Transcranial Doppler screening in sickle cell disease: The implications of using peak systolic criteria

AIM: To compare time average maximum mean velocity (TAMV) and peak systolic velocity (PSV) criteria of Trans Cranial Doppler (TCD) in their ability to predict abnormalities on magnetic resonance imaging (MRI)/magnetic resonance angiogram (MRA) in patients with sickle cell disease.

METHODS: A retrospective evaluation was performed of the outcomes in all patients with a Transcranial Doppler examination at our institution since the implementation of the hospital picture archiving and communication system (PACS) system in January 2003 through December 2012. All ultrasound imaging exams were performed by the same technologist with a 3 MHz transducer. Inclusion criteria was based upon the Transcranial Doppler procedure code in our PACS which had an indication of sickle cell disease in the history. The patient’s age and gender along with the vessel with the highest time averaged mean velocity as well as the highest peak systolic velocity was recorded for analysis. A subset of the study cohort also had subsequent MR imaging and Angiograms performed within 6 mo of the TCD examination. MRI results were categorized as having a disease related abnormality (vessel narrowing, collateral formation/moya-moya, or abnormal fluid attenuation inversion recovery signal in parenchyma indicative of prior stroke) or normal. The MRI results formed the comparison standards for TCD exams in evaluating intracranial injury. Sensitivity and specificity for the two TCD criteria (TAMV and PSV) were calculated to determine which could be a better predictor for intracranial vasculopathy /clinically occult strokes.

RESULTS: The study cohort for our institution was 110 patients with a total of 291 TCD examinations. These patients had a mean age of 7.6 years with a range from 2-18 years of age. Sixty-two of the 110 patients (56%) had two or more TCD exams. Thirty-seven patients (34%) had at least one MRI following a TCD examination. Of the 291 TCD examinations, 46 (16%) were conditional or abnormal by TAMV criteria. One hundred and sixteen (40%) were conditional or abnormal by PSV criteria. All studies that were abnormal by TAMV were also abnormal by PSV criteria. Seventy of the 116 (60%) studies which were conditional or abnormal by peak systolic criteria would not have been identified by time averaged mean maximum velocity criteria. The most frequent location of highest velocity measurement was noted to be in the middle cerebral artery regardless of whether it was measured by PSV or TAMV. From the 37 patients having one or more MRIs, 43 MRI exams were performed within 6 mo of a TCD examination. Twenty two (51%) MRIs had a disease related abnormality reported. When evaluating conditional or abnormal exams by PSV criteria against follow-up MRI/MRA, the sensitivity was 73% [16/(16 + 6)] and specificity was 81% [17/(4 + 17)]. When evaluating conditional or abnormal exams by TAMV criteria by follow-up MRI/MRA as the gold standard, the sensitivity was 41% [9/(9 + 13)] and the specificity was 100% [21/(21 + 0)]. In using conditional or abnormal criteria from PSV and TAMV to predict abnormalities on follow-up MRI/MR Angiogram, PSV was more sensitive (73% vs 41%) while TAMV was more specific (100% vs 81%).

CONCLUSION: Based on the data obtained at our institution and using the assumption that the best screening test is the one with the highest sensitivity, the peak systolic velocity could be the measurement of choice for TCD screening.

Cardiac functional magnetic resonance imaging at 7T: Image quality optimization and ultra-high field capabilities

BACKGROUND

7T cardiac magnetic resonance imaging (MRI) introduces several advantages, as well as some limitations, compared to lower-field imaging. The capabilities of ultra-high field (UHF) MRI have not been fully exploited in cardiac functional imaging.

AIM

To optimize 7T cardiac MRI functional imaging without the need for conducting B1 shimming or subject-specific tuning, which improves scan efficiency. In this study, we provide results from phantom and in vivo scans using a multi-channel transceiver modular coil.

METHODS

We investigated the effects of adding a dielectric pad at different locations next to the imaged region of interest on improving image quality in subjects with different body habitus. We also investigated the effects of adjusting the imaging flip angle in cine and tagging sequences on improving image quality, B1 field homogeneity, signal-to-noise ratio (SNR), blood-myocardium contrast-to-noise ratio (CNR), and tagging persistence throughout the cardiac cycle.

