MR imaging of the cisternal segment of the posterior group of cranial nerves: Neurovascular relationships and abnormal changes

Objective

To evaluate the detailed anatomic features, neurovascular relationships of the cisternal segment of the posterior group of cranial nerves (PGCN: IX, X, XI, XII); to evaluate the utility of magnetic resonance (MR) in demonstrating the PGCN with disorders caused by abnormal compression related to artery or tumor.

Methods

A total of 59 volunteers, 12 patients with abnormal symptom in the PGCN underwent three-dimensional (3D) Fourier transformation constructive interference in steady-state (CISS) MR imaging, and 22 of these volunteers and 12 patients also underwent MR angiography in which a time-of-flight (TOF) sequence was used to further distinguish the PGCN from the adjacent blood vessels. Anatomical features, neurovascular relationships of the PGCN in 59 volunteers and abnormal changes in 12 patients caused by neurovascular compression or tumor were observed from multi-planar reconstruction (MPR) images, cryomicrotome section and 3D-CISS MR imaging of cranial cadaver were used to testify the PGCN displayed in 59 volunteers.

Results

3D-CISS MR imaging depicted the proximal cisternal segment of the cranial nerves complex (CN IX, X, XI) at the oblique axial, sagittal planes in 100% (118/118), 99% (117/118) of 118 sides; CNXII in the oblique axial, sagittal planes in 90% (106/118), 91% (107/118) of 118 sides. At the sagittal planes, the CN IX, X, XI were found parallel to each other in the cisternal segment in 45.2% (53/117) of 117 sides, gathering into a bundle of nerves complex before entering the jugular foramen (JF) in 54.7% (64/117) of 117sides. VAs were blood vessels more often identified, they were found to be in contact with the PGCN in 28.0% (33/118) of 118 sides, and not in contact in 72.0% (85/118) of 118 sides. 3D-CISS MR imaging of volunteers revealed the similar result corresponding to cryomicrotome section and 3D-CISS MR imaging of cranial cadaver. Twelve patients with abnormal changes in the PGCN were all displayed well, among them 8 were pressed by arteries, 1 by arachnoid cyst, and 3 caused by tumors.

Conclusion

Use of 3D-CISS sequence enables accurate identification of the cisternal segment of the PGCN, neurovascular relationships and abnormal changes caused by neurovascular compression or tumor.     

Diffusion-weighted MR imaging in postoperative follow-up: Reliability for detection of recurrent cholesteatoma

Introduction

Cholesteatoma is a progressively growing process that destroy the neighboring bony structures and treatment is surgical removal. Follow-up is important in the postoperative period, since further surgery is necessary if recurrence is present, but not if granulation tissue is detected. This study evaluates if diffusion-weighted MR imaging alone can be a reliable alternative to CT, without use of contrast agent for follow-up of postoperative patients in detecting recurrent cholesteatoma.

Materials and methods

26 consecutive patients with mastoidectomy reporting for routine follow-up CT after mastoidectomy were included in the study, if there was loss of middle ear aeration on CT examination. MR images were evaluated for loss of aeration and signal intensity changes on diffusion-weighted sequences. Surgical results were compared with imaging findings.

Results

Interpretation of MR images were parallel with the loss of aeration detected on CT for all 26 patients. Of the 26 patients examined, 14 were not evaluated as recurrent cholesteatoma and verified with surgery (NPV: 100%). Twelve patients were diagnosed as recurrent cholesteatoma and 11 were surgically diagnosed as recurrent cholesteatoma (PPV: 91.7%). Four of these 11 patients had loss of aeration size greater than the high signal intensity area on DWI, which were surgically confirmed as granulation tissue or fibrosis accompanying recurrent cholesteatoma.

Conclusion

Diffusion-weighted MR for suspected recurrent cholesteatoma is a valuable tool to cut costs and prevent unnecessary second-look surgeries. It has the potential to become the MR sequence of choice to differentiate recurrent cholesteatoma from other causes of loss of aeration in patients with mastoidectomy.     

Long-term results of symptomatic fibroids treated with uterine artery embolization: In conjunction with MR evaluation

Objective

The aim of the present study is to determine long-term clinical efficacy of uterine fibroid embolization (UFE) for symptomatic fibroids in conjunction with MR evaluation.

