Bilateral symmetrical comparison of the proximal femur using 3D-CT models.

PURPOSE: Superimposed three-dimensional (3D)-models obtained from CT-images have been used to evaluate displacement of femoral neck fractures, but this method assumes symmetrical anatomy of normal femurs. The present study aimed to compare the spatial orientation of the left and right proximal femur, thus establishing if 3D models can be used as a reference standard for the evaluation of fracture displacement. METHODS: We generated 3D-CT-models of 20 patients with no skeletal pathology of the proximal femurs. Three observers independently determined the positions of the fovea and the femoral head, and a vector intersecting the centre points of the fovea and the femoral head defined the rotation. Differences in positions and rotations were determined by superimposing the 3D-CT-models of both femurs. RESULTS: The mean distance (95% CI) between positions of the left and right fovea was 3.1 mm (2.7-3.4) and between the left and right femoral head 2.8 mm (2.6-3.0). The minimal detectable change was 2.8 for the fovea and 2.3 for the femoral head, and the repeatability coefficients between 2.1-2.7 and 1.0-2.9, respectively. Mean difference in rotation of the femoral head was 6° (5.3-6.6) with a minimal detectable change of 8.8 and repeatability coefficients ranging from 5.8 to 10.0. CONCLUSIONS: Distances between the left and right femoral heads were larger than what could be explained by measurement error alone, suggesting that there may be minor side-to-side differences. However, these differences are small, and 3D-CT-models can be used as a reference standard to evaluate displacement of femoral neck fractures.

Intracranial Teratoma: Imaging, Intraoperative, and Pathologic Features: AIRP Best Cases in Radiologic-Pathologic Correlation.

Editor's Note.-RadioGraphics continues to publish radiologic-pathologic case material selected from the American Institute for Radiologic Pathology (AIRP) "best case" presentations. The AIRP conducts a 4-week Radiologic Pathology Correlation Course, which is offered five times per year. On the penultimate day of the course, the best case presentation is held at the American Film Institute Silver Theater and Cultural Center in Silver Spring, Md. The AIRP faculty identifies the best cases, from each organ system, brought by the resident attendees. One or more of the best cases from each of the five courses are then solicited for publication in RadioGraphics. These cases emphasize the importance of radiologic-pathologic correlation in the imaging evaluation and diagnosis of diseases encountered at the institute and its predecessor, the Armed Forces Institute of Pathology (AFIP). Online supplemental material is available for this article.

The Guyon's canal in perspective: 3-T MRI assessment of the normal anatomy, the anatomical variations and the Guyon's canal syndrome.

PURPOSES: (1) To revisit the anatomical boundaries of the canal, its contents and its two channels, (2) to describe the anatomical variations of the canal's borders and the variations of its contents, and (3) to discuss the clinical relevance of the Guyon's canal syndrome. METHODS: Two hundred and fifty MR wrists examinations were reviewed. MR spin echo T1-weighted axial slices were used to analyze the Guyon's canal. The anatomical boundaries, the cross-sectional area and length of the canal were calculated. The anatomical variations of the canal's walls and contents and their prevalence were sought. Changes related to Guyon's canal syndrome were also evaluated. RESULTS: From the 250 wrists, the anatomy of the Guyon's canal was normal in 168 (67.2%) wrists; 73 (29.2%) wrists presented with anatomical variations; and 9 (3.6%) wrists had derangements causing Guyon's canal syndrome. The cross-sectional area of the canal was 33 ± 11 mm² proximally and 45 ± 19 mm² distally. The canal's length was approximately 40 ± 4 mm. Among the 73 wrists with anatomical variations, there were aberrant muscles in 39 (53.4%) wrists, multiple ulnar nerve branching in 22 (30%) cases, increased amount of fat tissue inside the canal in 9 (12.3%) cases and hypoplastic hamulus in 3 (4.1%) cases. There were 9 (3.6%) symptomatic wrists with clinical and radiological features attributed to Guyon's canal syndrome. CONCLUSION: MRI is an excellent modality for the evaluation of the Guyon's canal.

MRI of the Achilles tendon: a comprehensive review of the anatomy, biomechanics, and imaging of overuse tendinopathies.

