Medical Image of the Month: Diaphragmatic Eventration

Figure 1. An upright PA chest radiograph demonstrates marked elevation of the left hemidiaphragm with associated superior migration of the gas-filled colon and mild mediastinal shift towards the right.

Figure 2. A: frontal. B: sagittal. A non-contrasted reconstruction of the chest demonstrates marked elevation of the left hemidiaphragm with associated superior migration of the abdominal viscera along with preservation of the integrity of the hemidiaphragm. These findings are consistent with a left hemidiaphragm eventration.

Clinical Presentation: A 66-year-old woman presented with a three-year history of progressive postprandial dyspnea and left-sided abdominal pain.  Physical exam revealed normal vital signs and bowels sounds over left lung fields on auscultation. Laboratory work revealed a mild normocytic anemia.  Imaging demonstrated marked left hemidiaphragm elevation with ipsilateral lung parenchyma volume loss and atelectasis along with a mild contralateral mediastinal shift.  A sniff test was consistent with left hemidiaphragm paralysis.

The patient underwent a left video-assisted thoracoscopy, and the left hemidiaphragm was noted to be so thin that the abdominal organs could be visualize through it. The central tendon of the left hemidiaphragm was extremely attenuated and larger than normal. The left hemidiaphragm muscle fibers were noted to be situated around the periphery and not providing any significant tension. The redundant left hemidiaphragm central tendon was excised, and the patient was discharged without symptoms one week later.

Discussion: Eventration of a hemidiaphragm is a rare condition where there is non-paralytic weakening and thinning of a hemidiaphragm resulting in elevation of the hemidiaphragm with retained attachments to the costal margins (1). An eventration usually results from a congenital failure of the fetal diaphragm to muscularized. It is usually unilateral, occurs more on the right than the left, affects the anteromedial portion of the hemidiaphragm, occurs more often in women, and is found after the age of 60 in the adult population. A total eventration of a hemidiaphragm may be indistinguishable from diaphragmatic paralysis and result in a false-positive sniff test – as in this case. When symptomatic, it can pose a diagnostic challenge as it may be confused with a traumatic diaphragmatic rupture in the right clinical setting. Asymptomatic adults do not require treatment.

Leslie Littlefield MD and Mohamed Fayed MD

Department of Pulmonary and Critical Care

University of California San Francisco Fresno

Fresno, CA USA

Reference

1. Black MC, Joubert K, Seese L, et al. Innovative and Contemporary Interventions of Diaphragmatic Disorders. J Thorac Imaging. 2019;34(4):236-247. [CrossRef] [PubMed]

Cite as: Littlefield L, Fayed M. Medical image of the month: diaphragmatic eventration. Southwest J Pulm Crit Care. 2020;21(1):9-10. doi: https://doi.org/10.13175/swjpcc036-20 PDF 

Medical Image of the Week: Thoracic Splenosis

Figure 1. A: Axial CT of the chest without intravenous contrast demonstrates a cluster of soft tissue nodules adjacent to the left posterior hemi-diaphragm (blue arrows). B: Axial CT of the chest without intravenous contrast demonstrates absence of the spleen and a surgical clip (blue arrow) consistent with a prior splenectomy.

Figure 2. Fused technetium 99m-label sulfur colloid uptake study and axial CT of the chest without intravenous contrast demonstrates uptake of radiotracer in the previously seen soft tissue nodules adjacent to the posterior aspect of the left hemi-diaphragm (red arrows) which confirms the diagnosis of thoracic splenosis.

A 38-year-old man with a history of a motor vehicle collision about 20 years prior to presentation which resulted in multiple left-sided rib fractures, a left-sided pneumothorax requiring chest tube placement, and a high-grade splenic laceration necessitating an emergent splenectomy that presents to outpatient pulmonary clinic for evaluation of pulmonary nodules at the request of his primary care physician. He is asymptomatic. He has a 20-pack-year of smoking history and currently smokes 6 cigarettes per day. He denies any significant exposures or recent infections. He has a family history significant for heart disease and depression, but no history of malignancy. His vital signs and physical examination are normal. He had a CT of the chest performed with representative images from the study shown in Figure 1.

A nuclear medicine scan was subsequently requested which demonstrated uptake of the technetium 99m-labeled sulfur colloid in the soft tissue nodules adjacent to left hemi-diaphragm (Figure 2) confirming the diagnosis of thoracic splenosis. No further treatment or diagnostic work up was required.