RESULTS

The results showed the capability of achieving improved image quality with high spatial resolution (0.75 mm × 0.75 mm × 2 mm), high temporal resolution (20 ms), and increased tagging persistence (for up to 1200 ms cardiac cycle duration) at 7T cardiac MRI after adjusting scan set-up and imaging parameters. Adjusting the imaging flip angle was essential for achieving optimal SNR and myocardium-to-blood CNR. Placing a dielectric pad at the anterior left position of the chest resulted in improved B1 homogeneity compared to other positions, especially in subjects with small chest size.

CONCLUSION

Improved regional and global cardiac functional imaging can be achieved at 7T MRI through simple scan set-up adjustment and imaging parameter optimization, which would allow for more streamlined and efficient UHF cardiac MRI.

Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

AIM: To review the benefits of single photon emission computed tomography (SPECT)/computed tomography (CT) hybrid imaging for diagnosis of various endocrine disorders.

METHODS: We performed MEDLINE and PubMed searches using the terms: “SPECT/CT”; “functional anatomic mapping”; “transmission emission tomography”; “parathyroid adenoma”; “thyroid cancer”; “neuroendocrine tumor”; “adrenal”; “pheochromocytoma”; “paraganglioma”; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.

RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the bio-distribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for ^99mTc-sestamibi parathyroid scintigraphy and ^99mTc-pertechnetate thyroid scintigraphy, ¹²³I- or ¹³¹I-radioiodine for staging of differentiated thyroid carcinoma, ¹¹¹In- and ^99mTc- labeled somatostatin receptor analogues for detection of neuroendocrine tumors, ¹³¹I-norcholesterol (NP-59) scans for assessment of adrenal cortical hyperfunction, and ¹²³I- or ¹³¹I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.

CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to improved diagnostic accuracy and meaningful impact on patient care.

Bipolar radiofrequency ablation of tibialchondroblastomas: A report of three cases

Chondroblastoma is a rare benign cartilaginous neoplasm of bone. The recurrence rate is high and complications are frequent following open curettage with bone grafting which is the standard treatment forchondroblastomas. We performed radiofrequency ablation in three cases of tibialchondroblastoma using the bipolar system. One patient experienced residual pain for which repeat ablation was performed. No other complications were observed during follow-up. Radiofrequency ablation may offer an effective alternative for the treatment of selected cases of chondroblastoma. The lesion characteristics which are likely to influence treatment outcome and the advantages offered by the bipolar system are discussed.

MDCT imaging following nephrectomy for renal cell carcinoma: Protocol optimization and patterns of tumor recurrence

The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carcinoma recurrence throughout the body by examining their appearances on computerized tomography (CT). CT imaging protocols will be discussed. The sites of recurrence have been categorized into 4 groups: chest and mediastinum, abdomen and pelvis, musculoskeletal, and neurological. For each site of recurrence, a representative CT image correlate with discussion is provided. The unique CT appearance of renal cell carcinoma recurrence and how it can be used in lesion detection will be discussed. Renal cell carcinoma recurrences are hypervascular like the primary tumor, which can aid in not only lesion detection but also in some cases, differentiation from other primary tumors. Through CT case review of various sites of recurrence, lesions are shown to be easily seen on arterial phase while sometimes being nearly inconspicuous on venous or delayed phases. Coronal and sagittal reconstructions can also improve diagnostic sensitivity. CT is the most commonly used imaging tool for surveillance of renal cell carcinoma recurrence after nephrectomy. Knowledge of sites of recurrence as well as the utility of arterial phase imaging and multiplanar reconstructions will aid in optimizing detection of disease recurrence.

Pulmonary fibrosis and emphysema: Is the emphysema type associated with the pattern of fibrosis?

AIM: To investigate whether the predominant emphysema type is associated with the high resolution computed tomography (HRCT) pattern of fibrosis in combined pulmonary fibrosis and emphysema (CPFE).

METHODS: Fifty-three smokers with upper lobe emphysema and lower lobe pulmonary fibrosis on - HRCT - were retrospectively evaluated. Patients were stratified into 3 groups according to the predominant type of emphysema: Centrilobular (CLE), paraseptal (PSE), CLE = PSE. Patients were also stratified into 3 other groups according to the predominant type of fibrosis on HRCT: Typical usual interstitial pneumonia (UIP), probable UIP and nonspecific interstitial pneumonia (NSIP). HRCTs were scored at 5 predetermined levels for the coarseness of fibrosis (Coarseness), extent of emphysema (emphysema), extent of interstitial lung disease (TotExtILD), extent of reticular pattern not otherwise specified (RetNOS), extent of ground glass opacity with traction bronchiectasis (extGGOBx), extent of pure ground glass opacity and extent of honeycombing. HRCT mean scores, pulmonary function tests, diffusion capacity (DLCO) and systolic pulmonary arterial pressure were compared among the groups.

