Diagnostic value of chemical shift artifact in distinguishing benign lymphadenopathy

Purpose

Today, distinguishing metastatic lymph nodes from secondary benign inflammatory ones via using non-invasive methods is increasingly favorable. In this study, the diagnostic value of chemical shift artifact (CSA) in magnetic resonance imaging (MRI) was evaluated to distinguish benign lymphadenopathy.

Subjects and methods

A prospective intraindividual internal review board-approved study was carried out on 15 men and 15 women having lymphadenopathic lesions in different locations of the body who underwent contrast-enhanced dynamic MR imaging at 1.5 T. Then, the imaging findings were compared with pathology reports, using the statistics analyses.

Results

Due to the findings of the CSA existence in MRI, a total of 56.7% of the studied lesions (17 of 30) were identified as benign lesions and the rest were malignant, whereas the pathology reports distinguished twelve malignant and eighteen benign cases. Furthermore, the CSA findings comparing the pathology reports indicated that CSA, with confidence of 79.5%, has a significant diagnostic value to differentiate benign lesions from malignant ones.

Conclusion

Our study demonstrated that CSA in MR imaging has a suitable diagnostic potential nearing readiness for clinical trials. Furthermore, CSA seems to be a feasible tool to differentiate benign lymph nodes from malignant ones; however, further studies including larger numbers of patients are required to confirm our results.     

Magnetic resonance imaging in fetal anomalies: What does it add to 3D and 4D US?

Objective

The objective of our study is to evaluate the contribution of adding MRI findings to sonographic data when assessing fetal anomalies and to determine how this addition may affect the management of pregnancy.

Study design

We prospectively examined 26 fetuses who had sonographically suspected congenital anomalies over a period of 1 year. 2D/3D and 4D ultrasound, Doppler and magnetic resonant imaging was done for all patients. MRI was done within 1 week following US examination. The maternal age range was 18-39 years. The gestational age range was 15-38 weeks (mean age = 29 weeks). Ultrasound and magnetic resonance findings were compared together.

Results

We reported different types of congenital anomalies including eight cases of isolated central nervous system anomalies, four abdominal, five musculoskeletal anomalies, seven cases of renal anomalies and two cases of Meckel Gruber syndrome. MRI and sonography showed concordant findings in 18 cases. MRI changed the diagnosis in five cases and provided additional information in three cases. Ultrasound was superior to magnetic resonance imaging in three cases.

Conclusion

Our results showed that fetal MR imaging can be used as a complementary modality to US in diagnosing fetal abnormality in which US findings are inconclusive or equivocal.     

Unenhanced MR Imaging in adults with clinically suspected acute appendicitis

Purpose

The purpose of the study was to evaluate unenhanced Magnetic Resonance Imaging (MRI) for the diagnosis of appendicitis or another surgery-requiring condition in an adult population scheduled for emergency appendectomy based on a clinical diagnosis of suspected acute appendicitis.

Materials and methods

The prospective study included 48 consecutive patients (29 female, 19 male, 18-70 years old, mean age = 37.1 years). MRI examination was designed to be comfortable and fast; no contrast was administered. The sequences were performed during quiet respiration. The MRI findings were reviewed by two radiologists and one surgeon independent of each other and compared with surgical and pathological records.

Results

According to the surgical and histopathological findings 30 of 48 patients (63%) had acute appendicitis. Of the remaining 18 patients, 4 patients had no reasons for the clinical symptoms and 14 patients had other pathology.For the three reviewers the performance of MRI in the diagnosis of acute appendicitis showed the following sensitivity, specificity and accuracy ranges: 83-93%, 50-83% and 77-83%. Moderate (κ = 0.51) and fair (κ = 0.31) interobserver agreements in the MR diagnosis of acute appendicitis were found between the reviewers. Sensitivity, specificity and accuracy values for overall performance of MRI in detecting pelvic abnormalities were 100%, 75% (3 of 4 healthy patients were identified by MRI) and 98%, respectively.