Materials and methods

Sixteen patients with a follow-up period of 4 years or longer were analyzed retrospectively. Ages ranged from 27 to 45 (mean 39.5) years. Mean follow-up periods were 5.8 years (range: 4.1-6.9 years). The symptom changes, in terms of menorrhagia and dysmenorrhea and bulk-related symptoms, were assessed. The primary embolic agent was polyvinyl alcohol particle (250-710 μm). All patients underwent preprocedural and long-term follow up MR imaging. Uterine volumes were calculated using MRI.

Results

Symptom improvements were reported for menorrhagia (8/9, 88.9%), dysmenorrhea (5/5, 100%), and bulk-related symptoms (7/9, 77.8%) at long-term follow up. Two patients (12.5%) had symptom recurrences at long-term follow-up. Tumor regrowth from incomplete infarction was a cause of recurrence in one patient and newly developed leiomyomas in the other one.One patient underwent hysterectomy because endometriosis developed 4 years after UFE.Of the 14 necrotic myomas on short-term follow up MR after UFE, eight (57.1%) demonstrated maintaining necrosis with further shrinkage and six (42.9%) were no longer visualized on long-term follow up MR images. Overall, the mean volume reduction rates of the predominant fibroid and uterus were 80.5%, 36.7% at long-term follow up, respectively.

Conclusion

UFE is an effective treatment for symptomatic fibroids with an acceptable long-term success rate. Long-term MR imaging after UFE revealed persistent necrotic fibroid, non-visualization of fibroids and tumor regrowth when incompletely infarcted.     

Hypothenar hammer syndrome: Long-term follow-up of selective thrombolysis by 3.0-T MR angiography

Objective

To assess the long-term outcome of selective thrombolysis in patients with hypothenar hammer syndrome by 3.0-T magnetic resonance (MR) angiography.

Materials and methods

Seven patients (6 men, 1 woman; mean age, 58.6 ± 14.4 years) were investigated. Long-term follow-up examinations (9-11 years post-interventional) were based on 3.0-T MR angiography. Pre- versus post-thrombolysis images and post-thrombolysis versus long-term follow-up images were compared with respect to arterial diameter. Additionally, changes in patients’ symptoms were assessed.

Results

The long-term follow-up examination showed worse contrast filling of the ulnar digits compared to the immediately post-interventional angiographic images only in one patient (14.3%), whereas worse contrast filling of the deep palmar arch or the ulnar artery was registered in three patients (42.9%). Three of seven patients (42.9%) reported worse symptoms, two patients (28.6%) stable symptoms at the long-term follow-up MR angiography. In two patients (28.6%) the change of symptoms could not be observed due to missing post-interventional clinical data.

Conclusions

At the long-term follow-up, clinically, mild progression was found rather often, whereas with respect to imaging findings progression at the ulnar digits was rare. We assume that collateral vessels might play a major role in the post-interventional follow-up. In many instances the patients’ symptoms are not in line with the angiographic findings.     

The meniscofibular ligament: an MRI study

Aim

To describe the appearances and determine the prevalence of the meniscofibular ligament (ligamentum fibulare-MFibL) on MRI of the knee.

Subjects and methods

Retrospective observational review of 160 knee MRI studies (152 patients) which was performed for a variety of clinical presentations over a period of 31 months. The images were assessed independently by two musculoskeletal radiology Fellows.

Results

The MFibL was optimally visualised on far lateral sagittal oblique fat suppressed PDW FSE images. The MFibL appeared as a curvilinear or straight, hypointense band of variable thickness extending between the inferior margin of the posterior third of the lateral meniscus and the fibular head. The ligament was demonstrated in 42.5% (n = 68) of the total knee MRI studies, but this prevalence increased to 63% (56/88) in the presence of fluid in the posterolateral corner of the joint.

Conclusion

The MFibL is commonly seen on far lateral fat suppressed oblique sagittal PD weighted MR images, particularly in the presence of fluid in the posterolateral corner, and should be recognised as a normal structure in the posterolateral corner of the knee.     

Assessment of peritrochanteric high T2 signal depending on the age and gender of the patients

Introduction

The aim of this study is to evaluate the incidence of peritrochanteric high T2 signal (peritrochanteric edema, peritendinitis) on routine MR imaging studies and to determine whether reporting peritrochanteric edema is always clinically relevant depending on the age and gender of the patients.