RESULTS: The predominant type of emphysema was strongly correlated with the predominant type of fibrosis. The centrilobular emphysema group exhibited a significantly higher extent of emphysema (P < 0.001) and a lower extent of interstitial lung disease (P < 0.002), reticular pattern not otherwise specified (P < 0.023), extent of ground glass opacity with traction bronchiectasis (P < 0.002), extent of honeycombing (P < 0.001) and coarseness of fibrosis (P < 0.001) than the paraseptal group. The NSIP group exhibited a significantly higher extent of emphysema (P < 0.05), total lung capacity (P < 0.01) and diffusion capacity (DLCO) (P < 0.05) than the typical UIP group. The typical UIP group exhibited a significantly higher extent of interstitial lung disease, extent of reticular pattern not otherwise specified, extent of ground glass opacity with traction bronchiectasis, extent of honeycombing and coarseness of fibrosis (0.039 > P > 0.000). Although the pulmonary arterial pressure was higher in typical UIP group relative to the NSIP group, the difference was not statistically significant.

CONCLUSION: In CPFE patients, paraseptal emphysema is associated more with UIP-HRCT pattern and higher extent of fibrosis than centrilobular emphysema.

Breast and lung metastasis from pancreatic neuroendocrine carcinoma

Pancreatic neuroendocrine tumors (PNETs) are an uncommon malignancy, accounting for a small percentage of all pancreatic malignancies. Due to their insidious course, most PNETs present with metastatic disease. Although reports in the literature describe PNET metastasis to the liver, lung and brain, to date there are no reports of stage IV disease involving the breast. Moreover, the lack of consensus regarding classification and treatment of this entity leaves practitioners without standards of practice or a firm base from which to formulate prognosis. In this report, the case of a previously healthy 51-year-old woman with stage IV PNET is examined. After combined neoadjuvant therapy with 5-fluorouracil, carboplatin, etoposide and radiation, surgical resection revealed metastatic PNET to the breast and lung, with no microscopic evidence of residual disease within the pancreas. An extensive analysis of the presentation, diagnosis, imaging modalities, treatment options, and prognosis is included in the discussion. As demonstrated by our review, there is a need for further studies to delineate inconclusive evidence with respect to subtype classification, treatment and prognosis of PNETs.

High-resolution computed tomography findings in humoral primary immunodeficiencies and correlation with pulmonary function tests

AIM

To compare high-resolution computed tomography (HRCT) findings between humoral primary immunodeficiencies (hPIDs) subtypes; to correlate these findings to pulmonary function tests (PFTs).

METHODS

We retrospectively identified 52 consecutive adult patients with hPIDs who underwent 64-row HRCT and PFTs at the time of diagnosis. On a per-patient basis, an experienced radiologist recorded airway abnormalities (bronchiectasis, airway wall thickening, mucus plugging, tree-in-bud, and air-trapping) and parenchymal-interstitial abnormalities (consolidations, ground-glass opacities, linear and/or irregular opacities, nodules, and bullae/cysts) found on HRCT. The chi-square test was performed to compare the prevalence of each abnormality among patients with different subtypes of hPIDs. Overall logistic regression analysis was performed to assess whether HRCT findings predicted obstructive and/or restrictive PFTs results (absent-to-mild vs moderate-to-severe).

RESULTS

Thirty-eight of the 52 patients with hPIDs showed common variable immunodeficiency disorders (CVID), while the remaining 14 had CVID-like conditions (i.e., 11 had isolated IgG subclass deficiencies and 3 had selective IgA deficiencies). The prevalence of most HRCT abnormalities was not significantly different between CVID and CVID-like patients (P > 0.05), except for linear and/or irregular opacities (prevalence of 31.6% in the CVID group and 0 in the CVID-like group; P = 0.0427). Airway wall thickening was the most frequent HRCT abnormality found in both CVID and CVID-like patients (71% of cases in both groups). The presence of tree-in-bud abnormalities was an independent predictor of moderate-to-severe obstructive defects at PFTs (Odds Ratio, OR, of 18.75, P < 0.05), while the presence of linear and/or irregular opacities was an independent predictor of restrictive defects at PFTs (OR = 13.00; P < 0.05).