Conclusion

Unenhanced fast MRI is feasible as an additional fast screening before the appendectomy. It may prevent unnecessary surgeries. The fast MRI examination can be adequately performed on an MRI unit of broad range of field strengths.     

Cerebral and cerebellar gray matter reduction in first-episode patients with major depressive disorder: A voxel-based morphometry study

Purpose

To investigate cerebral and cerebellar gray matter abnormalities in patients with first-episode major depressive disorder (MDD).

Materials and methods

We examined the structural difference in regional gray matter density (GMD) between 22 first-episode MDD patients and 30 age-, gender- and education-matched healthy controls by optimized voxel-based morphometry (VBM) based on magnetic resonance imaging.

Results

Compared with healthy controls, MDD patients showed decreased GMD in the right medial and left lateral orbitofrontal cortex, right dorsolateral prefrontal cortex (DLPFC), bilateral temporal pole, right superior temporal gyrus, bilateral anterior insular cortex, left parahippocampal gyrus, and left cerebellum. In addition, in MDD patients, there was a negative correlation between GMD values of the right DLPFC and the score of the depression rating scale.

Conclusions

Our findings provided additional support for the involvement of limbic-cortical circuits in the pathophysiology of MDD and preliminary evidence that a defect involving the cerebellum may also be implicated.     

Intraspinal primitive neuroectodermal tumor: Imaging findings in six cases

Purpose

To retrospectively review CT and MRI findings in a series of six intraspinal primitive neuroectoderal tumors and to find out their radiological features.

Methods

CT and MRI of six patients with surgically and pathologically proved intraspinal primitive neuroectoderal tumor were retrospectively reviewed. The tumor location, morphological features, signal intensity, calcification, contrast enhancement characteristics, involvement of paraspinal soft tissues and adjacent bony structures were assessed.

Results

Of six patients, four had extradural lesions and two had intradural, extramedullary lesions. Most lesions were well defined and manifested heterogeneous iso- or hypo-intense signal on T1-weighted imaging and hyper-intense signal on T2-weighted imaging and moderate attenuation on CT, and were heterogeneously enhanced after contrast enhancement. The lesion extending through the intervertebral foramen with a large paraspinal soft tissue mass formed was found in four patients and vertebral bone involvement was seen in four patients.

Conclusions

Although imaging findings are not specific of intraspinal primitive neuroectoderal tumor, this diagnosis could be suggested when MR imaging depicts an intradural, extramedullary or extradural large well-circumscribed mass which extends out from intervertebral foramen and invades paraspinal soft tissues or vertebral bones in a young patient.     

Imaging of cholangiolocellular carcinoma of the liver

Aim

Cholangiolocellular carcinoma (CoCC) is currently considered to originate from hepatic progenitor cells. The purpose of this study was to evaluate the imaging features of cholangiolocellular carcinoma of the liver.

Materials and methods

Five cases of surgically resected cases of CoCC from 4 institutions were retrospectively evaluated. All of the five patients underwent contrast-enhanced dynamic CT. MRI and angio-CT including CT during arterioportography (CTAP) and CT during hepatic arteriography were performed in 3 and 2 patients, respectively. Histological evaluation was also performed and was correlated with radiographic findings.

Results

On dynamic CT or MRI, the lesions presented hypervascular tumors with delayed washout in 2 cases and in the other 3 cases, the lesions showed peripheral enhancement with concentric delayed filling. On CTAP, the continued existence of portal veins or tiny spots of portal flow was identified in the tumors. Fibrous capsule or tumor necrosis was not observed.

Conclusion

CoCC tumors have the dual imaging characteristics of hepatocellular carcinoma and cholangiocarcinoma. The absence of a fibrous capsule, the absence of tumor necrosis, peripheral location within the liver, and the presence of portal venous penetration within the tumor also appear to be characteristic features.     

Assessment of congenital heart disease (CHD): is there a role for fetal magnetic resonance imaging (MRI)?