Materials and methods

We evaluated 79 consecutive bilateral hip MR images performed in our department between January 2006 and December 2006 (57 female, 22 male patients, mean age 49 years). Each study was evaluated for areas of T2 hyperintensity representing edema around the greater trochanter. Patients with a known fracture, tumor, history of radiation therapy, history of hip surgery and prothesis were excluded from the study. Patients with signal intensity alterations within the thickened gluteus medius/minimus tendons (tendinitis) or peritrochanteric bursal fluid accumulation (bursitis) were also excluded. All patients were scanned with our routine MR imaging protocol for hip imaging.

Results

In 55 of the 79 patients (70%) peritrochanteric edema was detected on MR images and 52 of these 55 patients (95%) had these changes on both hips. The median age was 56 years for the patients with peritrochanteric edema and 35.5 years for the patients without peritrochanteric edema. There was statistical significance between the median ages of the patients and a significant increased risk of peritrochanteric edema was found over 40 years of age. There was no significant difference between male and female patients.

Conclusion

Bilateral peritrochanteric high T2 signal may be a part of the degeneration process and we suggest that it may not be necessarily reported if the clinical findings do not support greater trochanteric pain syndrome.     

Detection of biliary and vascular anatomy in living liver donors: Value of gadobenate dimeglumine enhanced MR and MDCT angiography

Objective

To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard.

Methods

Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3 mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4 mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference.

Results

At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%.

Conclusions

MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy.     

Oculomotor paralysis: 3D-CISS MR imaging with MPR in the evaluation of neuralgic manifestation and the adjacent structures

Purpose

To evaluate the value of three-dimensional (3D) constructive interference in steady-state (CISS) magnetic resonance (MR) imaging with multi-planar reconstruction (MPR) in displaying the relationship between the oculomotor nerve and its adjacent structures for patients with oculomotor paralysis.

Materials and methods

17 consecutive patients with oculomotor paralysis were examined with 3D-CISS and conventional spin-echo (SE) sequences on a 1.5-Tesla MR system. Original transverse and MPR images were used for image interpretation. The features of the oculomotor nerve and its adjacent structures were identified. The diagnosis was surgically confirmed in all patients.

Results

Through 3D-CISS with MPR images, obvious relationship of the oculomotor nerve and its adjacent structures was demonstrated on 17 patients. Of those oculomotor nerves, 15 were compressed by the arteries (n = 15), one by the craniopharyngioma (n = 1), and another one by the neurofibroma (n = 1).

Conclusion

3D-CISS MR imaging with MPR provides an excellent way to characterize the relationship between the nerve and its adjacent structures in the cisternal segment of the oculomotor nerve in the patients with oculomotor paralysis. Moreover, this method shows anatomical details for imaging diagnosis and surgical procedure.     

Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

Purpose

The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI).

Materials and methods

We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps.

Results

Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions.

Conclusion

Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.     

Role of FIESTA combined with conventional MRI in the evaluation of traumatic brachial plexus roots injury

Purpose

Purpose was to evaluate the role of Fast imaging employing steady-state acquisition (FIESTA) together with conventional MR sequences in the evaluation of traumatic brachial plexus roots injury compared to post contrast MR and Spin Echo MR myelographic studies.

Patients and methods

In this prospective study, 16 patients with a mean age of 17.9 y who presented with traumatic brachial plexus roots injury in motor cycle and car accidents were studied with FIESTA, conventional MR, post contrast MR and MR myelography sequences. Imaging findings included: pseudo-meningocele/hemorrhage near the nerve root exit, failure of visualization of the nerve root (dorsal, ventral or both), retracted avulsed nerve root ends, spinal cord edema, and para spinal muscles edema and hemorrhage. Diagnostic accuracy was calculated for each MR sequence. Imaging findings were compared with the gold standard operative findings.

Results

FIESTA combined with conventional MR depicted pseudomeningoceles, non visualized nerve roots, cord displacement, and para spinal muscles abnormalities in 15 patients (93.8%), cord edema in four patients (25%). Pre and post contrast MR detected pseudomeningoceles and non visualized nerve roots in 13 patients (81.3%) while Spin Echo myelography detected pseudomeningoceles and non visualized nerve roots in 14 patients (87.5%). FIESTA combined with conventional MR showed the highest diagnostic accuracy (93.8%) compared to pre and post MR (81.3%) and Spin Echo myelography (87.5%).

Conclusion

It is crucial to differentiate between preganglionic and postganglionic injuries for optimal treatment planning in patients with BPI. Conventional MR imaging yielded suboptimal information regarding the fine details of nerve roots’ injury. MR myelography showed some artifacts that decreased overall diagnostic accuracy, FIESTA combined with conventional MR depicted nerve segments in greater detail and provided important information about the relationship of the nerves to nearby structures, it provided high contrast resolution between cerebrospinal fluid and solid structures, allowing the reconstruction of elegant multi-planar images that highlight the injured nerves. Contrast study is recommended in mild trauma cases with normal morphological study.     

Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

Background

Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium-enhanced MR imaging combined with MR colonography could be used to differentiate a benign from a malignant obstructing colon tumor.

Methods

Patients with benign colon tumor stenosis, based on diverticulitis, were asked to participate in the study. The same number of patients with verified colorectal cancer was included. Both groups had to be scheduled for surgery to be included. Two blinded observers analyzed the tumors on MR by placing a region of interest in the tumor and a series of parameters were evaluated, e.g. wash-in, wash-out and time-to-peak.

Results

14 patients were included. The wash-in and wash-out rates were significantly different between the benign and malignant tumors, and a clear distinction between benign and malignant disease was therefore possible by looking only at the MR data. Furthermore, MR colography evaluating the rest of the colon past the stenosis was possible with all patients.

Conclusion

The results showed the feasibility of using fast dynamic gadolinium-enhanced MR imaging to differentiate between benign and malignant colonic tumors. With a high intra-class correlation and significant differences found on independent segments of the tumor, the method appears to be reproducible. Furthermore, the potential is big in performing a full preoperative colon evaluation even in patients with obstructing cancer. Trial number: NCT00114829.     

Prostate cancer: 1.5 T endo-coil dynamic contrast-enhanced MRI and MR spectroscopy—correlation with prostate biopsy and prostatectomy histopathological data

Purpose

To investigate diagnostic accuracy of detection of prostate cancer by magnetic resonance: to evaluate the performance of T2WI, DCEMRI and CSI and to correlate the results with biopsy and radical prostatectomy histopathological data.

Materials and methods

43 patients, scheduled for radical prostatectomy, underwent prostate MR examination. Prostate cancer was identified by transrectal ultrasonographically (TRUS) guided sextant biopsy. MR examination was performed at 1.5T with an endorectal MR coil. Cancer localisation was performed on sextant-basis - for comparison between TRUS biopsy, MR techniques and histopathological findings on prostatectomy specimens.

Results

Prostate cancer was identified in all 43 patients by combination of the three MR techniques. The detection of prostate cancer on sextant-basis showed sensitivity and specificity: 50% and 91% for TRUS, 72% and 55% for T2WI, 49% and 69% for DCEMRI, and 46% and 78% for CSI.

Conclusion

T2WI, DCEMRI and CSI in combination can identify prostate cancer. Further development of MR technologies for these MR methods is necessary to improve the detection of the prostate cancer.     

Whole-body diffusion-weighted MR imaging with fat suppression by using STIR: Clinical utility for detection of primary malignancies in patients initially presented with metastasis

Purpose

The purpose of this study was to prospectively evaluate the usefulness of DW MR imaging with fat suppression by using short time inversion recovery (STIR) to detect primary malignancies for patients initially presented with metastasis by direct visual assessment.

Materials and methods

Twenty-nine consecutive patients presented with metastatic lesions were included in this study and underwent whole-body DW MR imaging for detection of the primary malignancies. Twenty-five healthy volunteers were included in this study as control subjects. Whole-body DW MR imaging was conducted with a multi-stack pulse sequence and two b values of 0 and 600 s/mm² and a coverage from head to knees. Three radiologists reviewed the whole-body DW MR images independently to detect the primary malignancies. Receiver operating characteristic (ROC) analysis was used to assess the overall accuracy of this imaging technique in direct visual detection of primary malignancies. Inter-observer agreement was assessed by using kappa analysis.

Results

For 82.8% (24/29) of the patients, primary malignancies were correctly identified with this whole-body DW MR imaging, and subsequently confirmed by biopsy and/or pathology. While for 17.2% (5/29) of patients, no definite primary malignancy was identified. ROC analysis yielded Az values of 0.907, 0.914, and 0.910 for the three reviewers, respectively. The sensitivity and specificity was 82.8% (24/29) and 100% (25/25) for the three viewers. The inter-observer agreement between each pair of reviewer was 0.935, 0.804, and 0.873, respectively.

Conclusion

For patients originally presented with metastases, whole-body DW MR imaging might have potential utility in detecting primary malignancies.     

