Approach to Acute Traumatic and Nontraumatic Diaphragmatic Abnormalities

Acute diaphragmatic abnormalities encompass a broad variety of relatively uncommon and underdiagnosed pathologic conditions, which can be subdivided into nontraumatic and traumatic entities. Nontraumatic abnormalities range from congenital hernia to spontaneous rupture, endometriosis-related disease, infection, paralysis, eventration, and thoracoabdominal fistula. Traumatic abnormalities comprise both blunt and penetrating injuries. Given the role of the diaphragm as the primary inspiratory muscle and the boundary dividing the thoracic and abdominal cavities, compromise to its integrity can yield devastating consequences. Yet, diagnosis can prove challenging, as symptoms may be vague and findings subtle. Imaging plays an essential role in investigation. Radiography is commonly used in emergency evaluation of a patient with a suspected thoracoabdominal process and may reveal evidence of diaphragmatic compromise, such as abdominal contents herniated into the thoracic cavity. CT is often superior, in particular when evaluating a trauma patient, as it allows rapid and more detailed evaluation and localization of pathologic conditions. Additional modalities including US, MRI, and scintigraphy may be required, depending on the clinical context. Developing a strong understanding of the acute pathologic conditions affecting the diaphragm and their characteristic imaging findings aids in efficient and accurate diagnosis. Additionally, understanding the appearance of diaphragmatic anatomy at imaging helps in differentiating acute pathologic conditions from normal variations. Ultimately, this knowledge guides management, which depends on the underlying cause, location, and severity of the abnormality, as well as patient factors. ©RSNA, 2024 Supplemental material is available for this article.

Thymic Imaging Pitfalls and Strategies for Optimized Diagnosis

Thymic imaging is challenging because the imaging appearance of a variety of benign and malignant thymic conditions are similar. CT is the most commonly used modality for mediastinal imaging, while MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT are helpful when they are tailored to the correct indication. Each of these imaging modalities has limitations and technical pitfalls that may lead to an incorrect diagnosis and mismanagement. CT may not be sufficient for the characterization of cystic thymic processes and differentiation between thymic hyperplasia and thymic tumors. MRI can be used to overcome these limitations but is subject to other potential pitfalls such as an equivocal decrease in signal intensity at chemical shift imaging, size limitations, unusual signal intensity for cysts, subtraction artifacts, pseudonodularity on T2-weighted MR images, early imaging misinterpretation, flow and spatial resolution issues hampering assessment of local invasion, and the overlap of apparent diffusion coefficients between malignant and benign thymic entities. FDG PET/CT is not routinely indicated due to some overlap in FDG uptake between thymomas and benign thymic processes. However, it is useful for staging and follow-up of aggressive tumors (eg, thymic carcinoma), particularly for detection of occult metastatic disease. Pitfalls in imaging after treatment of thymic malignancies relate to technical challenges such as postthymectomy sternotomy streak metal artifacts, differentiation of postsurgical thymic bed changes from tumor recurrence, or human error with typical "blind spots" for identification of metastatic disease. Understanding these pitfalls enables appropriate selection of imaging modalities, improves diagnostic accuracy, and guides patient treatment. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Computed tomography features and prevalence of focal diaphragmatic mineralization in 300 dogs

A focal area of mineral attenuation is commonly observed in the diaphragmatic crura of canine patients undergoing a thoracic CT. There is no mention of this finding in either the human or veterinary medicine literature. This retrospective study evaluates 300 canine thoracic CT studies with the aim of describing the CT appearance of this finding and establishing a prevalence in a large cohort of dogs. The presence of the mineral focus and its CT characteristics, including length, attenuation, and appearance, were recorded and correlated with the patient's signalments and anamnesis. The focus was observed in 43 of 300 studies (14.3%). The most common appearance was a thin, millimetric, toothpick-like mineral attenuating structure in the confluence of the diaphragmatic crura, just ventral to the aorta. There was no association with adjacent potentially pathological changes. A significant correlation was found between the presence of the focus and the patient's body weight (P = .03), as well as with a brachycephalic conformation (P = .03). This focus of mineralization represents a relatively common incidental finding in the canine diaphragm and has no evident association with pathology.

Analysis of the relationship between spinal alignment and retrocrural space area in adult spinal deformity surgery: Potential risk factors for acute celiac artery compression syndrome

PURPOSE

This study was designed to reveal the association between spinal parameters and RCS area in patients with adult spinal deformities treated with spinal correction surgery. We hypothesized that reduction of the retrocrural space (RCS) area is related to thoracolumbar alignment, which may cause acute celiac artery compression syndrome (ACACS).

METHODS

Eighty-nine patients (age: 68.4 ± 7.6 years; sex: 7 male/82 female) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parameters were measured, and the differences between these parameters were calculated. Postoperative T12 translation was measured and RCS area was evaluated using reconstructed computed tomography. The change of RCS area after surgery was defined as ΔRCS. Patients were divided into increased and decreased RCS groups by the ΔRCS value, and spinal parameters were compared between groups. The correlation between spinal parameters and ΔRCS was calculated.

RESULTS

The patients in the decreased RCS group had greater anterior T12 translation than those in the increased RCS group (p < 0.001). T12 translation was significantly correlated with ΔRCS (β = -0.31, p = 0.017). There were no correlations between ΔRCS and other spinal parameters.

CONCLUSION

Thoracolumbar alignment was associated with RCS area. Consistent with the hypothesis, overcorrection of the thoracolumbar junction was associated with reduced RCS area and might be one risk factor for ACACS.

