Supervised automatic procedure to identify new lesions in brain MR longitudinal studies of patients with multiple sclerosis.

PURPOSE: Identification of new enhancing lesions is a major endpoint of longitudinal brain magnetic resonance (MR) studies of multiple sclerosis (MS). To date, this is a visual, time-consuming procedure. We present here a supervised automated procedure (SAP) aimed at reducing the time needed to identify new MS enhancing lesions. MATERIALS AND METHODS: The SAP uses an algorithm including Cartesian coordinates of the lesions to be compared, their area and a constant (k). The procedure was validated for enhancing lesions on T1-weighted spin-echo images after intravenous administration of 0.1 mmol/kg of paramagnetic contrast agent, randomly selected from a dataset of a longitudinal MR study on ten relapsing-remitting MS patients followed for 2-5 years. During the validation session, two readers decided by consensus whether two lesions, present on the same slice of two examinations performed on subsequent dates, were the same or not. In this way, k was calibrated to obtain the same result from both visual inspection and automatic algorithm output. RESULTS: After evaluating of 25+/-5 (mean+/-standard deviation) lesions in each of ten different sessions with correction of k value, the k value became a stable value (0.45+/-0.05). CONCLUSIONS: Once the suitable value of k was found, SAP was able to identify new enhancing lesions, avoiding visual inspection, which is usually a lengthy procedure.

White matter lesions in migraine and right-to-left shunt: a conventional and diffusion MRI study.

Subjects with migraine with aura (MA) have a high prevalence of white matter lesions (WMLs) on magnetic resonance imaging (MRI). Moreover, right-to-left shunt (RILES), mainly due to patent foramen ovale, is frequently associated with MA. The aim of this study was to clarify the relationship between RILES and WML in MA. We enrolled 87 consecutive subjects affected by MA. Patients were screened for migraine characteristics and cerebrovascular risk factors. Transcranial Doppler was used to diagnose RILES and MRI with T2-weighted and diffusion-weighted imaging (DWI) to evaluate presence, number and volume of WMLs. RILES was present in 45% of patients. We did not detect any DWI hyperintense lesion; WMLs were present in 61% of patients on T2-weighted images. Presence of WMLs did not correlate with any migraine clinical feature, whereas the presence, number and volume of WMLs increased with subjects' age. There was no significant difference in the total volume and number of WMLs in the group with and without RILES. In conclusion, RILES does not increase the likelihood of finding WMLs in migraineurs.

Intracranial haemorrhage in patients on antithrombotics: clinical presentation and determinants of outcome in a prospective multicentric study in Italian emergency departments.

BACKGROUND: Intracranial haemorrhage (ICH) is the type of stroke associated with the highest death rate, and about 30% of ICH occurs in patients on antithrombotic treatment. This study relates clinical presentations and outcome of ICH patients on oral anticoagulant (OA) or antiplatelet (AP) therapy admitted to 33 Italian emergency departments (ED). METHODS: Consecutive patients were enrolled after cranial computed tomography (CT). Primary outcome was the Modified Rankin Scale (MRS) score at 3 months of follow-up. Common descriptive statistics were computed after stratification for traumatic or spontaneous ICH and identification of the anatomical location of bleeding. Multivariate logistic regression was used to assess predictors of death. RESULTS: We recruited 434 patients on AP therapy and 232 on OA. There were 432 spontaneous and 234 traumatic ICH patients. The proportions of AP and OA patients undergoing neurosurgery were 21.8 and 19.4%, respectively, while < 30% underwent procoagulant medical treatment. At the 3-month follow-up, the case fatality rate was 42.0%, while disability or death (MRS 3-6) was 68.1%. The odds ratio for death in OA versus AP patients was 2.63 (95% CI 1.73-4.00) in the whole population and 2.80 (95% CI 1.77-4.41) in intraparenchymal event patients. Glasgow Coma Scale, age, spontaneous event and anticoagulant use were found to be predictors of death both in traumatic and spontaneous events. CONCLUSION: This study confirms the high prevalence of death or disability in OA and AP patients with ICH. As far as the determinants of mortality and disability are concerned, the results of this study might be useful in the clinical management and allocation of resources in the ED setting. The observed low use of procoagulant therapy highlights the need for ED educational programmes to heighten the awareness of available and effective haemostatic treatments.

