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Radiology picture of the day

Radiology Picture of the Day — Sat, 30 Aug 2008 10:51:11 +0100

Due to a lack of submissions Radiology Picture of the Day has suspended new posts. Thank you to everyone who has submitted material in the past, and helped keep radpod going for so long. Please feel free to browse the archive. (Source: Radiology Picture of the Day)

Bilateral popliteal artery aneurysms

Radiology Picture of the Day — Wed, 20 Aug 2008 12:40:45 +0100

CTA of this patient shows bilateral popliteal artery aneurysms, patent on the left and thrombosed on the right. Popliteal artery aneurysms are the most common peripheral arterial aneurysm. They are usually true aneurysms resulting from atherosclerosis or arteriomegaly. False aneurysms may arise from knee trauma, surgery or infection. True aneurysms of the popliteal artery are commonly bilateral (50 to 70%) and frequently associated with abdominal aortic aneurysms (30 to 50% have a AAA). There is a strong male preponderance with a male to female ratio of 15:1. These aneurysms rarely rupture; the main complications are thrombosis and distal embolism. For this reason asymptomatic aneurysms greater than 2 cm diameter are considered for elective treatment with endovascular insertion of a covered stent, or with open surgical repair. Reference: Radiopaedia.org (Source: Radiology Picture of the Day)

Duodenal diverticulum draining ampulla of vater

Radiology Picture of the Day — Tue, 19 Aug 2008 12:00:51 +0100

This patient had biliary obstruction from a Klatskin tumour. On inserting a biliary drain from the left hepatic ductal system into the duodenum, the common bile duct was noted to drain into a duodenal diverticulum. On this image, it can be seen by following the course of the biliary catheter into the diverticulum. Duodenal diverticula are usually acquired pseudodiverticula and most arise along the concave border of the second or third parts of the duodenum. 75% arise within 2 cm of the ampulla of Vater and it is not uncommon for the ampulla to empty into the diverticulum. Insertion of the ampulla into a duodenal diverticulum is clinically important for several reasons. Firstly, it may cause difficulty with retrograde cannulation of ampulla during ERCP, or antegrade cannulation into the main duodenal lumen during percutaneous biliary intervention. Secondly, it is important to recognise if duodenal surgery is contemplated. Thirdly, stasis of duodenal contents within the diverticulum may cause partial obstruction of ampullary drainage, which is believed to predispose to biliary calculi, cholangitis and pancreatitis. References: 1. Medcyclopaedia.com 2. Schulze K. Review of duodenal diverticula, Radiology, 1992;183:554 (Source: Radiology Picture of the Day)

May-thurner syndrome

Radiology Picture of the Day — Sun, 17 Aug 2008 12:03:36 +0100

This patient presented with extensive left lower limb DVT that extended into the pelvis. CT abdomen/pelvis demonstrated compression of the left common iliac vein by the overlying right common iliac artery, consistent with May-Thurner syndrome. May-Thurner syndrome is deep venous thrombosis resulting from chronic compression of the left common iliac vein (CIV) against the lumbar vertebrae by the overlying right common iliac artery (CIA). Although both left and right CIVs lie deep to the right common iliac artery, the left CIV has a more transverse course and is predisposed to compression whereas the right CIV ascends more vertically and is therefore not similarly predisposed. First line treatment is with thrombolysis and stenting, which removes the clot and relieves the compression to prevent recurrence. Reference: Radiopaedia.org (Source: Radiology Picture of the Day)

Cerebellar haemangioblastoma

Radiology Picture of the Day — Tue, 12 Aug 2008 12:05:07 +0100

This coronal T1W post-gadolinium MR image shows a cystic cerebellar tumour with an enhancing mural nodule. The patient is a 20-year-old male. Pathologically-proven haemangioblastoma. Axial PD image shows prominent flow voids associated with the solid portion of the tumour, a frequent finding in haemangioblastoma. Also see these previous cases: case one; and case two. (Source: Radiology Picture of the Day)

Hyperparathyroidism

Radiology Picture of the Day — Tue, 05 Aug 2008 11:49:41 +0100

This patient had a long history of chronic renal failure. The plain x-ray of the hand shows typical changes of hyperparathyroidism, with resorption of subperiosteal bone on the radial side of proximal and middle phalanges of the 2nd and 3rd digits. This is most obvious in the proximal phalanx of the middle finger. (Source: Radiology Picture of the Day)

Facial colliculus syndrome

Radiology Picture of the Day — Sun, 03 Aug 2008 11:50:52 +0100

Constellation of neurological signs due to a lesion at the facial colliculus, involving * Abducens nerve (CN VI) nucleus * Facial nerve (CN VII) fibres at the genu * Medial longitudinal fasciculus and resulting in peripheral facial palsy and conjugate gaze palsy. The facial palsy is due to interruption of the ipsilateral facial nerve fibres at the genu as they arch behind the abducens nerve (CN VI) nucleus (thus forming the colliculus). The conjugate gaze palsy is due to involvement of innervation not only to the ipsilateral abducens nerve to lateral rectus, but also to the interneurons projecting into the medial longitudinal fasciculus which contribute to innervation of the contralateral medial rectus (thus coordinating conjugate gaze). This is not however always the case (this case), as you can see the dysconjugate gaze on the T2 FSE) Aetiology Causes of facial colliculs syndrome vary by age: * Young: o tumour o demyelination (e.g MS) o viral inection (e.g rhomboencephalitis) * Older: o vascular (e.g stroke - this case) References: D.A. Jacobsa and S.L. Galettaa “Neuro-Ophthalmology for Neuroradiologists” American Journal of Neuroradiology 28:3-8, January 2007 For more images of the case and many more, please visit Radiopaedia.org here. (Source: Radiology Picture of the Day)

Staphyloma

Radiology Picture of the Day — Wed, 30 Jul 2008 11:15:33 +0100

Staphyloma is the term given to an eye whose sclero-uveal coats are stretched (aka ectasia). This most commonly occurs posteriorly, athough anterior staphyloma also is recognised. Posterior staphyloma * progressive myopia (aka mega myope) most common cause. * glaucoma * scleritis * necrotizing infection * surgery / trauma * radiotherapy Anterior staphyloma Seen seconday to inflammation or infection of the sclero-corneal lining of the eye. References: 1. M Mafee, GE Valvassori, M Becker “Imaging of the Head and Neck” Thieme 2005 2nd Ed. 2. D Osborne, GN Foulks “Computed Tomographic Analysis of Deformity and Dimensional Changes in the Eyeball” Radiographics 1985; 153:699-674 For more on staphylomas please visit Radiopaedia.org here. (Source: Radiology Picture of the Day)