Purpose

To review our experience with fetal magnetic resonance imaging (MRI) to evaluate congenital heart disease (CHD).

Methods

We performed fetal MRI in 32 fetuses with an echocardiographically assessed CHD. Both direct and indirect signs of CHD were investigated. Direct signs considered were: morpho-volumetric abnormalities of the heart; malrotations; ventricular and atrial septal defects; anomalies of the origin, size and course of the great arteries. Indirect signs considered were: difficulty to recognize a “normal” anatomical structures in the reference projections; increase of the vascular size before a stenosis; hypertrophy of the papillary muscles; cardiomegaly and pericardial effusion. All MRI findings were compared with postnatal or autoptic findings.

Results

MRI allowed the CHD to be visualised by direct signs in 17 fetuses, indirect signs in 5 and both direct and indirect signs in 9 fetuses, excluding the prenatal echocardiographic suspect of hypoplastic left heart syndrome in 1 fetus.Postnatal echocardiograms or autoptic findings confirmed a normal heart in 1 fetus and CHD in 31 fetuses including a single cardiac anomaly or syndrome in 19 fetuses, 2 associated cardiac abnormalities in 11 and 3 cardiac anomalies in 1 fetus.However, in 2 fetuses MRI detected a ventricular septal defect successively disclosed by gold standard.

Conclusions

MRI is a promising method for further assessment of the cardiovascular pathologies diagnosed by echocardiography, and may be a valuable tool in assessing associated extracardiac anomalies.     

Wrist injuries in young adults: The diagnostic impact of CT and MRI

Purpose

To evaluate the diagnostic impact of MRI or/and multidetector CT in young patients with wrist injury and inconclusive or negative clinical examination and X-rays and to analyze variations in imaging strategies between a district general hospital (GH) and a university hospital (UH).

Materials and methods

A retrospective analysis of 34 young patients (mean age 23 years) with wrist trauma who underwent CT or/and MRI was performed. The injury was acute in 24, and chronic in 10 patients. Twenty-two patients were from a GH and 12 from a UH. Two experienced musculoskeletal radiologists blindly reviewed the imaging studies. The effect of cross-sectional imaging on patient care and treatment plan was evaluated.

Results

In 9 of 34 patients one or more fractures were diagnosed on cross-sectional imaging. The scaphoid was fractured in four patients, the lunate and/or the trapezium in three patients, the scaphoid together with the lunate in one patient, and finally the distal radius in one patient. Ligamentous trauma was identified solely on MRI in 11 patients (involving the TFCC in eight cases). In four patients with both imaging methods, CT revealed one fracture of the trapezium not seen on MRI, and one scapholunate fracture with MRI findings of distal radial fracture only. In two patients with normal CT, MRI revealed bone marrow oedema of the scaphoid in one and of the distal radius, lunate and triquetrum in the other.

Conclusion

Both CT and MRI might be considered in patients with acute or chronic wrist injury, clinical dilemma and normal initial radiographs, depending on the availability and the individual institution policies.     

Abnormal findings in hallucal sesamoids on MR imaging—Associated with different pathologies of the forefoot? An observational study

Background

To evaluate the prevalence and localization of abnormalities in the hallucal sesamoids detectable by magnetic resonance (MR) imaging in patients with forefoot pain and to determine which pathologies of tarsus, metatarsus and phalanges are associated with these abnormalities.

Materials and methods

The forefoot MRI examinations of 50 consecutive patients (32 females, 18 males; mean age 51 years, age range 20-86 years) were retrospectively analyzed by two musculoskeletal radiologists. A minimum of coronal and sagittal T1-weighted images and STIR images or T2-weighted images with fat saturation were performed on a 1.5-T scanner. Abnormal findings in the sesamoids were correlated with pathology in the I.MTP (metatarsal-phalangeal) joint, pathology in other parts of the forefoot and clinical information.