Evaluation of Gd-enhancement in brain MR of multiple sclerosis: image subtraction with and without magnetization transfer.

The aim of our study was to test the possibility of using image subtraction in detecting enhancing lesions in brain MR scans with and without magnetization transfer (MT) in multiple sclerosis (MS). Ten MS patients underwent 1.5-T MR imaging of the brain with spin-echo T1-weighted sequences with and without MT, repeated after 0.1 mmol/kg of an usual two-compartment paramagnetic contrast agent (Gadoteridol, Gd-HP-DO3A). Precontrast images were subtracted from postcontrast. Enhancing lesions were counted on the postcontrast images only (post-Gd), comparing pre- and postcontrast images by direct visual control (pre/post-Gd), and on the subtracted images (SI) only. Without MT, 36 enhancing lesions were counted on post-Gd, 36 on pre/post-Gd, and 59 on SI; using MT, 69, 52, and 50, respectively. Significant differences were found for pre/post-Gd without MT vs SI without MT ( p=0.028) and vs pre/post-Gd with MT ( p=0.012) as well as for pre/post-Gd with MT vs post-Gd with MT ( p=0.028). With pre/post-Gd, MT allowed the detection of 1.6 enhancing lesions per patient more than without MT. Whereas the SI without MT allow the detection of an increased number of enhancing lesions, SI with MT do not. An off-site final assessment allowed calculation of sensitivity and positive predictive value as follows: without MT were 63 and 94% (post-Gd), 67 and 100% (pre/post-Gd), 96 and 88% (SI); and with MT were 93 and 73% (post-Gd), 96 and 100% (pre/post-Gd), 91 and 98% (SI), respectively. Thus, SI seem to increase the sensitivity without MT; moreover, they could be used to correct the pseudoenhancement that impair post-Gd images with MT.

Volume measurement with magnetic resonance imaging of hippocampus-amygdala formation in patients with anorexia nervosa.

The purpose of our work was to evaluate the volume of hippocampus-amygdala formation (HAF) in patients with anorexia nervosa (AN), being this structure a crucial target for the glucocorticoid action in the adaptative stress-response. AN patients have biochemical hypercortisolism associated to normal ACTH levels, but do not develop the characteristic clinical features of glucocorticoid hypersecretion. Furthermore, in these patients cortisol levels usually do not suppress after dexametasone challenge. Twenty AN females (aged 30.0+/-5.1) with 10.5+/-4.2 yr of disease underwent a brain magnetic resonance (MR) examination during the recovery phase; an age-matched control group (CG) of 20 healthy female volunteers was also studied. Two interleaved T1-weighted spin-echo sequences for 46 contiguous 2-mm coronal slices (pixel 0.98(2) mm) were used. The volumes of both right and left HAFs were calculated with manual contouring from the third ventricle to the Sylvian aqueduct. IGF-I, T3, gonadotropins, 24-h urine free cortisol, and BMI were obtained for both patients (on admission and on present evaluation) and CG. Mann-Whitney, Wilcoxon and Spearman tests were used. AN patients showed a significant (p=0.0001) reduction of total (right plus left) HAF volume (6.6+/-1.3 cm3) when compared with CG (8.9+/-1.1). No significant difference was found between right and left HAF in both patients and CG. In AN patients, no significant correlation was found between the HAF and all the hormonal parameters or BMIs, while a trend towards significance was observed with duration of the disease (r=-0.398; p=0.082). MR imaging demonstrated a significant volume reduction o

MR dynamic enhancement of breast lesions: high temporal resolution during the first-minute versus eight-minute study.