CONCLUSION

CVID and CVID-like patients showed similar HRCT findings. Tree-in-bud and linear and/or irregular opacities predicted higher risks of, respectively, obstructive and restrictive defects at PFTs.

Image of tumor metastasis and inflammatory lymph node enlargement by contrast-enhanced ultrasonography

AIM: To compare the difference between tumor-induced lymph node enlargement and inflammation-induced lymph node enlargement by contrast-enhanced ultrasonography and pathological findings.

METHODS: A model of tumor-induced lymph node metastasis was prepared by embedding a VX2 tumor into the hind paws of white rabbits. A model of inflammation-induced enlargement was prepared by injecting a suspension of Escherichia coli into separate hind paws of white rabbits. Then, a solution of Sonazoid™ (GE Healthcare, Oslo, Norway) was injected subcutaneously in the proximity of the lesion followed by contrast-enhanced ultrasonography of the enlarged popliteal lymph nodes.

RESULTS: In the contrast-enhanced ultrasonography of the tumor-induced metastasis model, the sentinel lymph node was imaged. An area of filling defect was observed in that enlarged lymph node. In the histology examination, the area of filling defect corresponded to the metastatic lesion of the tumor. Contrast-enhanced ultrasonography of the model on inflammation-induced lymph node enlargement, and that of the acute inflammation model performed 3-7 d later, revealed dense staining that was comparatively uniform. The pathological findings showed acute lymphadenitis mainly due to infiltration of inflammatory cells. Contrast-enhanced ultrasonography that was performed 28 d post-infection in the acute inflammation model showed speckled staining. Inflammation-induced cell infiltration and fiberization, which are findings of chronic lymphadenitis, were seen in the pathological findings.

CONCLUSION: Sentinel lymph node imaging was made possible by subcutaneous injection of Sonazoid™. Contrast-enhanced ultrasonography was suggested to be useful in differentiating tumor-induced enlargement and inflammation-induced enlargement of lymph nodes.

Metformin and cancer: Technical and clinical implications for FDG-PET imaging

Metformin is the most widely used hypoglycemic agent. Besides its conventional indications, increasing evidence demonstrate a potential efficacy of this biguanide as an anticancer drug. Possible mechanisms of actions seem to be independent from its hypoglycemic effect and seem to involve the interference with key pathways in cellular proliferation and glycolysis. To date, many clinical trials implying the use of metformin in cancer treatment are on-going. The increasing use of ¹⁸F-2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in cancer evaluation raises a number of questions about the possible interference of the biguanide on FDG distribution. In particular, the interferences exerted by metformin on AMP-activated protein kinase pathway (the cellular energy sensor), on insulin levels and on Hexokinase could potentially have repercussion on glucose handling and thus on FDG distribution. A better comprehension of the impact of metformin on FDG uptake is needed in order to optimize the use of PET in this setting. This evaluation would be useful to ameliorate scans interpretation in diabetic patients under chronic metformin treatment and to critically interpret images in the context of clinical trials. Furthermore, collecting prospective data in this setting would help to verify whether FDG-PET could be a valid tool to appreciate the anticancer effect of this new therapeutic approach.

Tumor characteristics of ductal carcinoma in situ of breast visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography: Results from a retrospective study

AIM

To clarify clinicopathological features of ductal carcinoma in situ (DCIS) visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT).

METHODS

This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDG-PET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value (SUVmax) was compared with clinicopathological characteristics.

RESULTS

[F-18] FDG uptake was visualized in 28 lesions (53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation (P = 0.012 and 0.002, respectively), palpability (P = 0.030 and 0.024, respectively), use of core-needle biopsy (CNB) (P = 0.023 and 0.012, respectively), ultrasound-guided biopsy (P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging (MRI) (P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology (P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status (estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation (P = 0.019 and 0.001, respectively), use of CNB (P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI (P = 0.001 and 0.049, respectively) on multivariate analysis.

CONCLUSION

Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors (≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT.