Rectal villous tumours: MR features and correlation with TRUS in the preoperative evaluation

Aim

The aim of this study was to assess the clinical relevance of MR and transrectal ultrasonography (TRUS) imaging of rectal villous tumours to elucidate the correlation between imaging results and specific histopathological tumour features, such as tumour size (T) and lymph node involvement (N), in order to establish the better technique for the pre-surgical patient evaluation.

Patients and methods

23 cases of villous tumours of the rectum were studied with phased-array MR and TRUS. All patients underwent either surgical or endoscopic treatment. Final diagnosis was based on histopathological results. In particular, the following features were characterized by the imaging techniques mentioned above: lesion site, distance between lesion and ano-rectal junction, size, morphology and contrast enhancement of lesions, fluid layer around the lesion, alterations of the deep layers of the rectal wall, sphincter infiltration, presence or absence of mesorectal, iliac and obturatory lymphnode involvement.

Results

Histology established muscular involvement in 7 cases (T2), perirectal fat infiltration in 1 case (T3); in the remaining 15 cases, staging was Tis-T1. In 17/23 cases (73.9%) the lesions were correctly staged with both imaging techniques, whereas in 5/23 cases (21.7%) the lesions were overstaged. No cases were understaged. TRUS concorded with histological exams in 17/23 cases (73.9%). 5/23 cases (21.7%) were overstaged and 1/23 (4%) was understaged. MR and TRUS were in accordance in 20/23 cases (86.9%).

Discussion

Considering the frequent degeneration of villous tumours, correct preoperative identification and precise evaluation of these lesions, such as the detection of rectal wall invasion, is essential in deciding optimal treatment strategy. MRI and TRUS allow the identification of specific features of villous tumours and of malignant degeneration, allowing for a correct local disease staging.     

Value of multislice computed tomography in the diagnosis of acute mesenteric ischemia

Objective

To define the value of multislice computed tomography (CT) in the diagnosis of acute mesenteric ischemia (AMI).

Materials and methods

Two hundred patients (age range: 20-92 years) who were referred to the emergency CT department with a clinical suspicion of AMI were prospectively included in the study. CT examinations were performed with a multislice (16) CT scanner and the protocol included pre-contrast, arterial and venous phase acquisitions. Images were evaluated by using multiplanar reconstruction, maximum intensity projection and volume-rendering techniques at the CT workstation.

Results

Ninety-four patients (47%) underwent surgery for AMI or for other causes of acute abdominal pain. One hundred-six patients (53%) were followed conservatively according to clinical, radiologic and laboratory findings. Of the 94 patients who underwent surgery, 49 (25%) were found to have AMI. All of these 49 patients with a proven AMI diagnosis were diagnosed with CT. In the other 45 patients who underwent surgery, CT findings were negative for AMI. None of the patients, who were followed conservatively, were eventually diagnosed as having AMI except 1 patient. This patient was unfit for surgery although his clinical and radiologic findings were consistent with AMI and died in 3 days. The sensitivity and specificity values of CT for the detection of AMI were calculated to be 100% for each.

Conclusions

Multislice CT is an effective imaging technique for the diagnosis of AMI with excellent sensitivity and specificity values.     

Prediction of vascular involvement and resectability by multidetector-row CT versus MR imaging with MR angiography in patients who underwent surgery for resection of pancreatic ductal adenocarcinoma

Purpose

To compare the diagnostic value of dual-phase multidetector-row CT (MDCT) and MR imaging with dual-phase three-dimensional MR angiography (MRA) in the prediction of vascular involvement and resectability of pancreatic ductal adenocarcinoma.

Methods and materials

116 patients with proven pancreatic adenocarcinoma underwent both MDCT and combined MR imaging prior to surgery. Of 116 patients, 56 who underwent surgery were included. Two radiologists independently attempt to assess detectability, vascular involvement and resectability of pancreatic adenocarcinoma on both images. Results were compared with surgical findings and statistical analysis was performed.

Results

MDCT detected pancreatic mass in 45 of 56 patients (80.3%) and MR imaging in 44 patients (78.6%). In assessment of vascular involvement, sensitivities and specificities of MDCT were 61% and 96% on a vessel-by-vessel basis, respectively. Those of MR imaging were 57% and 98%, respectively. In determining resectability, sensitivities and specificities of MDCT were 90% and 65%, respectively. Those of MR imaging were 90% and 41%, respectively. There was no statistical difference in detecting tumor, assessing vascular involvement and determining resectability between MDCT and MR imaging (p = 0.5).