PURPOSE: To investigate the value of the early phase of MR enhancement of breast lesions. METHOD: To study 63 breast lesions (size 5-45 mm in diameter) in 56 patients, whole-breast and lesion-targeted precontrast T1 -weighted gradient-echo 2D sequences were acquired. After intravenous injection of Gd-DTPA (0.1 mmol/Kg), four targeted scans, each every 15 seconds during the first minute (1-m), and seven whole-breast scans, each every minute up to 8 minutes (8-m), were performed. The subtraction technique was used, and percent enhancement curves were obtained. The final diagnosis was obtained by histology for 36 lesions, including 28 malignancies, and by fine-needle aspiration cytology and at least 1-year negative follow-up for the remaining 27 benign lesions. RESULTS: Significant differences in enhancement between malignant and benign lesions were found using both techniques (p<0.0001). However the ratio between the median enhancement of malignant lesions and that of benign lesions was 6.7 (15 s), 4.8 (30 s), 4.6 (45 s), and 3.8 (60 s), descending from 4.3 to 2.5 from the second to the eighth minute. The overlap between the malignant and benign curves was 9% of the malignant range with the 1-m technique, and 50% with the 8-m technique. Three blinded observers obtained a 100% sensitivity with both techniques and a specificity of 94-97% with the 1-m technique and 83-89% with the 8-m technique. CONCLUSION: The first minute of Gd-enhancement allows a more prominent differentiation between malignant and benign breast lesions than the following times.

Adipose replacement and wall motion abnormalities in right ventricle arrhythmias: evaluation by MR imaging. Retrospective evaluation on 124 patients.

We reevaluated the magnetic resonance (MR) examinations of 38 healthy volunteers (control group, CG) and of 124 patients with RV arrhythmia with left bundle branch block (LBBB) morphology: 45 with episodes of RV sustained tachycardia and of polymorphic RV premature beats (RVST-PPB group); 36 with only RV outflow tract sustained or not sustained tachycardia (RVOTT group); 43 with RV monomorphic premature beats (RVMPB group). All the examinations were reevaluated in a blinded fashion for detecting myocardial adipose replacement (AR) and wall bulges or aneurysms. In RVST-PPB patients, no AR was observed in 9%; 1 RV region involvement, 0%; 2 regions, 4%; > or = 3 regions, 87%; left ventricle (LV), 15%. RVOTT patients: 28%, 53%, 14%, 5%, and 0% [corrected], respectively. RVMPB patients: 33%, 46%, 19%, 2%, and 0% [corrected], respectively. In CG, AR was observed in 11% (in RV outflow tract), RV bulges were detected in 75% [corrected] of RVST-PPB, 39% of RVOTT, and 14% of RVMPB patients, none of the CG; RV aneurysms in 33% of RVST-PPB patients, none of RVOTT patients, RVMBP patients, and CG. A significant difference among groups for RV and LV AR as well as RV bulges and aneurysms was found (p < 0.0001). In the direct comparisons, significant differences were found for: disease duration (RVST-PPB vs. RVMPB, p = 0.0396); RV AR (all the patients groups vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0001); RV aneurysms (RVST-PPB vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0002); bulges (all comparisons, p < 0.0174). AR is confirmed as a structural substrate in RV arrhythmias. Number and extension of MR abnormalities are correlated to different degrees of RV arrhythmias.

[Brain magnetic resonance with magnetization transfer in multiple sclerosis. Lesion hyperintensity before and after intravenous gadolinium administration]. / Risonanza Magnetica encefalica con trasferimento della magnetizzazione nella sclerosi multipla. Iperintensità lesionale prima e dopo somministrazione endovenosa di Gadolinio.

