Microscopy Coil Research Articles

High-resolution magnetic resonance imaging of teeth and periodontal tissues using a microscopy coil.

This study aimed to assess the performance of 2-dimensional (2D) imaging with microscopy coils in delineating teeth and periodontal tissues compared with conventional 3-dimensional (3D) imaging on a 3 T magnetic resonance imaging (MRI) unit. Twelve healthy participants (4 men and 8 women; mean age: 25.6 years; range: 20-52 years) with no dental symptoms were included. The left mandibular first molars and surrounding periodontal tissues were examined using the following 2 sequences: 2D proton density-weighted (PDw) images and 3D enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) images. Two-dimensional MRI images were taken using a 3 T MRI unit and a 47 mm microscopy coil, while 3D MRI imaging used a 3 T MRI unit and head-neck coil. Oral radiologists assessed dental and periodontal structures using a 4-point Likert scale. Inter- and intra-observer agreement was determined using the weighted kappa coefficient. The Wilcoxon signed-rank test was used to compare 2D-PDw and 3D-eTHRIVE images. Qualitative analysis showed significantly better visualization scores for 2D-PDw imaging than for 3D-eTHRIVE imaging (Wilcoxon signed-rank test). 2D-PDw images provided improved visibility of the tooth, root dental pulp, periodontal ligament, lamina dura, coronal dental pulp, gingiva, and nutrient tract. Inter-observer reliability ranged from moderate agreement to almost perfect agreement, and intra-observer agreement was in a similar range. Two-dimensional-PDw images acquired using a 3 T MRI unit and microscopy coil effectively visualized nearly all aspects of teeth and periodontal tissues.

Comparison of surface microscopy coil and ankle joint special phased array coil magnetic resonance imaging in assessing preoperative osteochondral lesions of the talus.

Lesion size is a major determinant of treatment strategies and predictor of clinical outcomes for osteochondral lesions of the talus (OLTs). Although magnetic resonance imaging (MRI) has been commonly used in the preoperative evaluation of OLTs, MRI has low reliability and usually overestimates or underestimates lesion size compared with intraoperative assessment. This study aims to determine whether the surface microscopy coil (SMC) can improve the accuracy of assessment of preoperative OLTs compared with conventional coil MRI, ankle joint special phased array coil (ASC). A total of 43 patients diagnosed with OLTs undertook preoperative MRI examination with both SMC and ASC were included in this prospective study from 2019 to 2022. The diameter of the lesion was measured in sagittal plane and coronal plane at its widest point and then the lesion area was calculated. Then MRI measurements were compared with arthroscopy or open-surgery measurements. The mean lesion area measured with ASC was significantly greater than that measured intraoperatively (95.07±44.60 vs. 52.74±29.86 mm2, P<0.001), while there was no significant difference between lesion area measured in SMC and intraoperatively (55.28±36.06 vs. 52.74±29.86 mm2, P=0.576). Diameter measured in ASC was significantly greater than that measured intraoperatively in both coronal plane (8.95±2.48 vs. 6.67±1.81, P<0.001) and sagittal plane (13.12±3.76 vs. 9.58±3.98, P<0.001). No significant difference between lesion diameter measured in SMC and intraoperatively in both coronal plane (6.44±2.59 vs. 6.67±1.81, P=0.608) or sagittal plane (10.23±3.69 vs. 9.58±3.98, P=0.194). Compared with surgical assessment, 39 of 43 cases were consistent with SMC assessment while only 26 of 43 cases were consistent with ASC assessment (39/43 vs. 26/43, P=0.002). Diameter measured with SMC was much more accurate than ASC MRI. Compared with ASC MRI, the SMC had a much higher concordance rate between preoperative assessment and surgical assessment.

Validation study of novel grading system for ulnar collateral ligament injury of the elbow with high-resolution magnetic resonance imaging.

