American Roentgen Ray Society Research Articles

Radiological Reasoning: Multiple Mesenteric Masses

Radiological Reasoning: Multiple Mesenteric MassesKhaled M. Elsayes1, Stephen M. Broski2 and Abouelmagd Makramalla3Audio Available | Share

Thymus in the Superior Mediastinum: Relationship With Strap Muscles

Thymus in the Superior Mediastinum: Relationship With Strap MusclesDae Hee HanAudio Available | Share

Radiological Reasoning: Postoperative Renal Mass

Received January 22, 2008; accepted after revision September 10, 2008. 1Department of Radiology, Section of Vascular and Interventional Radiology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201. Address correspondence to S. Regalado (sidreg3@yahoo.com). 2Department of Interventional Radiology, University of Chicago Hospitals, Chicago, IL. AJR 2010;194:S64–S68 0361–803X/10/1946–S64 © American Roentgen Ray Society OBJECTIVE Renal artery pseudoaneurysms are a known complication after partial nephrectomy. The endovascular management of renal artery pseudoaneurysms will be discussed.

AJR Teaching File: Diabetic Patient Presenting With Right Flank Pain and Fever

AJR 2010;194:WS31–WS33 0361–803X/10/1946–WS31 © American Roentgen Ray Society Clinical History A 57-year-old woman with a history of type 2 diabetes mellitus presented to the emergency department with right flank pain, fever, hypotension, and intractable emesis. Subsequently, the patient was referred to CT for evaluation. Laboratory studies were remarkable for leukocytosis and hyperglycemia, with a serum glucose level of 556 mg/dL. Blood cultures revealed Escherichia coli.

Thanatophoric Dysplasia: Role of 3D Sonography

Thanatophoric Dysplasia: Role of 3D SonographyLourens R. Pistorius, Gwendolyn T. R. Manten and Peter G. NikkelsAudio Available | Share

CT Findings of Primary Pigmented Nodular Adrenocortical Disease: Rare Cause of ACTH-Independent Cushing Syndrome

AJR 2010; 194:W541 0361–803X/10/1946–W541 © American Roentgen Ray Society CT Findings of Primary Pigmented Nodular Adrenocortical Disease: Rare Cause of ACTH-Independent Cushing Syndrome We read with great interest the article by Johnson and colleagues [1], “Adrenal Imaging With MDCT: Nonneoplastic Disease,” in the October 2009 issue of the AJR. The authors make a thorough and detailed description of the spectrum of CT findings in nonneoplastic adrenal diseases, enriched with high-quality and representative figures. The authors mention that adrenocorticotropic hormone (ACTH)-independent Cushing syndrome (CS) due to either adrenal adenoma or carcinoma is a major cause of adrenal hyperplasia [1]. Primary pigmented nodular adrenocortical disease (PPNAD) also is associated with ACTH-independent CS, but it is characterized by smallto normal-sized adrenal glands containing multiple small cortical pigmented nodules or macronodules, most often surrounded by an atrophic cortex [2, 3]. PPNAD is seen mostly in infants, children, or young adults and is characterized by elevated levels of plasma and urinary cortisol that are not suppressed or may be increased by high doses of dexamethasone (Liddle test) [2]. The clinical presentation of CS in this group of patients may be atypical, with common manifestations including an asthenic body habitus, short stature, severe osteoporosis, and severe muscle and skin wasting [2]. Atrophy of the cortex in CS patients is characteristic of PPNAD and reflects the autonomous function of these nodules and suppressed levels of pituitary ACTH [2–4]. Despite their small size—usually less than 6 mm—the nodules are visible at CT, and their visualization is facilitated by the surrounding cortical atrophy [3]. These two factors (i.e., atrophy and nodules) create an irregular contour of the gland (Fig. 1). This irregularity is distinctly abnormal and diagnostic for the disease, especially in younger patients [3]. The characteristic pigments—within the nodules or the adrenal limbs—contain lipofuscin, which may become partly melanized, forming neuromelanin and appearing at CT as hypodense dots a few mm in diameter (Fig. 1). The possibility of PPNAD should arise in young patients with classic CS or with atypical, subclinical, or cyclic hypercortisolism and adrenal glands of normal or reduced dimensions but with a knobby or irregular contour. More than 90% of the reported PPNAD cases are associated with Carney complex; a multiple neoplasia syndrome; or the complex of spotty skin pigmentation, myxomas, and endocrine overactivity [2, 4]. Findings of PPNAD should initiate a search for Carney complex diagnosis on the basis of established criteria because multiple neoplasias and especially cardiac tumors, a component of the syndrome, may be asymptomatic and are potentially fatal [2–4]. Nikos Courcoutsakis Eunice Kennedy Shriver, National Institute of Child Health and Human Development National Institutes of Health Bethesda, MD Democritus University of Thrace Alexandroupolis, Greece Panos Prassopoulos Democritus University of Thrace Alexandroupolis, Greece Constantine A. Stratakis Eunice Kennedy Shriver, National Institute of Child Health and Human Development National Institutes of Health Bethesda, MD

