Slideshow: Imaging of Facial Trauma

Slideshow: Imaging of Non-traumatic Intracranial Hemorrhages

Imaging of Non-traumatic Intracranial Hemorrhage from Rathachai Kaewlai

Pulmonary Infarction

Chest x-ray demonstrates a peripheral airspace opacity (arrows) that has a wedge-shaped configuration and a blunt medial apex pointing toward the hilum

Coronal-reformatted CT images confirm the presence of airspace opacity in the right middle lobe (arrows) with an embolus in the corresponding segmental pulmonary artery (arrowhead)

Facts: 

• Pulmonary embolic obstruction can occur with or without resultant pulmonary infarction
• In pulmonary embolism with infarction, process begins as "incomplete" infarct (intra-alveolar hemorrhage without necrosis of alveolar wall), which can go on to necrosis "infarct" especially in patients with underlying unhealthy lung
• On CXR, infarct is seen as a wedge-shaped, pleural-based consolidation with a rounded convex apex directing toward the hilum "Hampton hump"
• Often occurs in lower lobes
• Heals with scar formation

Reference

Dalen JE. Pulmonary embolism: what have we learned since Virchow? Chest 2002; 122:1440-1456.

Emphysematous Cystitis

Sagittal-plane ultrasound image of the bladder shows a linear hyperechoic structure with posterior "dirty shadowing" in the anterior aspect of the urinary bladder. There is no recent bladder catheterization. Upon decubitus positioning, this abnormality is immobile, suggesting extraluminal location. 

Axial non-contrast CT of the same patient demonstrates gas within the anterior and posterior walls of the urinary bladder (arrows).

Facts:

• Rare bladder inflammation with gas in bladder wall and surrounding tissues
• Generally caused by E.coli, K.pneumoniae or anaerobic gas-forming organisms
• Pathology: numerous gas filled intramural cysts on mucosal surface
• Risk factors: diabetes, immunocompromised state, urinary tract obstruction
• Most patients have mild forms of disease and respond well to antibiotics. Some have severe inflammation, gangrene and sepsis

Imaging:

• X-ray and CT usually is diagnostic with gas in the bladder wall, surrounding tissues and in the lumen in the absence of prior catheterization
• Ultrasound may show gas in the wall as hyperechoic lesions with posterior dirty shadowing. Visualization of posterior wall of urinary bladder may be limited if gas is present in the anterior aspect of the bladder. Decubitus scan helps localizing gas, whether inside the bladder lumen or in the wall
• CT helps detecting complications such as perforation or emphysematous pyelonephritis

Reference

Gillenwater JY, et al. Adult and pediatric urology, volume 1, 2002.

Petersen RO, et al. Urologic pathology, 2009.

Sternal Osteomyelitis

Chest radiograph of a patient who had sternal pain, fever and discharge shows no obvious bony abnormality.

Sagittal STIR and coronal T1W MR images demonstrate bone marrow edema with soft tissue changes in the sternum and right sternoclavicular joint (arrows). 

Facts:

• Uncommon infection of the sternum and sternoclavicular joint
• Usually affecting drug addicts, individuals with history of recent subclavian catheter placement, and patients with chronic debilitating illnesses
• Inciting organisms vary widely depending on demographics
• High failure rates of medical treatment alone. Typical treatment includes surgical debridement and en bloc removal

Imaging

• Radiograph is rarely helpful
• CT may show bone destruction but this may be late because damage begins in the joint. Surrounding soft tissue abnormalities are often a useful sign.
• MRI much more sensitive to detect joint and bone changes that are similar in findings to other areas of bone/joint infection

Reference: 

Shields TW et al. General Thoracic Surgery, 7th edition, 2009.

Early Signs of Ischemic Brain Injury on Noncontrast CT

Axial noncontrast CT images of the brain of two different patients presenting with acute stroke within 3 hours of symptom onset. The top row is images in a "brain" window, while the bottom row shows images in an "acute stroke" window. Early ischemic changes (cortical ribbon sign) of the right posterior inferior cerebral artery (left images) and right middle cerebral artery (right images) are much better appreciated on the acute stroke window.  