Splenosis is defined as auto-transplantation of splenic tissue following traumatic or surgical disruption of the spleen. Splenosis usually occurs in the abdomen, most commonly in the left upper quadrant (1,2). However, with disruption of the diaphragm in the setting of trauma, splenic tissue can migrate into the thoracic cavity, and most often settles in the inferior, posterior left pleural space (as in our patient).  The diagnosis of thoracic splenosis should be suspected when one sees left basilar pleural nodules/masses in the setting of a previous trauma necessitating a splenectomy. A technetium 99m-labeled sulfur colloid study will demonstrate uptake of the radiotracer in the auto-transplanted splenic tissue as this radiotracer has a strong affinity for tissue arising from the reticuloendothelial system.

Gregory Gardner MD¹, Kevin Breen¹, Tammer Elaini MD², and Tiffany Ynosencio MD²

¹Department of Internal Medicine

²Division of Pulmonary, Critical Care, Allergy and Sleep

University of Arizona College of Medicine

Tucson, AZ USA

References

1. Khosravi MR, Margulies DR, Alsabeh R, Nissen N, Phillips EH, Morgenstern L. Consider the diagnosis of splenosis for soft tissue masses long after any splenic injury. Am Surg. 2004 Nov;70(11):967-70. [PubMed]
2. Rosado-de-Christenson ML, Abbott GF. Diagnostic Imaging: Chest. 2^nd edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2012: 30-1.

Cite as: Gardner G, Breen K, Elaini T, Ynosencio T. Medical image of the week: thoracic splenosis. Southwest J Pulm Crit Care. 2018;16(5):285-6. doi: https://doi.org/10.13175/swjpcc066-18 PDF

Medical Image of the Week: Post-Traumatic Diaphragmatic Rupture

Figure 1. A: Admission portable chest radiograph, demonstrates elevation of the right hemidiaphragm of uncertain chronicity (large arrow, also shown in B and C). B: Study after 20 min, shows a moderate hemothorax (*). Mildly displaced fractures are evident, involving at least the3^rd and 5^th right ribs (small arrows). C: Follow up exam. A right chest tube (thin arrow in c) has been inserted, and the hemothorax is drained. Immediately after, a CT chest abdomen and pelvis is performed.

Figure 2. A-C: A large anterolateral diaphragmatic defect is diagnosed, as shown in the coronal images, from anterior to posterior (A-C), with displacement of the liver (L) and loops of bowel (B) into the chest. Note the discontinuity of the diaphragm (arrows in A, B and D). A small liver laceration is noted in the gallbladder bed (arrows in C). D:  Image, near the midline, showing atelectasis (A) in the posterior right lung base. Additional injuries (not shown), included, right ribs 2-11 fractures, gallbladder fossa liver, right adrenal hemorrhage, mesenteric root contusion and multiple pelvic fractures.

A 67-year-old woman was admitted after being struck by a vehicle, at high speed. She has a diaphragmatic rupture (Figures 1 and 2).

Diaphragmatic injuries occur in approximately 0.8%–8% of blunt trauma patients, largely from motor vehicle accidents (1). The mechanism of injury includes distortion of the chest wall with resulting shearing forces, or direct frontal impact with acute increased intraabdominal pressure (2).

Rupture of the left diaphragm is more common, presumably due to a protective mechanism by the liver, but also in part due to underdiagnoses (3). Most ruptures are large, posterolateral, between the lumbar and intercostal attachments (4).  Associated liver injuries are seen mostly with right diaphragmatic injuries (93 % vs. 24% with left injuries). Multiorgan abdominal injury and pelvic fractures are common (2).

In cases of associated hemothorax, pulmonary laceration/contusion, atelectasis, and phrenic nerve palsy, a diaphragmatic injury, may be masked on chest radiographs. Also, the positive pressure of ventilatory support may delay herniation of abdominal contents through the ruptured diaphragm (5).

Up to 12% to 66% cases of diaphragmatic rupture cases, are missed on chest radiograph. Suggestive findings include elevation of the hemidiaphragm, distortion or obliteration of the outline of the hemidiaphragm, and contralateral shift of the mediastinum (6,7).

On CT visualization of a diaphragmatic defect has most sensitivity and specificity for diaphragmatic injury (73% and 90%) respectively) (8). Intrathoracic herniation of abdominal contents has a sensitivity of 55% and a specificity of 100% (8). The “collar sign”, a waist-like constriction of the herniating hollow viscus at the site of the diaphragmatic tear, is usually seen sagittal and coronal multiplanar reformatted images (2,8). The “dependent viscera sign” (1), consists of bowel or solid organs fallen to a dependent position against the posterior ribs, due to lack of supported by the intact diaphragm. This may be an early sign of diaphragmatic tear on axial images, before visceral herniation is clearly seen on multiplanar reformatted images.

