18F]fluorodeoxyglucose uptake in neonatal acute lung injury measured by positron emission tomography

PURPOSE: Our goal was to investigate the role of serial dynamic contrast-enhanced SPGR MRI in the nonsurgical follow-up of patients with temporomandibular joint (TMJ) pain. METHOD: Ten patients (10 joints) with internal derangement of the TMJ were imaged with T1-weighted SE and serial postgadolinium SPGR MR pulse sequences. RESULTS: On T1-weighted images prior to treatment, the disk position was normal in one joint and anteriorly displaced without reduction in nine joints. After treatment, the disk remained normally positioned in one joint, was anteriorly displaced without reduction in eight joints, and was anteriorly displaced with reduction in one joint. The dynamic study after treatment showed a decrease in contrast enhancement of the posterior disk attachment in 7 of 10 joints. These seven patients had resolution or reduction in joint pain. CONCLUSION: These results suggest an association between a decrease in contrast enhancement of the posterior disk attachment and resolution or reduction in joint pain. This association was much stronger than the association between the clinical findings and the anatomy of the disk.     

Uses of magnetic resonance imaging (MRI) in presurgical evaluation of internal derangement of temporomandibular joint (TMJ)

Nine cases of unilateral internal derangement of TMJ indicated for surgical intervention, were selected for this study. The affected joints were imaged by MRI presurgically. The non-affected joints were also imaged as controls. MRI findings were correlated with intraoperative surgical findings. The results were absolutely accurate as regards degenerative joint pathosis and capsular rupture, and with high degree of accuracy (85.7%) in detection of disc displacement. Two cases of disc perforation were not detected by MRI. The results were promising and encouraging the use of this noninvasive imaging technique as presurgical aid in TMJ disorders.     

A balloon pumping technique for treatment of internal derangement of the temporomandibular joint

PURPOSE: This article reports on the use of a silicone or latex balloon to ablate adhesions associated with internal derangement of the temporomandibular joint (TMJ). MATERIALS AND METHODS: Wedge pressure catheters or Swan-Ganz catheters were used. The balloon was inflated with air and also moved forward and backward. RESULTS: TMJ arthroscopic balloon pumping therapy was performed on 11 joints in 11 cases of persistent closed locking. Ablation could be completed with only a balloon in seven joints. Maximal interincisal distances were increased in all cases. The increases ranged from a minimum of 3 mm to a maximum of 23 mm. TMJ pain was not recognized in any case in which 5 months or more had passed since surgery. TMJ noise (clicking) after surgery were recognized in six cases and was dependent on time after surgery. CONCLUSIONS: We are convinced that TMJ balloon pumping therapy is a useful and easy noninvasive method of ablation.     

Shoulder dystocia and symphysiotomy: a case report

Six patients were examined by CT following head trauma, with bleeding from the ear and trismus. The mandibular condyles were normal and MRI in two patients demonstrated a normally located meniscus. An unilateral comminuted temporal bone fracture (TBF) with multiple fracture lines and one or more fragments detached from the petrous bone was demonstrated by CT in every patient. On physical examination there was trismus, inability to chew and local pain in the temporomandibular joint (TMJ) without tenderness and swelling. Measurements of vertical and horizontal mandibular movement unequivocally demonstrated TMJ malfunction in comparison with 10 controls. The malfunction was presumably due to instability of the fractured petrous bone, base of the TMJ. Immobilising one TMJ results in blocking of both joints. Clinical improvement in 6-8 months and absence of symptoms of joint derangement on repeated physical examination were thought to be explained by restored petrous bone stability following healing of the fractures. The phenomenon of trismus following TBF with normal TMJ is rare and not yet reported.     

Value of increased MRI signal intensity in cervical arthrosis in myelopathies

The case of 52 patients with cervical myelopathy were reviewed to determine whether a high signal intensity lesion present on T2 weighted spin echo imaging appears to be an important indicator for predicting prognosis. Preoperatively, there were areas of increased signal intensity in 23 patients. The lesion was clearly demonstrated on T1 weighted images in only one case. Postoperatively, MRI was performed in 9 cases, one showed decreased signal intensity compared to the preoperative levels, and 8 had no change. The pre and postoperative clinical conditions of the patients whose preoperative MR images showed areas of increase signal intensity were not worse than those patients who did not have these areas of increased signal intensity. The postoperative recovery of the eight patients who exhibited no change of the signal intensity was very satisfactory. The pathophysiology of such an abnormality is presumed to be related to edema, myelomalacia or gliosis. However, the presence of these areas of high signal intensity does not appear to be an indicator of a bad clinical prognosis.     