Loss of gray-white differentiation

• Lenticular obscuration: loss of distinction among basal ganglia nuclei
• Insular ribbon sign: blending of densities of cortex and white matter of insula
• Cortical ribbon sign:  blending of densities of cortex and white matter of other lobes

Swelling of gyri producing sulcal effacement

Detectability

• Seen on less than 1/3 of patients imaged within 3 hours of symptom onset
• Detection influenced by infarct size, severity and time between symptom onset and imaging
• Large interobserver variability, which may be improved by the use of a structured scoring system such as Alberta Stroke Program Early CT Score (ASPECTS) or the CT Summit Criteria, as well as the use of better CT windowing and leveling (use of "acute stroke" window)

Implications of these signs to management

• More rapid these signs become evident, the more profound the degree of ischemia
• Presence, clarity and extent of these signs on noncontrast CT correlates with higher risk of hemorrhagic transformation after Rx with fibrinolytic agents
• Involvement of greater than 1/3 of MCA territory increases risk of intracranial hemorrhage, shown in a European trial in patients of less than 6-hour symptom onset. This criterion has been used as an exclusion from entry in several trials evaluating the benefit of IV fibrinolytic therapy in the 3- to 4.5-hour window

Reference:
Jauch EC, et al. Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 2013 (January)

Maisonneuve Fracture

Figure 1: AP and lateral ankle radiographs demonstrate a vertical fracture of the medial/posterior malleolus of the distal tibia without a fibular fracture.  

Figure 2: Full-length AP fibular radiograph shows a mildly displaced fracture of the fibular shaft at the junction between the proximal 1/3 and middle 1/3. 

Facts: Rotational Ankle Fractures

• Rotational ankle fractures are classified according to force direction applied to the foot, while the injured foot can be in a different position (supination/pronation, adduction/external rotation)
• AO/Weber classification: A, B, C fractures are differentiated by location of fibular fractures. 
• Fibular fracture below the syndesmosis = AO/Weber A (usually supination-adduction)
• Fibular fracture at the syndesmosis = AO/Weber B (~ supination and external rotation)
• Fibular fracture above the syndesmosis = AO/Weber C (~ pronation external rotation)

Facts: Maisonneuve Fractures

• High fibular fracture above the syndesmosis resulting from external rotation
• Often, there is injury to the medial ankle either a tranverse medial malleolar fracture, posterior malleolar fracture or disruption of the deltoid ligament
• Disruption of the syndesmosis and interosseous ligament up to the fibular fracture site
• Suspicious for this fracture if you see a 1) transverse medial malleolar fracture or 2) posterior malleolar fracture but no fibular fracture on the ankle radiographic series. In these situation, a full-length fibular radiograph should be taken

Reference:

Sakthivel-Wainford K. Self-assessment in limb x-ray interpretation, 2006

Rockwood CA, Green DP. Rockwood and Green's fractures in adults, 2005

ESWL-induced Perinephric Hematoma

Ultrasound image of the kidney shows a crescentic heterogeneous hypoechoic lesion in the perinephric space (arrows). The kidney is marked by the calipers. 

Axial unenhanced CT images confirm a thick left perinephric hematoma (stars) and several fragmented stones in the lower pole of the left kidney.

Facts

• ESWL (Extracorporeal Shock Wave Lithotrypsy) is a common and standard treatment for renal/proximal ureteric calculi in majority of patients
• Most common complication = microscopic hematuria
• Perinephric hematoma and infection (including pyelonephritis) can occur
• Incidence of hematoma varies depending on method of diagnosis. By US, incidence is about 0.1-0.6%. By CT/MRI, incidence rises to 20-25% of cases. 
• No clear correlation between number of shockwaves or intensity given and incidence of hematoma
• Most perinephric hematoma resolves spontaneously within 2 years and the renal function is preserved. They are mostly treated conservatively

