Staging of rectal cancer by double-contrast MR imaging using the rectally administered superparamagnetic iron oxide contrast agent ferristene and IV gadodiamide injection: results of a multicenter phase II trial.

The aim of this study was to assess the accuracy of double-contrast magnetic resonance imaging (MRI) with rectal application of the superparamagnetic iron oxide contrast agent (SPIO) ferristene and IV gadodiamide for preoperative staging of rectal cancer. In a randomized phase II dose-ranging trial, 113 patients were studied preoperatively with one of four different formulations of ferristene (Abdoscan) as an enema before MRI. T1-weighted spin-echo (T1w SE) and T2w turbo spin-echo (TSE) single-contrast images were obtained as well as T1w SE and gradient-echo (GRE) double-contrast images after IV gadodiamide injection (Omniscan). Images were assessed qualitatively, and TNM tumor stage was compared with histopathology. High-viscosity ferristene formulations were superior to low-viscosity formulations in tumor staging (accuracy 90% vs 74%, P < 0.01). There was no significant difference between high and low iron content ferristene. MRI had a sensitivity of 97%, specificity of 50%, and accuracy of 82% for staging of rectal carcinoma higher than T2 stage. At receiver operator characteristic (ROC) analysis, MR differentiation between T1/T2 and T3/T4 tumor stages yielded a ROC index of 0.848. Double-contrast MRI is an accurate method for preoperative staging of rectal cancer.

Methods: MRT.

MRI has become the imaging method of choice in special regions of the head and neck (e.g. nasopharynx, oropharynx, oral cavity, floor of the mouth). Superconducting MR-equipment with field strengths of 1.0-1.5 T are appropriate for the evaluation of the head and neck region. Signal acquisition is optimal with circular polarized head coils or with specially designed surface coils; the body coil is insufficient.When imaging tumors we need T1 contrast, T2 contrast and contrast medium information (enhancement information). For the T1 contrast T1-spin-echo is and remains the best sequence. For T2-contast T2 turbo-spin-echo with fat suppression has replaced the T2 spin-echo sequences because it is faster and shows good contrast between tumor and saturated fat tissue. Fat saturated T1 turbo-spin-echo enables best tissue contrast after Gd-DTPA application.

Oropharynx, oral cavity, floor of the mouth: CT and MRI.

Pretherapeutic staging of tumors of the oropharynx, the oral cavity and the floor of the mouth is important and should be thorough and exact to ensure appropriate therapy. Particularly important is the assessment of infiltration of deeper compartments and the topographic relationship of tumor to vascular structures (lingual artery and vein, hypoglossal nerve), or the presence of spread of the tumor across the midline. As spread of tumor may occur to a large degree underneath normal appearing mucosa, clinical assessment of the true tumor extent is difficult. In the last 20 years computed tomography (CT) has proved its value as a supplementary non-invasive method and established its role in modern diagnostic evaluation. Magnetic resonance imaging (MRI) is an non-invasive scanning method that offers excellent tissue contrast. Ultrasonography (US) is of secondary importance, but provides useful guidance due to its wide availability and its easy use. This paper aims to depict the possibilities of modern CT and MRI to provide 'one-stop-shopping' information to the clinician as a basis for the right therapeutic approach and correct estimation of the individual patient's prognosis. A clear problem oriented imaging strategy with standardized diagnostic criteria will lead to a cost effective evaluation.

0.2-Tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study.

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system for MRI of limbs and peripheral joints--the 0.2-T Artoscan (Esaote, Italy)--was used for imaging knee joint lesions. T1-weighted spin-echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 h after imaging, the sensitivity, specificity, and accuracy were respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 96%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tears of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the anterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articular cartilage lesions. The examination can be performed within 30-45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning.

[Prospective comparison of ARTOSCAN-MRI and arthroscopy in knee injuries]. / Prospektiver Vergleich von ARTOSCAN-MRT und Arthroskopie bei Kniegelenkverletzungen.

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 276 patients. A "dedicated system" for MRI of limbs and peripheral joints--the 0,2 Tesla ARTOSCAN (ESAOTE, Italy)--was used for imaging knee joint lesions. T1-weighted spin echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of bone and the femoropatellar joint were acquired. If necessary paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments, medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 hours after imaging, the sensitivity, specificity, and accuracy were respectively, 91, 92 and 91 per cent for tears of the medial meniscus; 80, 96, and 92 per cent for tears of the posterior meniscus; 100, 100, and 100 per cent for tears of the posterior cruciate ligament; 93, 98, and 99 per cent for tears of the anterior cruciate ligament; and 73, 100, and 92 per cent for full-thickness articular cartilage lesions. The examination can be performed within 30 to 45 minutes at a cost that is lower than that of diagnostic arthroscopy. ARTOSCAN imaging is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning.

Anatomic variants of the spermatic vein: importance for percutaneous sclerotherapy of idiopathic varicocele.