Congenital hyperinsulinism: Role of fluorine-18L-3, 4 hydroxyphenylalanine positron emission tomography scanning

Congenital hyperinsulinism (CHI) is a rare but complex heterogeneous disorder caused by unregulated secretion of insulin from the β-cells of the pancreas leading to severe hypoglycaemia and neuroglycopaenia. Swift diagnosis and institution of appropriate management is crucial to prevent or minimise adverse neurodevelopmental outcome in children with CHI. Histologically there are two major subtypes of CHI, diffuse and focal disease and the management approach will significantly differ depending on the type of the lesion. Patients with medically unresponsive diffuse disease require a near total pancreatectomy, which then leads on to the development of iatrogenic diabetes mellitus and pancreatic exocrine insufficiency. However patients with focal disease only require a limited pancreatectomy to remove only the focal lesion thus providing complete cure to the patient. Hence the preoperative differentiation of the histological subtypes of CHI becomes paramount in the management of CHI. Fluorine-18L-3, 4-hydroxyphenylalanine positron emission tomography (¹⁸F-DOPA-PET) is now the gold standard for pre-operative differentiation of focal from diffuse disease and localisation of the focal lesion. The aim of this review article is to give a clinical overview of CHI, then review the role of dopamine in β-cell physiology and finally discuss the role of ¹⁸F-DOPA-PET imaging in the management of CHI.

Diffusion weighted imaging in gynecological malignancies - present and future

The management of gynaecological malignancies has undergone a significant change in recent years with our improved understanding of cancer biogenetics, development of new treatment regimens and enhanced screening. Due to the rapid blooming of newer methods and techniques in gynaecology, surgery and oncology the scope and the role of imaging has also widened. Functional imaging in the form of diffusion weighted imaging (DWI) has been recently found to be very useful in assessing various tumours. Its ability to identify changes in the molecular level has dramatically changed the diagnostic approach of radiologists which was solely based on morphological criteria. It can improve the diagnostic accuracy of conventional magnetic resonance imaging, lend a hand in assessing tumour response to treatment regimens and detect tumour recurrence with better spatial resolution, negative radiation and diagnostic accuracy compared to positron emission tomography scan. The ability to quantify the diffusion has also lead to potential prediction of tumour aggressiveness and grade which directly correlate with the patient prognosis and management. Hence, it has become imperative for a radiologist to understand the concepts of DWI and its present and evolving role. In this article we present a brief description of the basics of DWI followed by its role in evaluation of female gynaecological malignancies.

Gastric blunt traumatic injuries: A computed tomography grading classification

AIM

To produce a radiological grading of gastric traumatic injuries.

METHODS

In our study, we retrospectively analyzed 32 cases of blunt gastric traumatic injuries and compared computed tomography (CT) data with patients' surgical or medical development. In all cases, a basal phase was acquired, and an intravenous contrast material was administered via an antecubital venous catheter with acquisition in the venous phase (70-90 s). In addition, a further set of delayed scans was performed 4-5 min after the first scanning session, without supplementary intravenous contrast material, to identify or better define areas of active bleeding. All CT examinations were retrospectively reviewed by two radiologists, with more than 5 years of experience in emergency radiology, to detect signs of gastric injuries and/or associated abdominal lesions according to literature data. Specific CT findings for gastric rupture include luminal content extravasation and discontinuity of the gastric wall, while CT findings suggestive of injury consisted of free peritoneal fluid, extraluminal air, pneumatosis, and thickening and hematoma of gastric wall.

RESULTS

We found 32 gastric traumatic injuries. In 22 patients (68.8%), the diagnosis was based on the surgical findings; in the other 10 patients (31.2%), the diagnosis was based on the clinical and CT radiological data. We observed discontinuity of the gastric wall and luminal content extravasation in 1 patient (3.1%); in 10 patients (31.2%), there was extra-luminal air in the peritoneum. In 28 patients (87.5%), there was peritoneal fluid, which was blood in 14 patients (hematoma in 11 patients and contrast material extravasation from active bleeding in 3 patients). In 15 patients (46.9%), there was gastric wall thickening. In 3 patients, it was possible to identify a prevalent involvement of the external layer of the gastric wall, whereas, in 2 patients, the inner side of the gastric wall presented with major involvement. In 3 patients (9.4%), pneumatosis of the gastric wall was detected. In 19 (59.4%) patients, the stomach was full. The fundus was the most frequently damaged part of the stomach because it was involved in 17 patients (53.1%). Based on the observed data, we identified four grades of gastric lesions.

CONCLUSION

A radiologic score is helpful for guiding the diagnosis and management (surgical or conservative) of gastric blunt traumatic injuries and stratify patients according to short-term outcomes.

