Gregory Chaljub

The Magnetic Resonance Imaging Appearance of Individual Structures of the Posterolateral Knee A Prospective Study of Normal Knees and Knees with Surgically Verified Grade III Injuries

The purpose of this study was to contrast the magnetic resonance imaging appearance of uninjured components of the posterolateral knee with that of injured structures, and to assess the accuracy of magnetic resonance imaging in identifying posterolateral knee complex injuries. Thin-slice coronal oblique T1-weighted images through the entire fibular head were used to identify the posterolateral structures in seven uninjured knees. The appearance of corresponding grade III injuries to these structures was identified prospectively in 20 patients and verified at the time of surgical reconstruction. The sensitivity, specificity, and accuracy of imaging for the most frequently injured posterolateral knee structures in this series were as follows: iliotibial band-deep layer (91.7%, 100%, and 95%), short head of the biceps femoris-direct arm (81.3%, 100%, and 85%), short head of the biceps femoris-anterior arm (92.9%, 100%, and 95%), midthird lateral capsular ligament-meniscotibial (93.8%, 100%, and 95%), fibular collateral ligament (94.4%, 100%, and 95%), popliteus origin on femur (93.3%, 80%, and 90%), popliteofibular ligament (68.8%, 66.7%, and 68%), and the fabellofibular ligament (85.7%, 85.7%, and 85.7%). Magnetic resonance imaging of the knee was accurate in the identification of these injuries.

Magnetic resonance imaging of the upper airway. Effects of propofol anesthesia and nasal continuous positive airway pressure in humans.

Background Anesthetic agents inhibit the respiratory activity of upper airway muscles more than the diaphragm, creating a potential for narrowing or complete closure of the pharyngeal airway during anesthesia. Because the underlying mechanisms leading to airway obstruction in sleep apnea and during anesthesia are similar, it was hypothesized that anesthesia-induced pharyngeal narrowing could be counteracted by applying nasal continuous positive airway pressure (CPAP). Methods Anesthesia was induced in ten healthy volunteers (aged 25-34 yr) by intravenous administration of propofol in 50-mg increments every 30-s to a maximum of 300 mg. Magnetic resonance images of the upper airway (slice thickness of 5 mm or less) were obtained in the awake state, during propofol anesthesia, and during administration of propofol plus 10 cm nasal CPAP. Results Minimum anteroposterior diameter of the pharynx at the level of the soft palate decreased from 6.6+/-2.2 mm (SD) in the awake state to 2.7+/-1.5 mm (P < 0.05) during propofol anesthesia and increased to 8.43+/-2.5 mm (P < 0.05) after nasal CPAP application. Anteroposterior diameter of the pharynx at the level of the dorsum of the tongue increased from 7.9+/-3.5 mm during propofol anesthesia to 12.9+/-3.6 mm (P < 0.05) after nasal CPAP. Pharyngeal volume (from the tip of the epiglottis to the tip of the soft palate, assuming this space to be a truncated cone) significantly increased from 2,437+/-1,008 mm3 during propofol anesthesia to 5,847+/-2,827 mm3 (P < 0.05) after nasal CPAP application. Conclusions In contrast to the traditional view that relaxation of the tongue causes airway obstruction, this study suggests that airway closure occurs at the level of the soft palate. Application of nasal CPAP can counteract an anesthesia-induced pharyngeal narrowing by functioning as a pneumatic splint. This is supported by the observed reduction in anteroposterior diameter at the level of the soft palate during propofol anesthesia and the subsequent increase in this measurement during nasal CPAP application.

Revisiting MRI for appendix location during pregnancy

OBJECTIVE The purpose of this study is to determine the location of the appendix in pregnant patients by MRI and to investigate the possibility of gradual upward displacement of the appendix during pregnancy. CONCLUSION The gradual upward displacement of the appendix during pregnancy was confirmed. MRI can be used for determination of the appendix localization in pregnant patients. Further studies with a larger number of patients will be helpful to answer this clinically relevant question.

The arthroscopic appearance of lipoma arborescens of the knee

Lipoma arborescens is a rare intra-articular lesion consisting of a villous lipomatous proliferation of the synovial lining. This case report draws attention to the history, physical findings, and arthroscopic appearance of lipoma arborescens, a rare lesion of the synovial lining of the knee. Arthroscopically, the lesion appears as a synovial lesion with numerous fatty-appearing globules and villous projections. In addition, magnetic resonance imaging is a valuable tool to differentiate the lesion from rheumatoid arthritis, pigmented villonodular synovitis, and synovial chondromatosis in those patients who present with a chronic, swollen, and painful joint.

Spinal-cerebrospinal fluid leak demonstrated by radiopharmaceutical cisternography

Cerebrospinal fluid (CSF) leaks are known to occur under several conditions: lumbar puncture performed for contrast myelography, spinal surgery, spinal stab wounds, fracture of the thoracic spine, inadvertent spinal puncture during epidural anesthesia, traumatic lumbar meningocele, and bronchopleural subarachnoid fistula due to bronchogenic carcinoma. Spontaneous spinal leaks are uncommonly encountered in neurosurgical practice, but they are increasingly recognized as a cause of spontaneous intracranial hypotension. Most CSF leaks are located at the cervicothoracic junction or in the thoracic spine. The disease is often self-limiting. A CSF leak can be detected directly by accumulation of radioactivity outside the subarachnoid space or suggested indirectly by the rapid disappearance of tracer from the subarachnoid space and early appearance in the urinary bladder. In this paper we present two unusual cases of CSF leak identified by radiopharmaceutical cisternogram.