BackgroundRecently, magnetic resonance imaging (MRI) classification of medial ulnar collateral ligament (UCL) tears has been introduced, but little is known about the relationship between MRI grading and medial joint laxity. It has been reported that microscopy coils could make it possible to achieve high-resolution images of upper extremities with a superior diagnostic ability to conventional MRI. However, there is no report that has compared the diagnostic reliability between microscopic and conventional MRI. The purpose of this study was to assess the relationship between MRI findings and medial joint laxity evaluated with stress ultrasound (US). Secondary objective was to compare the reliabilities of UCL evaluation between microscopic and conventional MRI.MethodsOne-hundred thirty baseball players who underwent MRI of the elbow for the diagnosis of UCL injury using both conventional and microscopy MRI were included in this study. They also underwent stress US for assessment of medial joint laxity against valgus stress. Our MRI grading system for UCL injuries was compared to medial joint laxity evaluated with stress US. The intrarater and interrater reliabilities of our grading system were assessed with both microscopic and conventional MRI.ResultsOur grading system was related to valgus stability, especially with microscopic MRI. The reliabilities were fair when combined with microscopic MRI, which exhibited better intrarater and interrater reliabilities than conventional MRI.ConclusionHigh-resolution microscopic MRI may contribute to the accurate diagnosis of UCL injuries.

MR-Eye: High-Resolution Microscopy Coil MRI for the Assessment of the Orbit and Periorbital Structures, Part 2: Clinical Applications.

In the first part of this 2-part series, we described how to implement microscopy coil MR imaging of the orbits. Beyond being a useful anatomic educational tool, microscopy coil MR imaging has valuable applications in clinical practice. By depicting deep tissue tumor extension, which cannot be evaluated clinically, ophthalmic surgeons can minimize the surgical field, preserve normal anatomy when possible, and maximize the accuracy of resection margins. Here we demonstrate common and uncommon pathologies that may be encountered in orbital microscopy coil MR imaging practice and discuss the imaging appearance, the underlying pathologic processes, and the clinical relevance of the microscopy coil MR imaging findings.

Clinical value of high-resolution dynamic contrast-enhanced (DCE) MRI in diagnosis of cutaneous squamous cell carcinoma.

While uncomplicated cases of skin squamous cell carcinoma (cSCC) can be treated with surgery topical therapy alone, more objective and non-invasive examination methods are needed to guide clinicians to make more detailed biopsy and surgical plans for lesions with atypical or subcutaneous growth. High-resolution magnetic resonance imaging (HR-MRI) is a novel skin imaging method. Prospective collection of 19 patients with clinically suspected cSCC. All patients underwent high-resolution DCE-MRI using a 70-mm microscopy coil before operation. The imaging features and results of surgical pathology were recorded. Ktrans , Kep , Ve values, and the time-signal curve (TIC) types were determined using DCE images. 16 cases of cSCC, 3 cases of acanthoma. The subcutaneous invasion of all lesions was clearly displayed, of which 8 lesions invaded the subcutaneous fat layer, 5 invaded the muscle layer, 1 invaded the periosteum, 2 invaded the cap fascia, and the layer of all lesions invasion judged by HR-MR imaging was consistent with the postoperative pathology. The main manifestations of cSCC were ill-defined margin, obvious inhomogeneous enhancement, higher perfusion parameters value and type-III TIC, while acanthoma showed well-defined and type-I TIC. Some imaging findings (such as boundary, enhancement) and DCE perfusion parameters of the two groups overlap. High-resolution DCE-MRI can fully and directly display the subcutaneous invasion of cSCC, and more work needs to be done to prove its value. Next, we will expand the sample size, and further explore its value in the differential diagnosis and prognosis evaluation of cSCC from acanthoma or other skin tumors.

The value of preoperative high-resolution MRI with microscopy coil for facial nonmelanoma skin cancers.