Era of diagnostic and interventional ultrasound

It is an era of diagnostic and interventional ultrasound (US). Various new techniques such as three-dimensional US (3D US), interventional US, and contrast-enhanced US (CEUS) have been introduced into clinical practice. Dr. Xu and his colleagues have taken advantage of these techniques and carried out a series of relevant studies. Their use of 3D US in the liver, gallbladder, liver tumor volumetry, guidance for ablation, and 3D CEUS has widened the application of 3D US in the clinic. They found that prognosis in patients with hepatocellular carcinoma (HCC) after thermal ablation with curative intent was determined by treatment response to ablation, pretreatment serum AFP, and liver function reserve. Tumor response to treatment was the most predictive factor for long-term survival. They compared the use of percutaneous microwave ablation and radiofrequency ablation for the treatment of HCC and found that both are effective methods in treating HCCs. The local tumor control, complications related to treatment, and long-term survival were equivalent for the two modalities. They first compared the enhancement patterns of HCC and intrahepatic cholangiocarcinoma (ICC) and proposed the diagnostic clues for ICC, liver angiomyolipoma (AML), gallbladder cancer, renal carcinoma, and renal AML, which have greatly enhanced the role of CEUS in the clinic. They also evaluated the diagnostic performance of CEUS in characterizing complex cystic focal liver lesions and the agreement between two investigators with different experience levels; and found that CEUS is especially useful for the young investigator. They assessed the effect of anti-angiogenic gene therapy for HCC treated by microbubble-enhanced US exposure and concluded that gene therapy mediated by US exposure enhanced by a microbubble contrast agent may become a new treatment option for HCC.

Radio-chemotherapy for bladder cancer: Contribution of chemotherapy on local control

The purpose of this study was to review the magnitude of contribution of chemotherapy (CT) in the local control of muscle invasive bladder carcinoma in the studies where a combined radio-chemotherapy (RCT) was used (how much higher local control rates are obtained with RCT compared to RT alone). Studies on radiotherapy (RT) and combined RCT, neo-adjuvant, concurrent, adjuvant or combinations, reported after 1990 were reviewed. The mean complete response (CR) rates were significantly higher for the RCT studies compared to RT-alone studies: 75.9% vs 64.4% (Wilcoxon rank-sum test, P = 0.001). Eleven of the included RCT studies involved 2-3 cycles of neo-adjuvant CT, in addition to concurrent RCT. The RCT studies included the one-phase type (where a full dose of RCT was given and then assessment of response and cystectomy for non-responders followed) and the two-phase types (where an assessment of response was undertaken after an initial RCT course, followed 6 wk later by a consolidation RCT for those patients with a CR). CR rates between the two subgroups of RCT studies were 79.6% (one phase) vs 71.6% (two-phase) (P = 0.015). The average achievable tumour control rates, with an acceptable rate of side effects have been around 70%, which may represent a plateau. Further increase in CR response rates demands for new chemotherapeutic agents, targeted therapies, or modified fractionation in various combinations. Quantification of RT and CT contribution to local control using radiobiological modelling in trial designs would enhance the potential for both improved outcomes and the estimation of the potential gain.

Amebic liver abscess: Clinico-radiological findings and interventional management

In its classic form, amebic liver abscess (ALA) is a mild disease, which responds dramatically to antibiotics and rarely requires drainage. However, the two other forms of the disease, i.e., acute aggressive and chronic indolent usually require drainage. These forms of ALA are frequently reported in endemic areas. The acute aggressive disease is particularly associated with serious complications, such as ruptures, secondary infections, and biliary communications. Laboratory parameters are deranged, with signs of organ failure often present. This form of disease is also associated with a high mortality rate, and early drainage is often required to control the disease severity. In the chronic form, the disease is characterized by low-grade symptoms, mainly pain in the right upper quadrant. Ultrasound and computed tomography (CT) play an important role not only in the diagnosis but also in the assessment of disease severity and identification of the associated complications. Recently, it has been shown that CT imaging morphology can be classified into three patterns, which seem to correlate with the clinical subtypes. Each pattern depicts its own set of distinctive imaging features. In this review, we briefly outline the clinical and imaging features of the three distinct forms of ALA, and discuss the role of percutaneous drainage in the management of ALA.

Role of serial multiparametric magnetic resonance imaging in prostate cancer active surveillance

AIM: To examine whether addition of 3T multiparametric magnetic resonance imaging (mpMRI) to an active surveillance protocol could detect aggressive or progressive prostate cancer.