Neglected Anatomical Areas in Ovarian Cancer: Significance for Optimal Debulking Surgery

Ovarian cancer (OC), the most lethal gynecological malignancy, usually presents in advanced stages. Characterized by peritoneal and lymphatic dissemination, OC necessitates a complex surgical approach usually involving the upper abdomen with the aim of achieving optimal cytoreduction without visible macroscopic disease (R0). Failures in optimal cytoreduction, essential for prognosis, often stem from overlooking anatomical neglected sites that harbor residual tumor. Concealed OC metastases may be found in anatomical locations such as the omental bursa; Morison's pouch; the base of the round ligament and hepatic bridge; the splenic hilum; and suprarenal, retrocrural, cardiophrenic and inguinal lymph nodes. Hence, mastery of anatomy is crucial, given the necessity for maneuvers like liver mobilization, diaphragmatic peritonectomy and splenectomy, as well as dissection of suprarenal, celiac, and cardiophrenic lymph nodes in most cases. This article provides a meticulous anatomical description of neglected anatomical areas during OC surgery and describes surgical steps essential for the dissection of these "neglected" areas. This knowledge should equip clinicians with the tools needed for safe and complete cytoreduction in OC patients.

Computed tomographic manifestations of celiac ganglia between hypertensive and non-hypertensive population

The celiac ganglion (CG) is associated with the sympathetic nervous system (SNS) and plays an important role in the pathogenesis of hypertension. The characteristics of the CG in patients with hypertension remain unknown. The aim of our study was to explore the differences in celiac ganglia (CGs) characteristics between hypertensive and non-hypertensive populations using computed tomography (CT). CGs manifestations on multidetector row CT in 1003 patients with and without hypertension were retrospectively analyzed. The morphological characteristics and CT values of the left CGs were recorded. The CT values of the ipsilateral adrenal gland (AG) and crus of the diaphragm (CD) were also measured. The left CG was located between the left AG and CD, and most CGs were long strips. The frequency of visualization of the left CGs was higher in the hypertension group than in the non-hypertension group (p < .05). There were no significant differences in the maximum diameter, size, and shape ratio of the left CGs between the two groups (p > .05). Except for the left CG in the arterial phase, the CT values of the left CG and AG in the non-hypertensive group were higher than those in the hypertension group (p < .05). The venous phase enhancement of the left CG in the non-hypertension group was significantly higher than that in the hypertension group (p < .05). Our findings reveal that CGs have characteristic manifestations in the hypertensive population. As important targets of the SNS, CGs have the potential to regulate blood pressure.

[Lesions of the paravertebral mediastinum]

BACKGROUND

Lesions of the paravertebral mediastinum are rare, and knowledge of possible differential diagnoses is essential for clinical practice.

OBJECTIVE/METHODS

To review common lesions of the paravertebral mediastinum.

RESULTS

The paravertebral mediastinum mainly includes fatty tissue and neurogenic structures. Imaging is commonly performed using computed tomography (CT) and magnetic resonance imaging (MRI). Neurogenic tumors are the most common lesions of the paravertebral mediastinum. Other pathologies include extramedullary hematopoiesis, lipomatous, lymphogenic, inflammatory, and cystic lesions. Moreover, also diaphragmatic hernias, vascular and esophageal pathologies may be found in the paravertebral mediastinum.

Diagnostic pitfalls in computed tomography of the chest

Anatomical variants and imaging artifacts on thoracic computed tomography (CT), when unrecognized as such, can lead to radiological misinterpretation and erroneous diagnosis. This is a concise review of 15 common CT diagnostic pitfalls due to anatomical variants and imaging artifacts which have potential to be misinterpreted as significant pathology, such as neoplasia, infection, traumatic injury, interstitial lung disease, pleural disease, or vascular lesions.

Three-dimensional morphogenesis of the human diaphragm during the late embryonic and early fetal period: Analysis using T1-weighted and diffusion tensor imaging

A precise understanding of human diaphragm development is essential in fetal medicine. To our knowledge, no previous study has attempted a three-dimensional (3-D) analysis and evaluation of diaphragmatic morphogenesis and development from the embryonic to the early fetal period. This study aimed to evaluate the morphogenesis and fibrous architecture of the developing human diaphragm during the late embryonic and early fetal periods. Fifty-seven human embryos and fetuses (crown-rump length [CRL] = 8-88 mm) preserved at the Congenital Anomaly Research Center of Kyoto University and Shimane University were analyzed. 3-D morphogenesis and fiber orientation of the diaphragm were assessed using phase-contrast X-ray computed tomography, T1-weighted magnetic resonance imaging (T1W MRI), and diffusion tensor imaging (DTI). T1W MR images and DTI scans were obtained using a 7-T MR system. The diaphragm was completely closed at Carnegie stage (CS) 20 and gradually developed a dome-like shape. The diaphragm was already in contact with the heart and liver ventrally in the earliest CS16 specimen observed, and the adrenal glands dorsally at CS19 or later. In the fetal period, the diaphragm contacted the gastric fundus in samples with a CRL ≥41 mm, and the spleen in samples with a CRL ≥70 mm. The relative position of the diaphragm with reference to the vertebrae changed rapidly from CS16 to CS19. The most cranial point of the diaphragm was located between the 4th and 8th thoracic vertebrae, regardless of fetal growth, in samples with a CRL of ≥16 mm. Diaphragmatic thickness was nearly uniform (0.15-0.2 mm) across samples with a CRL of 8-41 mm. The sternal, costal, lumbar parts, and the area surrounding the esophageal hiatus thickened with growth in samples with a CRL of ≥46 mm. The thickness at the center of the diaphragm and the left and right hemidiaphragmatic domes did not increase with growth. Tractography showed that the fiber orientation of the sternal, costal, and lumbar parts became more distinct as growth progressed in CS19 or later. All fibers in the costal and lumbar regions ran toward the left and right hemidiaphragmatic domes, except for those running to the caval opening and esophageal hiatus. The fiber orientation patterns from the right and left crura surrounding the esophageal hiatus were classified into three types. Distinct fiber directions between the costal and sternal and between the costal and lumbar diaphragmatic parts were observable in samples with a CRL of ≥46 mm. Anterior costal and sternal fibers ran toward the center. Fiber tracts around the center and the left and right hemidiaphragmatic domes; between the costal and lumbar orientations; and between the costal and sternal orientations showed a tendency for decreasing fractional anisotropy values with fetal growth and showed less density than other areas. In conclusion, we used 3-D thickness assessment and DTI tractography to identify qualitative changes in the muscular and tendonous regions of the diaphragm during the embryonic and early fetal periods. This study provides information on normal human diaphragm development for the progression of fetal medicine and furthering the understanding of congenital anomalies.