PURPOSE: To evaluate lesion contrast enhancement in brain magnetic resonance (MR) images with and without magnetization transfer pulse (MT) in patients affected with multiple sclerosis (MS). MATERIAL AND METHODS: Ten patients affected with relapsing-remitting MS underwent a 1.5-T (Magnetom Vision, Siemens) MR examination with T1-weighted spin-echo sequences without MT (TR/TE = 630/14 ms) and with MT (840/14 ms) using the following common parameters: 21 para-axial slices (thickness 5 mm, 10% gap); matrix 256 x 256; field of view 25 cm (rectangular 5/8); 2 excitations. The postcontrast sequences with and without MT were acquired in a randomized order, starting 5 minutes after the intravenous injection of 0.1 mmol/kg Gadoteridol (ProHance, Bracco). The images were blindly evaluated in four separate sessions: only the postcontrast images with MT (post-Gd with MT); only the postcontrast images without MT (post-Gd without MT); comparing the pre- and postcontrast images with MT (pre/post-Gd with MT); comparing the pre- and postcontrast images without MT (pre/post-Gd without MT). The number of hyperintense areas referred to contrast enhancement and the evaluation time were measured for each session. The Wilcoxon test was used for statistical analysis. RESULTS: The number of areas referred to lesion contrast enhancement per patient were as follows: post-Gd with MT, 6.9 +/- 6.8 (mean +/- standard deviation) (range 1-24); post-Gd without MT, 3.6 +/- 4.3 (0-14); pre/post-Gd with MT, 5.2 +/- 6.1 (1-21); pre/post-Gd without MT, 3.6 +/- 4.9 (0-16). A nonsignificant difference was found for the comparison between post-Gd without MT and pre/post-Gd without MT while significant differences were found between post-Gd with MT and pre/post-Gd with MT (p = .028), pre/post-Gd without MT and pre/post-Gd with MT (p = .012), as well as between post-Gd without and post-Gd with MT (p = .008). The mean evaluation time for the different sessions was always less than a minute, ranging from 33 seconds for pre/post-Gd without MT to 51 seconds for post-Gd with MT. CONCLUSIONS: The postcontrast sequence obtained with the MT pulse detects more active lesions than the postcontrast sequence without MT. However, the comparison with the plain images with the MT pulse is mandatory to exclude pseudoenhancement foci, i.e. hyperintense areas already present in the precontrast images with the MT pulse, without disruption of the blood-brain barrier. The post-Gd without MT sequence needs not be compared with the precontrast images without MT. Differences in evaluation time are practically negligible.

Double-contrast magnetic resonance examination of ulcerative colitis.

The aim of our work was to propose a double-contrast magnetic resonance examination (DCMRE) in the follow-up of ulcerative colitis (UC), comparing this new technique with X-ray double-contrast barium enema (DCBE). After preparation with colon-cleansing regimen used for DCBE, six UC patients and six control subjects underwent a 1.5-T examination: supine position, coronal and axial fat-spectral-saturation breath-hold gradient-echo T1-weighted sequences after intravenous hypotonization and 1500-2000 cc air insufflation. Without evacuating the primarily insufflated air, the same images were acquired after endorectal administration of negative superparamagnetic contrast agent (600 cc) and intravenous administration of positive paramagnetic contrast agent (0.2 mmol/kg). All patients had undergone DCBE in the four preceding weeks. We found significant increase in wall thickness of UC affected vs apparently unaffected segments (p = 0.0425) and vs CG (p = 0.0447), significant increase in enhancement percent of UC affected vs apparently unaffected segments (p = 0.0161) and vs CG (p = 0.0185), and no significant difference for enhancement percent of UC unaffected segments vs CG. DCMRE and DCBE localized the UC extension at the same sites in all patients. Double-contrast MR examination time was 20-30 min. This new method could be used in follow-up of UC patients.

Bowel preparation for the double-contrast barium enema: how to maintain coating with cleansing?