The Achilles tendon is the largest tendon in the body; it plays an important role in the biomechanics of the lower extremity. It can withstand great forces, especially during sporting exercises and pivoting. The pathologies related to the Achilles tendon are diverse and many carry undesirable consequences. We retrospectively analyzed the images of patients who underwent examinations of the ankle/foot region to review the anatomy of the Achilles tendon and its surroundings and to search for pathologies consistent with overuse injuries. The anatomy of the tendon is described from origin to insertion. The imaging characteristics of the Achilles tendon including pitfalls are reviewed. We also describe the Achilles overuse injuries: paratenonitis, tendinosis, tendon tear, atypical tear, tendon re-tear, retrocalcaneal bursitis, retro-Achilles bursitis, Haglund's deformity, and tendon calcification. We present other entities like tendon ossification and failed transplanted Achilles tendon, with emphasis on MRI.

Recombinant human bone morphogenetic protein 2-induced heterotopic ossification of the retroperitoneum, psoas muscle, pelvis and abdominal wall following lumbar spinal fusion.

A 45-year-old man presented with vertebral collapse at L5 as an initial manifestation of multiple myeloma and underwent spinal fusion surgery using recombinant human bone morphogenetic protein-2 (rhBMP-2). Subsequent computed tomography (CT) scans and X-rays revealed heterotopic ossification of the left psoas muscle, pelvis, and anterior abdominal wall. While the occurrence of heterotopic ossification has previously been reported when rhBMP-2 has been used for spinal fusion surgery, this case demonstrates that it can occur to a much greater degree than previously seen.

Multiple occult wrist bone injuries and joint effusions: prevalence and distribution on MRI.

This study aims (1) to assess the prevalence and distribution of multiple occult injuries of the carpal bones and the distal forearm in patients with wrist pain and negative radiographs following trauma and (2) to evaluate the distribution and significance of joint effusions in the wrists with multiple osseous injuries. One hundred and thirty-one subjects, 74 men and 57 women, were consecutively examined in two institutions. All were acute trauma patients with negative X-rays whose clinical examination suggested possible fracture at the wrist or the distal forearm. Magnetic resonance (MR) wrist imaging was performed with and without fat saturation sequences. The MR images were analysed for detection of occult trabecular contusions and cortical discontinuity in the carpus, the distal forearm and the metacarpal bases. The prevalence and distribution of the injuries were assessed along with the distribution of joint effusions. Eight patients were excluded due to inadequate image quality. Two patients had bilateral injury. A total of 125 wrists were analysed. Seventy-eight (62.4%) wrists had occult bone injuries. Among these 78, 53 (68%) wrists had more than one injured bone. Twenty-five wrists (32%) had one injured bone. The highest number of injured bones per wrist was six. Injuries with a visible fracture line were seen in 29 (37.1%) wrists on MRI. The distal radius was the most frequent location for occult fracture line (11 cases). The injuries without a fracture line (contusion) were present in 49 (63%) wrists; they were detected more frequently in the scaphoid (35 cases). The lunate (29 cases) and the triquetrum (26 cases) were almost equally affected. The bone that was less frequently injured was the pisiform (four cases). Joint effusions were present in all 53 wrists with multiple bone lesions but more often situated in the ulnocarpal space [27 (50.3%) wrists]. There was no correlation between effusions in multiple locations (grades III and IV) and multiple bone injuries. This study revealed the presence of multifocal trabecular contusions without correlation with increased joint effusions in patients with negative radiographs and persistent pain. The clinical significance of these findings deserves further investigation.

MRI of the median nerve and median artery in the carpal tunnel: prevalence of their anatomical variations and clinical significance.