MRI and clinical features in amyotrophic lateral sclerosis

MRI of the brain and spinal cord was performed in 21 patients with amyotrophic lateral sclerosis (ALS), 8 normal volunteers and 16 neurological disease controls. High signal was seen in the intracranial corticospinal tract in 16 of the 21 patients on T2-weighted and in 10 on proton density (PD)-weighted images. In one patient, the high signal on T2-weighted images became less marked with progression of the disease. Low signal intensity was seen in the motor cortex in 12 of the 21 patients. High signal in the anterolateral column of the spinal cord on T1 weighted images was seen in 14, and high signal in the lateral corticospinal tract on T2 weighted images was seen in 7 of the 21 patients. The relationship between the abnormal images and upper motor neurone signs remained unclear. High signal intensity was seen in the corticospinal tract in the brain on T2-weighted images in two normal volunteers and four disease controls, and on PD weighted images in three disease controls. Low signal intensity in the motor cortex on T2 weighted images was seen in three normal volunteers and four disease controls. However, high signal intensity was seen in the intracranial corticospinal tract on T1 weighted images in five patients with ALS who showed pronounced upper motor neurone signs including spastic paraparesis, but not in controls. Thus, abnormalities on MRI in the brain and spinal cord should be considered in the diagnosis of ALS, and high signal intensity of the intracranial corticospinal tract on T1-weighted images may reflect the severe pathological changes of the upper motor neurones in ALS.     

Contrast enhanced magnetic resonance imaging as a method to diagnose early inflammatory changes in the temporomandibular joint in children with juvenile chronic arthritis

OBJECTIVE: Recent studies have stressed early diagnosis of temporomandibular joint (TMJ) involvement in children with juvenile chronic arthritis (JCA) to initiate treatment before destruction of the condylar head and growth alterations take place. TMJ involvement is often asymptomatic, but studies with contrast enhanced magnetic resonance imaging (MRI) in other joints have shown that it is possible to detect the early inflammatory changes. METHODS: Thirty TMJ in 15 children with newly diagnosed JCA (mean age 12.0 years) were examined clinically, with radiographs and with MRI enhanced with gadolinium diethylene thiamine pentaacetic acid (Gd-DTPA). A control group of 10 healthy children (mean age 11.5 yrs) were examined clinically and with MRI. The MRI variables included T1 weighted images before and after administration of Gd-DTPA with and without fat suppression. RESULTS: MRI enhanced with Gd-DTPA indicated inflammatory activity in 87% of the patients. Conventional MRI without contrast medium proved to be insignificant in diagnosing early inflammatory changes. CONCLUSION: Enhanced MRI is very efficient in diagnosing early inflammatory changes of the TMJ and is a more sensitive method than the clinical examination and radiographs.     

Parallel implementations of individual-based models in biology: bulletin- and non-bulletin-board approaches

Low-field magnetic resonance imaging (MRI) was performed on the stifle joints of four normal adult mongrel dogs using a 0.064 Tesla scanner. Markers were placed on each stifle joint to serve as reference points for comparing gross sections with the images. A T1-weighted sequence was used to image one stifle joint on each dog in the sagittal plane and the other stifle joint in the dorsal plane. The dogs were euthanized immediately following MRI and the stifle joints frozen intact. Each stifle joint was then embedded in paraffin, again frozen, and sectioned using the markers as reference points. On T1-weighted images, synovial fluid had low signal intensity (dark) compared to the infrapatellar fat pad which had a high signal intensity (bright). Articular cartilage was visualized as an intermediate bright signal and was separated from trabecular bone by a dark line representing subchondral bone. Menisci, fibrous joint capsule, and ligamentous structures appeared dark. In the true sagittal plane, the entire caudal cruciate ligament was often seen within one image slice. The patella was visualized as an intermediate bright signal (trabecular bone) surrounded by a low intensity signal (cortical bone). The trochlea and the intercondylar notch were difficult areas to analyze due to signal volume averaging of the curved surface of these areas and the presence of several types of tissues.     