Diana Palacio MD, Veronica Arteaga MD, Berndt Schmidt MD

Department of Medical Imaging

The University of Arizona-Banner Medical Center

Tucson, AZ USA

References

1. Bergin D, Ennis R, Keogh C, et al. The "dependent viscera" sign in CT diagnosis of blunt traumatic diaphragmatic rupture. AJR Am J Roentgenol. 2001;177:1137-40. [CrossRef] [PubMed]
2. Shanmuganathan K, Killeen K, Mirvis SE, et al. Imaging of diaphragmatic injuries. J Thorac Imaging. 2000;15:104-11. [CrossRef] [PubMed]
3. Killeen KL, Mirvis SE, Shanmuganathan K. Helical CT of diaphragmatic rupture caused by blunt trauma. AJR Am J Roentgenol.1999;173:1611-6. [CrossRef] [PubMed]
4. Boulanger BR, Milzman DP, Rosati C, et al. A comparison of right and left blunt traumatic diaphragmatic rupture. J Trauma. 1993;35:255-60. [CrossRef] [PubMed]
5. Kuhlman JE, Pozniak MA, Collins J, Knisely BL. Radiographic and CT findings of blunt chest trauma: aortic injuries and looking beyond them. RadioGraphics. 1998;18:1085-1106. [CrossRef] [PubMed]
6. Iochum S, Ludig T, Walter F, et al. Imaging of Diaphragmatic Injury: A Diagnostic Challenge RadioGraphics 2002; 22:suppl. 1,S103-16. [CrossRef] [PubMed]
7. Gelman R, Mirvis SE, Gens D. Diaphragmatic rupture due to blunt trauma: sensitivity of plain chest radiographs. AJR Am J Roentgenol. 1991;156:51-7. [CrossRef] [PubMed]
8. Murray JG, Caoili E, Gruden JF, et al. Acute rupture of the diaphragm due to blunt trauma: diagnostic sensitivity and specificity of CT. AJR Am J Roentgenol. 1996;166:10. [CrossRef] [PubMed]

Cite as: Palacio D, Arteaga V, Schmidt B. Medical image of the week: post-trumatic diaphragmatic rupture. Southwest J Pulm Crit Care. 2018;16(3):143-5. doi: https://doi.org/10.13175/swjpcc030-18 PDF 

Medical Image of the Week: Hematopneumatoceles from Pulmonary Lacerations

Figure 1. Chest x-ray showing irregular patchy regions of ill-defined consolidation in the left upper lobe and lingula, as well as suggestion of cystic changes (arrow).

Figure 2. Chest CT axial views, soft tissue and lung windows at the level of the aortic arch (A), right pulmonary artery (B) and the heart (C) showing mixed consolidative and nodular left lung opacities suggestive of pulmonary contusions, as well as contrecoup injury in the right lung, in addition to multiple cystic spaces containing air-fluid levels consistent with pulmonary lacerations.

Figure 3. Chest CT coronal views, soft tissue and lung windows showing consolidative and nodular lung opacities as well as fluid layering in cystic spaces (red arrows). A shattered spleen (yellow arrow) is also seen.

A 17-year-old man was brought to the emergency room after a fall from a 50-foot bridge. He was hypoxemic on presentation, requiring endotracheal intubation. Chest computed tomography (CT) revealed bilateral airspace opacities consistent with pulmonary contusions, and multiple air-fluid levels diagnostic of pulmonary lacerations (Figures 1-3).

Pulmonary lacerations are rare complications of blunt chest trauma (1). They can be contained within the lung parenchyma or may extend through the visceral pleura causing a pneumothorax. Due to its elastic recoil, the surrounding lung tissue pulls back from the laceration resulting in a round or oval cavity that may fill with air (pneumatocele), blood (hematocele) or both (hematopneumatocele). Lacerations are often obscured on chest x-ray as they are usually surrounded by contusion, requiring a CT for detection (2). They are classified into four types according to the mechanism of injury: Type 1 (compression rupture injury, most common type, usually centrally located), Type 2 (shearing against the thoracic spine, involving the paraspinal region of the lower lobes), Type 3 (rib penetration into the lung periphery, usually associated with a pneumothorax) and Type 4 (adhesion tear, in regions of pleuropulmonary adhesions) (3). Pulmonary lacerations heal more slowly than contusions and may last up to several months, over time becoming increasingly filled with blood, before regressing (2).

Our patient underwent an exploratory laparotomy with a splenectomy. The pulmonary lacerations were managed conservatively. He was successfully extubated on day#10 and discharged home on day#14 with a plan to follow his lacerations with monthly chest radiography.

