Imaging of the diabetic foot diagnostic dilemmas

Multiple diagnostic imaging modalities are available and beneficial for the evaluation of the diabetic foot. There is not yet "one best test" for sorting out the diagnostic dilemmas commonly encountered. The differentiation of cellulitis alone from underlying osteomyelitis and the early detection of abscesses remain important diagnostic goals. Equally important, differentiation of osteomyelitis and neuroarthropathy remains a difficult job. This is often compounded by postoperative diabetic foot states status after reconstruction. Diagnostic evaluation often involves multiple studies that are complementary and that include conventional radiography, computed tomography, nuclear medicine scintigraphy, magnetic resonance imaging, ultrasonography, and positron emission tomography.     

Diagnosis of pulmonary embolism with various imaging modalities

Pulmonary embolism (PE) is a major health concern that affects approximately 600,000 new patients annually. The diagnosis of PE can be difficult to make, and several imaging studies have been developed to aid in this process. Initial evaluation involves the acquisition of a chest radiograph. Findings on radiography, however, are often non-specific. The gold-standard study historically has been pulmonary angiography, with increasing diagnostic yield since the implementation of digital subtraction technology. This is an invasive procedure, however, but the incidence of major complications is low. Less invasive modalities have been developed and include ventilation-perfusion lung scans. These are used as one of the initial screening tests in evaluation of patients with suspected PE. The presence of a high-probability scan usually indicates the presence of a PE, although few patients have high probability scans. The test is significantly affected by underlying pulmonary disease or previous PE. Given this, ventilation-perfusion lung scans are limited as a primary diagnostic tool in the evaluation of suspected PE. Helical computed tomography (CT) is currently under much scrutiny as a diagnostic tool for PE. Currently a prospective, multicenter trial evaluating its efficacy (PIOPED II) has been initiated, but the results are pending. Preliminary reports suggest the helical CT and venous phase CT may become a first line study in patient evaluation. The diagnosis of PE is challenging and several imaging modalities are currently used to assist the clinician. Currently, multiple modalities are often required to make the diagnosis. With the advent of new technology and improved imaging techniques, the diagnosis of PE will become easier.     

Magnetic resonance imaging of acute subarachnoid hemorrhage

The feasibility, safety, and diagnostic value of magnetic resonance (MR) imaging versus computerized tomography (CT) scanning were compared in 30 patients with clinical evidence of subarachnoid hemorrhage. Subarachnoid blood was identified more often and more information was available about the site and source of the hemorrhage on MR imaging than on CT. Magnetic resonance imaging could be used safely both before and after the operation, provided that nonferromagnetic clips were used and that comprehensive monitoring and cardiorespiratory support were available. Postoperative studies showed that artifacts from metallic implants and from patient movement caused less image degradation on MR images than on CT scans.     

Computed Tomography in the Diagnosis of Intra-abdominal Abscesses

The diagnosis of intra-abdominal abscess by radiographic means often relies on combining the results of several different imaging modalities. Computed tomography (CT) has been shown to be a safe, accurate and rapid diagnostic method of diagnosing these abscesses. Five patients with a variety of intra-abdominal abscesses are presented in whom the CT scan alone provided the correct diagnosis. The various imaging modalities available for the radiologic diagnosis of intra-abdominal abscess are described and are compared to CT diagnosis regarding their pitfalls.     

Diagnostic approach to the patient with jaundice following trauma.

BACKGROUND AND AIMS: Jaundice in trauma patients may reflect serious underlying pathology. The aim of this review was to determine the appropriate diagnostic approach to the patient with jaundice following trauma. METHODS: A MEDLINE search was performed to retrieve publications which outlined the causes of jaundice in trauma patients. RESULTS: The main causes of jaundice in trauma patients were found to be bilirubin overload caused by breakdown of transfused- and extravasated blood and hepatic dysfunction caused by sepsis, infections, initial shock and systemic hypotension. Bile duct injury or drug induced liver injury are rare. Liver function tests are often uninformative but commonly show a cholestatic pattern. Ultrasound, CT or ERCP are the diagnostic imaging methods most widely used. Abdominal ultrasound and CT may reveal specific organ injuries, bile duct dilatation, intraabdominal fluid collections, hematomas or acalculus cholecystitis. ERCP is often diagnostic and permits a therapeutic intervention when a bile duct injury is present. CONCLUSIONS: The primary aim of the diagnostic approach should be to identify all cases of bile duct injury or obstruction. Sepsis and infections should be actively looked for. The number of blood transfusions must be calculated. Ultrasound, CT or ERCP are the diagnostic imaging methods most widely used.     