Endoleak

Radiology Picture of the Day — Tue, 29 Jul 2008 11:16:19 +0100

An endoleak is characterised by persistent blood flow within the aneurysm sac following endovascular aneurysm repair (EVAR). Normally the aortic stent-graft used in EVAR excludes the aneurysm from the circulation by providing a conduit for blood to bypass the sac. Endoleak is a common complication of EVAR found in up to 40% of patients. It is seen on CTA, MRA and DSA as contrast opacification of the aneurysm sac outside the graft. Flow in the sac may also be detected on ultrasound. When an endoleak occurs, flow within the aneurysm sac is at systemic or near-systemic pressure. If untreated, the aneurysm may expand and is at risk of rupture. Aneurysm expansion following EVAR always warrants investigation for endoleak. There are several causes of endoleak which are classified into 5 types as follows: Type I – leak at graft attachment attachment site. Type II – aneurysm sac filling via branch vessel (most common). Type III – leak through defect in graft. Type IV – leak through graft fabric as a result of graft porosity. Type V – continued expansion of aneurysm sac without demonstrable leak on imaging (endotension). Types II and IV usually resolve spontaneously. Type I and III do not, and require immediate treatment. Endoleak may become evident intra-operatively, or months or years later. Therefore life-long imaging surveillance is necessary, usually performed with CTA. References: 1. Rosen RJ & Green RM. Endoleak Management following Endovascular Aneurysm Repair, Journal of Vascular and Interventional Radiology, 2008;19:S37-S43 2. Kaufman J & Lee M, Vascular & Interventional Radiology The Requisites, Mosby 2004 (Source: Radiology Picture of the Day)

Hippocampal dnet

Radiology Picture of the Day — Mon, 28 Jul 2008 13:08:35 +0100

A DNET is a benign intracortical mass, typically multinodular in appearance, with a ‘bubbly appearance’. It coexists with an area of cortical dysplasia, and is characteristically the cause of intractable partial seizures. It demonstrates essentially no growth over time, although very gradual increase in size has been described. Location - hippocampal formation and amygdala (most common) - (see case 1) - caudate nucleus - septum pellucidum DDx Medial temporal lobe - Tumours (in order of decreasing frequency) - Ganglioglioma - low grade astrocytoma - Pleomorphic xanthoastrocytoma - Cysts - neuroepithelial cyst - choriod fissure cyst - Other - herpes simplex encephalitis - usually some bilateral changes, and different presentation. - limbic encephalitis- usually some bilateral changes, and different presentation. - mesial temporal sclerosis - cortical dysplasia References: - Neuroradiology: The Requisites - Brain: Diagnostic imaging by Osborn For more images of the same case please visit here. For more on DNET please visit Radiopaedia.org here. (Source: Radiology Picture of the Day)

Subcutaneous emphysema

Radiology Picture of the Day — Tue, 15 Jul 2008 16:01:16 +0100

This patient had severe COPD and presented with spontaneous pneumothorax and respiratory distress. CXR and CT showed severe pulmonary emphysema, bilateral pneumothoraces, pneumomediastinum and extensive subcutaneous emphysema. Subcutaneous emphysema, strictly speaking, refers to air in the subcutaneous tissues. But the term is generally used to describe any soft tissue emphysema of the body wall or limbs, since the air often dissects into the deeper soft tissue and musculature along fascial planes. Causes of subcutaneous emphysema can be divided into: - Air arising internally (eg. pneumothorax, pneumomediastinum, pulmonary interstitial emphysema, perforated hollow viscus in the neck, fistula tract) - Air introduced externally (eg. penetrating trauma, surgery, percutaneous intervention) - Air produced de novo (gas-producing infections) Clinically subcutaneous emphysema is felt as crepitus and, if extensive, it may cause soft tissue swelling and discomfort. The condition is typically benign and treatment is directed at the underlying cause, while the subcutaneous air is absorbed over time. However in rare instances treatment may involve release of the air by surgical division of the soft tissues or placement of catheters. References: 1. Medscape.com 2. Beck PL, et al. Simple Construction of a Subcutaneous Catheter for Treatment of Severe Subcutaneous Emphysema. Chest 2002;121:647-649 (Source: Radiology Picture of the Day)

Acquired dacrocystocoele

Radiology Picture of the Day — Mon, 14 Jul 2008 16:01:21 +0100

80 year-old female with intermittent swelling at the right inner canthus for two years. Axial CT images show well-defined cystic lesion with mild dilatation of the proximal nasolacrimal duct (NLD) - arrow. Two-D reformatted images show continuity of the cyst with the NLD. No history of trauma or surgery. Dacrocystocele: cystic dilatation of the nasolacrimal apparatus secondary to proximal or distal obstruction of the NLD. It may be congenital or acquired. Congenital lesions should be differentiated from the more serious nasoorbital cephalocele. Acquired lesions occur in adults with history of: - Prior accidental trauma (e.g. LeFort 2 fracture), - Previous NLD iatrogenic injury (e.g. Caldwell-Luc, uncinectomy), - Post inflammatory or neoplastic stenosis. Reference: Harnsberger, et al. Diagnostic Imaging: Head & Neck. 2004. Amirsys. (Source: Radiology Picture of the Day)

Appendicitis in pregnancy

Radiology Picture of the Day — Sun, 13 Jul 2008 16:01:58 +0100

Appendicitis during pregnancy is a relatively rare condition, though it is thought that the incidence is similar to that of the non-gravid population at approximately 1 in 1500 pregnancies. The majority of appendicitis in pregnancy occurs during the second trimester when they are difficult to diagnose both clinically and by imaging. The clinical presentation of appendicitis is usually typical in early pregnancy (right lower quadrant pain, nausea/vomiting) but becomes more non-specific with advancing pregnancy. As pregnancy progresses the appendix migrates cephalad towards the right costal margin and may lead to pain referred to this location. Due to the lack of specificity of the preoperative evaluation, the pathologic diagnosis of appendicitis is confirmed in only 30% to 50% of cases. Additionally, timely intervention is crucial as there the fetal loss rate approaches 40% for perforated appendicitis. Therefore, imaging plays an important role in timely and accurate diagnosis. Graded compression ultrasound is commonly the initial imaging modality employed. Helical CT is a viable alternative but is typically avoided secondary to the relatively high fetal radiation dose. MR is emerging as an alternative for those patients that have a equivocal or non-diagnostic ultrasound examination but with continued high clinical suspicion of appendicitis. Findings on MR are similar to those seen on CT. The appendix is fluid distended to greater than 6-7mm in diameter with surrounding peri-appendiceal mesenteric fat stranding. When present, the appendicolith is less well visualized than on CT or ultrasound. The management of appendicitis is similarly surgical, either by laparotomy or laparoscopy. The prognosis is similar to that of non-gravid patients. Esben Vogelius, MD Reference: 1. Pastore PA, Loomis DM, Sauret J. Appendicitis in Pregnancy. J Am Board Fam Med 2006;19(6):621-626. 2. Pedrosa I, et al. MR Imaging Evaluation of Acute Appendicitis in Pregnancy. Radiology 2006;238:891-899. (Source: Radiology Picture of the Day)

