques showed no statistically significant difference in detecting islet cell tumors. In conclusion, dynamic MRI is the best method for detecting pancreatic adenocarcinoma. As the fat suppression technique has the advantage of being non-invasive, this method is suitable for screening studies of pancreatic adenocarcinoma. However, no advantage was recognized in using the fat suppression technique for detecting an islet cell tumor in comparison with plain MRI.     

Reoperation for recurrent coronary artery disease: results of 200 consecutive cases

OBJECTIVE: To quantify first-pass enhancement of cervix carcinoma using fast dynamic MRI. To assess the accuracy of dynamic contrast-enhanced colour-coded MRI for determining tumour invasion into surrounding pelvic tissues. METHODS: Gadolinium enhanced dynamic MRI at one image every 2 s was performed in 47 patients with cervical carcinoma and five controls. First-pass contrast enhancement of cervix carcinoma and surrounding pelvic tissues was quantified. Automated colour-coded images were constructed using the dynamic parameters slope, amplitude and timing of enhancement. Of 47 patients, 28 underwent surgery and colour coded images were correlated with histological findings. RESULTS: First-pass contrast enhancement imaging of cervix carcinoma required a temporal resolution of dynamic MRI of one image every 3-4 s. Cervix carcinoma first-pass was more rapid and intense than that of other pelvic tissues (P<0.001) with the exception of normal myometrium (P>0.05). Binary colour coding, however, was not reliable for tumour delineation or for accurate assessment of tumour invasion into the parametria or the bladder wall. Overestimation of the extent of tumour invasion occurred in 15, 16 and nine out of 28 patients, respectively, using amplitude, slope and timing of enhancement as parameters. CONCLUSION: Dynamic contrast-enhanced colour-coded MRI of cervix carcinoma has limited value for assessing the extent of tumour spread and tumour staging.     

Video-assisted thoracoscopic surgery for spontaneous hemopneumothorax

PURPOSE: This study examined the usefulness of magnetic resonance imaging (MRI) in assessing whether parotid tumors were located in the superficial or deep lobe. PATIENTS AND METHODS: Eight patients with parotid gland tumors underwent MRI using a spin echo pulse sequence. T1- and T2-weighted images were obtained. To assess tumor localization in the parotid gland, two anatomic landmarks were used: 1) a line connecting the lateral surface of posterior belly of digastric muscle and lateral surface of the cortical bone of ascending ramus (facial nerve [FN] line) and 2) the relationship to the retromandibular vein (RV). Results of all MRI examinations were compared with the surgical findings. RESULTS: Seven of eight cases were correctly diagnosed using the FN line criterion. Five of eight cases were correctly diagnosed using the RV criterion. CONCLUSION: MRI is an excellent modality to show tumor localization in the parotid gland.