Bedeutung der PET für die Chirurgie des Schilddrüsenkarzinomrezidivs

Background

The early detection of recurrent thyroid cancer and focussed surgery are essential for patients’ prognosis. Using I-131 whole body scintigraphy is often not sufficient to detect recurrent carcinoma making other imaging methods necessary to identify the tumor. Recent studies showed that positron emission tomography-computed tomography (PET/CT) is able to identify recurrent carcinoma and metastasis at an early stage.

Objective

The aim of this study was an evaluation of the impact of PET/CT on diagnostic and operation strategies in recurrent thyroid cancer.

Methods

A review of the literature was carried out combined with a case report from the daily practice. Furthermore, flow charts were created to clarify the aftercare procedure.

Results

In patients with recurrent thyroid cancer PET/CT significantly increased the identification of recurrent tumors and metastases. Depending on the subtype of cancer, different tracers are used. The use of a metabolically active tracer which shows the increase of tumor metabolism and the morphological correlation of the tumor using a CT scan enable preoperative planning for a focussed surgical approach.

Conclusions

The PET/CT procedure should be an integral part of the aftercare procedure in thyroid cancer for early identification of recurrent tumors and to enable focussed surgery.     

Unnecessary Tests and Procedures in Patients Presenting with Solid Tumors of the Pancreas

Background

A computed tomography (CT) scan is often the only study needed prior to surgery for resectable solid pancreas masses. However, many patients are evaluated with multiple studies and interventions that may be unnecessary.

Methods

We conducted a retrospective review of patients who presented to the Johns Hopkins Multidisciplinary Pancreas Cancer Clinic with a clearly resectable solid pancreas mass, >1 cm in size over a 2-year period (6/2007–6/2009) and underwent resection. Pancreas specialists reviewed patient records and identified an index CT with a solid pancreas mass deemed to be resectable for curative intent. Data were collected on all studies and interventions between the index CT and the surgery.

Results

A total of 101 patients had an index CT. Following the index CT and before surgery, 78 patients had at least one CT, 19 had magnetic resonance imaging, 9 had a positron emission tomography scan, and 66 underwent pancreatic biopsy. Patients underwent a mean of three studies with a mean added cost of $3,371 per patient. Preoperative tests and interventions were associated with a longer time to definitive surgical intervention.

Conclusion

Wide variation exists for evaluation of newly discovered resectable solid pancreas masses, which is associated with delays to surgical intervention and added costs.     

Cyst and cystlike lesions of the foot

A variety of cyst and cystlike lesions may present in the osseous structures of the foot. Such lesions are infrequent in their occurrence, and often cannot be diagnosed on the basis of radiographic appearance. In addition to the morphologic data that can be derived from evaluation of standard radiographs, other diagnostic radiographic studies such as tomography, CT scanning, radionuclide bone imaging, angiography, or other studies may be required to ascertain the nature and extent of cystlike lesions of the foot. This is dependent on histopathologic information derived from biopsy. A variety of cyst and cystlike lesions of the foot are presented with a review of their basic morphology and histopathologic, clinical, and prognostic characteristics.     

Radiation exposure from diagnostic imaging in severely injured trauma patients

BACKGROUND: Trauma patients often require multiple imaging tests, including computed tomography (CT) scans. CT scanning, however, is associated with high-radiation doses. The purpose of this study was to measure the radiation doses trauma patients receive from diagnostic imaging. METHODS: A prospective cohort study was conducted from June 1, 2004 to March 31, 2005 at a Level I trauma center in Toronto, Canada. All trauma patients who arrived directly from the scene of injury and who survived to discharge were included. Three dosimeters were placed on each patient (neck, chest, and groin) before radiologic examination. Dosimeters were removed before discharge. Surface doses in millisieverts (mSv) at the neck, chest, and groin were measured. Total effective dose, thyroid, breast, and red bone marrow organ doses were then calculated. RESULTS: Trauma patients received a mean effective dose of 22.7 mSv. The standard "linear no threshold" (LNT) model used to extrapolate from effects observed at higher dose levels suggests that this would result in approximately 190 additional cancer deaths in a population of 100,000 individuals so exposed. In addition, the thyroid received a mean dose of 58.5 mSv. Therefore, 4.4 additional fatal thyroid cancers would be expected per 100,000 persons. In all, 22% of all patients had a thyroid dose of over 100 mSv (mean, 156.3 mSv), meaning 11.7 additional fatal thyroid cancers per 100,000 persons would result in this subgroup. CONCLUSION: Trauma patients are exposed to significant radiation doses from diagnostic imaging, resulting in a small but measurable excess cancer risk. This small individual risk may become a greater public health issue as more CT examinations are performed. Unnecessary CT scans should be avoided.     