Vertebral artery dissection

Radiology Picture of the Day — Thu, 10 Jul 2008 12:02:07 +0100

This 32 year-old male presented with neck pain, vertigo and vomiting. The axial diffusion-weighted image (inset) shows restricted diffusion in the right cerebellum consistent with an infarct. The infarct is in the territory of the posterior inferior cerebellar artery. Note sparing of the lateral medulla (also PICA territory). The axial T1-weighted, fat-saturated image of the neck (main image), shows high signal in the location of the right vertebral artery (click image for arrow), consistent with dissection. Magnetic resonance angiography of the extracranial cerebral vessels (not shown) demonstrated reduced flow in the right vertebral artery. Cranial artery dissection may be due to: trauma or cervical manipulation; hypertension; migraine; vigorous physical activity (eg weightlifting); vasculopathy such as fibromuscular dysplasia or Marfan’s syndrome; or sympathomimetic drug abuse. Arterial dissection may also be idiopathic. The principle complications are stroke and transient ischaemic attack, due to embolisation of thrombus and to vessel narrowing. When there is intracranial extension, there may also be subarachnoid haemorrhage. Management is usually by anticoagulation to prevent thromboembolic complications. References: Osborn A. Diagnostic Neuroradiology. Mosby 1994. Grossman RI, Yousem DM. Neuroradiology: The Requisites. 2nd edition. Mosby 2003. (Source: Radiology Picture of the Day)

Chiari i malformation

Radiology Picture of the Day — Tue, 08 Jul 2008 12:42:04 +0100

This patient presented with headaches on coughing or sneezing. The sagittal T2-weighted image above shows a typical Chiari type I malformation, with peg-like tonsils descending well below the foramen magnum. In this case there is no cervical cord syrinx, a common association. This video shows a time-resolved phase-contrast CSF flow study. It is short, and best appreciated by setting ‘repeat’ on your viewer. Movement is shown as either white or black, depending on direction. Stationary structures are grey. The normal pulsatile movement of CSF around the cord is shown. CSF movement in the prepontine cistern is somewhat attenuated. Flow in the 4th ventricle and aqueduct is markedly attenuated. Of note, the cerebellar tonsils are seen to dephase (move) during the cardiac cycle. (Source: Radiology Picture of the Day)

Dehiscent lamina papyracea

Radiology Picture of the Day — Sun, 06 Jul 2008 16:01:27 +0100

Brain MRI was requested for this 45 YO patient with diplopia to rule out multiple sclerosis. Axial & coronal images show focal dehiscence of the left lamina paprycea with focal herniation of orbital fat into ethmoid sinus (arrows). The medial rectus muscle has slight irregular contour. No previous history of trauma or surgery. Dehiscence of the lamina paprycea may be congenital or acquired (after trauma or surgery). The characteristic feature of dehiscence is a bony defect in the medial orbital wall or an inward displacement of the wall into the ethmoidal complex. The orbital fat and the medial rectus muscle often protrude through this gap into the ethmoidal bulla, which is usually small in size. Other orbital structures like optic nerve or even the globe itself may herniate. Clinical relevance: this abnormality when recognized should be reported to otolaryngologists to avoid possible complications e.g. perforation of the orbital wall and damage to the globe & extra-ocular muscles during FESS (Functional Endoscopic Sinus Surgery). Reference: Makariou et al. Dehiscence of the lamina papyracea: MRI findings. Case Report. Clinical Radiology Extra (2004) 59. (Source: Radiology Picture of the Day)

Cisterna chyli

Radiology Picture of the Day — Thu, 03 Jul 2008 12:29:01 +0100

83 male had a CT for follow-up of gastrointestinal stromal tumour. A low-density structure (arrow) is seen in a right retrocrural location, adjacent to the azygous vein (curved arrow). While this might be mistaken for lymphadenopathy, it could be followed superiorly to a thin vascular structure in the posterior mediastinum. The retrocrural structure represents the cisterna chyli, and its continuation in the thorax is the thoracic duct. Not normally seen on CT, it is however a normal structure, and should be recognised as such. The cisterna chyli drains lymph from the abdomen - a variable number of intestinal and lumbar lymph trunks. Under cover of the right crus is its typical location, in front of the bodies of L1 and L2. The thoracic duct commences at the upper end of the cysterna chyli, at the T12 level. It inclines to the left as it ascends, passing behing the oesophagus. At the left lung apex it arches forward over the dome of the pleura to enter the confluence of left subclavian and internal jugular veins. Reference: McMinn RMH. Last’s Anatomy. 9th edition. Churchill Livingstone. 1994. (Source: Radiology Picture of the Day)

Ganglioglioma of the optic nerve

Radiology Picture of the Day — Wed, 02 Jul 2008 13:44:30 +0100

This patient presented with gradual decrease in vision, and partial excision confirmed a ganglioglioma of the optic nerve. Gangliogliomas are a low grade tumour (WHO Grade I or II) which typically occur in the temporal lobes of young patients and present with temporal lobe epilepsy. 80% of cases are found in (Source: Radiology Picture of the Day)

Post-intubation tracheal stenosis

Radiology Picture of the Day — Tue, 01 Jul 2008 04:27:13 +0100

This road traffic accident victim was intubated (endotracheal tube) for 2 weeks. He developed dyspnea and stridor following extubation. CT scan shows upper tracheal stenosis. Axial images show circumferential irregular granulation tissue internal to normal appearing tracheal ring. 3D external rendering shows location and length of the stenosis. 3D internal rendering “virtual endoscopy” shows the upper orifice of the stenosis (long arrow) distal to vocal cords (short arrows). Post-intubation stenosis may be acute or chronic: Acute: results from edema of the tracheal wall or intraluminal granulation tissue (as in present case). Dynamic imaging shows little change in tracheal dimensions. Chronic: results from fibrosis with deformity of tracheal cartilage. CT scan shows deformity of the tracheal cartilage or posterior tracheal membrane with absent or mild thickening of mucosa & submucosa. Dynamic imaging may show tracheomalacia. Reference: Webb R and Higgins B: Thoracic imaging: The trachea. Lippincott Williams & Wilkins 2005. (Source: Radiology Picture of the Day)