METHODS: Twenty-three patients with low risk disease were enrolled on this active surveillance study, all of which had Gleason score 6 or less disease. All patients had clinical assessments, including digital rectal examination and prostate specific antigen (PSA) testing, every 6 mo with annual 3T mpMRI scans with gadolinium contrast and minimum sextant prostate biopsies. The MRI images were anonymized of patient identifiers and clinical information and each scan underwent radiological review without the other results known. Descriptive statistics for demographics and follow-up as well as the sensitivity and specificity of mpMRI to identify prostate cancer and progressive disease were calculated.

RESULTS: During follow-up (median 24.8 mo) 11 of 23 patients with low-risk prostate cancer had disease progression and were taken off study to receive definitive treatment. Disease progression was identified through upstaging of Gleason score on subsequent biopsies for all 11 patients with only 2 patients also having a PSA doubling time of less than 2 years. All 23 patients had biopsy confirmed prostate cancer but only 10 had a positive index of suspicion on mpMRI scans at baseline (43.5% sensitivity). Aggressive disease prediction from baseline mpMRI scans had satisfactory specificity (81.8%) but low sensitivity (58.3%). Twenty-two patients had serial mpMRI scans and evidence of disease progression was seen for 3 patients all of whom had upstaging of Gleason score on biopsy (30% specificity and 100% sensitivity).

CONCLUSION: Addition of mpMRI imaging in active surveillance decision making may help in identifying aggressive disease amongst men with indolent prostate cancer earlier than traditional methods.

Imaging pancreatic islet cells by positron emission tomography

It was estimated that every year more than 30000 persons in the United States - approximately 80 people per day - are diagnosed with type 1 diabetes (T1D). T1D is caused by autoimmune destruction of the pancreatic islet (β cells) cells. Islet transplantation has become a promising therapy option for T1D patients, while the lack of suitable tools is difficult to directly evaluate of the viability of the grafted islet over time. Positron emission tomography (PET) as an important non-invasive methodology providing high sensitivity and good resolution, is able to accurate detection of the disturbed biochemical processes and physiological abnormality in living organism. The successful PET imaging of islets would be able to localize the specific site where transplanted islets engraft in the liver, and to quantify the level of islets remain alive and functional over time. This information would be vital to establishing and evaluating the efficiency of pancreatic islet transplantation. Many novel imaging agents have been developed to improve the sensitivity and specificity of PET islet imaging. In this article, we summarize the latest developments in carbon-11, fluorine-18, copper-64, and gallium-68 labeled radioligands for the PET imaging of pancreatic islet cells.

Value of acoustic radiation force impulse elastography for the assessment of ascites syndrome

AIM: To assess the feasibility of performing acoustic radiation force impulse (ARFI) elastography in patients with ascites and its predictive value for the cirrhotic or non-cirrhotic etiology of ascites. METHODS: Our study included 153 patients with ascites, mean age 58.8 ± 13.1 years. One hundred and fifteen (75.2%) patients had ascites in the context of cirrhosis, 29 (18.9%) had non-cirrhotic ascites (diagnosed by clinical, ultrasound, endoscopic and/or laparoscopic criteria) and in 9 (5.9%) cases we could not establish the etiology of ascites. We performed 10 ARFI measurements and the median value was calculated and expressed in meters/second (m/s). Among the 29 patients with non-cirrhotic ascites were included: 20 laparoscopically demonstrated peritoneal carcinomatosis with histological confirmation, 7 acute pancreatitis with ascites which later resolved, and one case each of lymphatic ascites and ascites in the context of a liver abscess. In 11 of the 20 patients with peritoneal carcinomatosis, the liver structure was homogenous in the ultrasound examination and in 9 patients the ultrasound exam revealed liver metastases. RESULTS: We could not obtain valid ARFI measurements in 5 patients (3.2%). The mean liver stiffness measurements by means of ARFI were statistically significantly higher in patients with cirrhotic ascites than in those with non-cirrhotic ascites: 3.04 ± 0.70 vs 1.45 ± 0.59 m/s (P < 0.001). For a cut-off value of 1.8 m/s for predicting cirrhosis (and ascites in the context of cirrhosis), as obtained in a previous study, ARFI had 98.1% sensitivity, 86.2% specificity, 96.4% positive predictive value, 92.5% negative predictive value and 95.6% accuracy for predicting cirrhotic ascites. For a cut-off value of 1.9 m/s the accuracy was 94.9% and for a 2 m/s cut-off value it was 92.8%. CONCLUSION: ARFI elastography is feasible in most patients with ascites and has a very good predictive value for the cirrhotic or non-cirrhotic etiology of ascites.