Imaging: US and CT

• Crescent-shaped collection surrounding the affected kidney
• Hypoechoic on US, hyperattenuating on non-contrast CT and no enhancement after IV contrast
• Displacement or compression of adjacent renal parenchyma
• Differentiate from subcapsular hematoma by appearance and pressure effect to underlying kidney.
• "Page" kidney occurs when (usually) subcapsular hematoma causes chronic renal parenchymal compromise and then hypertension

Reference:
Labanaris AP, Kuhn R, Schott GE, Zugor V. Perirenal hematomas induced by extracorporeal shock wave lithotripsy (ESWL). Therapeutic management. TheScientificWorldJOURNAL 2007;7:1563-1566.

Pyonephrosis

 Longitudinal ultrasound image of the right kidney shows moderate right hydroureteronephrosis (arrows) with internal debris.

Longitudinal image of the right ureter (arrows) shows a stone (arrowhead) in the distal ureter causing proximal hydroureter. 

Facts:

• Bacterial infection of urine associated with ureteral obstruction, AKA infected hydronephrosis. Accumulation of pus in the renal pelvis and calices of the kidney
• Common causes are ureteric obstruction by stone and ureteropelvic junction (UPJ) obstruction
• Septic patients with high fever, flank pain and tenderness
• Any febrile patients with hydronephrosis should be suspected of having pyonephrosis
• Ultrasound: echogenic urine and debris in the hydronephrotic kidney
• Prompt drainage essential 

Reference:

Hodler J, Von Schulthess GK, Zollikofer ChL. Diseases of the abdomen and pelvis 2010-2013

"Thai Radiology News" Image Quiz & Answer 1/2555

Author: พ.ญ.​ นิธิมา ศักดิ์โสภาวิวัฒน์  คณะแพทยศาสตร์โรงพยาบาลรามาธิบดี

Editor: น.พ. รัฐชัย แก้วลาย คณะแพทยศาสตร์โรงพยาบาลรามาธิบดี

For Thai Radiology News Vol. 1/2555

ประวัติ:

ผู้ป่วยชาย อายุ 27 ปีมาตรวจที่แผนกฉุกเฉินด้วยอาการเจ็บคอด้านขวา ร่วมกับอาการกลืนเจ็บ กลืนลำบาก เป็นมาประมาณ 10 วัน ต่อมามีไข้ และหายใจลำบาก

ภาพที่ 1 เป็น axial CT ส่วนคอแสดงให้เห็น rim-enhancing fluid collection ทางด้านขวา หน้าต่อ carotid space. ภายใน carotid space ไม่เห็น internal jugular vein ที่ปกติ แต่ถูกแทนที่ด้วย hypodense filling defect ร่วมกับผนังของหลอดเลือดดำมี enhancement. ภาพที่ 2 เป็นภาพ coronal reformation เพ่ิมเติม แสดงให้เห็น filling defect ภายใน internal jugular vein ข้างขวาและ enhancement ของผนังหลอดเลือดนี้. ภาพที่ 3 เป็นภาพ axial CT ทรวงอกใน lung window แสดงให้เห็น pulmonary nodules ขนาดเล็กกว่าหนึ่งเซนติเมตรในปอดทั้งสองข้าง บางอันมี cavity ภายใน สังเกตว่า nodules มักอยู่ที่รอบนอกของปอด (Image courtesy of University of Maryland Medical Center, MD, USA)

การวินิจฉัยโรค            Lemierre Syndrome

Discussion             ผู้ป่วยรายนี้มาพบแพทย์เนื่องจากมีการอักเสบติดเชื้อที่ต่อมทอนซิลและเกิด peritonsillar abscess ทำให้มี thrombophlebitis ของ internal jugular vein ที่อยู่ติดกันและมี septic emboli กระจายไปยังปอดทั้งสองข้าง  โรคติดเชื้อในช่องปากและคอที่มีภาวะแทรกซ้อนเช่นนี้รู้จักกันในชื่อ Lemierre syndrome ซึ่งตั้งตามชื่อแพทย์ผู้รายงานกรณีผู้ป่วย 20 ราย ในปี พ.ศ. 2479 (1) ในปัจจุบันพบโรคนี้น้อยมากเนื่องจากมีการใช้ยาปฏิชีวนะกันอย่างแพร่หลาย แต่การวินิจฉัยภาวะนี้ให้รวดเร็ว แม่นยำ ยังมีความสำคัญเพราะหากได้รับการรักษาช้าอาจทำให้เสียชีวิตได้