Disk displacement of the temporomandibular joint: correlation of magnetic resonance tomography and clinical findings

PURPOSE: To evaluate the value of magnetic resonance imaging (MRI) in symptomatic patients with different degrees of internal derangement. MATERIAL AND METHODS: We prospectively investigated 117 temporomandibular joints (TMJ) of 59 symptomatic patients and 31 asymptomatic volunteers and correlated this with clinical parameters. RESULTS: There was a positive correlation between the degree of internal derangement and deformity of the disc, maximal mouth opening, signal intensity of the posterior band, thickness of the bilaminar zone, proliferative bony changes, size of the condyle and reduced translation movement of the condyle, which in addition moved upward and backward. Patients most often complained of pain which was dependent on the degree of disc displacement and condylar changes. Clinical parameters were found to be inaccurate in predicting disc displacement. CONCLUSION: Patients with internal derangement of the temporomandibular joint may be asymptomatic. Patients history may give the only pointer to the disorder.     

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis

OBJECTIVES: To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS: The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS: Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS: It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality.     

Effects of microwave tissue coagulation on the livers of normal rabbits: a comparison of findings of image analysis and histopathological examination

The livers of normal rabbits were subjected to microwave tissue coagulation (MTC), and comparison was made of the subsequent time-course changes in tissue observed on MRI, CT and histopathological examination. 16 rabbits were used. MTC was performed with a 21 gauge needle electrode inserted into the liver at laparotomy. 1-2 h after thermal coagulation, a region with slightly lower attenuation than that of surrounding normal liver parenchyma was observed on CT, and no enhancement was detected. With MRI, change from high signal intensity to iso-signal intensity from the inner zone to the margin was found on T1 weighted images (T1WI), and heterogeneous high signal intensity was observed on T2 weighted images (T2WI). On Gd-DTPA enhanced MRI, no enhancement occurred. 1-4 weeks after coagulation, the cellular structure at the site of coagulation was lost on histological examination, and the tissue became necrotic. On CT, homogeneous water density was observed, and no enhancement was detected. With MRI, regions of iso- or slightly low signal intensity were observed on T1WI, and regions of heterogeneous high to low signal intensity were seen on T2WI. After 1 week, a granulation layer consisting mainly of fibrous tissue developed, and a ring-shaped enhancement was observed in the low signal intensity region on T1WI and in the high signal intensity region on T2WI. The ring-shaped enhancement was also noted on CT. MRI appears to be useful for observation of time-course changes following MTC therapy because of its sensitivity in the detection of tissue changes.     

Quality management--a challenge for the health care system in Poland

From April 1993 to December 1993, we prospectively studied the knees of 15 patients (mean age, 48 +/- 11 yr) receiving long-term hemodialysis (mean duration, 9 +/- 4 yr) using magnetic resonance imaging (MRI) techniques including, T1 weighted spin-echo, multiplanar gradient recalled, and postcontrast T1 with chemical shift-selective, fat-saturation pulse sequences. Analysis of these images revealed that the three findings most indicative of hemodialysis-related arthropathy were intramedullary, cortical and soft tissue lesions. Knee pain was significantly correlated with the presence of soft tissue lesions. Cortical lesions were usually associated with soft tissue lesions. Inflammatory changes adjacent to soft tissue lesions were demonstrated in postcontrast studies in all patients with soft tissue lesions. Increases in water content in those lesions appeared to increase the signal intensity. Our results indicate that MRI is useful in demonstrating the extent of hemodialysis-related arthropathy involvement, especially in hemodialysis patients suffering from knee pain.     