"Mega" Cisterna Chyli: A Case Report and Review of the Literature

Enlarged cisterna chyli is an infrequently encountered entity and is most often an asymptomatic, incidental finding on imaging for other reasons. The pathogenesis of cisterna chyli enlargement is not well elucidated and includes infectious, inflammatory, and idiopathic causes. In this report, we present the rare case of an asymptomatic, markedly dilated "mega" cisterna chyli in a 60-year-old female.

Ovarian cancer reporting lexicon for computed tomography (CT) and magnetic resonance (MR) imaging developed by the SAR Uterine and Ovarian Cancer Disease-Focused Panel and the ESUR Female Pelvic Imaging Working Group

OBJECTIVES

Imaging evaluation is an essential part of treatment planning for patients with ovarian cancer. Variation in the terminology used for describing ovarian cancer on computed tomography (CT) and magnetic resonance (MR) imaging can lead to ambiguity and inconsistency in clinical radiology reports. The aim of this collaborative project between Society of Abdominal Radiology (SAR) Uterine and Ovarian Cancer (UOC) Disease-focused Panel (DFP) and the European Society of Uroradiology (ESUR) Female Pelvic Imaging (FPI) Working Group was to develop an ovarian cancer reporting lexicon for CT and MR imaging.

METHODS

Twenty-one members of the SAR UOC DFP and ESUR FPI working group, one radiology clinical fellow, and two gynecologic oncology surgeons formed the Ovarian Cancer Reporting Lexicon Committee. Two attending radiologist members of the committee prepared a preliminary list of imaging terms that was sent as an online survey to 173 radiologists and gynecologic oncologic physicians, of whom 67 responded to the survey. The committee reviewed these responses to create a final consensus list of lexicon terms.

RESULTS

An ovarian cancer reporting lexicon was created for CT and MR Imaging. This consensus-based lexicon has 6 major categories of terms: general, adnexal lesion-specific, peritoneal carcinomatosis-specific, lymph node-specific, metastatic disease -specific, and fluid-specific.

CONCLUSIONS

This lexicon for CT and MR imaging evaluation of ovarian cancer patients has the capacity to improve the clarity and consistency of reporting disease sites seen on imaging.

KEY POINTS

• This reporting lexicon for CT and MR imaging provides a list of consensus-based, standardized terms and definitions for reporting sites of ovarian cancer on imaging at initial diagnosis or follow-up. • Use of standardized terms and morphologic imaging descriptors can help improve interdisciplinary communication of disease extent and facilitate optimal patient management. • The radiologists should identify and communicate areas of disease, including difficult to resect or potentially unresectable disease that may limit the ability to achieve optimal resection.

Qualitative assessment of chronic pain management in patients undergoing computed tomography-guided procedures

Background

To study the qualitative efficacy and safety of percutaneous pain management under CT guidance. The success rate of medical management for chronic pain in long term is very less. This study aids in evaluating the clinical success rate in each CT-guided pain management procedure we have done.

Results

Among the 60 patients, 39 (65%) were male patients and 21 (35%) were female patients. We did 40 celiac plexus neurolysis (66.7%), 13 radiofrequency ablations (21.6%), 4 stellate ganglion neurolysis (6.7%), and 3 trigeminal nerve neurolysis (5%). The average pre-procedural pain score in all the procedures was 7 which was significantly reduced to 1 in 24 h and 1 and 3 months.

Conclusion

Percutaneous pain management under CT guidance by virtue of its precise needle placement offers effective pain relief. It has a lower rate of complications, reduces the need for repeat procedures, and ultimately increases the quality of life.

The Importance of the Posterolateral Area of the Diaphragm Muscle for Palpation and for the Treatment of Manual Osteopathic Medicine

The eupneic act in healthy subjects involves a coordinated combination of functional anatomy and neurological activation. Neurologically, a central pattern generator, the components of which are distributed between the brainstem and the spinal cord, are hypothesized to drive the process and are modeled mathematically. A functionally anatomical approach is easier to understand although just as complex. Osteopathic manipulative treatment (OMT) is part of osteopathic medicine, which has many manual techniques to approach the human body, trying to improve the patient's homeostatic response. The principle on which OMT is based is the stimulation of self-healing processes, researching the intrinsic physiological mechanisms of the person, taking into consideration not only the physical aspect, but also the emotional one and the context in which the patient lives. This article reviews how the diaphragm muscle moves, with a brief discussion on anatomy and the respiratory neural network. The goal is to highlight the critical issues of OMT on the correct positioning of the hands on the posterolateral area of the diaphragm around the diaphragm, trying to respect the existing scientific anatomical-physiological data, and laying a solid foundation for improving the data obtainable from future research. The correctness of the position of the operator's hands in this area allows a more effective palpatory perception and, consequently, a probably more incisive result on the respiratory function.

Revising the classification of lung sequestrations

PURPOSES

The classification of lung sequestrations distinguishes between extralobar and intralobar types, according to their venous drainage - systemic vs pulmonary - and the presence or absence of independent pleura. However, imaging, surgical and/or pathological findings often differ from this description. The objectives of this article are to quantify the percentage of lung sequestrations that do not fit the classic description of extra- and intralobar types and to evaluate the accuracy of the currently used classification.