Radiological Reasoning: 88-Year-Old Man With Abdominal Pain and Dilated Biliary Tree and Pancreatic Duct

AJR 2010;194:S46–S50 0361–803X/10/1946–S46 © American Roentgen Ray Society Objective Marked intraand extrahepatic biliary ductal dilatation and a questionable pancreatic mass were incidentally discovered on CT of an 88-year-old man. The most important diseases to be considered in this case scenario are pancreatic adenocarcinoma, ampullary carcinoma, intraductal papillary mucinous neoplasm (IPMN), and chronic pancreatitis. We will focus our review on the dilatation of the biliary and pancreatic ducts and assess each entity separately.

Radiographic Pneumonitis Patterns and Low Pulmonary Toxicity After Helical Tomotherapy

AJR 2010; 194:W459 0361–803X/10/1945–W459 © American Roentgen Ray Society Radiographic Pneumonitis Patterns and Low Pulmonary Toxicity After Helical Tomotherapy We read with interest the recent article by Park et al. [1] describing early CT pneumonitis patterns after thoracic radiotherapy via helical tomotherapy. This retrospective study reported on 77 target lesions in 25 patients treated from 2005 to 2007 for either primary lung cancer or metastases with doses of 40 to 50 Gy in 3 to 20 fractions. Only five patients developed grade 2 pneumonitis requiring steroids, and no grade 3 toxicities were observed. The distribution of pneumonitis was commonly peripheral to the target, with skip areas and a centrifugal pattern. Radiation-induced lung parenchymal changes occur adjacent to high-dose areas, irrespective of technique. A small study from Japan detailed the radiographic changes that may occur with multiple-field arrangements at doses less than 20 Gy. Lung density changes were not seen outside the portals of the static beams [2]. The volume of lung receiving greater than 20 Gy has been shown to correlate with clinical development of pneumonitis using conventional fractionation [3]. The shape of these radiographic changes after tomotherapy differs from 3D conformal conventional fields, which produce predictable changes mostly along the perihilar regions because of the use of anteroposterior and oblique portals (Fig. 1). The helical nature of tomotherapy delivers the dose via 360°, and the inverse planning involved in beamlet arrangement makes the shape of these changes unique. The significance of the radiographic changes, in our experience, is not clinically relevant. The University of Wisconsin dose-escalation study suggests that the increased conformality of tomotherapy allows higher total lung tumor dose without significant (≥ grade 3) toxicity [4]. We have seen radiographic changes similar to those described by Park et al. [1], and only 13% of our patients required temporary steroids for clinical grade 2 pneumonitis. None developed grade 3 pneumonitis in spite of significant dose escalation. Importantly, nonpulmonary toxicity, such as esophagitis, also may be reduced with tomotherapy. We believe that tomotherapy represents a safe technology for delivery of thoracic intensity-modulated radiotherapy. We agree that the radiographic changes observed after treatment must be interpreted differently than those with conventional 3D conformal radiotherapy. Jarrod B. Adkison Minesh Mehta University of Wisconsin Madison, WI

Indications for CT-Guided Percutaneous Thoracic Biopsy

Indications for CT-Guided Percutaneous Thoracic BiopsyStefan S. Bielack, Dorothe Carrle and Godehard FriedelAudio Available | Share

Difference Between Enterography and Enteroclysis

Difference Between Enterography and EnteroclysisFrank ParrishAudio Available | Share

ACR Membership Benefits to Medical Physicists

As a longtime member of the American Association of Physicists in Medicine and the current chair of the ACR Commission on Medical Physics, I would like to offer the following observation: the expertise and perspective that the medical physicist community contributes to the practice of radiology is so valuable to the ACR and the American Roentgen Ray Society (ARRS) that the importance of your participation in its deliberations and work cannot be overstated. The American Association of Physicists in Medicine, the ACR, and the ARRS play important roles in the way our profession develops, how radiology affects the field of medicine, and the impact of outside forces on our specialty.