The added value of SPECT/CT in the painful foot and ankle: A review of the literature

IntroductionFoot and ankle injuries are common. Radiographic assessment is difficult because of the complex anatomy. In the past decade SPECT/CT made its introduction in assessing bone pathology, it combines both morphologic and pathologic imaging in one image aiming to increase sensitivity and specificity when compared with MRI or CT alone. The purpose of this review was to provide a literature overview on the diagnostic value of SPECT/CT in foot and ankle pathology.MethodsA literature search was conducted in the databases of PubMed and EMBASE between January 2004 and September 2019 for articles describing the diagnostic value of SPECT/CT in foot and ankle pathology. For assessment of methodological quality of each study included in the analysis, QUADAS-2 checklist was used. Main outcomes were change of management, improved diagnosis and symptomatic improvement.ResultsA total of eight studies were identified describing the diagnostic value of SPECT/CT in foot and ankle pathology based on patient data. The combined analysis shows that change of management and improved diagnosis occurred in 48–62% and 40–79% of the patients when compared with other imaging modalities and/or clinical assessment. Symptomatic improvement due to treatment based on SPECT/CT findings occurred in 92% of the patients.ConclusionSPECT/CT is useful when diagnosis based on other imaging modalities is inconclusive or when treatment based on these modalities does not lead to the desired symptomatic improvement.     

Prospective audit of cross-sectional imaging and radiation exposure in general surgical patients

INTRODUCTION

Most patients admitted with an acute surgical problem undergo some imaging during their in-patient stay. As computed tomography (CT) scanning becomes more readily available, it is becoming the mainstay of assessment. Recent studies have commented on the potential adverse effects of early cross-sectional imaging. This audit aimed to determine the use of early cross-sectional imaging and associated radiation dose in an acute surgical cohort.

PATIENTS AND METHODS

Data from 500 acute surgical patients were prospectively collected over a 3-month period. CT scans were undertaken, the effect on subsequent diagnostic and management decisions and the potential associated risks were evaluated.

RESULTS

Almost 40% of subjects underwent CT scanning. Of these, 20% did not alter management and could be deemed unnecessary. The radiation exposure equated to an age- and gender-specific risk of fatal cancer induction between 1 in 1675 and 1 in 7130.

CONCLUSIONS

Early-cross sectional imaging provides a valuable diagnostic adjunct. Decisions to expose patients to potentially hazardous radiation need to acknowledge the anticipated benefits versus risks.     

Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests

OBJECT: The aim of this study was to assess the diagnostic yield of imaging tests performed in patients in whom the cause of subarachnoid hemorrhage (SAH) had not been demonstrated on initial angiography. METHODS: By reviewing medical records of 806 patients with SAH who had been admitted during a 6.5-year period, the authors identified 86 in whom initial transfemoral catheter angiography failed to reveal the cause of SAH. Clinical and radiological data were analyzed to determine the diagnostic yield of subsequent catheter angiography, computerized tomography (CT) angiography, magnetic resonance (MR) angiography, and MR imaging of the brain and spine for various subtypes of SAH (bleeding not visualized on CT studies [CT-negative SAH], perimesencephalic SAH, and nonperimesencephalic SAH). Of 41 patients with nonperimesencephalic SAH, 36, 32, and 21 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 23 patients (18 with Gd and 15 with susceptibility contrast sequences), and spine MR imaging in 17. Of 36 patients with perimesencephalic SAH, 31, 23, and 17 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 18 patients (17 with Gd and 11 with susceptibility contrast sequences), and spine MR imaging in 14. Of nine patients with SAH not visualized on CT scanning, three, one, and six underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in eight patients (five with Gd and three with susceptibility contrast sequences), and spine MR imaging in seven. The cause of SAH could be determined in only four patients, all with nonperimesencephalic SAH. The only test that yielded a diagnosis was catheter angiography (three aneurysms on the second and one on the third angiography, all surgically secured). Diffusion-weighted MR imaging demonstrated small, deep infarcts in five patients. CONCLUSIONS: Repeated catheter angiography remains the most sensitive test to determine the cause of SAH that is not demonstrated on initial angiography, particularly in the subtype of nonperimesencephalic SAH. Newer, noninvasive imaging techniques provide little diagnostic yield.     