Rathke’s cleft cyst

Radiology Picture of the Day — Mon, 30 Jun 2008 12:17:14 +0100

Rathke’s cleft cyst is a non-neoplastic epithelium-lined cyst arising from the embryologic remnants of Rathke’s pouch. On imaging it is a well-defined non-enhancing midline cyst in the sellar region, arising between the anterior and intermediate lobes of the pituitary. 40% are purely intrasellar and 60% have suprasellar extension. Purely suprasellar lesions are rare. On CT it is typically non-calcified and of homogenous low density. Uncommonly it may be of mixed isodensity and low density, or contain small curvilinear calcifications in the wall. On MRI the signal characteristics vary according to the cyst content which may be mucoid or serous. On T1, 50% are hyperintense and 50% are hypointense. On T2, 70% are hyperintense and 30% are iso or hypointense. 70% have a small non-enhancing intracystic nodule consisting of mucinous material; this feature is virtually pathognomic of a Rathke’s cleft cyst. There is no contrast enhancement of the cyst but a thin enhancing rim of adjacent compressed pituitary tissue may be seen. The main differential differential diagnoses are craniopharyngioma, cystic pituitary adenoma and other non-neoplastic cysts such as an arachnoid cyst or epidermoid cyst. Rathke’s cleft cysts are typically asymptomatic and are found in up to 1/3 of autopsies. If large, they may cause visual disturbance due to compression of the optic chiasm or pituitary dysfunction due to compression of adjacent pituitary tissue. References: 1. Osborn A. & Preece M. Intracranial Cysts: Radiologic-Pathologic Correlation and Imaging Approach, Radiology 2006; 239:650-664 2. StatDx 3. eMedicine.com (Source: Radiology Picture of the Day)

Ependymal cyst

Radiology Picture of the Day — Fri, 27 Jun 2008 08:15:57 +0100

This 53-year-old patient presented with headaches. CT and MRI demonstrated a large non-enhancing thin-walled cyst following CSF signal in the lateral and 3rd ventricles, causing obstructive hydrocephalus. Histology of the excised lesion confirmed an ependymal cyst. Ependymal cysts are benign neuroepithelial cysts lined by ependymal cells, thought to arise from sequestration of developing neuroectoderm during embryogenesis. They are thin-walled and contain clear serous fluid secreted by the lining ependyma. They are most commonly intraventricular, typically in the lateral ventricles, but rarely may be found in the periventricular white matter or subarachnoid spaces. Most are small and asymptomatic. On imaging they are well-defined, thin-walled and do not contrast enhance. On CT they are isodense to CSF. On MRI they follows CSF signal on all sequences and do not demonstrate diffusion restriction. Occasionally the cyst may be hyperintense to CSF if there is a high protein content. The main differential diagnoses, which may be difficult to distinguish, are intraventricular arachnoid cyst and asymmetric ventricles. Other diagnoses to consider, although they have distinguishing features, are choroid plexus cyst, epidermoid cyst, neurocysticercosis and porencephalic cyst. References: 1. Osborn A. & Preece M. Intracranial Cysts: Radiologic-Pathologic Correlation and Imaging Approach, Radiology 2006; 239:650-664 2. StatDx (Source: Radiology Picture of the Day)

Secondary hyperparathyroidism

Radiology Picture of the Day — Thu, 26 Jun 2008 03:30:19 +0100

Plain X-ray hands of a young patient with CRF shows signs of secondary hyperparathyroidism (HPTH): -Irregular, frayed and ill-defined cortical outline, pronounced at radial aspect of middle phalanges –> subperiosteal bone resorption -Multiple lytic expansile lesions –> brown tumors (arrows) -Osteosclerosis -Accentuated trabecular pattern (non essential trabeculae are resorbed; those that remain appear prominent). Renal osteodystrophy: - Constellation of musculoskeletal abnormalities that occur in patients with CRF. Manifestations include: -Osteomalacia (adults) / rickets (children). -Secondary HPTH: bone resorption, osteosclerosis, soft tissue & vascular calcifications and brown tumors. -Aluminum intoxication if the patient is on dialysis (beyond description here). Comment: Subperiosteal bone resorption is the hallmark of HPTH and is first identified in hands. References: 1. Manaster B.J.: Handbook of skeletal radiology: Trauma 1997. Mosby. 2. Youchum and Rowe’s: Essentials of Skeletal Radiology 2005. Lippincott, Williams & Wilkins (Source: Radiology Picture of the Day)

Thrombosed prosthetic tricuspid valve in ebsteins anomaly

Radiology Picture of the Day — Thu, 19 Jun 2008 16:01:33 +0100

A 68-year-old woman with known Ebstein’s anomaly (EA) was admitted for the investigation of progressive breathlessness, reduced exercise tolerance (NYHA grade 2) and increasing leg swelling. On the current admission, a 64-slice coronary CT was undertaken to exclude hemodynamicaly significant coronary disease. Thrombus was identified lodged between the medial valve flap and the valve ring. Multiphasic cine CT throughout the cardiac cycle demonstrated immobility of the tricuspid valve leaflets. Ebstein’s anomaly is a rare congenital cardiac malformation characterized by apical displacement of the septal and posterior tricuspid leaflets, resulting in atrialization of the right ventricle. Medical management includes treatment for heart failure and complex cardiac arrhythmias. Surgical tricuspid valve repair is undertaken in severe cases of tricuspid regurgitation. Recent technical advances in cardiac CT, using retrospective ECG-gated image reconstruction, have allowed evaluation of both native and prosthetic cardiac valves. In the current case, echocardiography was unable to clearly depict the precise etiology for the malfunctioning valve, which was subsequently diagnosed as thrombus-related using cardiac CT. (Source: Radiology Picture of the Day)

Hyperostosis frontalis interna

Radiology Picture of the Day — Wed, 18 Jun 2008 16:01:00 +0100

Hyperostosis frontalis interna is characterised by benign overgrowth of the inner table of the frontal bone. It is seen most commonly seen in older females. The aetiology is unknown. The condition is generally of no clinical significance and an incidental finding. It is typically bilateral and symmetrical, and may extend to involve the parietal bones. It may also diffusely involve the skull, a variant known as hyperostosis calvariae diffusa. The skull thickening may be sessile or nodular, and may affect the bone in a focal or diffuse manner. Other differential diagnoses for focal skull thickening include Paget’s disease, fibrous dysplasia, metastases and meningioma. Reference: 1. Medcyclopaedia.com 2. Radiopaedia.org (Source: Radiology Picture of the Day)