METHODS

A retrospective search identified all children with a confirmed lung sequestration diagnosed and treated in our Hospital over the last 10 years. Two senior pediatric radiologists reviewed their contrast-enhanced computed tomography chest scans and evaluated the main anatomical features that define sequestrations, including pleura, arterial and venous pattern, airways and lung parenchyma. We compared the imaging-, surgical- and pathological findings to those described for extra- and intralobar sequestrations.

RESULTS

25 children (20 M, 5 F) conform the series. Only 13 lesions (52%) filled all criteria described for an extra- or intralobar sequestration. The remaining 12 lesions (48%) had at least one differing criteria, including incomplete independent pleura (n = 2; 8%), mixed systemic and pulmonary arterial supply (n = 1; 4%) or venous drainage (n = 3; 12%), normal connection to airway (n = 1; 4%) and/or coexistent congenital lung anomalies (n = 11; 44%).

CONCLUSION

Lung sequestrations seem to represent a spectrum of anomalies rather than separated entities. Therefore, a detailed description of their main anatomical features could be more relevant for clinicians and surgeons that the rigid distinction in intra- and extralobar sequestration currently applied.

Imaging findings of lesions in the middle and posterior mediastinum

Lesions in the middle and posterior mediastinum are relatively rare, but there are some useful radiological clues that can be used to diagnose them precisely. It is useful to determine the affected mediastinal compartment and the locations of the main thoracic nerves on medical images for diagnosing such mediastinal lesions. Neurogenic tumors can occur in the middle mediastinum, although they generally arise as posterior mediastinal tumors. Based on the above considerations, we review various characteristic imaging findings of middle and posterior mediastinal lesions, and their differential diagnoses.

Routes of Transdiaphragmatic Migration from the Abdomen to the Chest

The diaphragm serves as an anatomic border between the abdominal and thoracic cavities. Pathologic conditions traversing the diaphragm are often incompletely described and may be overlooked, resulting in diagnostic delays. Several routes allow abdominal contents or pathologic processes to spread into the thorax, including along normal transphrenic structures, through congenital defects in the diaphragm, through inherent areas of weakness between muscle groups, or by pathways created by tissue destruction, trauma, or iatrogenic injuries. A thorough knowledge of the anatomy of the diaphragm can inform an accurate differential diagnosis. Often, intraperitoneal pathologic conditions crossing the diaphragm may be overlooked if axial imaging is the only approach to this complex region because of the horizontal orientation of much of the diaphragm. Multiplanar capabilities of volumetric CT and MRI provide insight into the pathways where pathologic conditions may traverse this border. Knowledge of these characteristic routes and use of multiplanar imaging are critical for depiction of specific transdiaphragmatic pathologic conditions.^©RSNA, 2020.

Trans-diaphragmatic Pathologies: Anatomical Background and Spread of Disease on Cross-sectional Imaging

The diaphragm is not only a sheet of muscle separating the abdominal and thoracic cavities: it plays an essential role in ventilation and can act as a gateway for the spread of different disease processes between the abdominal and the thoracic cavity. Careful attention to the appearance of the diaphragm on various imaging modalities is essential to ensure the accurate diagnosis of diaphragmatic disorders, which may be secondary to functional or anatomical derangements.

Imaging evaluation of diaphragmatic injuries: Improving interpretation accuracy

Diaphragmatic Injuries (DIs) remain a challenging diagnosis with potential catastrophic delayed complications. A high degree of suspicion in every case of severe blunt thoracoabdominal trauma or penetrating thoracoabdominal injury is essential. This review will present the evidence and controversies on this topic providing a practical tutorial for radiologists hoping to improve their interpretive accuracy for both blunt and penetrating DIs. The imaging signs of diaphragmatic injuries will be explained with emphasis on multidetector CT. Diagnostic pitfalls, available protocols and other issues will be presented.

Unravelling the Mysteries of Traumatic Diaphragmatic Injury: An Up-to-Date Review

Traumatic diaphragmatic injury (TDI) is an underdiagnosed condition that has recently increased in prevalence due to its association with automobile collisions. The initial injury is often obscured by concurrent thoracic and abdominal injuries. Traumatic diaphragmatic injury itself is rarely lethal at initial presentation, however associated injuries and complications of untreated TDI such as herniation and strangulation of abdominal viscera have serious clinical consequences. There are 2 primary mechanisms of TDIs: penetrating TDI which tend to be smaller, more difficult to detect, and result in fewer complications; and blunt TDIs which are larger and have higher overall mortality due to associated injuries or delayed complications. The anatomy of thoracic and abdominal cavities distinguishes the epidemiology, pathophysiology, symptoms, treatment, and prognosis of right versus left TDI. Although there is no definitive radiologic sign for diagnosing TDI, many signs have been introduced in the literature and the concurrent presence of multiple signs increases the sensitivity of TDI detection. Conservative versus surgical management depends on mechanism of TDI, side, and most importantly the associated injuries.

The Anatomic Characteristics of the Retroperitoneal Oblique Corridor to the L1-S1 Intervertebral Disc Spaces

STUDY DESIGN

This is a cross-sectional study.

OBJECTIVE

To investigate the oblique corridor to the L1-S1 intervertebral disc space between the psoas muscle and the great vessels in cadaveric specimens bilaterally and the location of genitofemoral nerve and the diaphragmatic crura relative to the oblique corridor.

SUMMARY OF BACKGROUND DATA

Although use of oblique lumbar interbody fusion is rapidly expanding, the morphometric data related to the procedure are limited.

METHODS

Twelve fresh-frozen full-torso cadaveric specimens were dissected to examine the oblique corridor to access the L1-S1 space in a static state and with mild retraction of the psoas. The level at which the genitofemoral nerve pierces from the psoas major and the diaphragmatic crura originate from the lumbar vertebral body was also investigated.