Results

Signal abnormalities of the sesamoids were found in 7 patients out of 50 (14%). Two patients presented a bone marrow edema (BME) in both sesamoids, in 1 patient only the lateral one was affected; all three associated with pathology and pain in the I.MTP joint. In four patients only the medial sesamoid was affected, not associated with pathology in the I.MTP joint but with pathology in other parts of the forefoot.

Conclusion

The prevalence of signal abnormalities in hallucal sesamoids was 14%. BME of the lateral sesamoid or of both were predominantly associated with pathology in the I.MTP joint. In contrast, signal abnormalities of the medial sesamoid, without affection of the lateral one, were associated with pathology in other parts of the forefoot suggesting an overuse injury as a result of compensating posture.     

Use of foetal MRI in diagnosing hepatic hemangioendotheliomas: A report of four cases

Objective

To examine the appearance of foetal hepatic hemangioendotheliomas using prenatal magnetic resonance imaging (MRI) and to conclude whether MRI provides additional information to that obtained with ultrasonography (US).

Materials and methods

Four foetuses with hepatic hemangioendotheliomas were evaluated by US and MRI between 2005 and 2008. MRI was performed on four foetuses at 33 + 4, 37 + 4, 24 and 21 + 6 weeks gestation following US evaluations that demonstrated foetal abdominal tumours. The prenatal US and MRI findings were compared with the postnatal physical examination, enhancement computed tomography (CT) and serial ultrasound examinations, or with the pathology exams, retrospectively.

Results

All four foetuses showed very similar prenatal MRI findings. In each case, the foetal MRI detected an isolated vascular hepatic tumour with low T1 and inhomogeneous high T2 signal intensity. In one case, multiple scalp hemangiomas were detected in the postnatal physical examination, but not with the prenatal US and MRI exams. In the other three cases, the prenatal US and MRI findings were in complete agreement with the postnatal diagnoses.

Conclusion

Prenatal MRI is effective in the assessment of foetal hepatic hemangioendotheliomas. Prenatal MRI may provide a useful adjunct to US in assessing foetal hepatic tumours.     

Assessing the Impact of Incidental Findings in a Lung Cancer Screening Study by Using Low-dose Computed Tomography

Purpose

To assess the prevalence and nature of incidental findings (IF) seen in low-dose computed tomographies (LDCT) from a lung cancer screening study for at-risk individuals.

Materials and Methods

Radiology reports from LDCTs of 4073 participants of a lung cancer screening study were retrospectively reviewed for findings other than lung nodules, that is, IFs, which were regarded as actionable. The frequency, nature, and expected cost of these IFs, and their anticipated follow-up were estimated.

Results

There were 880 IFs described in 782 study participants (19%); the median age of the participants was 62 years (range, 46-80 years). More IFs were found in men (55%) than in women. The majority of these findings were noncardiovascular (76%), for which imaging was suggested for 74%. There were 7 severe IFs (0.8%) that merited immediate attention. Seven known cancers were diagnosed from follow-ups of the IFs. The majority of IFs (n = 486 [55%]) would require imaging follow-up if clinically indicated, with an estimated total a cost of CAN$45,500 to CAN$51,000 to provide initial diagnostic workup.

Conclusion

IFs on lung cancer screening studies are not uncommon and frequently require imaging or other follow-up for definitive diagnoses and to assess their clinical relevance. The implication of IFs has to be considered when determining a cost-effective and ethical protocol for the utilisation of LDCT in a high-risk population.     

Characteristic findings in images of extra-pancreatic lesions associated with autoimmune pancreatitis

Purpose

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by a variety of extra-pancreatic involvements which are frequently misdiagnosed as lesions of corresponding organs. The purpose of this study was to clarify the diagnostic imaging features of extra-pancreatic lesions associated with autoimmune pancreatitis.

Materials and methods

We retrospectively analyzed diagnostic images of 90 patients with autoimmune pancreatitis who underwent computer-assisted tomography, magnetic resonance imaging, and/or gallium-67 scintigraphy before steroid therapy was initiated.