Lipohaemarthrosis

Radiology Picture of the Day — Tue, 17 Jun 2008 11:23:55 +0100

This knee x-ray shows a comminuted intra-articular tibial plateau fracture and a fat-fluid level in the suprapatellar pouch consistent with a lipohaemarthrosis. Lipohaemarthrosis results from an intra-articular fracture when fat and blood from the bone marrow is extruded into the joint space. It is most commonly seen in the knee but has also been described in the shoulder, elbow and hip. On x-ray the fat-fluid level is seen with a horizontal beam. The fat-fluid level may also be detected with ultrasound, CT or MRI. A lipohaemarthrosis is significant because it indicates the presence of an intra-articular fracture - if a fracture is not seen on x-ray, further imaging is required. Reference: Costa DN et al. Sonographic and CT Findings in Lipohemarthrosis. American Journal of Roentgenology 2007;188:W389 (Source: Radiology Picture of the Day)

Congenital lobar emphysema

Radiology Picture of the Day — Sun, 15 Jun 2008 16:01:12 +0100

The right middle lobe is hyperlucent, hyperexpanded with attenuated vascularity. It compresses adjacent parenchyma with RUL collapse. CLE is a disorder affecting neonates and young infants and is usually associated with acute or subacute respiratory distress. Various bronchial and alveolar abnormalities can cause this disorder and in some cases the cause is unknown. The most common detected abnormality is absence or hypoplasia of cartilage rings of major and branch bronchi with resultant bronchial collapse during exhalation. This results in inhalational air entry but collapse of the narrow bronchial lumen during exhalation. The bronchial obstruction leads to progressive hyperinflation and air trapping, usually involving only one pulmonary lobe. CLE has two forms: hypoalveolar (fewer than expected number of alveoli) and polyalveolar (greater than expected number of alveoli). Reference: Collins & Stern: Chest Radiology: The Essentials: 2008. Lippincott Williams & Wilkins (Source: Radiology Picture of the Day)

Perimesencephalic haemorrhage

Radiology Picture of the Day — Thu, 12 Jun 2008 13:12:12 +0100

Perimesencephalic haemorrhage is a distinct type of subarachnoid haemorrhage confined to the basal cisterns around the midbrain (typically the interpeduncular and prepontine cisterns). 95% of cases have a normal cerebral angiogram and the source of bleeding is not identified; the cause is thought to be a venous bleed. In these cases rebleeding and ischaemia are rare and the prognosis is excellent. The other 5% of cases are due to a vertebrobasilar aneurysm and the prognosis is worse. References: 1. Van der Schaaf IC, et al. Venous Drainage in Perimesencephalic Hemorrhage. Stroke 2004;35:1614-1618 2. Birgitta K, et al. Perimesencephalic Hemorrhage: Exclusion of Vertebrobasilar Aneurysms With CT Angiography. Stroke 1999;30:1103-1109 (Source: Radiology Picture of the Day)

Diverticulosis

Radiology Picture of the Day — Wed, 11 Jun 2008 11:50:49 +0100

This patient had a recent barium enema which resulted in barium impaction in numerous colonic diverticula. Barium impacted in diverticula often persist for weeks or months, and sometimes for years. This property has been exploited in at least one known case to treat refractory colonic diverticular bleeding using barium impaction therapy. Inspissated barium may also form a barolith which is a rare cause of bowel obstruction. References: 1. Matsuhashi N. et al, Barium Impaction Therapy for Refractory Colonic Diverticular Bleeding, American Journal of Roentgenology 2003; 180:490-492 2. Chapman A. & El-Hasani S., Colon ischaemia secondary to barolith obstruction, The British Journal of Radiology, 1998; 71:983-984 (Source: Radiology Picture of the Day)

Acl ganglion cyst

Radiology Picture of the Day — Mon, 09 Jun 2008 16:01:03 +0100

Along with ganglion cysts arising from the alar folds that cover the infrapatellar fat pad, ACL ganglion cysts (also commonly referred to simply as ACL cysts) make up the vast majority of intra-articular ganglion cysts of the knee. These are uncommon findings, with the prevalence of ACL ganglion cysts has been reported to be between 0.3 - 1.3% of knee MRIs, and are usually incidental findings. Knee pain, benign the most common presenting complaint, is usually attribuatable to other pathology. ACL ganglion cysts are histologically identical to the ganglion cysts seen elsewhere, most commonly around the wrist. The pathogenesis remains controversial with two theories being favoured: 1. sequelae of ACL mucoid degeneration 2. herniation of synovial tissue through a defect in the joint capsule or tendon sheath MRI is better at detecting these lesions than standard anterior portal approach arthroscopy as the surface of the ligament is often intact. In fact the ligament may appear entirely normal . A posterior approach will allow the arthroscopist to detect changes by probing the ligament, and will allow potential aspiration of the cysts. Typically the cysts appear as regions of high T2 signal, often multiloculated, centred on the distal ACL. Often there is some irregularity to the bone subjacent to the tibial attachment. References - Resnick and Kransdorf “Bone and Joint Imaging” 3rd Edition, Elsevier - D Bergin et al “Anterior Cruciate Ligament Ganglia and Mucoid Degeneration: Coexistence and Clinical Correlation” AJR 2004; 182:1283-1287 - CC Roberts et al “Advanced MR Imaging of the Cruciate Ligaments” Magn Reson Imaging Clin N Am 15 (2007) 73–86 (Source: Radiology Picture of the Day)

Gallbladder adenomyomatosis

Radiology Picture of the Day — Sun, 08 Jun 2008 16:01:20 +0100

Adenomyomatosis is a benign hyperplastic condition of the gallbladder consisting of hyperplasia of the gallbladder wall with hernation of mucosal epithelium into the wall. The latter results in intramural diverticula lined by epithelium, also known as Rokitansky-Aschoff sinuses. Cholesterol crystals, sludge or stones often precipitate within the bile trapped within these sinuses. Adenomyomatosis may involve the gallbladder diffusely but is usually focal, most commonly in the fundus. Ultrasound often demonstrates non-specific gallbladder wall thickening. Small echogenic foci within the wall with V-shaped comet tail artefact, as shown in this case, represents cholesterol crystals within the Rokitansky-Aschoff sinuses. This finding, when present, is highly specific for gallbladder adenomyomatosis. Hyperechoic sludge and stones may also be seen within the sinuses in the wall. Contrast-enhanced CT and MRI may show abnormal gallbladder wall thickening and enhancement, but this also has a differential diagnosis including polyposis, adenoma and carcinoma. However, if the Rokitansky-Aschoff sinuses are of sufficient size, they may be seen as cystic spaces within the thickened wall which suggests the diagnosis. Gallbladder adenomyomatosis is usually an asymptomatic incidental finding but may rarely cause abdominal pain. There is no malignant potential. Reference: Boscak AR et al, Gallbladder adenomyomatosis, Radiographics 2006;26:941-946 (Source: Radiology Picture of the Day)