AIM: Poor mucosal coating, due to excess of fluid in the colon lumen, is a problem when the oral lavage method (4 litres of an iso-osmotic saline solution containing polyethylene glycol) is used as a preparation for double-contrast barium enema. Our aim was to assess the value of prior administration of sennosides to obtain a clean colon with a reduced volume of polyethylene glycol (PEG)-saline solution, but maintaining good mucosal coating. MATERIALS AND METHODS: After a 2-day low-residue diet, three different oral preparations were compared: (i) 4 litres of a PEG-saline solution (SELG) and 15 mg of bisacodyl (116 patients, SELG-4 group); (ii) 156 mg of sennosides, 15 g of magnesium sulphate, and 2 litres of water (116 patients, SennMg group); (iii) 156mg of sennosides and 2 litres of SELG (116 patients, SennSELG group). Compliance, complaints, cleansing, mucosal coating, and fluid retention were evaluated. RESULTS: Compliance was > 94% in every group. A higher percentage of mild nausea was observed in SELG-4 group, of mild abdominal cramping in SennMg group, of substantial abdominal cramping in SennSELG group (P < 0.02). Cleansing was better in SennSELG than in both the SELG-4 (P = 0.0003) and SennMg (P = 0.0353) group. Mucosal coating was better in SennMg than both SELG-4 (P = 0.0034) and SennSELG (P < 0.0001) group. There was more residual fluid in the SennSELG group than both in SELG-4 (P = 0.0029) and SennMg (P = 0.0059) group. CONCLUSION: For colon cleansing, the combination of sennosides and PEG-saline solution was better than either the 4 litre PEG protocol or the combination of sennosides and magnesium sulphate. For mucosal coating, the protocol combining sennosides and magnesium sulphate was more effective than either protocols using the PEG-saline solution. This may be due to the interaction of residual magnesium ions in the colon lumen with the barium suspension.

MR angiography of internal carotid arteries: breath-hold Gd-enhanced 3D fast imaging with steady-state precession versus unenhanced 2D and 3D time-of-flight techniques.

PURPOSE: The purpose of this work was to compare Gd-enhanced breath-hold fast imaging with steady-state precession (Gd-FISP) with unenhanced time-of-flight (TOF) sequences in evaluating internal carotid arteries (ICAs). METHOD: Thirty patients underwent three unenhanced TOF sequences [2D traveling saturation (Travelsat); 3D tilted optimized nonsaturated excitation (TONE); TOF 3D Multislab] and two breath-hold 3D Gd-FISP sequences with automated intravenous contrast agent injection (axial and coronal). ICAs were classified as normal (no stenosis); with mild (<30%), moderate (30-70%), or severe stenosis; or occluded (100%). Digital subtraction angiography (DSA) with aortic arch injection was used as a reference technique. RESULTS: DSA revealed 20 normal ICAs; 11 mild, 9 moderate, and 14 severe stenoses; and 2 occlusions. DSA and all MR angiography (MRA) sequences diagnosed the occlusion of four common carotid arteries. The TOF 2D overestimated 10 stenoses, TOF 3D TONE 9, and TOF 3D Multislab 5; Gd-FISP 3D overestimated only 2 of them, reaching the highest sensitivity and specificity for severe stenoses. Significant differences were found between the overestimation of Gd-FISP and each of the three unenhanced sequences (0.0020 < p < 0.0313, Wilcoxon and McNemar tests). Severe artifacts were observed with TOF techniques only. CONCLUSION: Gd-FISP is an interesting, largely artifact-free improvement for MRA of ICAs.

Compared effect of a genetically engineered glucagon and hyoscine N-butylbromide on double-contrast barium meal study.

The aim of this study was to compare the effects of a genetically engineered glucagon (geG) and hyoscine N-butylbromide (HBB) on the quality of double-contrast barium meal (DCBM) study. Two hundred sixty-four patients scheduled for DCBM were randomized to receive intravenously geG 0.25 mg (geG-25), or geG 0.5 mg (geG-50), or HBB 20 mg as hypotonic agent. The evaluation concerned: duration of isolated visualization of the stomach (A); gastric mucosal coating (B); visualization of areae gastricae (C); quality of duodenal cap (D) and loop (E) study; delay, if any, of duodenal study (F). Global significant differences (P from 0.0183 to < 0.0001) were found for A, C, D, and F. GeG-50 allowed the longest isolated gastric visualization (P < 0.0001); geG-25 allowed more extensive visualization of areae gastricae than HBB (P = 0.0006); HBB allowed a better study of duodenal cap (P = 0.0052) and loop (P = 0.0190) than geG-25; geG-50 prolonged the examination time (P < 0.01). No adverse effect was observed with geG within 1 h after DCBM. In conclusion, geG can be safely used as a hypotonic agent in DCBM. When DCBM is focused on the stomach, 0.25 mg of geG is the optimal choice; if DCBM is focused on the duodenum, 0.5 mg of geG (with a prolonged examination time) or 20 mg of HBB (with a less effective study of the stomach) should be used.