Results

AIP was frequently (92.2%) accompanied by a variety of extra-pancreatic lesions, including swelling of lachrymal and salivary gland lesions (47.5%), lung hilar lymphadenopathy (78.3%), a variety of lung lesions (51.2%), wall thickening of bile ducts (77.8%), peri-pancreatic or para-aortic lymphadenopathy (56.0%), retroperitoneal fibrosis (19.8%), a variety of renal lesions (14.4%), and mass lesions of the ligamentum teres (2.2%). Characteristic findings in CT and MRI included lymphadenopathies of the hilar, peri-pancreatic, and para-aortic regions; wall thickening of the bile duct; and soft tissue masses in the kidney, ureters, aorta, paravertebral region, ligamentum teres, and orbit.

Conclusions

Recognition of the diagnostic features in the images of various involved organs will assist in the diagnosis of autoimmune pancreatitis and in differential diagnoses between autoimmune pancreatitis-associated extra-pancreatic lesions and lesions due to other pathologies.     

Radiological assessment of mesenteric and retroperitoneal cysts in adults: is there a role for chemical shift MRI?

Objective

The purpose of this study was to assess the potential role for chemical shift magnetic resonance imaging (MRI) in identifying lymphangiomas from other cystic mesenteric and retroperitoneal masses.

Materials and methods

A retrospective search of radiology database identified 24 consecutive patients with mesenteric and retroperitoneal cysts (nine men, 15 women; mean age, 41 years; age range, 19-75 years) who had undergone MR which included in-phase and opposed-phase chemical shift imaging. Signal intensity (SI) decrease between in-phase and opposed-phase MR images of the cyst was evaluated qualitatively by two radiologists. Ultrasound (US), computed tomography (CT), and MRI findings of the morphological appearances of all the cystic lesions that demonstrated significant signal drop on chemical shift MR were also recorded.

Results

Of mesenteric and retroperitoneal cysts, 33% (8/24) revealed qualitative decrease in intensity on opposed-phase MR images relative to that seen on in-phase images. On ultrasound, these cysts demonstrated anechoic simple fluid. Their mean CT attenuation was 13 HU (range: 5-20 HU). Signal loss on fat-suppressed T1-weighted sequences was displayed only by a single cyst. None of the lesions with qualitative SI decrease on opposed-phase MR showed suggestion of lipid on US and CT.

Conclusion

The presence of intra cystic lipid detected by chemical shift MR may not be overt on cross-sectional imaging such as US and CT. Chemical shift MRI provides additional sensitivity and specificity as an imaging test for demonstration of lipid within mesenteric and retroperitoneal cysts enabling a higher diagnostic yield for lymphangioma leading to more appropriate patient management.     

Hepatic caudate vein in Budd-Chiari syndrome: Depiction by using magnetic resonance imaging

Objective

To study the visibility of the caudate vein and its diameter on MR imaging in healthy people and in patients with Budd-Chiari syndrome.

Materials and methods

In this study there were 14 patients with Budd-Chiari syndrome and 54 healthy subjects without hepatic lesion or liver disease, all of whom had upper abdominal enhanced MRI. The visibility of the caudate vein and its diameter on MR images was compared between Budd-Chiari patients and healthy subjects, and among Budd-Chiari patients, the correlation between the visibility of caudate vein and extrahepatic collaterals were compared.

Results

Caudate vein was noted in 64% of patients with Budd-Chiari syndrome and in 7% of healthy subjects (P = 0.000). The diameter of the caudate vein visualized on MR imaging in Budd-Chiari syndrome was significantly larger than that in healthy group (7.3 ± 3.9 mm vs 2.6 ± 0.6 mm, P = 0.037). Among Budd-Chiari patients, both caudate vein and extrahepatic collateral veins were noted in 9 patients, only extrahepatic collateral veins were noted in 4 patients and neither caudate vein nor extrahepatic collateral veins were noted in 1 patient. No correlation was found between the visibility of caudate vein and that of extrahepatic collateral vein in patients with Budd-Chiari (P = 0.375).