Diastematomyelia

Radiology Picture of the Day — Thu, 05 Jun 2008 16:01:16 +0100

This patient presented in her 40s for assessment of possible metastatic malignancy. An incidental finding of diastematomyelia was made. There was associated fusion anomaly of vertebrae at the thoracolumbar junction. A small syrinx was present above the cord split. At the level shown, the cord is split into two hemicords, and divided by a fibrous or osseous spur. Diastematomyelia is associated with congenital spinal deformity in 85%, including segmentation anomalies, laminar fusion, dysraphism, tethered cord, thickened filum terminale, and scoliosis. There is an association with Chiari II malformation. Diastematomyelia may be classified as type I (two separate dural sacs surround each hemicord) or type II (single dural sac and arachnoid space, no osseus spur). Reference: Ross JS, et al. Diagnostic Imaging: Spine. Amirsys 2004 (Source: Radiology Picture of the Day)

Acl mucoid degeneration

Radiology Picture of the Day — Wed, 04 Jun 2008 16:01:41 +0100

Along with tears and anterior cruciate ligament ganglion cysts, mucoid degeneration is a relatively common cause of increased signal within the ACL. The appearance can mimic that of acute or chronic interstitial partial tears of the ACL, however in the case of mucoid degeneration secondary signs of ACL injury are usually absent. Secondary signs include: bone bruising, meniscal tears, anterior subluxation of the tibia, and other ligament injuries. Typically patients present with knee pain, or restricted movement, although often other potential causes for the patient’s symptoms are found. The pathogenesis remains controversial. Possible aetiologies include: - age related (senescent) degeneration, - congenital or acquired synovial tissue entrapment between ACL fibers It is postulated that mucoid degeneration may be a predisposing factor to the formation of ACL ganglion cysts. On MRI the ligament is thickened, and ill-defined with a “celery stalk” appearance. It’s signal is increased on all sequences.Intact fibres are best seen on T2 weighted sequences. On arthroscopic examination the ligament is mechanically intact, but mucoid material can be expressed by probing. MRI is better at detecting mucoid degeneration than arthroscopy as the surface of the ligament is often intact. In fact the ligament may appear entirely normal especially using the standard anterior portal approach. A posterior approach will allow the arthrosopist to detect changes by probing the ligament. This is also true of ACL ganglion cysts. References - CC Roberts et al “Advanced MR Imaging of the Cruciate Ligaments” Magn Reson Imaging Clin N Am 15 (2007) 73–86 - D Bergin et al “Anterior Cruciate Ligament Ganglia and Mucoid Degeneration: Coexistence and Clinical Correlation” AJR 2004; 182:1283-1287 - Resnick and Kransdorf “Bone and Joint Imaging” 3rd Edition, Elsevier - P Papadopoulou “The Celery Stalk Sign” Radiology 2007;245:916-917 (Source: Radiology Picture of the Day)

Discitis

Radiology Picture of the Day — Tue, 03 Jun 2008 11:41:33 +0100

This 29 year old IV drug abuser attended his local A & E with back pain. This was centred at the L2 level on clinical examination. The lumbar spine films shows: 1. Loss of height of L1/L2 joint space 2. Endplate sclerosis 3. Indistinct endplates These early changes may progress to destruction and fusion. IV drug abusers are a classical group for discitis as bloodborne bacteria enter the vertebra and cross via small vessels into the disc. Reference: Dahnert W. Radiology Review Manual (Source: Radiology Picture of the Day)

Lipoma of the filum terminale

Radiology Picture of the Day — Mon, 02 Jun 2008 11:14:40 +0100

Fat in the filum terminale is not an infrequent occurence, seen in 4 - 6%, and is usually easily detected on MRI (especially T2* sequences, as a result of chemical shift artefact). It is usually an incidental finding of no clinical concern. In some individuals however it is associated with spinal dysraphism, thickening of the filum terminale (>3mm) and tethering of the spinal cord. Imaging findings: CT: If large enough then fat density (-90 to -30HU) can be seen below the level of the conus. If small, and depending on the quality of the CT scanner, the size of the patient, and the amount of quantum mottle, it may be inapparent. MRI: Signal follows that of fat. - hyperintense on T1 and T2 FSE - saturates on fat saturation sequences - demonstrates chemical shift artefact - no enhancement. Differential diagnosis: There is little DDx when the presence of fat is confirmed, however other filum terminale lesions can be considered only to be eliminated. References 1. E Brown et al “Prevalence of incidental intraspinal lipoma of the lumbosacral spine as determined by MRI.” Spine. 1994 Apr 1;19(7):833-6. 2. K Koeller et al “Neoplasms of the Spinal Cord and Filum Terminale: Radiologic-Pathologic Correlation” RadioGraphics 2000; 20: 1721-1749. 3. JM Provenzale et al “Duke Radiology Case Review: Imaging, Differential” Published 1997 Lippincott Williams & Wilkins ISBN:0397516134 (Source: Radiology Picture of the Day)

Congenital diaphragmatic hernia

Radiology Picture of the Day — Thu, 29 May 2008 16:01:01 +0100

This coronal obstetric ultrasound (head to right of image, thorax centre, abdomen left) shows the stomach and heart both within the thorax. The diaphragm can be seen as a vertical curved echogenic line separating abdomen and thorax. The heart is displaced to the foetus’ right. Congenital diaphragmatic hernia is due to failure of fusion of one of the pleuroperitoneal canals at around 8 weeks gestation. It is more common on the left (75-90%). The hernia may contain stomach, intestines, liver or spleen. CDH detected antenatally are often large, and perinatal mortality may be as high as 80%. Mortality is predominantly due to pulmonary hypoplasia, thought to be due to mass effect on the developing lung. The sonographic findings of CDH are: cardiomediastinal shift; stomach at same transverse level as heart; and portal veins in thorax (Doppler). CDH should be included in the differential diagnosis of right thoracic mass, as liver may simulate cystic adenomatoid malformation or pulmonary sequestration. Signs suggesting a poor prognosis are: large size; early gestational age at diagnosis; intrathoracic liver; small contralateral lung; associated abnormalities; and bilateral CDH. Lung-head ratio (2 axial diameters of lung multiplied, and divided by head circumference) may be used to give an indication of pulmonary hypoplasia. LHR < 1.0 is associated with a poor prognosis, and >1.4 a good prognosis. Foetal MRI may be helpful in further assessing the hernia and associated pulmonary hypoplasia. Foetuses with an antenatal diagnosis of CDH should be delivered in a tertiary referral centre with access to neonatal intensive care and paediatric surgical facilities. Reference: Callen PW. Ultrasonography in Obstetrics and Gynaecology. 4th edition. WB Saunders, 2000 (Source: Radiology Picture of the Day)