RESULTS

The mean width of oblique corridor in the static state and with mild psoas retraction, respectively, were as follows: on the right side: (L1-2) 13.33 and 16.75 mm; (L2-3) 15.42 and 21.42 mm; (L3-4) 16.58 and 22.67 mm; (L4-5) 12.75 and 21.17 mm; (L5-S1) 5.92 and 12.00 mm; on the left side: (L1-2) 16.75 and 19.67 mm; (L2-3) 18.50 and 25.33 mm; (L3-4) 20.58 and 28.00 mm; (L4-5) 18.17 and 26.08 mm; and (L5-S1) 5.83 and 12.00 mm. The level at which the genitofemoral nerve pierces from the psoas major was between L2 and L4. The diaphragmatic crura originates from L1 to L3.

CONCLUSION

The oblique corridor allows access to the L1-L5 discs from both sides, but it is larger on the left side. The corridor between the iliac vessels and the psoas for L5-S1 is difficult to be applied clinically. Mild psoas retraction can moderately enlarge the oblique corridor. The genitofemoral nerve and diaphragmatic crura may be encountered in this approach and should be carefully observed.

LEVEL OF EVIDENCE

5.

Resection of retrocrural germ cell tumor metastases: Two surgical approaches

OBJECTIVES

The goals of retrocrural metastasectomy are complete resection with preservation of the diaphragmatic function while avoiding phrenic nerve injury and spinal cord ischemia. We describe 2 approaches for metastasectomy depending on the pattern of metastases.

METHODS

Between 1999 and 2017, 44 patients underwent 50 retrocrural metastasectomies. In case of lower retrocrural, bilateral retrocrural, and or additional retroperitoneal and abdominal metastases, an abdominal approach with mobilization of the liver and the kidney followed by longitudinal incision of the diaphragmatic crus was performed. In case of upper retrocrural metastases and additional thoracic disease, a thoracic approach was performed. The Kaplan-Meier method and log-rank test were used to analyze survival and prognosticators.

RESULTS

The minor morbidity, major morbidity, and mortality were 16.6%, 0%, and 0% for the abdominal approach, respectively, and 15.4%, 3.8%, and 0% for the thoracic approach. There was no phrenic nerve palsy, diaphragmatic hernia, or spinal cord ischemia. Additional retroperitoneal, mediastinal, pulmonary, or further resection was necessary in 10, 25, 9, and 6 cases, respectively. In all cases, a R0 resection was achieved. The 15-year survival rate was 95%.

CONCLUSIONS

Depending on the pattern of metastases, a complete retrocrural metastasectomy with low morbidity and without mortality by thoracic or abdominal approach is possible. Both approaches preserve diaphragmatic function. Furthermore, the lateral abdominal approach provides a good view and might lead to less tension at the spinal arteries and therefore might reduce the risk of paresis. Good long-term survival is achievable. These patients should be operated on in specialized centers.

Management of Residual Mass in Germ Cell Tumors After Chemotherapy

PURPOSE OF REVIEW

The purpose of this review is to educate medical oncologists on the management of patients with residual germ cell tumors and the role of surgical resection after platinum-based chemotherapy.

RECENT FINDINGS

Patients with non-seminomatous testicular cancer and residual enlarged retroperitoneal lymph nodes > 1 cm following induction chemotherapy with normal tumor markers should undergo a post-chemotherapy retroperitoneal lymph node dissection. All patients with primary mediastinal non-seminoma should undergo surgical resection of the mediastinal mass post-chemotherapy. These are complex surgeries and require expert surgeons in high-volume centers. Patients with advanced testicular seminoma who have residual masses less than 3 cm after chemotherapy can be observed without further intervention. Patients with a residual mass > 3 cm should be evaluated with PET scan after 6 weeks of chemotherapy. Residual mass with negative PET scan can be followed by surveillance while a positive PET scan requires further work up to rule out active disease.

Variant morphology and arterial supply of diaphragmatic crura with probe patent foramen ovale

Crura are the posterior pillars of the tendino-muscular partition between thoracic and abdominal cavity. This study highlights bilaterally an unfamiliar morphology of diaphragmatic crura with uncommon origin of inferior phrenic artery and accompanying atrial septal defect in a 63-years-old female cadaver with scoliosis. An attempt is made to portray the clinical implications of these variations. In addition authors have discussed the embryological and genetic basis of these variations. In the recent few decades, surgical correction of scoliosis involving intervention with the crura has gained pace. Knowledge about the normal as well as variant crural morphology is imperative for the surgeons to decide the correct approach during spinal corrective surgeries and for radiologist to prevent any diagnostic pitfall. Familiarity about the variant origin of inferior phrenic artery may prevent complications during treatment of pathological conditions related to inferior phrenic artery. Preoperative awareness about the coexisting atrial septal defect is vital for anesthesiologists promoting them to administer cardioprotective anesthetic drugs. To the best of our knowledge, description of such a combination of variations in anatomical literature is rare and scarcely reported. Awareness of these anatomical variations is relevant for operating surgeons, radiologists, anesthesiologists and anatomists.

Supradiaphragmatic origin of the renal artery; frequency on contrast-enhanced MR imaging

PURPOSE

The purpose of this study was to evaluate extremely rare cases of supradiaphragmatic origin of the renal artery, with magnetic resonance (MR) imaging findings.

METHODS

The study included 9 patients diagnosed with supra-diaphragmatic originating renal artery between 2010 and 2017. The patients were 7 females and 2 males with a mean age of 58.25 years (range, 41-71 years). MR imaging was applied to all patients.

RESULTS

In 2 patients, lumen loss was of a moderate degree, and mild in 3 patients. Renal artery stenosis was not observed in the remaining 4 patients. None of the patients had advanced luminal stenosis. The distance of the renal arteries to the diaphragmatic crus was 24 mm at the longest and 8 mm at the shortest. Congenital anomaly was found in 6 patients. Of the 9 patients, 7 had concomitant hypertension, and 2 had no history of hypertension.

