High-resolution contrast-enhanced MRI of the uterus with a phased-array multicoil

High-resolution contrast-enhanced dynamic MRI of the uterus can be performed with the combination of a phased-array multicoil and fast GE techniques. This technique can improve the ability to visualize normal anatomy of the uterus and periuterine tissues, including vascular structures and pelvic ligaments, and to detect pathologic processes of the uterus and determine their extent.     

Preoperative staging of rectal carcinoma by magnetic resonance imaging with a pelvic phased-array coil

BACKGROUND: The use of surface coils for magnetic resonance imaging (MRI) allows enhanced image definition and so potentially more accurate staging of colorectal cancer. Endorectal coil imaging is invasive, operator dependent and impossible in a high proportion of patients due to rectal stricture. The phased-array pelvic coil, however, is non-invasive and applicable to all rectal tumours. METHODS: A pelvic phased-array coil was used for preoperative MRI staging of 38 primary rectal carcinomas. Results were expressed according to the Dukes and tumour nodes metastasis (TNM) classifications. After resection of the tumour, the stage predicted on MRI was compared with the pathological classification. RESULTS: The overall accuracy of preoperative staging with the pelvic phased-array coil was 55 per cent for both Dukes class and T stage. Assessment of nodal involvement gave an overall accuracy for MRI of 76 per cent with a sensitivity of 57 per cent and specificity of 88 per cent. CONCLUSION: Use of a pelvic phased-array coil did not improve the staging accuracy of MRI to a clinically useful level.     

Endovascular occlusion with a new mechanical detachable coil

OBJECTIVE: Metallic coils have been used for vascular embolization for many years but controlled-release coils have only recently become commercially available. Most of these devices are microcoils that were manufactured primarily for the packing of intracerebral aneurysms; therefore, they lack radial force and are not ideal agents for the occlusion of high-flow lesions such as pulmonary arteriovenous malformations (PAVMs). The objective of this study was to review our experience with a new detachable coil based on the conventional Gianturco-Wallace coil. SUBJECTS AND METHODS: The new detachable coil was initially used for the treatment of varicocele in 20 patients. Subsequently, the coil was used in 48 patients during 90 procedures for the treatment of PAVMs. RESULTS: A total of 548 coils were used. Complete occlusion of the testicular vein was achieved in all patients with varicocele. Successful occlusion of the PAVM being treated was achieved in all patients, and no instances of recanalization were documented in any of the patients who returned for follow-up angiography. Forty-one coils had to be removed completely from the catheter before detachment because of inappropriate size or position. Eight coils failed to detach easily, and six of these had to be removed. Most of these device failures were associated with kinking of the screw thread mechanism between the coil and the delivery wire. CONCLUSION: The Jackson detachable coil allows safer, more accurate, and more distal embolization of PAVMs than is possible with nondetachable coils. Complications associated with its use have been few.     

Tibiofibular syndesmosis: high-resolution MRI using a local gradient coil

The purpose of this study was to validate the accuracy of the assessment of ventricular function by first-pass radionuclide angiography (FPRNA) with 123I myocardial tracers and a multicrystal gamma camera. METHODS: Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction were measured in 69 patients by FPRNA using 123I myocardial tracers (126 +/- 7 MBq) and 99mTc tracers (541 +/- 141 MBq) on a multicrystal gamma camera with a high-sensitivity collimator. For 44 patients, ejection fraction values measured by 123I-FPRNA were compared to those estimated by equilibrium radionuclide angiography (ERNA). Visual wall-motion analysis was also performed to judge clinical acceptability of 123I-FPRNA images for identification of wall-motion abnormality. RESULTS: Mean LVEFs (%) estimated by 123I-FPRNA and by 99mTc-FPRNA were 49.6 +/- 13.6 and 49.1 +/- 14.1, respectively (nonsignificant p value). An excellent correlation was found between LVEFs estimated by 123I-FPRNA and 99mTc-FPRNA (r = 0.96, s.e.e. = 1.9%). Values of LVEF measured by 123I-FPRNA also demonstrated excellent correlation with those measured by ERNA (r = 0.95, s.e.e. = 2.2%). A good correlation was also noted between right ventricular ejection fractions measured by 123I-FPRNA and 99mTc-FPRNA (r = 0.72, s.e.e. = 4.0%). The Spearman rank correlation coefficient between 123I-FPRNA and ERNA wall-motion scores was 0.87 (n = 135, p < 0.001). CONCLUSION: Resting ventricular function can be reliably measured with 123I-FPRNA in combination with a multicrystal gamma camera. This indicates that the assessment of ventricular function is feasible in conjunction with 123I myocardial imaging without an increase in cost or radiation dose to patients.     

High-resolution magnetic resonance tomography of the lesser pelvis using an endorectal coil

Spatial resolution of MRI within the true pelvis can be increased by a factor of 12 using an endorectal coil. The value of this new method for demonstrating the prostate, the rectum, the cervix and vagina and of pathological processes of these organs was examined in 89 patients and the results compared with conventional body coil MRI. In 25 patients who underwent radical surgery the results of the preoperative studies were compared with the histological findings. Detailed recognition of anatomical structures was markedly improved by using the endorectal coil. Diagnosis of carcinoma of the prostate and extension of the tumour was accurately assessed in 33 patients. Preoperative staging was correct in 87%, compared with 73% when using a body coil. The difference was less marked in examinations for carcinomas of the rectum, the cervix and vagina. Nevertheless, staging was more accurate in a few cases with a better recognition of recurrences. MRI with endorectal coils will have an important role in diagnosis of carcinomas of the prostate in the future. Its use in the diagnosis of carcinomas of the rectum and cervix must be subject to further studies.     

Ultrasound-guided fine needle biopsy of pancreatic masses: results of a multicenter study

OBJECTIVE: The aim of this study was to investigate the results of ultrasound-guided fine needle biopsy of pancreatic masses in a large multicenter series. METHODS: This study collected the data of 510 patients who had a final diagnosis available and who had undergone ultrasound-guided fine needle biopsy of the pancreas. Retrieval rate, sensitivity, specificity, and overall diagnostic accuracy of the whole series, by three different bioptic procedures (cytology, histology, and cytology plus histology) were evaluated. The reliability of ultrasound-guided fine needle biopsy to allow a correct diagnosis in the different pancreatic pathologies was calculated. Finally, any complications were collected. RESULTS: For cytology, histology, and cytology plus histology, retrieval rate values were: 94%, 96%, and 97%; sensitivity was: 87%, 94%, and 94%, specificity: 100%; and diagnostic accuracy: 91%, 90%, and 95%, respectively. Ultrasound-guided fine-needle biopsy correctly diagnosed all the cases of pancreatic metastases or non-Hodgkin's lymphoma (23 of 510 cases as 5%; in eight of 23 it led to the first diagnosis of the primary tumor) and all the cases of abscesses, 97% of the cases of pseudocysts, 86% of pancreatic adenocarcinomas, 62% of cystic neoplasms, 35% of the cases of chronic pancreatitis (in this case, the bioptic procedures were reviewed), and 33% of neuroendocrine tumors. There were complications in one case of asymptomatic peripancreatic hematoma, three cases of vaso-vagal reactions, and 21 cases of pain. CONCLUSION: Ultrasound-guided fine needle biopsy of the pancreas is efficacious, without any difference between the various bioptic modalities (with the exception of chronic pancreatitis, in which histology is better). The technique is safe. Moreover, the procedure allows the identification of patients affected by pancreatic tumors other than adenocarcinoma (in our survey 5% of the total); in about one third of these patients it leads to the diagnosis of the primary tumor, thus avoiding inappropriate treatments.