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AJR 2010; 194:W1 0361–803X/10/1942–W1 © American Roentgen Ray Society Radiation Dose and Screening for Vesicoureteral Reflux We read with interest the review by Dr. Lim [1] concerning recent advances in the diagnosis of vesicoureteral reflux (VUR). The article provides an otherwise excellent review of the current controversy regarding VUR screening methods; however, we are concerned by the lack of attention given to the radiation dose from 99mTc-dimercaptosuccinic acid (DMSA) renal scans. At our institution, a DMSA renal scan performed in a 1-year-old child carries a 1.3-fold higher radiation dose than continuous fluoroscopy voiding cystourethrography (VCUG), a 10-fold higher radiation dose than pulsed fluoroscopy VCUG, and a 200-fold higher radiation dose than radionuclide cystography [2]. Importantly, because of the lack of clinical guidelines or standardized dosimetry, there is marked variation in the administered radiation dose for children undergoing nuclear medicine scans [3]. As a result, these figures may, in fact, underestimate the excess radiation dose associated with a systemic abandonment of the bottom-up (i.e., early cystography) approach in favor of the top-down (i.e., early DMSA scan) approach. It has been postulated that adoption of the top-down approach would result in a decrease in the number of patients diagnosed with VUR who are not actually at risk of renal damage, clearly a worthy and admirable goal. However, relatively little evidence is yet available to support this claim, and both the American Academy of Pediatrics and the American Urological Association continue to recommend the bottom-up approach in screening children at risk of VUR [4, 5]. Thus, a commitment to the as low as reasonably achievable (ALARA) principle for our young patients would seem to suggest that providers should shift to the topdown approach only after a preponderance of evidence shows that the clinical benefits merit the inevitable accompanying increase in radiation dose. Jonathan C. Routh Richard S. Lee Jeanne S. Chow Children’s Hospital Boston Harvard Medical School Boston, MA

Radiological Reasoning: Congenital Sensorineural Hearing Loss

Received August 18, 2008 accepted after revision March 14, 2009. 1Both authors: Department of Radiology, Children’s National Medical Center, 111 Michigan Ave., Washington, DC 20010. Address correspondence to N. Kadom (nkadom@cnmc.org). AJR 2010;194:WSXX–WSXX 0361–803X/10/1943–WS1 © American Roentgen Ray Society OBJECTIVE A 12-year-old girl with an outside diagnosis of bilateral profound to severe sensorineural hearing loss came to the pediatric hearing and speech center for cochlear implant evaluation. CT evaluation showed bilateral marked vestibular aqueduct enlargement along with bilateral hypoplasia of the cochlea, minor dysplasia of the vestibules, and bilaterally underdeveloped lateral semicircular canals. The patient received a left cochlear implant and is doing well.

Radiological Reasoning: A Child With Posterior Plagiocephaly

Received September 11, 2009; accepted after revision March 14, 2009. 1Both authors: Department of Radiology, Children’s National Medical Center, 111 Michigan Ave., Washington, DC 20010. Address correspondence to N. Kadom (nkadom@cnmc.org). AJR 2010;194:WS5–WS9 0361–803X/10/1943–WS5 © American Roentgen Ray Society OBJECTIVE A 10-month-old girl presented with an abnormal left posterior head shape and was referred for head CT to evaluate for the possibility of lambdoid craniosynostosis. At CT, a diagnosis of deformational plagiocephaly was made. An understanding of CT criteria to differentiate posterior deformational plagiocephaly from abnormal head shape caused by lambdoid craniosynostosis is necessary to help make the correct diagnosis.

Radiological Reasoning: Pediatric Midline Nasofrontal Mass

Received September 11, 2009; accepted after revision March 14, 2009. 1Both authors: Department of Radiology, Children’s National Medical Center, 111 Michigan Ave., Washington, DC 20010. Address correspondence to N. Kadom (nkadom@cnmc.org). AJR 2010;194:WS10–WS13 0361–803X/10/1943–WS10 © American Roentgen Ray Society OBJECTIVE The purpose of this article is to discuss the CT findings in a case of nasofrontal midline mass in a child.

Can Dependent Atelectasis Affect the Performance of Automated Lung Nodule Matching?

AJR 2010; 194:W246 0361–803X/10/1942–W246 © American Roentgen Ray Society Can Dependent Atelectasis Affect the Performance of Automated Lung Nodule Matching? We read with great interest the article by Tao et al. [1], who reported high performance of an automated lung nodule matching program in screening serial chest CT scans. The authors arbitrarily classified nodules as solid parenchymal, solid juxtavascular, solid juxtapleural, or ground-glass opacity. Of those nodules, the matching rate was lowest for juxtapleural nodules. We think that the performance of the lung nodule matching program used in that study was influenced by the presence or absence of dependent atelectasis because a solid parenchymal nodule can assume a juxtapleural location with the development of dependent atelectasis, as we experienced in two patients (Figs. 1 and 2) who underwent CT for lung cancer screening and metastasis workup, respectively. The implication of our observation is that, with persistent dependent atelectasis, peripheral lung nodules will tend to become juxtapleural rather than parenchymal and will become less likely to be matched on serial CT scans. More important, we wonder whether this lung nodule matching program will be able to match nodules in cases in which the nodules look parenchymal on one CT scan and subsequently become juxtapleural on another scan, with development of dependent atelectasis. Jin Kyoung Oh Dae Hee Han Seoul St. Mary’s Hospital The Catholic University of Korea Seoul, Korea