In vivo MRI characteristics of lipoma arborescens utilizing fat suppression and contrast administration

Lipoma arborescens or villous lipomatous proliferation of the synovium is a rare lesion. We describe the in vivo imaging characteristics of lipoma arborescens of the knee utilizing fat suppression techniques and contrast medium administration. As expected, the lesion demonstrated signal loss when utilizing fat suppression. In addition, no contrast enhancement was noted. When a synovial process demonstrates isointensity with subcutaneous fat on all pulse sequences and no contrast enhancement, lipoma arborescens should be the primary diagnosis consideration.

Allergic fungal sinusitis with cranial base erosion

Allergic fungal sinusitis (AFS) usually follows a slow, nonaggressive course. However, massive bone destruction can occur, with extension of the disease process outside of the confines of the sinuses.

The role of MR cholangiopancreatography in the evaluation of pregnant patients with acute pancreaticobiliary disease

This study aimed to determine the usefulness of MR cholangiopancreatography (MRCP) in the evaluation of pregnant patients with acute pancreaticobiliary disease and its additional value over ultrasound. MRI studies of pregnant patients who were referred because of acute pancreaticobiliary disease were included. MR images and patient charts were reviewed retrospectively to determine clinical outcome and the results of other imaging studies. 18 pregnant patients underwent MRCP because of right upper quadrant pain (n = 6), pancreatitis (n = 9), cholangitis (n = 1) or jaundice (n = 2). 15 patients were also evaluated with ultrasound. Biliary dilatation was detected in eight patients by ultrasound, but the cause of biliary dilatation could not be determined by ultrasound in seven patients. MRCP demonstrated the aetiology in four of these patients (choledocholithiasis (n = 1), Mirizzi syndrome (n = 1), choledochal cyst (n = 1) and intrahepatic biliary stones (n = 1)) and excluded obstructive pathology in the other four patients. MRCP was unremarkable in the seven patients who had no biliary dilatation on ultrasound. Three patients underwent only MRCP; two had choledocholithiasis and one cholelithiasis and pancreatitis. Choledocholithiasis diagnosed with MRCP (n = 3) was confirmed by endoscopic retrograde cholangiopancreatography. Mirizzi syndrome (n = 1) and a choledochal cyst (n = 1) were confirmed by surgery. The patients with normal MRCP (n = 12) and one patient with intrahepatic stones improved with medical treatment. MRCP appears to be a valuable and safe technique for the evaluation of pregnant patients with acute pancreaticobiliary disease. Especially when ultrasound shows biliary dilatation, MRCP can determine the aetiology and save the patient from unnecessary endoscopic retrograde cholangiopancreatography by excluding a biliary pathology.

Blastomycosis of the lumbar spine: case report and review of the literature, with emphasis on diagnostic laboratory tools and management

Abstract We report on the conservative and surgical management of a patient with blastomycosis of the lumbar spine, causing severe and crippling deformity. The diagnosis was made through biopsy. Curative removal, reconstruction and realignment of the spine were achieved. Imaging modalities were highlighted, with a detailed discussion of the histology and conservative and surgical management. We emphasize the importance of early, aggressive treatment of blastomycosis to prevent deformity and disability, and to enable identification of the best management of a destructive lesion with deformity. This case demonstrates that empirical treatment should not be used in cases of unusual sinus and abscess locations. Specific diagnosis and early treatment are indicated to prevent dreadful complications and spinal deformity resulting from blastomycosis. Aggressive antifungal therapy can cure the disease but does not control complications related to deformity. The latter can only be addressed by surgical reconstruction. We review the literature of surgical treatment, focusing on abscess drainage, bone fusion and posterior instrumentation in the absence of addressing the deformity component.

3D CT Imaging Method for Measuring Temporal Bone Aeration

Objective --3D volume reconstruction of CT images can be used to measure temporal bone aeration. This study evaluates the technique with respect to reproducibility and acquisition parameters. Material and methods --Helical CT images acquired from patients with radiographically normal temporal bones using standard clinical protocols were retrospectively analyzed. 3D image reconstruction was performed to measure the volume of air within the temporal bone. The appropriate threshold values for air were determined from reconstruction of a phantom with a known air volume imaged using the same clinical protocols. The appropriate air threshold values were applied to the clinical material. Results --Air volume was measured according to an acquisition algorithm. The average volume in the temporal bone CT group was 5.56 ml, compared to 5.19 ml in the head CT group ( p = 0.59). The correlation coefficient between examiners was > 0.92. There was a wide range of aeration volumes among individual ears (0.76-18.84 ml); however, paired temporal bones differed by an average of just 1.11 ml. Conclusions --The method of volume measurement from 3D reconstruction reported here is widely available, easy to perform and produces consistent results among examiners. Application of the technique to archival CT data is possible using corrections for air segmentation thresholds according to acquisition parameters.