OBJECTIVE: Anatomical variations of the median nerve and the persistent median artery (PMA) in the carpal tunnel (CT) are important to understand for their clinical and surgical significance. The aim of this cohort retrospective study was to investigate the prevalence of aberrant median nerve branches and persistent median artery in the CT in a selected population using magnetic resonance imaging (MRI). MATERIALS AND METHODS: MR wrist images of 194 patients, 77 males and 117 females, aged 12-80 years were randomly selected and retrieved from our clinical and radiology data base. The MR examinations were performed using either 1.5-T or 3.0-T magnet using a cylindrical receive-transmit wrist coil for all cases. The course of the bifurcation of the median nerve was followed on axial T2-weighted and axial proton density fat saturated images and classified as either proximal, within, or distal to the CT. The flexor retinaculum proximally and the metacarpal bases were used as anatomic landmarks to subdivide these three categories. In addition, the median artery was searched in order to assess the prevalence of its presence inside the CT. A total of 194 wrists were analyzed by two musculoskeletal-trained radiologists. They were blinded on the population age, gender, and the sides of the wrists. Agreement was reached by consensus. RESULTS: Among the 194 wrists, there was bifurcation of the nerve proximal to the CT in 12 (6.1%) wrists. There was nerve bifurcation within the CT in 36 (18%) wrists. Nerve bifurcation distal to the CT was more frequently observed, occurring in 147 (75%) wrists. Only one nerve trifurcation was seen within the CT. There was no gender predominance for the nerve bifurcation within the tunnel. There were 107 right wrists and 87 left wrists. On the right side, bifurcation of the nerve within the CT was seen in 21 (19.6%) wrists; and on the left side bifurcation of the nerve was present in 15 (17.2%) wrists. Statistically, we found no significant difference in the prevalence of the bifid nerve within the tunnel in the subgroups based on age, gender, or side of the wrists. A persistent median artery (PMA) within the tunnel was observed in 21 (11%) wrists--10 males and 11 females. Of these, four (19%) cases were presented with coexistent PMA and bifid median nerve within the tunnel. Statistically, we found that the two variations are not independent traits, and their covariance is not null. CONCLUSION: There was a high prevalence of bifid median nerve (19%) and PMA (11%) within the tunnel regardless of gender or age. The PMA was more frequent on the left side.

Congenital absence of the semimembranosus muscle: case report.

Congenital anomalies of the muscles of the lower extremity are rare. A case of complete absence of the semimembranosus muscle incidentally found with magnetic resonance imaging is reported. The patient was a 55-year-old female presenting with knee pain and no previous history of trauma. Clinical and imaging findings were consistent with meniscal tears. Two cases of uncommon distal insertion of the semimembranosus tendon are also described to illustrate the anatomical variations in this area. The anatomical and biomechanical relations between the semimembranosus muscle and the posteromedial corner of the knee are examined in this case report.

New packaging methods of body packers: Role of advanced imaging in their detection. A case study.

Body packing is one of the common ways to traffic illicit drugs. Drug mules usually swallow or insert drugs within the gastrointestinal tract or other orifices. Detection of such drug packets has become difficult because of the constantly improving packaging techniques and the sophistication used by traffickers. Suspected obstruction or perforated hollow viscus requires employment of appropriate radiological procedures and techniques for accurate detection and precise diagnosis. A delay diagnosis and inappropriate action may carry disastrous physical consequences for the body packers. It is crucial for radiologists to acquire enough experience to deduce different types of drug packets from their imaging characteristics and to accurately guide emergency physicians and security officials. The packets are not always radiodense, therefore they can be difficult to detect on conventional abdominal radiographs. In this report, the authors illustrate 5 cases with different packaging methods and materials that give rise to radiological challenges.

Ruptured Berry Aneurysm as the initial presentation of Polycystic Kidney Disease: A case report and review of literature.

Intra-cranial saccular aneurysms, also known as Berry aneurysms, have a well-known association with autosomal dominant polycystic kidney disease (ADPKD). Aneurysmal rupture can be the initial presentation of the disease. ADPKD has two types of gene mutations: PKD1 and PKD2. The latter one is of a milder form presenting later in life. Imaging plays a crucial role in the diagnosis and assessment in order to provide adequate management of these patients however, there are no official standardized guidelines established for screening of these intracranial aneurysms.

Pulmonary venous varix associated with mitral regurgitation mimicking a mediastinal mass: A case report and review of the literature.

Pulmonary vein varix is an unusual cause of a mediastinal mass on a chest radiograph. It may be found as an isolated malformation or as a sequela of pulmonary venous hypertension. We encountered a case presenting with left hemiparesis and a past medical history of rheumatic heart disease. The chest radiograph revealed a well-defined mediastinal mass that turned out to be a hugely dilated pulmonary vein on contrast enhanced computed tomography of the chest. The computed tomography of the brain and upper abdomen revealed bilateral cerebral infarction and splenic infarction. In the literature, one-third of the reported cases of pulmonary vein varix are acquired secondary to mitral valve disease.

Magnetic resonance imaging of the triangular fibrocartilage complex lesions: a comprehensive clinicoradiologic approach and review of the literature.