The extent and depth of facial nonmelanoma skin cancers and the involvement of adjacent structures are critical features for surgical planning, but they are difficult to assess clinically. High-resolution MRI (HR-MRI) with microscopy coil may facilitate detailed evaluation of skin lesions. The authors performed this prospective study to determine the value of high-resolution microscopy coil MRI in the preoperative evaluation of nonmelanoma skin cancer. Between October 2018 and August 2019, 16 lesions from fifteen consecutive patients with facial nonmelanoma skin cancer were evaluated using high-resolution microscopy coil MRI about tumor extent, depth, margins, characteristic, and their spatial relationship with adjacent structures. The preoperative HR-MRI results were compared with the intraoperative findings and with the histopathology, with special note to the depth of invasion. Among the 16 lesions, HR-MRI imaging was found to provide accurate evaluation of tumor extent, depth, and margins and determine whether there was involvement of adjacent structures. The tumor depth measured on HR-MRI showed good correlation with histopathologic results (CCC: 0.973), and Bland-Altman analysis finding no significant bias existed between the two measurements. All lesions except one were completely resected with primary excision. Only one lesion required further excision. During follow-up for 3-15months, no tumor recurrence was observed in any case. HR-MRI is an accurate, noninvasive imaging technique that can be used as preoperative evaluation tool for facial nonmelanoma skin cancer. It can accurate predict tumor depth, margins, and involvement of structure. The valuable information it provided facilitates surgeons optimize surgical planning.

MR-Eye: High-Resolution Microscopy Coil MRI for the Assessment of the Orbit and Periorbital Structures, Part 1: Technique and Anatomy.

Microscopy coil MR imaging of the orbits has been described previously as a technique for anatomic depiction. In the first part of this 2-part series, the improvement in spatial resolution that the technique offers compared with conventional MR imaging of the orbits is demonstrated. We provide a guide to implementing the technique, sharing pearls and pitfalls gleaned from our own practice to make implementation of microscopy coil MR imaging at your own center easy. As a quick reference guide to the small-scale structures encountered when reading the studies, a short anatomy section is included, which doubles as a showcase for the high-quality imaging that can be obtained. In the second part, our experience of microscopy coil MR imaging in day-to-day clinical practice takes it far beyond being a useful anatomic educational tool. Through a series of interesting cases, we highlight the added benefit of microscopy coil MR imaging compared with standard orbital MR imaging.

Characterization of Carotid Plaque Components by Quantitative Susceptibility Mapping.

Intraplaque hemorrhage in the carotid artery is related to an increased risk of cerebrovascular ischemic events. We aimed to investigate whether quantitative susceptibility mapping can characterize carotid artery plaque components and quantify the severity of intraplaque hemorrhage. For this ex vivo quantitative susceptibility mapping study, 9 carotid endarterectomy specimens were imaged on a 3T MR imaging scanner using a 3D multi-echo gradient-echo sequence and a microscopy coil. The samples were examined histologically using immunostains, including glycophorin A and Prussian blue. The areas of erythrocytes, iron deposits, calcification, and fibrous matrices observed on stained sections were compared with quantitative susceptibility mapping findings and their mean susceptibility values. Intraplaque hemorrhage and iron deposits were observed only in areas hyperintense on quantitative susceptibility mapping; calcifications and fibrous matrices were prevalent in hypointense areas. The mean susceptibility values for necrotic cores with intraplaque hemorrhage but no iron deposits, cores with iron deposits but no intraplaque hemorrhage, cores without either intraplaque hemorrhage or iron deposits, and cores with calcification were 188 ± 51, 129 ± 49, -11 ± 17, and -158 ± 78 parts per billion, respectively. There was a significant difference in the mean susceptibility values among the 4 histologic components (P < .01). The mean susceptibility values of the whole plaque positively correlated with the percentage area positive for glycophorin A (r = 0.65, P < .001) and Prussian blue (r = 0.47, P < .001). Our findings suggest that quantitative susceptibility mapping can characterize the composition of carotid plaques and quantify the degree of intraplaque hemorrhage and iron deposits.

In Vivo Molecular Characterization of Abdominal Aortic Aneurysms Using Fibrin-Specific Magnetic Resonance Imaging.