Udit Chaddha MD¹, Darren Maehara MD¹, Ioan Puscas DO¹, Ashley Prosper MD², and Ramyar Mahdavi MD¹

¹Division of Pulmonary, Critical Care and Sleep Medicine and ²Department of Radiology

Keck School of Medicine of the University of Southern California

Los Angeles, CA USA

References

1. Nishiumi N, Maitani F, Tsurumi T, Kaga K, Iwasaki M, Inoue H. Blunt chest trauma with deep pulmonary laceration. Ann Thorac Surg. 2001;71(1):314-8. [CrossRef] [PubMed]
2. Kaewlai R, Avery LL, Asrani AV, Novelline RA. Multidetector CT of blunt thoracic trauma. Radiographics. 2008;28(6):1555-70. [CrossRef] [PubMed]
3. Wagner RB, Crawford WO, Schimpf PP. Classification of parenchymal injuries of the lung. Radiology. 1988;167(1):77-82. [CrossRef] [PubMed]

Cite as: Chaddha U, Maehara D, Puscas I, Prosper A, Mahdavi R. Medical image of the week: hematopneumatoceles from pulmonary lacerations. Southwest J Pulm Crit Care. 2017;15(1):46-8. doi: https://doi.org/10.13175/swjpcc078-17 PDF 

April 2017 Imaging Case of the Month

Michael B. Gotway, MD and John K. Sweeney, MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, Arizona USA

Clinical History: An 86-year-old man with a previous history of transcatheter aortic valve implantation 1 year earlier, coronary artery disease status-post coronary artery bypass grafting surgery 12 years earlier, atrial fibrillation on warfarin, and pacemaker placement 8 years earlier presented with altered mental status.

The patient’s white blood cell count was borderline elevated at 10.3 x 10³/mcl (normal, 4.8 – 10.8 x 10³/mcl)  and hyponatremia was noted (serum sodium = 129 mEq/L, normal =  136 – 145 mEq/L). The patient’s anticoagulation profile was within the therapeutic range (INR = 1.4), and the platelet count was normal. Oxygen saturation on room air was normal. The patient’s medication list included warfarin, digoxin, aspirin, metoprolol, montelukast, and atorvastatin.

Frontal chest radiography (Figure 1) was performed.

Figure 1. Frontal (A) and lateral (B) chest radiography.

Which of the following statements regarding the chest radiograph is most accurate? (Click on the correct answer to proceed to the second of eight pages)

1. Frontal chest radiography shows a cavitary lung mass
2. Frontal chest radiography shows focal consolidation suggesting aspiration pneumonia
3. Frontal chest radiography shows increased pressure edema
4. Frontal chest radiography shows malposition of the patient’s left subclavian pacemaker
5. Frontal chest radiography shows rib fractures

Cite as: Gotway MB, Sweeney JK. April 2017 imaging case of the month. Southwest J Pulm Crit Care. 2017;14(4):141-52. doi: https://doi.org/10.13175/swjpcc042-17 PDF

Medical Image of the Week: Subcutaneous Calcification in Dermatomyositis

Figure 1. Thoracic CT scan in lung windows showing non-specific interstitial disease secondary to dermatomyositis.

Figure 2. Pelvic CT scan showing subcutaneous calcifications (encircled).

A 36-year old woman was referred to our Interstitial Lung Disease (ILD) clinic for evaluation of dyspnea. A high-resolution CT scan of the chest showed perivascular reticular and ground glass opacities with air trapping, consistent with non-specific interstitial pneumonitis (Figure 1). She was diagnosed with connective tissue associated ILD. On review of previous images extensive subcutaneous calcifications were seen (Figure 2).

Calcinosis is an uncommon manifestation of dermatomyositis in adults (1). It is usually seen around areas of frequent trauma like the hands and elbows. In her case, a pelvic inflammatory disease may have been a trigger for this calcinosis. Calcinosis is a difficult complication to treat with some success seen with diltiazem, aluminum hydroxide, and even alendronate in children. Surgical excision may be required in some cases.

Bhupinder Natt MD

Division of Pulmonary, Allergy, Critical Care and Sleep

Banner-University Medical Center, Tucson (AZ)

Reference

1. Chander S, Gordon P. Soft tissue and subcutaneous calcification in connective tissue diseases. Curr Opin Rheumatol. 2012 Mar;24(2):158-64. [CrossRef] [PubMed]

Cite as: Natt B. Medical image of the week: subcutaneous calcification in dermatomyositis. Southwest J Pulm Crit Care. 2016;13(6):317-8. doi: https://doi.org/10.13175/swjpcc130-16 PDF 

Medical Image of the Week: Pneumomediastinum

Figure 1. Chest X-ray PA view.