CONCLUSIONS

The anomaly of supradiaphragmatic origin of the renal artery is rare but may be associated with renal artery stenosis, which may then result in hypertension. The clinician should investigate renal artery origin anomalies and renal artery compression syndrome in hypertensive cases where the cause cannot be explained.

Crus Atrophy: Accuracy of Computed Tomography in Diagnosis of Diaphragmatic Paralysis

PURPOSE

The aim of this study was to measure the association between crus atrophy as depicted by computed tomography (CT) and fluoroscopic diagnosis of hemidiaphragmatic paralysis in patients with suspected diaphragmatic dysfunction.

MATERIALS AND METHODS

A retrospective review of patient data was approved by our institutional review board and was HIPPA-compliant. We reviewed 90 patients who had undergone diaphragmatic fluoroscopy; 72 had CT scans available for measurement of crus thickness at the levels of the celiac and superior mesenteric arteries and the L1 vertebral body. Receiver operating characteristic analysis was used to determine the threshold of crus thinning that best distinguished a paralyzed hemidiaphragm from a nonparalyzed one.

RESULTS

Hemidiaphragmatic paralysis caused significant crus thinning at the celiac artery level (mean±SD, 1.7±0.6 vs. 3.6±1.3 mm, P=0.017, on the right; 1.1±0.4 vs. 3.0±1.4 mm, P=0.001, on the left) and the L1 vertebral level (mean±SD, 1.5±0.7 vs. 4.4±1.6 mm, P=0.018, on the right; 1.5±0.6 vs. 3.6+1.7 mm, P=0.017, on the left). On axial CT, thinning to ≤2.5 mm at the celiac artery level identified paralysis of the hemidiaphragm with a sensitivity of 100% and a specificity of 86% on the right and with a sensitivity of 100% and a specificity of 64% on the left. On coronal CT, thinning to ≤2.5 mm at the L1 vertebral level identified paralysis of the hemidiaphragm with a sensitivity of 100% and a specificity of 88% on the right and with a sensitivity of 100% and a specificity of 77% on the left.

CONCLUSIONS

Atrophy of the crus assessed by CT is a good discriminator of paralyzed versus nonparalyzed hemidiaphragm in patients with suspected diaphragmatic dysfunction.

Radiological classification of retroperitoneal hematoma resulting from lumbar vertebral fracture

PURPOSE

Lumbar vertebral fracture (LVF) infrequently produces massive retroperitoneal hematoma (RPH). This study aimed to systematically review the clinical and radiographic characteristics of RPH resulting from LVF.

METHODS

For 193 consecutive patients having LVF who underwent computed tomography (CT), demographic data, physiological conditions, and outcomes were reviewed from their medical records. Presence or absence of RPH, other bone fractures, or organ/vessel injury was evaluated in their CT images, and LVF or RPH, if present, was classified according to either the Orthopaedic Trauma Association classification or the concept of interfascial planes.

RESULTS

RPH resulting only or dominantly from LVF was found in 66 (34.2%) patients, whereas among the others, 64 (33.2%) had no RPH, 38 (19.7%) had RPH from other injuries, and 25 (13.0%) had RPH partly attributable to LVF. The 66 RPHs resulting only or dominantly from LVF were radiologically classified into mild subtype of minor median (n = 35), moderate subtype of lateral (n = 11), and severe subtypes of central pushing-up (n = 13) and combined (n = 7). Of the 20 patients with severe subtypes, 18 (90.0%) were in hemorrhagic shock on admission, and 6 (30.0%) were clinically diagnosed as dying due to uncontrollable RPH resulting from vertebral body fractures despite no anticoagulant medication.

CONCLUSIONS

LVF can directly produce massive RPH leading to hemorrhagic death. A major survey of such pathology should be conducted to establish appropriate diagnosis and treatment.

Imaging the posterior mediastinum: a multimodality approach

The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information.

Imaging findings in fetal diaphragmatic abnormalities

Imaging plays a key role in the detection of a diaphragmatic pathology in utero. US is the screening method, but MRI is increasingly performed. Congenital diaphragmatic hernia is by far the most often diagnosed diaphragmatic pathology, but unilateral or bilateral eventration or paralysis can also be identified. Extralobar pulmonary sequestration can be located in the diaphragm and, exceptionally, diaphragmatic tumors or secondary infiltration of the diaphragm from tumors originating from an adjacent organ have been observed in utero. Congenital abnormalities of the diaphragm impair normal lung development. Prenatal imaging provides a detailed anatomical evaluation of the fetus and allows volumetric lung measurements. The comparison of these data with those from normal fetuses at the same gestational age provides information about the severity of pulmonary hypoplasia and improves predictions about the fetus's outcome. This information can help doctors and families to make decisions about management during pregnancy and after birth. We describe a wide spectrum of congenital pathologies of the diaphragm and analyze their embryological basis. Moreover, we describe their prenatal imaging findings with emphasis on MR studies, discuss their differential diagnosis and evaluate the limits of imaging methods in predicting postnatal outcome.

Retrocrural space involvement on computed tomography as a predictor of mortality and disease severity in acute pancreatitis

Background

Because computed tomography (CT) has advantages for visualizing the manifestation of necrosis and local complications, a series of scoring systems based on CT manifestations have been developed for assessing the clinical outcomes of acute pancreatitis (AP), including the CT severity index (CTSI), modified CTSI, etc. Despite the internationally accepted CTSI having been successfully used to predict the overall mortality and disease severity of AP, recent literature has revealed the limitations of the CTSI. Using the Delphi method, we establish a new scoring system based on retrocrural space involvement (RCSI), and compared its effectiveness at evaluating the mortality and severity of AP with that of the CTSI.