BackgroundThe incidence of abdominal aortic aneurysms (AAAs) will significantly increase during the next decade. Novel biomarkers, besides diameter, are needed for a better characterization of aneurysms and the estimation of the risk of rupture. Fibrin is a key protein in the formation of focal hematoma associated with the dissection of the aortic wall and the development of larger thrombi during the progression of AAAs. This study evaluated the potential of a fibrin‐specific magnetic resonance (MR) probe for the in vivo characterization of the different stages of AAAs.Methods and Results AAAs spontaneously developed in ApoE−/− mice following the infusion of angiotensin‐II (Ang‐II, 1 μg/kg−1·per minute). An established fibrin‐specific molecular MR probe (EP2104R, 10 μmol/kg−1) was administered after 1 to 4 weeks following Ang‐II infusion (n=8 per group). All imaging experiments were performed on a clinical 3T Achieva MR system with a microscopy coil (Philips Healthcare, Netherlands). The development of AAA‐associated fibrin‐rich hematoma and thrombi was assessed. The high signal generated by the fibrin probe enabled high‐resolution MR imaging for an accurate assessment and quantification of the relative fibrin composition of focal hematoma and thrombi. Contrast‐to‐noise‐ratios (CNRs) and R1‐relaxation rates following the administration of the fibrin probe were in good agreement with ex vivo immunohistomorphometry (R 2=0.83 and 0.85) and gadolinium concentrations determined by inductively coupled plasma mass spectroscopy (R 2=0.78 and 0.72).ConclusionsThe fibrin‐specific molecular MR probe allowed the delineation and quantification of changes in fibrin content in early and advanced AAAs. Fibrin MRI could provide a novel in vivo biomarker to improve the risk stratification of patients with aortic aneurysms.

In Vivo High-Frequency Ultrasound for the Characterization of Thrombi Associated with Aortic Aneurysms in an Experimental Mouse Model

The development of abdominal aortic aneurysm (AAA) associated thrombi plays an important role during the onset and progression of AAAs. The aim of this study was to evaluate the potential of high-frequency ultrasound for characterization of AAA associated thrombi in an apolipoprotein-E-deficient mouse-model. Ultrasound measurements were performed using a high-resolution ultrasound system (Vevo770, FUJIFILM VisualSonics, Inc., Toronto, ON, Canada) with a 30 MHz linear-array transducer (RMV707 B). Magnetic resonance imaging with a 3 Tesla scanner (Achieva MR system, Philips Healthcare, Best, The Netherlands) and a single-loop microscopy coil was performed as a reference standard. All stages of aneurysm development were evaluated by histologic analyses. The “signal-thrombus-matrix” to “signal-blood” ratio on high-frequency ultrasound measurements showed a strong correlation (R2 = 0.81, p < 0.05) with the state of extracellular matrix remodeling. Furthermore, size measurements derived from the high-frequency ultrasound correlated well with magnetic resonance imaging and histology. This study demonstrated that high-frequency ultrasound enables the reliable in vivo quantification of extracellular matrix remodeling at various stages of thrombus development, based on the thrombus echogenicity.

Ankle Traction During MRI of Talar Dome Osteochondral Lesions.

The objective of our study was to assess the impact of axial traction during MRI of talar dome osteochondral lesions using a small-FOV coil. A prospective study of 33 patients undergoing high-resolution MRI of the ankle using a microscopy coil with and without axial traction was performed. Two radiologists independently measured the tibiotalar joint space width and semiquantitatively graded intraarticular joint fluid dispersion, cartilage surface visibility of the osteochondral lesion, and cartilage surface visibility elsewhere in the tibiotalar joint before and after traction. Patients were instructed to report any discomfort during ankle traction. None of the patients reported discomfort or other symptoms during ankle traction. The tibiotalar joint space significantly increased (increase in cartilage-cartilage distance, 0.5-0.7 mm; all, p < 0.05) after traction compared with before traction. The degree of intraarticular joint fluid dispersion and the cartilage surface visibility at the osteochondral lesion and elsewhere in the tibiotalar joint improved after traction (all, p < 0.05). Traction MRI of the ankle is safe and technically feasible. This study is the first to date to investigate the effect of ankle traction on the MRI assessment of talar dome osteochondral lesions. Traction improves cartilage surface visibility of talar dome osteochondral lesions.