Lemierre syndrome ส่วนใหญ่เกิดจากการติดเชื้อ anaerobic Fusobacterium necrophorum เมื่อมีการติดเชื้อที่ช่องคอ ทอนซิลหรือช่องปากแล้วอาจมีการแพร่กระจายโดยตรง, ผ่านทางหลอดเลือดรอบๆต่อมทอนซิลหรือผ่านทางท่อน้ำเหลืองไปยัง internal jugular vein ทำให้เกิด thrombophlebitis และ septic emboli กระจายไปยังอวัยวะอื่นๆ ได้  ที่พบบ่อยที่สุดคือปอด (79-100%) ผู้ป่วยส่วนมากเป็นวัยรุ่นแต่ก็พบได้ทุกอายุ มักมาพบแพทย์ด้วยอาการเจ็บคอ มีไข้ บวมกดเจ็บ และอาการอื่นๆ ขึ้นกับตำแหน่งการแพร่กระจายของ septic emboli (2, 3).

การตรวจทาง imaging มีบทบาทมากในการวินิจฉัยภาวะนี้ อัลตราซาวด์สามารถแสดงให้เห็นลิ่มเลือดที่อยู่ภายใน internal jugular vein ได้ดี ไม่ว่าจะเป็นชนิดที่มีการอุดกั้นหรือไม่ก็ตาม หรืออาจเห็นลักษณะ venous distension, absent flow หรือ non-compressible vein. การตรวจด้วย CT ร่วมกับการให้สารทึบรังสีชนิดฉีดจะแสดงขอบเขตของการติดเชื้อ เช่น peritonsillar abscess ได้ดีกว่าอัลตราซาวด์ และแสดงภาพลิ่มเลือดเป็น filling defect ภายในหลอดเลือดดำ  หลอดเลือดดำดังกล่าวอาจมีขนาดใหญ่ขึ้นร่วมกับมี fat stranding รอบๆ และมี enhancement ของผนังหลอดเลือด. การตรวจเอกซเรย์ปอดอาจพบว่ามี pulmonary nodules, masses, cavitary lesions, focal airspace disease ได้แต่การทำเอกซเรย์คอมพิวเตอร์จะให้รายละเอียดได้ดีกว่า ความผิดปกติที่พบในปอดมักอยู่ที่บริเวณรอบนอก (periphery) ของเนื้อปอด เข้าได้กับ septic emboli  หากสงสัยภาวะนี้ ผู้ป่วยควรได้รับการตรวจ CT ของทรวงอกและคอในคราวเดียวกัน  การรักษาได้แก่การให้ยาปฏิชีวนะ ยาละลายลิ่มเลือด และการผ่าตัด (4).

เอกสารอ้างอิง

1.            Lemierre A. On certain septicemias due to anaerobic organisms. Lancet 1936; 1:701-703.

2.            Karkos PD, Asrani S, Karkos CD, et al. Lemierre's syndrome: A systematic review. Laryngoscope 2009; 119:1552-1559.

3.            Vargiami EG, Farmaki E, Tasiopoulou D, et al. The Lemierre syndrome. Eur J Pediatr 2010; 169:411-414.

4.            Weeks DF, Katz DS, Saxon P, Kubal WS. Lemierre syndrome: report of five new cases and literature review. Emerg Radiol 2010; 17:323-328.

Avulsion of the Anterior Superior Iliac Spine

A pelvic radiograph demonstrates an avulsion fracture (arrows) of the right anterior superior iliac spine (ASIS) in a 14-year-old boy. 