OBJECTIVE: This article illustrates the frequent lesions of the triangular fibrocartilage complex (TFCC) by means of magnetic resonance imaging. METHODS: We performed a retrospective chart review of the magnetic resonance images of 109 patients from our database. All subjects had history of trauma, and all underwent both radiographic and magnetic resonance imaging examination of the wrist. The changes (degeneration, tears) of the TFCC were assessed. RESULTS: Ten patients were excluded because of incomplete imaging protocol (4 patients) and low-quality images (6 patients). From the 99 wrists remaining, the TFCC was normal in 30 (30.3%). Degenerative changes were found in 40 (40.4%) wrists. Partial and complete tears were present in 17 (17.1%) and 12 (12.1%) wrists, respectively. CONCLUSION: The TFCC lesions in acute traumatic wrists should not be overlooked; they may contribute to wrist pain and disability after treatment of existing bone injuries.

Postlymphoproliferative disorder affecting bone after a renal transplantation.

OBJECTIVE: To illustrate a posttransplant lymphoproliferative lymphoma presenting as a solitary osseous lesion situated in the rib. CLINICAL FEATURES: A 53-year-old man was referred to a surgical department because of persistent local pain over the lower part of his left posterior hemithorax. Due to a previous history of chronic glomerulonephritis, a renal transplant was performed 7 years previously, followed by immunosuppressive therapy with azathioprine cyclophosphamide. INTERVENTION AND OUTCOME: Surgical removal of the rib lesion was performed because of the patient's history of the organ transplant. The histological study of the surgically removed tissue revealed diffuse infiltration of the marrow by lymphoid-like cells. There was evidence of interstitial fibrosis, and further immunohistochemical examination showed the presence of B cells in the specimen confirming the diagnosis of B-cell lymphoma. CONCLUSION: This case report discusses an unusual presentation of a lymphoma induced by immunosuppressive therapy in a patient who had received an organ transplant. Such lesions may appear in any organ or system, although this is distinctively unusual to involve the skeletal system.

Magnetic resonance assessment of the double-crush phenomenon in patients with carpal tunnel syndrome: a bilateral quantitative study.

Our main goal was to assess the coexistence of narrowed cervical foramens and cervical canal stenosis in patients with carpal tunnel syndrome (CTS). We took magnetic resonance (MR) images of 120 wrists and 480 foramens in 60 age and sex matched subjects (30 patients with CTS and 30 controls). All patients had nerve conduction velocity tests before MR examination. We measured the volume of the carpal canal in all participants bilaterally. We also quantified the cross-sectional areas of the cervical foramens on both sides from C4 to T1 and measured the diameter of the cervical canal in all participants. We searched for the prevalence and location of cervical spondylosis and disc prolapse on the side of the symptomatic wrist(s). All patients had CTS-related neurophysiological findings. There was no correlation between the symptoms and the reduced carpal canal volume. The mean (SD) area of the foramens was 109.5 (12.8) mm2 in the patients compared with the controls 126.4 (28.7) mm2 (p = 0.007). Cervical spondylosis and disc prolapse were more common in the patients than the controls at the C5-C6 and C6-C7 levels, and their locations were on the same side as the symptoms in the wrist(s) in 50% of cases. There was no difference in the size of the cervical canal between the two groups. The higher incidence of narrowed cervical foramens in the patients and its concordance with affected nerve roots on the same side as the CTS symptoms support the hypothesis of a double-crush phenomenon.

MRI spectrum of bone changes in the diabetic foot.

PURPOSES: (1) To assess the prevalence of bone marrow changes in the diabetic foot and (2) to discuss the clinical significance of these changes. METHODS: 85 patients with radiographic and magnetic resonance imaging (MRI) foot examinations were selected. Inclusion criteria were clinical diagnosis of diabetes and bone changes on radiographs and MRI. The material was selected from the image storage (PACS) system. We searched for vascular (infarct and necrosis), traumatic (bruise and occult fractures), destruction and debris, dislocation, osteochondritis, osteomyelitis. Five patients had bilateral examinations. A total of 90 feet were evaluated. RESULTS: From 90 feet, 17 (18.9%) presented with vascular changes, from them, 11 feet had infarct and 6 feet had necrosis. Twenty (22.2%) feet had traumatic changes; of them, 10 (50%) had edema on MRI. Five (25%) cases had occult fracture on MRI; and 5 (25%) had visible fracture on both X-ray and MRI. Bone destruction was detected in 8 (8.9%) feet. Bony debris was visualized in three of them. Bone dislocation was visualized in 11 (12.2%) feet. There was evidence of osteochondritis in twenty-four (26.7%) feet. Osteomyelitis was diagnosed in ten (11.1%) feet. CONCLUSION: Diabetic foot is a challenge for both clinicians and radiologists due to its complexity. The bone derangements inherent to the diabetic foot can be evaluated with high accuracy with MRI.