Methods

We reviewed CT images of 257 patients with AP taken within 3–5 days of admission in 2012. The RCSI scoring system, which includes assessment of infectious conditions involving the retrocrural space and the adjacent pleural cavity, was established using the Delphi method. Two radiologists independently assessed the RCSI and CTSI scores. The predictive points of the RCSI and CTSI scoring systems in evaluating the mortality and severity of AP were estimated using receiver operating characteristic (ROC) curves.

Principal Findings

The RCSI score can accurately predict the mortality and disease severity. The area under the ROC curve for the RCSI versus CTSI score was 0.962±0.011 versus 0.900±0.021 for predicting the mortality, and 0.888±0.025 versus 0.904±0.020 for predicting the severity of AP. Applying ROC analysis to our data showed that a RCSI score of 4 was the best cutoff value, above which mortality could be identified.

Conclusion

The Delphi method was innovatively adopted to establish a scoring system to predict the clinical outcome of AP. The RCSI scoring system can predict the mortality of AP better than the CTSI system, and the severity of AP equally as well.

Prognostic implication of retrocrural lymph node involvement revealed by (18)F-FDG PET/CT in patients with uterine cervical cancer

OBJECTIVES

Lymph node involvement in cervical cancer is an indication of poor prognosis and the risk tends to increase according to the level of lymph node involvement. However, the specific prognostic significance of retrocrural lymph node involvement has not been well characterized because of its small size and deep location. The aim of this study was to assess its prognostic value.

PATIENTS AND METHODS

A total of 217 patients with newly diagnosed International Federation of Gynecology and Obstetrics (FIGO) stage IA2-IVA cervical cancer were retrospectively enrolled. All the patients had undergone pretreatment (18)F-fluorodeoxy-D-glucose ((18)F-FDG) PET/CT. Of these patients 145 were treated with concurrent chemoradiotherapy, and in this group we assessed the relationship of retrocrural lymph node involvement with the risk of disease progression.

RESULTS

Retrocrural lymph node involvement was seen in 7.4% of patients (16/217). All of them had para-aortic lymph node involvement and 56% of the 16 patients (9/16) had concomitant supraclavicular lymph node involvement. In the patients treated with concurrent chemoradiotherapy it was found that the higher the level of (18)F-FDG-positive lymph nodes detected in them, the worse the progression-free survival experienced by them (none vs. pelvic, pelvic vs. para-aortic, para-aortic vs. retrocrural; P<0.05); however, there was no difference in progression outcome between retrocrural and supraclavicular areas (P=NS). On multivariate Cox proportional hazard analysis, the highest level of (18)F-FDG PET/CT-positive lymph nodes in the para-aortic [hazard ratio (HR) 6.05, 95% confidence interval (CI) 2.18-16.81], retrocrural (HR 17.05, 95% CI 5.34-54.44), and supraclavicular areas (HR 19.56, 95% CI 7.15-53.54) was a significant prognostic factor.

CONCLUSION

The highest level of lymph node involvement in para-aortic, retrocrural, supraclavicular areas was a significant prognostic factor for progression in uterine cervical cancer patients who were treated with concurrent chemoradiotherapy. Retrocrural lymph node involvement shows a similar outcome with supraclavicular involvement, but leads to a worse outcome in terms of progression compared with para-aortic lymph node involvement.

Acute prevertebral abscess secondary to infected pancreatic pseudocyst

We report a case of a middle aged, man with diabetes who presented with dysphagia and odynophagia. On evaluation, he was diagnosed to have an acute prevertebral abscess with an unusual aetiology, an infected pseudocyst of pancreas. Contrast-enhanced CT revealed an enhancing collection in the prevertebral space extending to the retrogastric space and communicating with the body of the pancreas via the oesophageal hiatus. Transoral incision and drainage of the prevertebral abscess were performed. Nasogastric tube was placed in the prevertebral space for continuous drainage and daily irrigation. Supportive intravenous broad spectrum antibiotic therapy along with the surgical intervention led to the resolution of the prevertebral abscess and the infected pancreatic pseudocyst.

Extrapleural and cardiophrenic lymph nodes: prevalence, clinical significance and diagnostic value

PURPOSE

The aim of this study was to evaluate the prevalence, clinical meaning and diagnostic value of extrapleural and cardiophrenic nodes occasionally observed on computed tomography (CT) scans of the chest.

MATERIALS AND METHODS

We included 750 consecutive patients who underwent CT of the chest for different clinical purposes (340 nonneoplastic patients, 270 with extrathoracic neoplasms, 120 with intrathoracic neoplasms, 20 with pleural metastasis) and 91 patients with histologically proven malignant pleural mesothelioma (MPM). For each group of patients, we analysed the presence of extrapleural and cardiophrenic nodes, their number (single or multiple) and their size.

RESULTS

The prevalence of cardiophrenic nodes between 6 and 10 mm and >10 mm was significantly higher in patients with MPM (28.6 and 26.4 %, respectively) than in all other categories of patients, except for patients with pleural metastasis (30 and 25 %, respectively). The prevalence of extrapleural nodes, independently from their size, was significantly higher in patients with MPM (68 %) compared with all other groups, including patients with pleural metastasis (5 %; p < 0.0001).

CONCLUSIONS

Cardiophrenic nodes >5 mm and extrapleural nodes of any size have a significant diagnostic value in malignant pleural disease, either primary or secondary, whereas they are extremely rare in other neoplastic or nonneoplastic diseases.

Influence of surrounding tissues on biomechanics of aortic wall

The present study investigates effects of surrounding tissues and non-uniform wall thickness on the biomechanics of the thoracic aorta. We construct two idealised computational models exemplifying the importance of surrounding tissues and non-uniform wall thickness, namely the uniform-thickness model and the histology image-based model. While the former neglects a connective tissue layer surrounding the aorta, the latter takes it into account with non-uniform wall thickness. Using plane strain finite element analysis, stress distributions in the aortic media between the two models are compared. The histology image-based model substantially enhances the uniformity of stress throughout the aortic media. Furthermore, the altered mechanical properties of surrounding tissues change the stress distribution. These results suggest that surrounding tissues and non-uniform wall thickness should be included in biomechanical analysis to better understand regional adaptation of the aortic wall during normal physiological conditions or pathological conditions such as aortic aneurysms and dissections.