Facts: Pelvic Avulsions

• Avulsion of pelvic bones usually found in young, skeletally immature athletes.
• Forceful contraction of the attached muscle while the athlete actively engages in kicking, running or jumping.
• Three major locations: ASIS (sartorius attachment), anterior inferior iliac spine (AIIS, rectus femoral attachment) and ischial tuberosity (hamstrings and adductor attachment).
• 50% of cases at ischial tuberosity, 23% ASIS, 22% AIIS (of all pelvic avulsions).
• Localized swelling and tenderness at the site of avulsion fracture. Limited motion from pain.

Imaging

• Plain radiography usually sufficient for diagnosis. 
• Comparison view helpful to ensure that abnormality is not a secondary center of ossification.
• Pitfalls: secondary ossification center, osseous mass seen as a delayed presentation mimicking neoplasm.

References

Davies AM, Johnson KJ, Whitehouse RW. Imaging of the hip & bony pelvis: techniques and applications. 

Beaty JH, Rockwood CA, Kasser R. Rockwood and Wilkins' fractures in children. 

Acute Isodense Subdural Hematoma

Plain and contrast-enhanced axial CT images of the brain show an isodense subdural hematoma (SDH, arrows) in the left cerebral convexity, much better appreciated on post-contrast image. There is also a thinner right frontal convexity SDH. 

Facts: Isodense Subdural Hematoma (SDH)

• Subdural blood collection that has similar attenuation with the gray matter
• Acute SDH appears as a high density collection with declining density with time. It passes "isodense" state mostly in subacute phase (2-6 weeks after initial trauma)
• Isodense SDH poses diagnostic dilemma because it is not apparently seen on CT
• In acute setting this can be seen in anemic patients (acute isodense SDH). Experimental data showed that Hb 8-10 g/dl will be isodense to the adjacent brain

Reference:

Smith, Jr., WP, Batnitzky S, Rengachary SS. Acute isodense subdural hematomas: a problem in anemic patients. AJR 1981; 136:543-546. 

Is Plain Radiography Sensitive Enough to Detect Pneumoperitoneum?

An upright chest radiograph shows a large amount of pneumoperitoneum under the right hemidiaphragm of a patient who has peptic ulcer perforation found at surgery.

Facts: Pneumoperitoneum & GI perforation

• Common
• Requires a breach through all layers of hollow viscus that would allow escape of intraluminal content into the peritoneal cavity
• Results in peritonitis, either localized or generalized

Detectability Rate of Imaging

• Plain radiography sensitivity ranges from 50% to 98% depending on the technique (upright chest, upright abdomen, left lateral decubitus, supine abdomen) and additional postural maneuver
• Recent study of 1,723 patients with GI perforation shows that radiography (either upright chest, upright abdomen or both) has positivity rate of almost 90%. 10% of radiographs did not show free air despite patients having GI perforation. Highest positivity rate was seen with gastric and duodenal perforation (94%), but lowest with appendiceal perforation (7%)

Reference:

Bansal J, Jenaw RK, Rao J, et al. Effectiveness of plain radiography in diagnosing hollow viscus perforation: study of 1,723 patients of perforation peritonitis. Emerg Radiol 2011 December.

Pneumothorax on Ultrasound

M-mode ultrasound images of the lungs (right and left) show a normal "lung sliding" on the right side "Right" and absence of it on the left side "Left".

Facts:

• Ultrasound can be performed to diagnose pneumothorax with high accuracy
• Normal "lung sliding" is seen when pleura moves against the chest wall during respiration. The movement is easily seen on real-time imaging and can be captured on M-mode ultrasound
• M-mode US shows normal lung sliding as a "seashore sign", in which the motion of pleura/lung produces sand-like granular appearance on the image. The non-mobile chest wall shows several uninterrupted band or "sea"
• Some diseases may produce "loss of lung sliding", most notably pneumothorax

Pneumothorax on US

• Absence of lung sliding shown on real-time imaging
• On M-mode as "barcode sign" or "stratosphere sign" (see above image labeled "left")
• More specific sign is the "lung point sign"

Our case: left pneumothorax (confirmed with radiography)

Reference:

Lichtenstein DA, Menu Y. A bedside ultrasound sign ruling out pneumothorax in the critically ill. Chest 1995; 108:1345-48.