Radiation Dose and Screening for Vesicoureteral Reflux

AJR 2010; 194:W1 0361–803X/10/1942–W1 © American Roentgen Ray Society Radiation Dose and Screening for Vesicoureteral Reflux We read with interest the review by Dr. Lim [1] concerning recent advances in the diagnosis of vesicoureteral reflux (VUR). The article provides an otherwise excellent review of the current controversy regarding VUR screening methods; however, we are concerned by the lack of attention given to the radiation dose from 99mTc-dimercaptosuccinic acid (DMSA) renal scans. At our institution, a DMSA renal scan performed in a 1-year-old child carries a 1.3-fold higher radiation dose than continuous fluoroscopy voiding cystourethrography (VCUG), a 10-fold higher radiation dose than pulsed fluoroscopy VCUG, and a 200-fold higher radiation dose than radionuclide cystography [2]. Importantly, because of the lack of clinical guidelines or standardized dosimetry, there is marked variation in the administered radiation dose for children undergoing nuclear medicine scans [3]. As a result, these figures may, in fact, underestimate the excess radiation dose associated with a systemic abandonment of the bottom-up (i.e., early cystography) approach in favor of the top-down (i.e., early DMSA scan) approach. It has been postulated that adoption of the top-down approach would result in a decrease in the number of patients diagnosed with VUR who are not actually at risk of renal damage, clearly a worthy and admirable goal. However, relatively little evidence is yet available to support this claim, and both the American Academy of Pediatrics and the American Urological Association continue to recommend the bottom-up approach in screening children at risk of VUR [4, 5]. Thus, a commitment to the as low as reasonably achievable (ALARA) principle for our young patients would seem to suggest that providers should shift to the topdown approach only after a preponderance of evidence shows that the clinical benefits merit the inevitable accompanying increase in radiation dose. Jonathan C. Routh Richard S. Lee Jeanne S. Chow Children’s Hospital Boston Harvard Medical School Boston, MA

Ability to Reduce the Incidence of Pneumothorax in Transthoracic CT-Guided Biopsy

Ability to Reduce the Incidence of Pneumothorax in Transthoracic CT-Guided BiopsyMassimo De Filippo1, Raffaele Averna1 and Maurizio Zompatori2Audio Available | Share

AJR Teaching File: An Uncommon Cause of Spinal Canal Stenosis

AJR 2009;193:S56–S58 0361–803X/09/1933–S56 © American Roentgen Ray Society Clinical History A 77-year-old man presented with neurogenic claudication of the lower limbs that had gradually progressed over the past 8 months. The pain was worse on the left side. Relevant medical history included lumbar spinal canal stenosis treated by left L4 laminectomy 5 years earlier. There was no associated sensory disturbance. MRI of the lumbar spine was performed.

Prone Breast Dual-Time-Point PET/CT Compared With MRI for Determining Breast Cancer

AJR 2009; 193:W77 0361–803X/09/1931–W77 © American Roentgen Ray Society Prone Breast Dual-Time-Point PET/CT Compared With MRI for Determining Breast Cancer We compliment Imbriaco et al. [1] on their well-presented article on the use of dual-time-point PET/CT standardized uptake values to distinguish malignant from benign breast lesions. The authors used a prone technique to compare lesions seen on MRI with lesions seen at both time points on the prone PET/CT breast scans. However, in the Discussion section the authors state, “Finally, to our knowledge, this is the first study in the English-language literature to directly compare 18F-FDG PET/CT performed in the prone position and breast MRI in patients with suspected breast cancer.” We would like to point out that this indicates that the authors overlooked the work of many other researchers. In 1999, in the AJR Yutani et al. [2] report results on prone breast PET. Admittedly, they did not compare their results to MRI. However, Imbriaco et al. [1] do cite as their reference 35 the article by Goerres et al. [3] in which prone PET/CT images were most certainly compared with breast MRI. Furthermore, there are two recent articles by Moy et al. [4, 5] in which not only is prone breast PET/CT compared with MRI, but also the 3D volume data sets were registered and superimposed for a better comparison of the breast lesions. This is not meant to be an exhaustive list but merely an indication that prone PET/ CT and MRI have been compared previously in the English-language literature. Gerald Q. Maguire, Jr. Royal Institute of Technology Stockholm, Sweden Marilyn E. Noz Fabio Ponzo New York University School of Medicine New York, NY