Conclusion

Gadolinium enhanced dynamic MR imaging can visualize hepatic caudate vein frequently. The visibility and dilation of hepatic caudate veins on MR imaging in Budd-Chiari syndrome were more frequent than in control subjects. MR depiction of a caudate vein may help differentiate Budd-Chiari from cirrhosis.     

Ileal Crohn's disease: MRI with endoscopic correlation

Purpose

To evaluate activity staging of Crohn's disease (CD) measured with MR-enterography using ileoscopy as reference standard.

Materials and methods

A prospective study was made of 61 patients with CD. All patients underwent MR-enterography and ileoscopy. MRI activity was measured by means of an ad hoc developed score, as well as by analysis of the imaging findings, and was compared with the SES-CD score obtained via ileoscopy. Examinations were performed using a 1.0 T scanner.

Results

MRI score discriminates between active and inactive disease with an area under the ROC curve of 0.941. Overall correlation with the standard reference SES-CD score was moderate to strong (Spearman's r = 0.62 p < 0.001).Agreement between both methods in staging patients with ileal CD as inactive, mild or moderate to severe was good (Cohen's κ = 0.60). Differences in means of the MRI activity scores of the three groups showed statistical significance (p < 0.01).

Conclusions

The MRI score is a reliable predictor of activity in ileal CD and can stage patients in a way comparable to endoscopy. 1.0 T scans are valid for performing radiological evaluation of ileal Crohn's disease.     

Detection of hepatocellular carcinoma by Gd-EOB-DTPA-enhanced liver MRI: Comparison with triple phase 64 detector row helical CT

Purpose

To compare the diagnostic performance of Gd-EOB-DTPA-enhanced MRI with that of triple phase 64-MDCT in the detection of hepatocellular carcinoma (HCC).

Patients and methods

Thirty-four patients with 52 surgically proven lesions underwent Gd-EOB-DTPA-enhanced MRI and triple phase 64-MDCT. Two observers independently evaluated MR and CT imaging on a lesion-by-lesion basis. Sensitivity, positive and negative predictive values and reproducibility were evaluated. The diagnostic accuracy of each modality was assessed with alternative-free response receiver operating characteristic (ROC) analysis.

Results

Both observers showed higher sensitivity in detecting lesions with MRI compared to CT, however, only the difference between the two imaging techniques for observer 2 was significant (P = 0.034). For lesions 1 cm or smaller, MRI and CT showed equal sensitivity (both 62.5%) with one observer, and MRI proved superior to CT with the other observer (MRI 75% vs. CT 56.3%), but the latter difference was not significant (P = 0.083). The difference in positive and negative predictive value between the two imaging techniques for each observer was not significant (P > 0.05). The areas under the ROC curve for each observer were 0.843 and 0.861 for MRI vs. 0.800 and 0.833 for CT and the differences were not significant. Reproducibility was higher using MRI for both observers, but the result was not significant (MRI 32/33 vs. CT 29/33, P = 0.083).

Conclusion

Gd-EOB-DTPA-enhanced MRI tended to show higher diagnostic accuracy, sensitivity and reproducibility compared to triple phase 64-MDCT in the detection of hepatocellular carcinoma, however statistical significance was not achieved.     

CT and MR imaging characteristics of infantile hepatic hemangioendothelioma

Aim

This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment.

Materials and methods

CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated.

Results

A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors <1.0 cm, >2.0 cm and 1.0-2.0 cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients.

Conclusion

Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.     

Evaluation of suspicious nipple discharge with MRI: review of 50 cases

Purpose

To determine the role of MRI in the evaluation and management of patients with suspicious nipple discharge and normal mammographic and US evaluation.