Imaging studies in the diagnosis of urogenital trauma

Polytraumatized patients often present with urological injuries. After hemodynamic stability is maintained urologists are consulted to evaluate diagnostic and therapeutic interventions. The following article describes how to handle the work-up of patients with injuries to specific urogenital organs: the importance of clinical examination, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), angiography as well as organ-specific radiologic studies such as intravenous pyelography or cystography are discussed. CONCLUSION: Even though injuries to the urogenital tract are rarely initially life--threatening, a fast, reliable and adequate diagnostic algorithm has to be established to avoid any delay of specific treatment. Urologists should be familiar with the indications, range and accuracy of these procedures in the diagnosis of urogenital trauma.     

Noninvasive imaging of the renal arteries.

Currently, four screening/diagnostic studies are available that provide imaging of the renal arteries: duplex ultrasonography, CT angiography, MR angiography, and intravenous DSA. Intravenous DSA is no longer used because of better imaging with MR and CT angiography. MR angiography, CT angiography, and duplex ultrasonography provide excellent sensitivity and specificity when performed by experienced personnel. The screening test of choice depends on the availability, expertise, and cost at individual centers.     

Molekulare Bildgebung in der onkologischen Chirurgie

Background

Diagnostic imaging with positron emission tomography (PET) is becoming increasingly more involved in oncological therapy management.

Objectives

How can PET be helpful in oncological surgery?

Methods

After a short introduction into the basic principles of PET the current state of imaging as well as indications and limitations of the method are described.

Results

The PET is a functional and quantitative imaging technique, enabling detection and characterization of tumors. It is applied in pretherapeutic staging as well as in follow-up and therapy assessment. The use of PET changes the therapy management in about one third of all oncology patients. New radiopharmaceuticals and novel technologies expand the diagnostic potential.

Discussion

Hybrid imaging with PET computed tomography (CT) and PET magnetic resonance imaging (MRI) further improves diagnostic imaging and increases the acceptance of PET further.     

Detection of blood blister-like aneurysm and intramural hematoma with high-resolution magnetic resonance imaging

Blood blister-like aneurysms (BBAs) tend to have a more precipitous clinical course, enlarging rapidly and rebleeding frequently. Nevertheless, they often present a diagnostic challenge because of the characteristic morphological features of a wide neck and shallow outpouching of the medial wall. The authors present the case of a 34-year-old woman who suffered a subarachnoid hemorrhage whose cause could not be determined on the initial imaging with digital subtraction (DS) angiography and CT angiography. Interestingly, MR imaging studies obtained on the 7th day revealed an intramural hematoma on the dorsal wall of the left internal carotid artery, which helped in the diagnosis of BBA on the third DS angiography study obtained on the 8th day, and in the surgical intervention on the 10th day. This case supports the hypothesis that focal dissection contributes to the formation of BBAs. Use of MR imaging in the subacute stage, in addition to DS and CT angiography, might be helpful in the diagnosis of BBAs.     

Obturator hernia: A case report and review of the literature

INTRODUCTIONAn obturator hernia is a rare condition but is associated with the highest mortality of all abdominal wall hernias. Early surgical intervention is often hindered by clinical and radiological diagnostic difficulty. The following case report highlights these diagnostic difficulties, and reviews the current literature on management of such cases.PRESENTATION OF CASEWe present the case of an 86-year-old lady who presented with intermittent small bowel obstruction, clear hernial orifices, and right medial thigh pain. Pre-operative CT imaging was suggestive of an obstructed right femoral hernia. However, intra-operatively the femoral canal was clear and an obstructed hernia was found passing through the obturator foramen lying between the pectineus and obturator muscles in the obturator canal.DISCUSSIONObturator hernias are notorious for diagnostic difficulty. Patients often present with intermittent bowel obstruction symptoms due to a high proportion exhibiting Richter's herniation of the bowel. Hernial sacs can irritate the obturator nerve within the canal, manifesting as medial thigh pain, and often no hernial masses can be detected on clinical examination. Increasing speed of diagnosis through early CT imaging has been shown to reduce the morbidity and mortality associated with obturator hernias. However, over-reliance on CT findings should be cautioned, as imaging and operative findings may not always correlate.CONCLUSIONA high suspicion for obturator hernia should be maintained when assessing a patient presenting with bowel obstruction particularly where intermittent symptoms or medial thigh pain are present. Rapid clinical and appropriate radiological assessment, followed by early surgery is critical to successful treatment.     