Effect of copolymer-1 on serial gadolinium-enhanced MRI in relapsing remitting multiple sclerosis.

We examined the effect of Copolymer-1 (Cop1) on magnetic resonance (MR) imaging changes in 10 patients with relapsing-remitting multiple sclerosis (RRMS). Monthly gadolinium (Gd)-enhanced MR imaging was performed for 9 to 27 months in the pretreatment period followed by 10 to 14 additional months during Cop1 treatment. MR images were evaluated by two radiologists (F.S. and R.C.P.) masked to the scan date. We found a 57% decrease in the frequency of new Gd-enhancing lesions and in the mean area/month of new Gd-enhancing lesions in the Cop1 treatment period compared with the pretreatment period (0.92 versus 2.20 lesions per month and 22 mm2 versus 43 mm2 area/month; p = 0.1, Wilcoxon signed rank test). Percentage change in lesion load area on T2-weighted images showed a decrease in the accumulation of lesion area during treatment, which was significant for the patient group with a longer pretreatment period (p = 0.05, Friedman test). These results demonstrate a reduction in the number of new Gd-enhancing lesions and in the lesion load during Cop1 treatment compared with the preceding period without therapy and are suggestive of an effect of Cop1 on MR abnormalities observed in multiple sclerosis.

Magnetic resonance imaging of the breast in characterizing positive or uncertain mammographic findings.

A total of 38 suspected primary (26) or recurrent (12) breast tumors underwent enhanced magnetic resonance imaging (MRI) of the breast after positive (19) or uncertain (19) mammography. Spin echo T1-weighted images before and after intravenous administration of 0.15 mmol/kg Gd-DTPA, the latter ones at 1, 3, and 5 min, were obtained to characterize the mammographic findings. When contrast enhancement was absent, the same images were also obtained at 10 min. Evident and early focal enhancement was considered as an MRI sign of malignancy. All the lesions were submitted to histological examination (seven by core-biopsy only). Mammography results were 23 true positives and 15 false positives. MRI results were 22 true positives, 13 true negatives, 2 false positives, and 1 false negative. Twelve uncertain-mammography cases became true negatives at MRI; 1 uncertain-mammography case was the only MRI false negative; 1 positive-mammography cases became true negative at MRI. Resting on this limited series of patients, MRI is confirmed as a useful imaging technique after uncertain mammography.

[The role of T2*-weighted gradient-echo magnetic resonance sequences in the study of suspected dorsal-lumbosacral vertebral metastases]. / Ruolo delle sequenze di Risonanza Magnetica gradient-echo T2*-pesate nello studio delle sospette metastasi vertebrali dorso-lombosacrali.

INTRODUCTION: Magnetic resonance (MR) imaging showed high reliability in detecting spine metastases with spin-echo (SE) sequences, T1-weighted sequences being generally more sensitive than T/-weighted ones. We investigated the value of T2*-weighted gradient-echo (GE) sequences in studying spine metastases. MATERIALS AND METHODS: Twenty patients with established diagnosis of primary carcinoma and clinically suspected thoracic and/or lumbosacral spine metastases underwent .5-T MR imaging and 99mTc-HDP bone scan. The disagreement of GET2*- versus SET2-weighted images as well as versus bone scan and the disagreement of total MR results versus bone scan results were evaluated by McNemar test. The agreement of GET2*- versus SET1-weighted images was evaluated by Cohen's kappa. RESULTS: Of a total of 111 MR signal abnormalities consistent with metastasis, 109 (98.2%) were T2*-hyperintense, whereas only 50 (45.1%) were T2-hyperintense (p < .0001) and 51 (45.9%) were detected with bone scan (p < .0001). Of a total of 121 MR and/or bone scan findings consistent with metastasis, 111 (91.7%) were MR positive, with high disagreement with 61 (50.4%) positive at bone scan (p < .00001). T2*-hyperintensity associated with T1-hypointensity (with or without T2-hyperintensity) was the most frequent pattern (104/111), 93.7%). CONCLUSIONS: T2*-weighted GE sequences seem to be more effective than T2-weighted SE sequences and as effective as T1-weighted SE sequences. MR imaging confirms its ability in detecting abnormalities consistent with spine metastases.