Anatomic connections of the diaphragm: influence of respiration on the body system

The article explains the scientific reasons for the diaphragm muscle being an important crossroads for information involving the entire body. The diaphragm muscle extends from the trigeminal system to the pelvic floor, passing from the thoracic diaphragm to the floor of the mouth. Like many structures in the human body, the diaphragm muscle has more than one function, and has links throughout the body, and provides the network necessary for breathing. To assess and treat this muscle effectively, it is necessary to be aware of its anatomic, fascial, and neurologic complexity in the control of breathing. The patient is never a symptom localized, but a system that adapts to a corporeal dysfunction.

CT of blunt diaphragmatic rupture

The diagnosis of blunt diaphragmatic rupture (BDR) is difficult and often missed, leaving many patients with this traumatic injury at risk for life-threatening complications. The potential diagnostic pitfalls are numerous and include anatomic variants and congenital and acquired abnormalities. Chest radiography, despite its known limitations, may still be helpful in the early assessment of severe thoracoabdominal trauma and for detecting initially overlooked BDR or late complications of BDR. However, since the development of helical and multidetector scanners, computed tomography (CT) has become the reference standard; thus, knowledge of the CT signs suggestive of BDR is important for recognition of this injury pattern. A large number of CT signs of BDR have been described elsewhere, many of them individually, but the use of various appellations for the same sign can make previously published reports confusing. The systematic description and classification of CT signs provided in this article may help clarify matters and provide clues for diagnosing BDR. The authors describe 19 distinct CT signs grouped in three categories: direct signs of rupture, indirect signs that are consequences of rupture, and signs that are of uncertain origin. Since no single CT sign can be considered a marker leading to a correct diagnosis in every case of BDR, accurate diagnosis depends on the analysis of all signs present.

A malignant retroperitoneal mass--a rare presentation of recurrent thymoma

A 60-year-old man presented with a suspected retroperitoneal mass, after primarily resected thymoma (type B1/B2, Masaoke stage 1). A germ cell tumour was excluded and a diagnostic biopsy was performed. The mass appeared to be a local recurrence of the primary thymoma, for example, a droplet metastasis, progressed to type B3.

Retrocrural Lymph Node Metastasis Disclosed by (18)F-FDG PET/CT: A Predictor of Supra-diaphragmatic Spread in Ovarian Cancer

PURPOSE

Retrocrural lymph nodes (RCLNs) communicate with retroperitoneal and posterior mediastinal LNs. It is possible that, when RCLNs are involved, supra-diaphragmatic extension will occur in abdomino-pelvic cancers. The authors investigated performance of (18)F-FDG PET/CT to diagnose RCLN metastasis and whether RCLN metastases were associated with supra-diaphragmatic lymphatic metastases of ovarian cancer.

MATERIALS AND METHODS

Sixty-seven patients with stage IV ovarian cancer who had undergone (18)F-FDG PET/CT were included in this retrospective study. Diagnostic performance of (18)F-FDG PET/CT for RCLN metastasis was evaluated. Patients were divided into two groups by presence or absence of supra-diaphragmatic LN metastasis. The prevalences of RCLN metastasis between the two groups were compared and the odds ratio was calculated.

RESULTS

Sensitivity and specificity of (18)F-FDG PET/CT for RCLN metastasis were 96.3 and 100%, respectively. Of the 67 study subjects, 27 patients had RCLN metastases (40.3%). Fifty patients had supra-diaphragmatic LN metastases. (18)F-FDG PET/CT showed 26 RCLN metastases in patients with supra-diaphragmatic LN metastases (54.5%), and only 1 in patients without supra-diaphragmatic LN metastasis (5.9%), and the difference between two groups was statistically significant (P < 0.05). The odds ratio that patients with RCLN metastasis would have supra-diaphragmatic LN metastasis was 17.3 (95% confidence interval = 2.1 to 140.9, P = 0.008).

CONCLUSION

Performance of (18)F-FDG PET/CT to diagnose RCLN metastasis was excellent. RCLN metastasis revealed by (18)F-FDG PET/CT was strongly associated with supra-diaphragmatic LN spread of ovarian cancer. Thus, RCLN metastasis could be used as a predictor of supra-diaphragmatic lymphatic metastasis of ovarian cancer.

Morphological features and clinical feasibility of thoracic duct: detection with nonenhanced magnetic resonance imaging at 3.0 T

PURPOSE

To evaluate the detection of the thoracic duct using nonenhanced magnetic resonance imaging (MRI) and to determine the influence of some related disorders on the lymphatic duct.

MATERIALS AND METHODS

Highly fluid-sensitive sequence and fat-suppressed T2-weighted imaging (FS-T2WI) were performed in a total of 139 cases. The axial and coronal images were used to locate the thoracic duct and the measurement and evaluation of its dimensions were performed using a 3D maximum intensity projection (MIP) reconstruction image. The differences in the dimensions among control, portal hypertension, and common bile duct obstruction groups were compared using one-way analysis of variance.

RESULTS

The cisterna chyli was shown in 91% of cases on FS-T2WI, while the thoracic duct appeared in 70% of the MIP images. The common configuration of the cisterna chyli was tubular or saccular in 73%. Eighty thoracic ducts had a slight turn declining to the left at the level of T8-10. There was a significant difference in the transverse diameter of the thoracic duct between the portal hypertension group and other groups (F = 5.638, P = 0.005).

CONCLUSION

Nonenhanced MRI is feasible for locating and depicting the morphological features of the thoracic duct. Portal hypertension may influence the dimension of the thoracic duct.