Glenohumeral and scapulohumeral kinematic analysis of patients with traumatic anterior instability wearing a shoulder brace: a prospective laboratory study

Study design

A retrospective case review of patients who underwent 18F sodium fluoride PET/CT imaging of the spine with postoperative pain following vertebral fusion.

Objective

To determine the benefit of 18F sodium fluoride PET/CT imaging in the diagnosis of persistent pain in the postoperative spine.

Summary of background data

The diagnosis of pain generators in the postoperative spine has proven to be a diagnostic challenge. The conventional radiologic evaluation of persistent pain after spine surgery with the use of plain radiographs, MRI, and CT can often fall short of diagnosis in the complex patient. 18F sodium fluoride PET/CT imaging is an alternative tool to accurately identify a patient’s source of pain in the difficult patient.

Methods

This retrospective study looked at 25 adult patients who had undergone 18F sodium fluoride PET/CT imaging. All patients had persistent or recurrent back pain over the course of a 15-month period after having undergone spinal fusion surgery. All patients had inconclusive dedicated MRI. The clinical accuracy of PET/CT in identifying the pain generator and contribution to altering the decision making process was compared to the use of CT scan alone.

Results

Of the 25 patients studied, 17 patients had increased uptake on the 18F sodium fluoride PET/CT fusion images. There was a high-level correlation of radiotracer uptake to the patients’ pain generator. Overall 88% of the studies were considered beneficial with either PET/CT altering the clinical diagnosis and treatment plan of the patient or confirming unnecessary surgery.

Conclusion

18F sodium fluoride PET/CT proves to be a useful tool in the diagnosis of complex spine pathology of the postoperative patients. In varied cases, a high correlation of metabolic activity to the source of the patient’s pain was observed.

     

<Superscript>99m</Superscript>Tc-HDP bone scintigraphy and <Superscript>18</Superscript>F-sodiumfluoride PET/CT in primary staging of patients with prostate cancer

Introduction/Aim

Correct staging of patients with prostate cancer is important for treatment planning and prognosis. Although bone scintigraphy with ^99mTc-phosphonates (BS) is generally advised for staging by guidelines in high risk prostate cancer, this imaging technique is hampered by a high rate of inconclusive results and moderate accuracy. Potentially better imaging techniques for detection of bone metastases such as ¹⁸F-sodiumfluoride PET/CT (NaF PET/CT) are therefore being evaluated. In this observational cohort study we evaluate the performance and clinical impact of both BS and NaF PET/CT in primary staging of patients with prostate cancer.

Methods

The first of two cohorts consisted of patients who received a BS while the second included patients who received a NaF PET/CT for primary staging of prostate cancer. For both cohorts the number of positive, negative and equivocal findings, calculated diagnostic performance of the imaging modality in terms of sensitivity and specificity, as well as the impact on clinical management were studied. The ranges of the diagnostic performance were calculated both assuming that equivocal findings were positive and assuming that they were negative for bone metastases. For the NaF PET/CT cohort the number of patients with signs of lymph node metastases on low dose CT were also recorded, including the impact of these findings on clinical management.

Results

One-hundred-and-four patients underwent NaF PET/CT, whereas 122 patients underwent BS. Sensitivities of 97–100 and 84–95% and specificities of 98–100 and 72–100% were found on a patient basis for detection of bone metastases with NaF PET/CT and BS, respectively. Equivocal findings warranted further diagnostic procedures in 2% of the patients in the NaF cohort and in 16% in the BS cohort. In addition NaF PET/CT demonstrated lymph node metastases in 50% of the included patients, of which 25% showed evidence of lymph node metastases only.

Conclusion

Our data indicate better diagnostic performance of NaF PET/CT compared to BS for detection of bone metastases in primary staging of prostate cancer patients. Less equivocal findings are encountered with NaF PET/CT. Moreover, NaF PET/CT has additional value over BS since lymph node metastases are encountered frequently.

     

Correlative anatomy for the mediastinum

Diseases of the mediastinum comprise a wide spectrum of benign and malignant entities that share the same anatomic site within the chest. Correct management often requires a multidisciplinary approach. Diagnostic imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, and positron emission tomography play a major role in the diagnosis of mediastinal diseases and in guiding minimally invasive diagnostic procedures, minimizing the risk of imaging-guided biopsies. This article describes the mediastinal anatomy, correlating the findings of plain radiography, CT, and MRI.