Helical versus conventional CT in detecting meniscal injuries.

PURPOSE: We compared volumetric helical and conventional CT in the study of meniscal injuries. MATERIAL AND METHODS: Thirty-three patients with suspected meniscal tear underwent helical and conventional CT. Common parameters were 512 x 512 matrix, 14-15 cm FOV, 120 kV and 175 mA; helical CT was performed with 2 mm beam thickness, 1.5 mm/s table feed, 1 mm reconstruction index and conventional CT with 2 s scan time, 1 mm slice thickness and 1 mm table feed. All scans were photographed with a Laser printer using the same window (180/100). All patients also underwent sagittal and coronal T2* GE MRI at .5-T; slice thickness was 5 mm and interslice gap 1 mm. Nonparametric scales were used to study the menisci, as follows: for CT we had A = no visible injury; B = diffuse hypodensity (degenerative condition); C = questionable meniscal tear; D = unquestionable meniscal tear. For MRI, we had A = no visible injury; B = grade 1 or 2 injury; C = grade 3 injury; D = grade 4 injury. We used the 1-4 MR grading by Lotysch et al. and by Crues et al. MRI was used as the gold standard. The agreement between helical CT, conventional CT and MRI was calculated with kappa statistics. RESULTS: Helical and conventional CT found 23 and 15 patterns A, 6 and 10 B, 3 and 1 C and 1 and 7 D, respectively. MRI found 15 A, 8 B, 3 C and 7 D. There was no agreement between helical CT and MRI and between helical CT and conventional CT because of the meniscal tears underestimated by the former. Agreement was very high between conventional CT and MRI (p < .001). DISCUSSION AND CONCLUSIONS: The main result of our experience is that helical CT appears less sensitive than conventional CT in detecting meniscal tears. The helical CT section profile (more roundish than that of conventional CT) and the lower radiation dose used by helical CT (with increased quantum noise) may have played a key role in its underestimation of meniscal tears.

Magnetic resonance evaluation of autonomous thyroid nodules treated by percutaneous ethanol injection.

Magnetic resonance (MR) imaging was used to evaluate the effect of ultrasound-guided percutaneous ethanol injection (PEI) of autonomous thyroid nodules (ATNs). Nine patients affected with ATN (3.7-32.2 mL volume) underwent PEI (4-19 mL ethanol, subdivided in 3-6 weekly procedures). MR imaging (1.5 T) was performed before each alcoholization and 1 month after the last PEI procedure with the following parameters: T1- (550/12) and T2-weighted (2200/160) spin-echo images; 4-mm slices, 10% gap; coronal planes. A further seven patients with normal thyroid function, who had undergone PEI 6-18 months before, underwent an MR examination with the same parameters. The signal-to-noise ratio (S/N) of ATN and extranodular gland, as well as ATN volume, were evaluated on the T2-weighted images. On T1-weighted images, ATNs appeared mostly hypointense before treatment, with hyperintense areas during treatment, and were lightly hyperintense 6-18 months after treatment. S/N on T2-weighted images: extranodular gland 3.5-9.2; ATNs, before treatment 13.2-19.7, before the last procedure 7.7-11.6, 1 month after the last procedure 5.6-10.9; previously treated ATNs, 4.3-8.2. No significant volume reduction was observed with MR 1 month after the last procedure. The MR examination time was about 15 minutes. In conclusion, the effect of PEI on ATNs can be evaluated with an MR examination that is not very time consuming.