Is Triangular Fibrocartilage Complex Injury Associated with Extensor Carpi Ulnaris Tendinitis or Tenosynovitis? A Case-control Comparative Study: Level 3 Evidence

Hypothesis: After treatment of triangular fibrocartilage complex (TFCC) injuries, the ulnar wrist may experience persisting pain, suggesting the presence of some other pathology. We compared the wrists of patients who have TFCC injuries before treatment with those of volunteers who have no ulnar wrist pain. We hypothesized that TFCC injuries are frequently complicated by extensor carpi ulnaris (ECU) tendinitis or tenosynovitis. Methods: Altogether, 46 volunteers (21 male, 25 female; mean age 30.8 years) who had no pain in the ulnar wrist and 46 TFCC patients (22 male, 24 female; meanage35.5years)with a positive fovea sign andwhosepain diminishedafter injection of 0.5ml lidocaine at the ulnar fovea were compared. In all, 20 right and 26 left wrists of the volunteers were evaluated, as were 22 right and 24 left wrists of the patients. Wrists of both groups underwent magnetic resonance imaging (MRI).Wristswere imagedwith the subject prone, arms over the head, and forearm pronated. A microscopy coil was placed on the center of the ulnar head. All MRI scans were obtained using a 1.5-T system (Gyroscan NT Intera; Philips Medical Systems, Best, The Netherlands). Coronal and axial twodimensional gradient-echo images were obtained. ECU tendon pathology (tendinopathy or tear) was classified into three categories (T1: normal; T2: multiple cracks; T3: changed intensity of tendon). Surrounding ECU tendon pathologies (e.g., tenosynovitis) were also classified into three categories (S1: normal; S2: effusion in sheath; S3 disruption of sheath) (Figure 1). There were some overlaps. The width, depth, opening angle, and radius of the curvature of the ECU groove were determined using imaging software based on a previous report (Figure 2) (reference 1). The image slice in which the ECU groove was largest was chosen for measurement. Statistical analysis was performed with ManneWhitney’s U-test. A P< 0.05 significance level was used in all cases. Results: T2 pathology in the patient group (T1: 29; T2: 15; T3: 20) was significantly more frequent than in the volunteers (39; 4; 20, respectively). Surrounding pathology S2 was significantly more frequent in the patient group (S1: 35; S2:11; S3: 0) than in the volunteers (40; 4; 0, respectively). There were no significant differences between groups regarding the width, depth, opening angle, or radius of the curvature.

High-Resolution Microscopy-Coil MR Imaging of Skin Tumors: Techniques and Novel Clinical Applications.

High-resolution magnetic resonance (MR) imaging performed with a microscopy coil is a robust radiologic tool for the evaluation of skin lesions. Microscopy-coil MR imaging uses a small surface coil and a 1.5-T or higher MR imaging system. Simple T1- and T2-weighted imaging protocols can be implemented to yield high-quality, high-spatial-resolution images that provide an excellent depiction of dermal anatomy. The primary application of microscopy-coil MR imaging is to delineate the deep margins of skin tumors, thereby providing a preoperative road map for dermatologic surgeons. This information is particularly useful for surgeons who perform Mohs micrographic surgery and in cases of nasofacial neoplasms, where the underlying anatomy is complex. Basal cell carcinoma is the most common nonmelanocytic skin tumor and has a predilection to manifest on the face, where it can be challenging to achieve complete surgical excision while preserving the cosmetic dignity of the patient. Microscopy-coil MR imaging provides dermatologic surgeons with valuable preoperative anatomic information that is not available at conventional clinical examination.

In vivo characterization of abdominal aortic aneurysms using an elastin specific molecular MR probe

Background Rupture of abdominal aortic aneurysms (AAAs) is the third most common cause of death in cardiovascular diseases. Despite this high significance, there is still controversy regarding the management of AAAs, as diameter is currently the only accepted parameter to assess risk of rupture. Elastin is the key protein for maintaining stability of the aortic wall. The aim of this study was to evaluate a novel small-molecular-weight elastin-specific MR probe for the in-vivo assessment of aortic wall integrity in AAAs. Methods ApoE-knockout-mice (ApoE-/-) were infused with angiotensin-II (Ang-II) for up to four weeks (1000 ng/ kg/min) to induce AAA formation. An elastin-specific MR probe (Lantheus Medical Imaging, USA) was administered 1, 2, 3 and 4 weeks following Ang-II infusion. Mice were scanned at each time point pre, post control agent (Gd-DTPA) and after administration of the elastin-specific probe. Imaging was performed using a 3T Philips-Achieva MR-scanner equipped with a microscopy coil. Imaging parameters of 3D IR-MRI: spatial resolution = 0.1 × 0.1 mm, 0.5 mm slice-thickness, TR/ TE = 28/8.2 ms. Additionally 3D-T1 mapping was performed. Ex-vivo tissue samples were analysed by inductively-coupled-plasma mass-spectroscopy (ICP-MS), histological staining and electron microscopy. Results