MRI of the cuboid bone: analysis of changes in diabetic versus non-diabetic patients and their clinical significance.

OBJECTIVES: (1) To investigate the association between diabetes and marrow changes in the cuboid; and (2) to evaluate the influence of age, gender, body mass index (BMI) and use of insulin in the occurrence of marrow changes in the cuboid. RESEARCH DESIGN AND METHODS: MR and X-ray foot examinations of 237 patients [94 males, 143 females; mean age, 47.1 years (range 16-93 years)], five of whom underwent bilateral examinations, were reviewed. MR and radiographic studies were analyzed for the presence of marrow edema and fractures in the cuboid. Findings were correlated with demographic data (age, gender) and clinical information (BMI and use of insulin). RESULTS: Two hundred and forty two feet - 69 diabetic and 173 non-diabetic - were retrospectively evaluated. There was a higher prevalence of marrow edema and fractures in the diabetic cuboid (n=31, 45%) compared to non-diabetic cuboid (n=25, 14%, p=0.02). A fracture line was seen in fourteen (20%) diabetic cuboid bones compared to 4 (2%) in non-diabetic cuboid bones (p<0.0001). Eleven (79%) cases of cuboid fractures in the diabetic population were radiographically occult. Multivariate data analysis revealed an adjusted odds ratio of 4.416 (95% CI; 2.307, 8.454) for the relationship between marrow changes (edema and fractures) in the cuboid and diabetes. For each year of age, the odds of changes in the cuboid increased by 2.2% (95% CI; 1.001, 1.044). CONCLUSION: Despite not bearing weight, the cuboid bone is more vulnerable to marrow edema and fractures in diabetic patients compared to non-diabetic patients. Age seems to be an influential factor.

Tuberculous spondylitis presenting as severe chest pain.

This case report describes a 32-year-old male who presented to an emergency department with severe chest pain and a history of cough, fever, night sweats, loss of appetite and weight. Chest radiography revealed a left upper lobe consolidation and multiple compression deformities in the thoracic spine. Magnetic resonance imaging demonstrated significant kyphosis and vertebral plana at two thoracic levels. Anterior compression of the spinal cord and adjacent soft tissue masses were also noted.

Osmolarity: a decisive parameter of bowel agents in intestinal magnetic resonance imaging.

The aim was to evaluate the importance of the osmolarity of different oral agents for bowel distension and the level of related adverse events. The longitudinal design included the exposition of different oral MR agents on two separate occasions. Four groups of volunteers were randomly given 350 ml gastrografin of three different concentrations and water. On the second occasion they received mannitol, iohexol or iodixanol with equivalent osmolarities, but the control group (water) received mannitol. We recorded the outcomes as the degree of bowel distension determined as the mean bowel section area and the total level of discomfort recorded from a visual analogue scale (VAS). The statistical analysis included scatter plots with the best-fitted line with linear regression to study the association between osmolarity and section area and the association between osmolarity and adverse events. A dose-response association was found between increasing osmolarity levels and bowel area in square centimeters (P = 0.00001). A similar dose-response association existed between increasing levels of osmolarity and adverse events (P = 0.001). Osmolarity appears to be more important for bowel distension than the physico-chemical characteristics of the nonabsorbable oral agents. The optimum osmolarity level is determined by the patient's tolerance of the adverse events.

Deforming lipoblastomatosis of the lower extremity.

OBJECTIVE: Lipoblastomatosis is a rare disorder in infants and children and nonexistent in adults. We discuss a case of a newborn child with lipoblastomatosis extensively involving the pelvis and lower extremities. The clinical and radiological characteristics of the disorder are discussed. CLINICAL FEATURES: A 2-month-old male had an enlarging deformity of the pelvis and lower extremities with progression of the condition from birth. There was no family history related to the disease. No other clinical abnormalities were present. INTERVENTION AND OUTCOME: Lipoblastomatosis is initially treated with surgical excision of the lipomatous neoplastic tissue. The postsurgical outcome is satisfactory; however, the likelihood of recurrence has been reported. CONCLUSION: We present the features of lipoblastomatosis, an uncommon disorder affecting infants and children. The clinical and radiologic manifestations of the disease are assessed with emphasis on magnetic resonance imaging.