Patients and methods

A total of 50 patients with suspicious nipple discharge and normal mammographic and US evaluation prospectively underwent MRI. The first 16 patients underwent routine breast MRI, while MR-ductography with image fusion at the console was added for the last 34 patients.

Results

In 22 of 25 high-risk and malignant lesions, MRI showed enhancement whereas it was normal in three cases. In 25 benign cases (resolution of discharge/benign non-proliferative breast disease), MRI was negative in 22 cases and falsely positive in three cases.

Conclusion

In this clinical setting, MRI shows excellent sensitivity, PPV and NPV. A negative result on MRI would support clinical follow-up as opposed to surgery.     

Differential diagnosis between metastatic tumors and nonsolid benign lesions of the liver using ferucarbotran-enhanced MR imaging

Purpose

To evaluate ability of ferucarbotran-enhanced MR imaging (MRI) in differentiating metastases from nonsolid benign lesions of the liver according to signal-intensity characteristics.

Materials and methods

Sixty-six consecutive patients, who had 138 focal hepatic lesions (26 cysts, 11 hemangiomas, and 101 metastases), underwent ferucarbotran-enhanced MRI. The signal-intensity pattern of each kind of lesion relative to the liver parenchyma on ferucarbotran-enhanced T2* and heavily T1-weighted gradient-echo images were assessed and categorized into the following three categories: high-intensity and iso-intensity, respectively (category A), high and low (category B), and iso- and low-intensity (category C). For category B, lesions were subdivided into two groups based on single-shot half-Fourier RARE images: category B1 (not significantly high-intensity) and category B2 (significantly high-intensity).

Results

Category A had 11 hemangiomas and 2 metastatic tumors, category B1 had 97 metastatic tumors, category B2 had 2 metastatic tumors and 9 cysts, and category C had 17 cysts. When a tumor with a signal intensity of category A was considered to be hemangioma, category B1 metastasis, and category B2 and C cyst, the diagnostic accuracy for differentiating these lesions was 97% (134/138).

Conclusion

The combination of signal-intensity pattern on ferucarbotran-enhanced T2*- and heavily T1-weighted gradient-echo MRI has ability to differentiate liver metastases from nonsolid benign lesions. However, T2-weighted single-shot half-Fourier RARE imaging should also be employed to achieve better performance.     

Dynamic MR dacryocystography in patients with epiphora

Objective

The purpose of this study was to investigate the diagnostic value of dynamic MRI dacryocystography (dMR-DCG) for the assessment of nasolacrimal drainage system (NLDS).

Methods

The study population consisted of 35 patients with a history of epiphora. Each patient underwent bilateral dMR-DCG and conventional dacryocystography (DCG) to assess the NLDS. Two radiologists, who were unaware of the clinical data, evaluated the images separately for the level of obstruction at the nasolacrimal passage and the presence or absence of lacrimal sac dilatation. The findings from the dMRI-DCG and DCG images were compared. DCG was considered to be the gold standard imaging technique.

Results

dMRI-DCG had a sensitivity of 90.5% and a specificity of 89.3% to detect nasolacrimal passage. In 24 out of 70 NLDS that were assessed, there was 100% agreement between the dMRI-DCG and DCG images in the detection of the obstructed level in the nasolacrimal pathway. The lacrimal sac dilatation finding detected by DCG was not observed by dMRI-DCG in only two patients, in whom there was a prior history of dacryocystorhinostomy (DCR) operation. These findings suggest that dMRI-DCG has 94.3% sensitivity and 100% specificity for the diagnosis of lacrimal sac dilatation.

Conclusion

dMRI-DCG is an easily performed, minimally invasive imaging technique to identify the presence or absence of obstruction and its level, and lacrimal sac dilatation in the evaluation of NLDS. dMRI-DCG does not require the use of contrast material and ionizing radiation and provides functional information by depicting dynamic behaviour. Thus, dMRI-DCG could be useful as a reliable diagnostic imaging technique in many patients prior to surgery.