Symptoms of temporomandibular joint osteoarthrosis and internal derangement 30 years after non-surgical treatment

To evaluate the long-term condition of temporomandibular joints (TMJs) affected by osteoarthrosis and internal derangement, 99 patients treated non-surgically between 1958 and 1962 were recalled for follow-up. The patients, 16 men and 83 women (mean age 58.2 years) with either reducing or permanent disk displacement, were submitted to a structured interview concerning previous treatment, masticatory function, and the presence of symptoms of osteoarthrosis and internal derangement of the masticatory system, and of complaints of the musculoskeletal system in general. A control group, consisting of eight men and 27 women (mean age 58.9 years) without complaints of the masticatory system, matching the patient group for sex, age and state of dentition, was included in the study to avoid simply documenting age-related joint conditions. Satisfaction with the treatment outcome was high. Chewing ability of the the patients did not differ from that of the controls, although patients more often expected pain and difficulty with opening the mouth wide. The main TMJ symptoms of the patients had decreased significantly; patients reported joint noises more often than controls. It is concluded that, despite some persisting symptoms, the non-surgical treatment approach of TMJ osteoarthrosis and internal derangement provides long-lasting satisfactory subjective results and is well-accepted by the patients.     

Cost effectiveness in optometric health care

A case of sclerosing epithelioid fibrosarcoma and its appearance on MRI is presented. The tumor showed a zonal architecture on MRI with a large central core of very low signal intensity and a peripheral rim of intermediate to high signal intensity on T1- and T2-weighted spin echo pulse sequences. The core showed decreased cellularity with dense collagen deposition on histologic examination, and the peripheral zone increased cellularity with increased nuclear atypia. The presence of a prominent region of very low signal intensity on T1- and T2- weighted images can be seen with neural tumors, giant cell tumor of the tendon sheath, aggressive fibromatosis, and, in rare instances, with soft tissue sarcomas rich in collagen.     

Resistance to antiretroviral drugs]

A sample of 30 subjects, 15 with and 15 without subjective temporomandibular joint (TMJ) complaints (noises, sounds), underwent a clinical examination, a sonography and an axiography, to detect TMJ clicking. The clinical examination found 22 noisy joints in a total of 60 TMJs considered. Axiography found 19 noisy joints and sonography 32. While 90% of the examined joints showed agreement between axiography and clinical examination (with a little higher sensitivity demonstrated by clinical examination with respect to axiography), 20% of the joints were positive for clicking in sonography only. Sonography showed a high sensitivity in detection of joint noises which suggests its utility as a screening test for early detection of craniomandibular disorders.     

Airway obstruction caused by an oleothorax

PURPOSE: This article describes the possible role of various peptides in producing pain and inflammation in the temporomandibular joint (TMJ). MATERIAL AND METHODS: Current research findings on the spectrophotometric quantification of TMJ synovial fluid for neuropeptide Y (NPY), serotonin (5HT), and interleukin-1beta (IL-1beta) are presented. FINDINGS: NPY was found in high levels in the synovial fluid of arthritic TMJs with resting pain, and serotonin (5-HT) was found in patients with pain perceived on mandibular movement. These pain-related mediators were also associated with restricted mandibular mobility. Interleukin-1beta (IL-1beta) was found to be strongly associated with hyperalgesia over the TMJ as well as resting pain. Anterior open bite as a clinical sign of joint destruction was found to be associated with high levels of NPY and IL-1beta in the synovial fluid. IL-1beta was also related to the radiographic signs of joint destruction. CONCLUSIONS: Interaction between the peripheral nervous system (sensory and sympathetic nerves) and the immune system is probably of importance for the modulation of pain and inflammation in the TMJ, but this subject has to be investigated further with experimental clinical studies.     

Regional changes in hippocampal T2 relaxation and volume: a quantitative magnetic resonance imaging study of hippocampal sclerosis