Invasive pulmonary fungal infection

Radiology Picture of the Day — Wed, 28 May 2008 16:01:10 +0100

Sagittal reformat from a CT scan of the chest, performed on a 14 year-old female with acute myeloblastic leukaemia. The image shows a rounded cavity in the apical right upper lobe, with a non-dependant soft-tissue nodule within it. There is some subtle ground-glass opacity surrounding the lesion. There were several other similar lesions in the right lung (not shown). The imaging features, combined with the clinical history, are characteristic of invasive fungal infection, most commonly due to Aspergillus spp.. Care should be taken to avoid confusion with mycetoma, which occurs in patients with pre-existing lung cavities, is gravity-dependant, and lacks the ground-glass halo. Invasive aspergillosis occurs in immunosuppressed individuals and carries a 65-90% mortality rate if improperly treated. Cavitation occurs in the recovery phase, and thus tends to indicate a better prognosis. Reference: Abramson S. The Air-Crescent Sign. Radiology. 2001; 218:230-232 (Source: Radiology Picture of the Day)

Hypothalamus

Radiology Picture of the Day — Tue, 27 May 2008 16:01:27 +0100

The hypothalamus is the location of many specific lesions as well as hosting more traditional lesions. (a relatively comprehensive list is located here). Its anatomy is to many of us somewhat mysterious. As the name would suggest, below the thalamus, and is intimately associated with both the limbic system and the pituitary gland. Boundaries Its boundaries are in some places poorly defined (outlined in blue in this figure) - Anterior: Lamina terminalis, with optic chiasm at its lower border and anterior commissure above. - Superior: an imaginary line drawn between the anterior and posterior commissures. - Posterior: an imaginary line sloping antero-inferiorly from the posterior commissure to the mamillary bodies. - Inferior (floor): infundibular stalk, tuber cinereum and mamillary bodies (from front to back) For more details about fiber tracts and nuclei please visit the brand new Radiopaedia.org here. References: 1. SN Saleem et al “Lesions of the Hypothalamus: MR Imaging Diagnostic Features” RadioGraphics 2007;27:1087-1108 2. HJ Kretschmann and W Weinrich “Cranial neuroimaging and clinical neuroanatomy” 3rd edition Thieme 3. RajMohan V, Mohandas E. The limbic system. Indian J Psychiatry 2007;49:132-9 (Source: Radiology Picture of the Day)

Craniopharyngioma

Radiology Picture of the Day — Mon, 26 May 2008 16:01:54 +0100

Craniopharyngiomas are derived from remnants of the craniopharyngeal duct (narrowing which separates Rathke’s pouch from the primitive oral cavity), and can occur anywhere along the infundibulum (from floor of the third ventricle, to the pituitary gland). There is a bimodal distribution, with the first peak between the ages of 10 - 14 years and the second peak in the 7th decade. There are two main types of craniopharyngiomas: * adamantinomatous (paediatric) * papillary (adult) ( … read more ) MRI Imaging findings depend on the histological subtype and on the size and content of the cysts. T1 signal intensity varies depending on cyst contents, and can appear hyperintense due to protein, blood products, and/or cholesterol (in the classic adamantinomatous type). In the papillary variety, solid components appear isointense on T1-weighted images. Contrast enhancement is typical, with either thin enhancement of the cyst wall, or diffuse heterogeneous enhancement of the solid components. T2 signal is high in both solid and cystic components, but is variable depending on content of fluid. On T2* weighted sequences calcification may be seen as areas of signal drop out and blooming. For more images of this case please visit the brand new Radiopaedia.org here. References: 1. Atlas SW, ed: Magnetic Resonance Imaging of the Brain and Spine. 2nd ed. Lippincott-Raven; 1995: 894-8. 2. SN Saleem et al “Lesions of the Hypothalamus: MR Imaging Diagnostic Features” RadioGraphics 2007;27:1087-1108 3. eMedicine.com - craniopharyngioma (Source: Radiology Picture of the Day)

Fibrolipomatous hamartoma

Radiology Picture of the Day — Sun, 25 May 2008 16:01:19 +0100

MR imaging demonstrates fusiform median nerve enlargement which is caused by thickening of nerve bundles and fatty and fibrous proliferation. The serpiginous low-intensity structures represent thickened nerve fascicles, surrounded by evenly distributed fat of high signal intensity on this T1-weighted image. A spaghetti-like appearance is seen in the coronal plane. The median nerve is the most commonly involved nerve The MR imaging characteristics of fibrolipomatous hamartoma are pathognomonic, obviating the need for biopsy for diagnosis. Reference: Jain TP, et al. Fibrolipomatous hamartoma of median nerve. Australasian Radiology. 51 Supplement 2:B98-B100, October 2007. (Source: Radiology Picture of the Day)

Pott’s disease

Radiology Picture of the Day — Thu, 22 May 2008 11:58:57 +0100

Explanation: Pott’s disease, or tuberculous spondylitis, is named after Percivall Pott. Discitis caused by the tuberculosis organism, Mycobacterium tuberculosis progresses to involve the vertebral bodies, and eventually extends beyond the spine. The radiological findings in this case are - loss of disc height - sclerosis and irregularity of adjacent end-plates - loss of height of the lower vertebral body - paravertebral soft tissue mass (Source: Radiology Picture of the Day)

Extralobar sequestration

Radiology Picture of the Day — Tue, 20 May 2008 11:52:27 +0100

Explanation: Bronchopulmonary sequestration is a congenital malformation resulting from abnormal budding of the foregut, characterised by disorganised pulmonary parenchyma without normal pulmonary arterial or bronchial communications. Sequestration may be intralobar or extralobar (as in this case). Extralobar sequestrations have their own pleural covering, and venous drainage is systemic (to the azygous system in this case). Ninety percent of extralobar sequestrations are at the left base, contiguous with the diaphragm. Radiographically an extralobar sequestration usually appears as a homogeneous mass lesion. Antenatal ultrasound may identify the mass. Identification of the vascular connections is critical in making the diagnosis. References: Webb WR, Higgins CB Thoracic Imaging, Lippincott, Williams & Wilkins, 2005. (Source: Radiology Picture of the Day)