In vivo MR imaging of the human skin at subnanoliter resolution using a superconducting surface coil at 1.5 tesla

To demonstrate the feasibility of a highly sensitive superconducting surface coil for microscopic MRI of the human skin in vivo in a clinical 1.5 Tesla (T) scanner. A 12.4-mm high-temperature superconducting coil was used at 1.5T for phantom and in vivo skin imaging. Images were inspected to identify fine anatomical skin structures. Signal-to-noise ratio (SNR) improvement by the high-temperature superconducting (HTS) coil, as compared to a commercial MR microscopy coil was quantified from phantom imaging; the gain over a geometrically identical coil made from copper (cooled or not) was theoretically deduced. Noise sources were identified to evaluate the potential of HTS coils for future studies. In vivo skin images with isotropic 80 μm resolution were demonstrated revealing fine anatomical structures. The HTS coil improved SNR by a factor 32 over the reference coil in a nonloading phantom. For calf imaging, SNR gains of 380% and 30% can be expected over an identical copper coil at room temperature and 77 K, respectively. The high sensitivity of HTS coils allows for microscopic imaging of the skin at 1.5T and could serve as a tool for dermatology in a clinical setting.

Comparison of Malignant Skin Tumor Thickness and Relative Depth of Invasion Estimates from Preoperative MR-Microscopy and Pathological Evaluation

Tumor thickness and relative depth of invasion are prognostic parameters considered when developing treatment plans for malignant skin tumors. Although conventional magnetic resonance (MR) imaging techniques cannot identify small tumors, use of microscopy coils considerably improves spatial resolution. Some studies have shown that this technique is efficacious in preoperative assessment of relative depth of invasion; however, its ability to provide accurate measurements of tumor thickness remains unconfirmed. The purpose of this pilot study was to evaluate the usefulness of preoperative MR-microscopy in determining tumor thickness and relative depth of invasion of malignant skin tumors. Magnetic resonance images of malignant skin tumors in seven female patients (six with basal cell carcinoma and one with malignant melanoma) were obtained using a 1.5 T system and a 47-mm or 23-mm microscopy coil. Tumors were then excised, fixed, dehydrated, embedded, and stained with hematoxylin and eosin. We then compared MR-microscopy and pathology values for thickness and relative depth of invasion of each tumor. Both techniques produced similar measurements of tumor thickness and relative depth of invasion. MR-microscopy is very useful for accurate preoperative estimation of not only relative depth of invasion, but also thickness of malignant skin tumors.

Accuracy of Preoperative MRI with Microscopy Coil in Evaluation of Primary Tumor Thickness of Malignant Melanoma of the Skin with Histopathologic Correlation

ObjectiveThe purpose of this study was to evaluate the accuracy of a preoperative MRI with microscopy coils in determining the primary tumor thickness of malignant melanoma with histopathologic correlation.Materials and MethodsEleven patients with histopathologically confirmed malignant melanoma were included in this study. MR images of the tumors were obtained with a 47-mm microscopy coil on 1.5T MR scanners and were evaluated by two radiologists, who assessed the thickness of the primary tumor on T2-weighted images (T2WI) and gadolinium-enhanced T1-weighted images with fat suppression (Gd-T1WI) and compared the results with the histopathologic findings as the reference standard. Correlations between tumor thickness on MRI and histopathologic examination were assessed using concordance correlation coefficients (CCCs). Inter- and intraobserver variabilities of tumor measurements were also assessed by intraclass correlation coefficient (ICC).ResultsAmong the 11 cases included in the study, 10 cases from the same number of patients were managed with surgical excision and one case was confirmed with punch biopsy. The primary tumor thickness measured on T2WI showed better correlation with histopathologic results, as compared with measurements taken on Gd-T1WI: the CCC of measurements on T2WI ranged from 0.64 to 0.78, indicating a substantial agreement, whereas the CCC of measurements on Gd-T1WI ranged from 0.50 to 0.61, indicating a moderate to substantial agreement. Inter- and intraobserver agreements of readers 1 and 2 were excellent for both T2WI and Gd-T1WI, with ICC ranging from 0.86 to 0.99.ConclusionMR imaging with microscopy coils may be an accurate technique in the preoperative assessment of tumor thickness in malignant melanoma, especially on T2-weighted images.