PURPOSE: To evaluate percutaneous sclerotherapy of idiopathic varicocele in left internal spermatic vein variants. MATERIALS AND METHODS: The left spermatic vein was embolized with a liquid sclerosing agent in 386 patients (mean age, 29.5 years) with idiopathic varicocele. Success and complication rates were assessed and correlated with spermatic vein variant. Doppler ultrasound was performed 3 and 6 months after therapy in 263 patients. RESULTS: The success rate was 93.8% (n = 362). Perforation of the vein was the most common complication (n = 24). The recurrence rate was 3.8% (10 of 263 patients). Success and complication rates were associated with spermatic vein variant. Type IVb (intact valve of the main trunk, insufficient collateral vessels; n = 73) was of special importance: 67% (16 of 24) of all perforations occurred and 54% (13 of 24) of all unsuccessful interventional procedures were performed in patients with this variant. CONCLUSION: Sclerotherapy is a safe and effective alternative treatment of idiopathic varicocele. It can be performed on an outpatient basis. Success depends on the anatomic variant.

MRI of peripheral joints with a low-field dedicated system: a reliable and cost-effective alternative to high-field units?

In the age of health care cost containment new imaging technology has to meet diagnostic requirements as well as economic limitations. In the MR sector new dedicated systems promise reliable diagnostic information at considerably lower costs than whole-body imagers. Within the past 18 months we have examined 2200 patients with acute and chronic lesions of peripheral joints (knee, ankle, foot, elbow, wrist, hand) in a 0.2T dedicated MR system (ARTOSCAN, Esaote Biomedica, Genoa, Italy). We report our experience with this system focusing on its special features, cost-effectiveness and on diagnostic accuracy of low-field MR studies of the knee in correlation with arthroscopy and in comparison with high-field whole-body imagers.

[MRI of the knee joint: first results of a comparison of 0,2-T specialized system and 1,5-T high field strength magnet]. / MRT des Kniegelenks: Erste Ergebnisse eines Vergleichs von 0,2-T-Spezialsystem mit 1,5-T-Hochfeldmagnet.

PURPOSE: Diagnostic accuracy and image quality of a specialised system for MR examinations of peripheral joints were evaluated. MATERIALS AND METHODS: 20 patients with acute or chronic injuries of the knee were examined using a low-field MR system (0.2 T). For comparison, all patients were also studied with a 1.5 T high field strength magnet and all diagnoses were correlated with arthroscopic findings. RESULTS: We found compatible diagnostic accuracies (cruciate ligaments 90%, menisci 75-90%) and good image quality ratings for the low field system ("good" and "excellent" image quality in 83% of cases). CONCLUSION: The low-field MR-system offers low-cost MR examinations of peripheral joints with good image quality and reliable diagnostic information.

[Computerized tomography staging of carcinomas of the uterus]. / Computertomographisches Staging von Karzinomen des Uterus.

In the staging of uterine carcinoma, CT is used for the assessment of uterus size and configuration, tumor infiltration into the pelvic soft tissues, involvement of the ureters with urine retention, and lymph node enlargement. Evaluation of parametrial infiltration, which is of utmost importance for therapeutic strategy, is less reliable. CT tends to over-stage parametrial infiltration and is thus inferior not only to MRI, but also to clinical examination if parametrial infiltration is excluded. Partial volume effects may obscure or mimic tumor invasion into the bladder or rectal wall and thus reduce CT accuracy. The value of CT for the staging of uterine carcinoma lies in the assessment of advanced stages of cervical carcinoma and lymph node involvement.

[The MRT of the breast with 2D-spin-echo and gradient-echo sequences in diagnostically problematic cases]. / MRT der Mamma mit 2D-Spinecho- und Gradientenecho-Sequenzen in diagnostischen Problemfällen.

One or both breasts of 296 patients with equivocal clinical or mammographic findings were examined with MRI. T1-weighted spin-echo (SE) and gradient-echo (FFE) sequences were acquired before and after i.v. application of Gadolinium DTPA. 50 lesions with enhancement after Gd-DTPA were biopsied--26 carcinomas, 17 proliferating mastopathic tissues, 5 fibroadenomas and 1 abscess were found. Contrast enhanced MRI with 2D-SE and FFE sequences is an effective technique for evaluating suspicious breast lesions with high diagnostic accuracy.

[The value of computed tomography in the diagnosis of the local and lymph node recurrences of head and neck tumors]. / Wertigkeit der Computertomographie bei der Diagnose von Lokal- und Lymphknotenrezidiven von Kopf-Hals-Tumoren.

544 CT studies of 231 patients were evaluated retrospectively to assess the role of CT in posttherapeutic monitoring of patients with head and neck tumours. CT (80%) was inferior to clinical evaluation (87%) in diagnosing recurrent malignancy due to a lack of specificity (76 vs. 92%). With CT small recurrencies were missed. Occasionally evaluation of the oral cavity was impaired by metal artifacts (dental fillings). However with larger recurrent tumours, CT offered important additional information regarding extent, infiltration of deeper compartments and bony destruction in 51% of the cases. CT (95%) was superior to clinical evaluation (80%) in diagnosing recurrent lymph node metastases. A baseline CT study at about 6-8 weeks after the end of therapy is of great importance for follow-up studies.

Diagnosis and treatment of the N0 neck in carcinomas of the upper aerodigestive tract: current status of diagnostic procedures.

Diagnostic procedures currently utilized for determining nodal status in patients with head and neck primary carcinomas are reviewed. Diagnostic procedures include clinical palpation, computed tomography, magnetic resonance imaging and ultrasound. Each technique is discussed on the basis of clinical experience at the Technical University of Munich.