Intussusception Reduction

A "scout" radiograph before intussusception reduction procedure shows a soft tissue mass (arrows) in the right upper quadrant representing the intussusception. There is no free air.

Contrast enema for reduction shows the intussusception (arrows) in the right upper quadrant. It was successfully reduced.

Facts

• Image-guided liquid or air reduction of intussusception is the treatment of choice
• Contraindications for image-guided reduction = peritonitis, free intraperitoneal air due to perforation, in shock or sepsis
• Choice between air, liquid, contrast enema reduction of intussusception depends on radiologist experience and local preference/practice. Most radiologists prefer to use air and it is now generally accepted as the technique of choice
• Air pressure: between 80 and 120 mmHg
• Contrast: bag positioned approximately between 3 ft and 6 ft above the patient
• Reduction rate between 80% to 95%

Preparation for Reduction

• Notify the referring physician and surgeon
• Patient must be stable, well-hydrated and has no evidence of peritonitis
• IV line in place
• A large-bore needle at hand (if you use air reduction)

Complications

• Perforation rates with air enema less than 1%
• Recurrence 10% of cases

Reference:

1. Daldrup-Link HE, Gooding CA. Essentials of Pediatric Radiology: A Multimodality Approach, 2010.

2. Hodler J, Von Schulthess GK, Zollikofer CL. Diseases of the Abdomen and Pelvis 2010-2013: Diagnostic Imaging and Interventional Techniques, 2010.

Intussusception: Ultrasound

A longitudinal US image shows a "pseudokidney" sign of intussusception (arrows). Arrowheads point to enlarged mesenteric lymph nodes within the intussusceptum.

A transverse US image shows a "target" sign with a hypoechoic ring of the intussuscepiens surrouning the central echogenic area of intussusceptum. Arrowheads point to enlarged nodes.

Facts

• A segment of bowel (intussusceptum) prolapses into a more distal bowel segment (intussuscepiens)
• Most frequently seen in the first two years of life but can be seen up to 4 years. If older child has intussusception, looks for a lead point such as polyp, Meckel diverticulum, lymphoma, duplication cyst.
• Classic triad: colicky pain, vomiting and bloody (red currant jelly) stools (seen in less than 25% of cases)
• X-ray is positive in only 50% of cases, and is not reliable in diagnosing this condition

Ultrasound Findings

• Modality of choice to diagnose intussusception
• "Target" sign = hypoechoic ring with an echogenic center on transverse US image
• "Pseudokidney" sign = hypoechoic bowell wall extending along a hyperechoic mucosa
• Helpful in searching for a lead point. US can provide a specific diagnosis in one-third of these cases.

Reference:

1. Daldrup-Link HE, Gooding CA. Essentials of Pediatric Radiology: A Multimodality Approach, 2010.

2. Hodler J, Von Schulthess GK, Zollikofer CL. Diseases of the Abdomen and Pelvis 2010-2013: Diagnostic Imaging and Interventional Techniques, 2010.

Tension Pneumothorax

Chest radiograph shows a very large left pneumothorax (stars) causing mass effect to the mediastinum (shifting, arrows), deep costophrenic sulcus and collapsed left lung.

Facts

• One-way valve effect causing continuous air collection within pleural space resulting in collapse of the lung on the affected side and compression of opposite lung
• Poor lung compliance and increased airway pressure leads to ineffective gas exchange
• Mass effect on mediastinal structures cause decreased venous return and decreased cardiac output
• Symptoms and signs: chest pain, dyspnea, respiratory distress, tachypnea, dyspnea, cyanosis, elevated jugular venous pressure, absent breath sounds, tracheal deviation and hemodynamic compromise
• This is a clinical diagnosis and confirmation with radiography is not recommended. Needle decompression should be immediately performed

Imaging

• Again, this is a clinical diagnosis. Yet imaging may be performed and shows large pneumothorax, mediastinal shifting, flat hemidiaphragm

Reference:

Greenberg MI. Greenberg's Text-atlas of Emergency Medicine, 2005.