Conclusion

MDCT and MR imaging with MRA demonstrated an equal ability in detection, predicting vascular involvement, and determining resectability for a pancreatic ductal adenocarcinoma.     

Imaging patterns in elastofibroma dorsi

Introduction

Elastofibroma dorsi is a rare pseudotumor of the soft tissues. Its clinico-radiologic characteristics lead to a correct diagnosis.

Material and methods

We followed 43 patients with elastofibroma dorsi with a confirmed histological diagnosis or on the basis of typical imaging pattern (ultrasound, CT, MR) confirmed by evolution.

Results

Elastofibroma is prevalent in females, its onset occurs around 60 years of age and is most frequently localized in the deep subscapular region (93%), bilateral in 54% of cases. In 7% it was found in an atypical isolated suprascapular region, in 7% it was synchronous to that in the subscapular region. Four ultrasound patterns were detected: Type I (54%) inhomogeneous fasciculated, Type II (22%) inhomogeneous aspecific, Type III (15%) hyperechogeneous, Type IV (9%) hypoechogeneous. Three patterns were detected at CT and MR: Type A (84%) inhomogeneous fasciculated corresponding to Types I and III and partially to Type II ultrasound pattern, Type B (8%) inhomogeneous aspecific corresponding to Type II ultrasound pattern; Type C (8%) homogeneous isodense or isointense to the muscle corresponding to Type IV ultrasound pattern.

Conclusion

A solid, slow-growing lesion, in the deep periscapular region in females aged between 50 and 60 years, with a typical fasciculated pattern is pathognomonic of elastofibroma dorsi and bilateral location convalidates diagnosis. Ultrasound is sufficient to orientate diagnosis. CT and/or MR are reserved only for non-fasciculated ultrasound patterns, when site is atypical or in candidates for surgery. Biopsy is reserved only in cases where integrated imaging shows a non-fasciculated pattern to differentiate it from other malignant lesions.     

Imaging characteristics of pilomyxoid astrocytomas in comparison with pilocytic astrocytomas

Purpose

Pilomyxoid astrocytoma (PMA) is a recently described astrocytic tumor that has been previously diagnosed as pilocytic astrocytoma (PA). The purpose of this study was to describe the imaging features of PMAs in comparison with PAs.

Materials and methods

We retrospectively reviewed CT/MR images and medical records of 10 patients with PMA and 38 patients with PA. The mean ages of patients with PMA and PA were 10 and 15 years, respectively. Imaging features including location, composition, enhancement pattern, presence of calcification, hemorrhage, and leptomeningeal dissemination were compared in patients with two tumor types.

Results

Six PMAs (60%) occurred at the suprasellar area and the cerebellum was the most common (45%) site of PA. Solid component was dominant in eight PMAs (80%) and in 19 PAs (50%). All of the PMAs containing solid mass (n = 8) included non-enhancing portion while 12/37 (32%) PAs included non-enhancing solid portion (p < 0.05). Leptomeningeal dissemination was noted in five PMAs (50%) and one PA (3%) (p < 0.05). Other imaging findings were not significantly different.

Conclusion

A younger age, more frequent occurrence at the suprasellar area, mainly solid mass containing non-enhancing portion, and more frequent leptomeningeal dissemination are helpful differential features of PMAs as compared to PAs.     

MR imaging features of ventricular noncompaction: Emphasis on distribution and pattern of fibrosis

Objective

The purpose of this study is to describe morphologic features and delayed contrast-enhancement pattern of the noncompaction of the left ventricle in cardiac magnetic resonance (MR) imaging.

Methods

We retrospectively reviewed morphological cardiac MR imaging findings of ventricular noncompaction in 15 patients (eight men, seven women, and ages 6 months to 73 years old, mean 22 year). In 10 patients delayed contrast enhanced images were obtained after the morphological examination.

Results

In all patients, noncompaction was seen in the apical and midventricular-lateral segment. Basal-septal segment involvement was not determined in any patients. Noncompacted/compacted ratio was 2-4.5 (mean 3). In nine patients, right ventricular involvement was observed in addition to left ventricular noncompaction. Delayed contrast-enhancement was seen in eight out of 10 patients not only involved segments but also normal segments of the heart.

Conclusion

Cardiac MR imaging is a valuable imaging method in patients with suspected ventricular noncompaction by showing increased trabeculations, deep intertrabecular recesses and fibrosis. Fibrosis is a common finding in ventricular noncompaction.     

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.