Lisfranc fracture-dislocation

Radiology Picture of the Day — Sun, 18 May 2008 16:01:01 +0100

Napoleon’s surgeon Lisfranc’s name is given to this fracture-dislocation of the midfoot. Lisfranc injuries are of 2 types: 1. Homolateral (shown): lateral dislocation of metatarsals 1-5 or 2-5. 2. Divergent: lateral dislocation of metatarsals 2-5 and medial dislocation of the first metatarsal. Cuniform and base of metatarsal fractures are often associated. Commonest contemporary causes are: 1. Road traffic accident 2. Diabetes - a manifestation of a neuropathic joint (this case) Reference: Primer of Diagnostic Imaging. Weissleder et al. p407 (Source: Radiology Picture of the Day)

Retrocaecal appendicitis

Radiology Picture of the Day — Fri, 16 May 2008 09:56:37 +0100

This 36 year-old male presented with right loin-to-groin pain, and was thought to have renal colic despite absence of blood in the urine. A CT KUB was performed, and the sagittal image above shows the typical features of acute appendicitis. There are two appendicoliths in this retrocaecal appendix, a markedly distended lumen (appendix diameter 17mm, normal (Source: Radiology Picture of the Day)

Melas

Radiology Picture of the Day — Thu, 15 May 2008 01:45:05 +0100

This diffusion-weighted MR image shows cortical ribbon-like high signal consistent with diffusion restriction in a patient with known MELAS and an acute presentation with confusion and focal neurological deficit. Mitochondrial myopathy, lactic acidosis and stroke (MELAS) is a genetic mitochondrial disorder. It may be sporadic or familial via the maternal line. Patients often present with sudden-onset global or focal neurological deficits. Other presentations include migraines and seizures. There is typically an associated proximal myopathy. During attacks restricted diffusion may be present in cortex, subcortical white matter, and basal ganglia. High T2 signal may also be present in these locations, and there may be nonspecific periventricular and deep white matter high signal in addition. T2 signal changes may persist, and encephalomalacia can be seen in previously affected areas. Proton MR spectroscopy will often demonstrate elevated lacate in apparently unaffected brain, and in CSF. Reference: Lin DDM, Crawford TO and Barker PB. Proton MR spectroscopy in the diagnostic evaluation of suspected mitochondrial disease. AJNR 2003;24:33-41 (Source: Radiology Picture of the Day)

Leptomeningeal haemosiderosis

Radiology Picture of the Day — Tue, 13 May 2008 16:01:28 +0100

This patient presented with bilateral sensorineural hearing loss and dizziness. The axial T2-weighted MR image above shows signal loss over the cerebellar folia, a characteristic finding in leptomeningeal (a.k.a. superficial) haemosiderosis. Leptomeningeal haemosiderosis typically presents with hearing loss and vestibular dysfunction as the vestibulocochlear nerve is particularly sensitive to it. Presentation may be with other cranial neuropathies, or cerebellar dysfunction. The condition may also be asymptomatic. The aetiology is considered to be repeated subarachnoid haemorrhages, and a search for a source is indicated. This should include spinal MR. Amyloid angiopathy has been described as a cause. Reference: Linna J, et al. Subarachnoid hemosiderosis and superficial cortical hemosiderosis in cerebral amyloid angiopathy. AJNR 2008;29:184-186 (Source: Radiology Picture of the Day)

Tuberculosis of the spine

Radiology Picture of the Day — Sun, 11 May 2008 16:01:09 +0100

Extradural and paraspinal mass in patient with tuberculous discitis with resultant destruction of the disc and extension into the adjacent vertebral bodies. Subligamentous spread of disease is typical and evident on this image. Due to the local destruction there is resultant gibbus deformity of the thoracic spine. There is also spinal stenosis at the level in question by the extradural cold abcess. Tuberculous spondylitis is also called Pott’s disease of the spine (Source: Radiology Picture of the Day)

Sickle cell anaemia

Radiology Picture of the Day — Thu, 08 May 2008 16:01:29 +0100

Sickle cell anaemia is an autosomal recessive genetic disease leading to production of a defective form of haemoglobin, haemoglobin S (HbS) causing sickle shaped erythrocytes. The major consequence of these sickled erthrocytes is that they much less deformable causing obstruction in the microcirculation. Manifestations in the spleen include splenomegaly in childhood, with splenic infarction and autosplenectomy in adults. Skeletal manifestations include avascular necrosis of the femoral head and H -shaped vertebrae. This AXR shows massive splenomegaly and bilateral femoral head AVN. Reference: eMedicine (Source: Radiology Picture of the Day)

Cervical incompetence

Radiology Picture of the Day — Wed, 07 May 2008 16:01:35 +0100

A sagittal transvaginal ultrasound image of the cervix at 21 weeks gestation shows funnelling of the proximal cervix, and reduction of the functional length to 10mm. Cervical incompetence is variably defined, however a cervical length of (Source: Radiology Picture of the Day)

Retained surgical sponge

Radiology Picture of the Day — Tue, 06 May 2008 16:01:16 +0100

Gossypiboma is the name given to a retained surgical sponge, pad, or towel (gossypium (Latin), cotton; + plboma (Swahili), place of concealment). Retained foreign bodies can cause either an acute inflammatory response or a chronic fibrinous response and so there is a very wide variation in the time course in which they are discovered, as evidence in a diverse array of case reports in the surgical and radiologic literature. The sponge in the above picture was found over a decade after an exploratory laparotomy for trauma as an incidental finding on a study performed for an unrelated reason. Policies and procedures such as thorough surgical instrument counts and intraoperative x-rays are designed to prevent this complication, however retained surgical instruments continue to be occur at a rate estimated to be around one in 1500 laparotomies. It has been proposed that routine intraoperative x-rays are cost effective and should be performed for high-risk procedures despite correct instrument counts. Surgical sponges are easily identified by the use of barium-impregnated threads woven into one side of the cloth. Reference: N Engl J Med. 2003;348(3):228, 229-235 (Source: Radiology Picture of the Day)

Chondrosarcoma of petrous apex

Radiology Picture of the Day — Mon, 05 May 2008 16:01:13 +0100

This axial T2-weighted MR image shows a high signal lesion in the petrous apex region, also involving the clivus. The lesion is expansile and there is evidence of bone destruction. Histopathology demonstrated chondrosarcoma. Chondrosarcomas of the skull base are typically off-midline, destructive lesions with high T2 signal and strong but heterogeneous contrast-enhancement. Approximately 50% demonstrate chondroid matrix calcification (best seen on CT). Skull base chondrosarcoma has a better prognosis than skull base chordoma, with an 80% 5-year progression-free survival after resection and radiotherapy. References: 1. Osborn A. Diagnostic Neuroradiology Mosby 1994 2. Cho YH, et al. Chordomas and chondrosarcomas of the skull base: comparative analysis of clinical results in 30 patients. Neurosurg Rev 2008;31(1):35-43 (Source: Radiology Picture of the Day)