OBJECTIVE: The principal MRI features of hippocampal sclerosis are volume loss and increased T2 weighted signal intensity. Minor and localised abnormalities may be overlooked without careful quantitation. Hippocampal T2 relaxation time (HT2) can be quantified, but previously has only been measured on a few thick coronal slices with interslice gaps. In this study HT2 was measured along the entire length of the hippocampus on contiguous slices and used, with quantitative measures of hippocampal volume (HV) and distribution of atrophy, to better define the range of hippocampal sclerosis. METHODS: Thirty patients with temporal lobe epilepsy, 10 patients with extratemporal localisation related epilepsy and extratemporal lesions, and 20 control subjects were studied using MRI T2 relaxometry and volumetry. RESULTS: In controls and patients, HT2 was higher in the anterior than the posterior hippocampus. Using HV, morphometric, and HT2 data, patients with temporal lobe epilepsy were classified as unilateral diffuse hippocampal sclerosis (n=16), unilateral focal (n=6), bilaterally affected (n=6), and normal (n=2). In patients with unilateral hippocampal sclerosis, the anterior hippocampus was always affected. In three patients with normal HV, HT2 measurements disclosed unilateral focal abnormalities that corresponded to the EEG lateralisation of epileptic activity. Patients with bilateral hippocampal involvement had an earlier onset of epilepsy than patients with unilateral hippocampal sclerosis. CONCLUSIONS: Measurement of regional abnormalities of HT2 along the length of the hippocampus provides further refinement to the MRI assessment of the hippocampi in patients with temporal lobe epilepsy and is complementary to volumetric and morphological data.     

High signal intensity of globus pallidus on T1-weighted MRI in liver cirrhosis patients: clinical and pathological study

In some patients with liver cirrhosis, the globus pallidus shows high signal intensity on T1-weighted MRI. The relationship was examined between high signal intensity on T1-weighted images and pathological conditions such as liver function, portal venous pressure and metal concentrations in brain. The signal of the globus pallidus on T1-weighted imaging became highly enhanced in accordance with prolongation of prothrombin time, deterioration of ICG R15, or decrease in choline esterase and the Fisher ratio. Furthermore, the high signal intensity was also seen in patients with high portal pressure and large varices. In histopathological study, remarkable atrophy and loss of nerve cells were observed in globus pallidus with high signal intensity on T1-weighted imaging, changes that were similar to those in with patients with manganese poisoning. The manganese concentration in autopsied globus pallidus with high signal intensity on T1-weighted imaging showed a 9.5-fold increase compared with that with normal intensity. In conclusion, the deposition of manganese in the globus pallidus, which is accompanied with the nerve cell deciduation, brings about the high signal intensity of the globus pallidus on T1-weighted MRI in patients with liver cirrhosis.     

Amyloid arthropathy of the hip joint: MR demonstration of presumed amyloid lesions in 152 patients with long-term hemodialysis

The aim of this study was to determine the spectrum of MR findings of presumed amyloid arthropathy of the hip joints in patients on long-term hemodialysis. We prospectively performed T1- and T2-weighted spin-echo imaging on 152 consecutive patients on hemodialysis. The duration of hemodialysis ranged from 5 months to 24 years, 2 months (mean: 8 years, 8 months). The frequency, location, and signal intensity of bone lesions were assessed. In 12 cases with contrast-enhanced MR examination, enhancement pattern of bone lesions, synovial lesions, and intra-articular lesions were characterized. Bone lesions presumed to be amyloid deposits were identified in 60 patients (39%). Magnetic resonance imaging revealed that amyloid lesions were more extensive than anticipated by plain radiographs. All bone lesions showed decreased signal intensity on T1-weighted images. On T2-weighted images, bone lesions showed increased signal intensity in 32 patients (54%), decreased signal intensity in 11 patients (18%), and both increased and decreased signal intensity in 17 patients (28%). Following intravenous injection of gadolinium-based contrast, all bone lesions showed moderate enhancement. Synovial thickening could not be identified on T1- and T2-weighted images. However, contrast-enhanced images showed thickened synovial membrane, which could be differentiated from joint fluid. Intra-articular nodules showed decreased or intermediate signal intensity on T1-weighted images and decreased signal intensity on T2-weighted images; the intra-articular nodules were contiguous with subchondral bone lesions. Magnetic resonance imaging is useful for evaluating the distribution and extent of amyloidosis of the hip joints in patients undergoing long-term hemodialysis.     

Leiomyosarcoma of the maxillary sinus: CT and MRI findings

This report describes the CT and MRI appearances of a leiomyosarcoma of the maxillary sinus. CT showed frank bony destruction, no calcification and a low attenuation area within the mass. MRI showed intermediate intensity on T1 weighted images, intermediate to slightly high signal intensity on T2 weighted images and moderate inhomogeneous enhancement. Precise identification of the extent of the tumour, especially of orbital invasion, is of utmost importance because local recurrence is common after the resection of leiomyosarcomas.