Figure 2. CT scan of chest.

A 38-year-old gentleman was flown to the emergency room after being involved in a motor vehicle accident. In the field, he had a Glasgow Coma Scale of about 7 and cricothyrotomy was performed to establish an airway. He sustained severe head and chest injuries, with extensive subcutaneous emphysema.  Chest X-ray (Figure 1) and CT scan (Figure 2) revealed pneumomediastinum with classical “continuous diaphragm sign” (red arrows), lucent streaks outlining the ascending aorta (blue arrows) and extensive subcutaneous emphysema (block arrows). Subdural and subarachnoid hemorrhage was detected on CT scan of head. His neurological status worsened over next 24 hours and he was confirmed brain dead.

Ramasubramanian Baalachandran MD, Naser Mahmoud MD, and Laura Meinke MD

Department of Medicine

University of Arizona

Tucson, Arizona

References

1. Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol. 1996;166:1041-8. [CrossRef] [PubMed]
2. Levin B. The continuous diaphragm sign. A newly-recognized sign of pneumomediastinum. Clin Radiol.1973;24(3):337-8. [CrossRef] [PubMed]

Reference as: Baalachandran R, Mahmoud N, Meinke L. Medical image of the week: pneumomediastinum. Southwest J Pulm Crit Care. 2014;9(3):189-90. doi: http://dx.doi.org/10.13175/swjpcc123-14 PDF

Medical Image of the Week: Fat Embolism Syndrome

A 33-year-old man presented to the emergency department with shortness of breath and hemoptysis. He was discharged two days prior after hospitalization for a motor vehicle accident, in which he suffered a fracture of the shaft of the right femur. He had undergone open reduction and internal fixation of the fracture four days prior to this admission. He had diffuse parenchymal disease on his admission chest x-ray. A CT scan of the chest demonstrated multilobar ground glass opacities (Figure 1).

Figure 1. Thoracic CT scan showing ground glass opacities.

Bronchoscopy demonstrated progressively bloody BAL aliquots in two different lobes, consistent with diffuse alveolar hemorrhage (DAH). His workup for other etiologies was negative, and he was given a diagnosis of DAH secondary to fat embolism syndrome.

Joshua Malo, MD and Kenneth S. Knox, MD

Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine

University of Arizona, Tucson, AZ

Reference as: Malo J, Knox KS. Medical image of the week: fat embolism syndrome. Southwest J Pulm Crit Care. 2014;8(4):246. doi: http://dx.doi.org/10.13175/swjpcc041-14 PDF

Medical Image of the Week: Cervical Fracture and Dislocation

Figure 1. Panel A: Computerized tomography (CT) scan of the neck showing C5-C6 fracture and dislocation (arrow). Panel B: Accompanying magnetic resonance imaging (MRI) of the neck.

A 25 year old woman was a restrained driver in a rollover motor vehicle accident (MVA) and suffered a C5-C6 fracture-dislocation with spinal cord injury (Figure 1). She developed neurogenic stunned myocardium, symptomatic bradycardia and neurogenic shock. Her cardiac ultrasound has been previously presented and can be viewed by clicking here. After developing the adult respiratory distress syndrome and multi-system organ failure she had multiple cardiac arrests and died after 5 days in the intensive care unit.

Evan D. Schmitz, MD

Richland, Washington

Reference as: Schmitz ED. Medical image of the week: cervical fracture and dislocation. Southwest J Pulm Crit Care. 2014;8(4):204. doi: http://dx.doi.org/10.13175/swjpcc030-14 PDF 

Medical Image of the Week: Aortic Tear

Figure 1.  Portable chest x-ray demonstrating widened mediastinum with an apical cap, consistent with aortic rupture.

A 56-year old man presented as a trauma victim with the chief complaint of severe back pain. He was hemodynamically acceptable on arrival, but arrested shortly after this portable film was obtained (Figure 1). Emergency Department (ED) thoracotomy revealed a 3 cm longitudinal tear of the thoracic aorta and he exsanguinated in the ED.

Jarrod M. Mosier, MD

Department of Medicine and Emergency Medicine

Emergency Medicine-Critical Care Program

University of Arizona

Tucson, Arizona

Reference as: Mosier JM. Medical image of the week: aortic tear. Southwest J Pulm Crit Care. 2013;7(5): . doi: http://dx.doi.org/10.13175/swjpcc152-13 PDF