Fracture of the Lateral Process of Talus

AP view of the foot shows a small avulsion fracture (arrow) of the lateral process of the talus.

Facts: Lateral Process of Talus

• Lateral process is a broad-based, wedge-shaped prominence of the lateral talar body that articulates with the fibula and posterior facet of talus
• Anchor point for lateral talocalcaneal, anterior and posterior talofibular ligaments

Facts: Fracture of the Lateral Process of Talus

• Axial loading with elements of dorsiflexion and eversion or external rotation
• High incidence among snowboarders, sometimes called "snowboarder fracture"
• Can be difficult to diagnose clinically, easily confused with ankle sprain
• Pain localized anteroinferior to the distal end of fibula

Imaging

• Important to look specifically at this area in patients presenting with lateral ankle pain following trauma
• Small, nondisplaced fracture can be overlooked. CT may be warranted if suspicion persists in a normal-looking x-ray series
• Hawkins classified this fracture into 3 types: 1) large single fragment, 2) large comminuted fragment, 3) small, extra-articular fragment

Reference:

Browner BD, Levine AM, Jupiter JB, et al. Skeletal Trauma: Basic Science, Management, and Reconstruction, 2009.

Ileal Diverticulitis

Axial CT image shows an ileal diverticulum (arrow) with surrounding inflammation (arrowheads). Thin arrow = normal appendix.

Sagittal CT image again confirms the presence of an inflamed ileal diverticulum. Note a normal cecum.

Facts

• Two percents of population have small-bowel diverticula
• These can be congenital or acquired.
• Acquired diverticula are common in jejunum and terminal ileum. They are mucosal herniation along the mesenteric border.
• About 6-10% of patients with small-bowel diverticula develop complications (-itis, hemorrhage, obstruction, intussusception)

Imaging

• CT can show inflammatory change around the diverticulum with mural thickening of the adjacent bowel loops. The appendix and cecum are normal.

Reference:

Gourtsoyiannis NC. Radiologic Imaging of the Small Intestine, 2002.

Predictors of Cervical Spine Fractures and Fracture Risk

Flow diagram (originally published by Blackmore CC, et al, Radiology 1999) demonstrating a prediction rule for determination of risk of cervical spine fracture in blunt trauma patients. Percentages indicate the risk of fracture for each group with 95% CIs. Area under the ROC curve = 0.87

Facts:

• Three common options exist to "clear" cervical spine in trauma patients: clinical evaluation, radiography or CT
• Canadian C-spine Rule (CCR) or NEXUS criteria are generally used by emergency physicians and trauma surgeons to determine which patients require imaging clearance
• Among patients who, based on CCR or NEXUS, need imaging clearance: an issue exists whether to choose x-ray vs. CT
• In general, CT is preferred for patients with moderate or high likelihood of having C-spine injury given its higher accuracy, cost-effectiveness and ease of performance. However, C-spine CT has not been tested as cost-effective among patients with low likelihood of C-spine injury - practice has been different from one place to another

According to Blackmore CC, et al

• We can stratify patients into groups of different fracture probabilities by using 4 predictors: severe head injury, high-energy cause, age and focal neurologic deficit
• Definition of severe head injury = intracranial hematoma, brain contusion, skull fracture or unconsciousness
• Definition of high-energy cause = high-speed MVC (greater than 30 mph), pedestrian struck by car
• Definition of moderate-energy cause = low-speed MVC, MVC at unknown speed, bicycle accident, motorcycle accident or fall
• Definition of focal deficit = those that could be in a spinal cord or spinal nerve distribution

Reference:

Blackmore CC, Emerson SS, Mann FA, Koepsell TD. Cervical spine imaging in patients with trauma: determination of fracture risk to optimize use. Radiology 1999; 211:759-765.