Primary haemangiopericytoma outside muscle cone in fossa orbitalis: a case report and review.

Orbital haemangiopericytoma (HPC) is a rare tumor with great histological variability and unpredictable clinical and biological behavior. The precise cell type origin is uncertain. A case report is provided. A 24-year-old male patient visited an ophthalmologist because of proptosis, strabismus, and movement limitation of the right eye one year ago. These symptoms worsened rapidly. Histopathology, MRI methods and microscopy coil were applied to study the features of HPC. The tumor was removed and the histological examination revealed that it was a primary HPC of the orbit. MRI determined the size, location, circumscription, morphological detail, growth pattern, and relationship between masses and surrounding tissues. The genesis location of this HPC was rare, and its internal morphological characters were different from cases reported in the literature. The new type of microscope showed more details of tumor MR image characters objectively.

Magnetic resonance imaging-determined subretinal fluid volume in an uveitic patient.

To describe the usefulness of the magnetic resonance imaging-determined subretinal fluid volume to evaluate the therapeutic effect on the retinal detachment caused by uveitis with the clouded media. We obtained the images by half-Fourier single-shot rapid acquisition with relaxation enhancement magnetic resonance imaging using a microscopy coil. We measured the area of subretinal fluid on each image and calculated the volume of subretinal fluid by multiplying the total area by the slice thickness. A 56-year-old male who had lost his central visual field developed bullous retinal detachment in both eyes associated with uveitis. We treated him with steroid pulse therapy. We could not accurately evaluate the improvement of retinal detachment by ophthalmoscopy and ultrasonography as a result of the clouded media. We measured the volume of the subretinal fluid using magnetic resonance imagings. The volume of the subretinal fluid was observed to gradually decrease. These methods enable us to obtain clear magnetic resonance images within 2 seconds per slice. The reproducibility of the volumetry obtained by magnetic resonance imaging was excellent. The adaptation of half-Fourier single-shot relaxation enhancement imaging performed with a surface coil makes it possible to evaluate the volumetry of a targeted space while also being useful for evaluating the effect of the treatment.

Correlation of Histopathology With Magnetic Resonance Imaging in Kienböck Disease

Diagnosis and treatment remain controversial for Kienböck disease. A few reports have correlated magnetic resonance imaging (MRI), which is essential for early diagnosis, and histopathology of Kienböck biopsy specimens, but histopathological correlations of whole lunate bones or histological slices compared with MRI images are lacking. The purpose of this study was to compare presurgical MRI scans with corresponding histological slices of Kienböck-diseased lunates. We excised whole lunates at the time of surgery from 6 patients with Kienböck disease (stage IIIB) undergoing tendon-ball replacement or a Graner procedure. We stained paraffin-embedded, coronally sectioned specimens with hematoxylin-eosin and compared them with presurgical coronal scans using MRI with a 47-mm microscopy surface coil. Toward the center of the lunates, the signal intensity in the proton density-weighted images was reduced, whereas the dorsal and palmar sides of the lunates exhibited no changes in intensity. In correlation, histopathological findings revealed strongly disrupted trabeculae toward the center of the lunates and intact trabeculae in the dorsal side of the lunates. Likewise, the necrotic and vitalized bone exhibited low and high signal intensities, respectively, in the proton density-weighted images; however, in the fast-field echo images, there were no correlations with histopathological observations. Proton density-weighted MRIs but not fast-field echo images using a 47-mm microscopy coil reflected the extent and localization of the necrotic area in Kienböck-diseased lunates, as evidenced by comparison with histological analyses of the lunate specimens. Proton density-weighted MRIs accurately reflect the vascular status of the lunate and may help plan treatment on a case-by-case basis.