Computer-aided diagnosis for contrast-enhanced ultrasound in the liver

Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. The basic concept of CAD is to provide computer output as a second opinion to assist radiologists’ image interpretations by improving the accuracy and consistency of radiologic diagnosis and also by reducing the image-reading time. To date, research on CAD in ultrasound (US)-based diagnosis has been carried out mostly for breast lesions and has been limited in the fields of gastroenterology and hepatology, with most studies being conducted using B-mode US images. Two CAD schemes with contrast-enhanced US (CEUS) that are used in classifying focal liver lesions (FLLs) as liver metastasis, hemangioma, or three histologically differentiated types of hepatocellular carcinoma (HCC) are introduced in this article: one is based on physicians’ subjective pattern classifications (subjective analysis) and the other is a computerized scheme for classification of FLLs (quantitative analysis). Classification accuracies for FLLs for each CAD scheme were 84.8% and 88.5% for metastasis, 93.3% and 93.8% for hemangioma, and 98.6% and 86.9% for all HCCs, respectively. In addition, the classification accuracies for histologic differentiation of HCCs were 65.2% and 79.2% for well-differentiated HCCs, 41.7% and 50.0% for moderately differentiated HCCs, and 80.0% and 77.8% for poorly differentiated HCCs, respectively. There are a number of issues concerning the clinical application of CAD for CEUS, however, it is likely that CAD for CEUS of the liver will make great progress in the future.

Imaging and review of a large pre-auricular pilomatrixoma in a child

A 10-year-old girl presented with a mildly tender mass in the right preauricular region. The mass became larger, and the overlying skin turned purple. There was no clinical response to a course of either cephalexin or clarithromycin. The remainder of the head and neck examination was normal including normal facial nerve function. Lyme titers and a computed tomographic (CT) scan with contrast of the facial region were obtained. The CT scan demonstrated the lesion to be superficial to the parotid gland. The lyme titer was elevated and doxycycline was begun. The mass appeared to reduce in size after doxycycline treatment, but then grew and turned erythematous. The lesion was surgically excised and was vascular with calcification and cheesy inclusions. The mass was quite close to the skin and the clinical diagnosis at the time of surgery was a pilomatrixoma, which was corroborated on pathological evaluation.

Lipoma of the pancreas, a case report and a review of the literature

Lipomas of the pancreas are very rare. There are fewer than 25 reported cases of lipoma originating from the pancreas. We present a case of pancreatic lipoma in a 61-year-old woman with magnetic resonance imaging findings and confirmatory histological findings. We discuss and highlight the radiological features distinguishing a pancreatic lipoma from other fatty lesions of the pancreas and pancreatic liposarcoma and provide a brief review of the literature.

Use of computed tomography in the management of colorectal cancer

Computed tomography (CT) plays an important role in the management of colorectal cancer (CRC). The use of CT (colonography) as a screening tool for CRC has been validated and is expected to rise over time. The results of prior studies suggest that CT is suboptimal for assessment of local T stage and moderate for N stage disease. Recent advances in CT technology are expected to lead to some improvement in staging accuracy. At present, the main role of CT in pre-treatment imaging assessment lies in its use for the detection of distant metastases, especially in the liver. In a select group of patients, routine post-treatment surveillance with CT confers survival benefits. The role of CT for post-treatment assessment has been radically altered and improved with the advent of fusion positron emission tomography/CT. Perfusion CT shows promise as another functional imaging modality but further experience with this technique is necessary before it can be applied to routine clinical practice.

Exploration of sex-specific and age-dependent COVID-19 fatality rate in Bangladesh population

Coronavirus disease-2019 (COVID-19), a respiratory tract infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health emergency and a threat the entire world. The COVID-19 shows a wide spectrum of clinical presentations, severity, and fatality rates. Although the fatal outcomes of the COVID-19 pandemic are evident in all age groups, the most devastating impact on the health consequences and death from COVID-19 are associated with older adults, especially older men. COVID-19 pandemic is affecting different countries in the world especially in the 65+ years age male group. In fact, several genes involved into the regulation of the immune system are strategically placed on the X-chromosome and trigger a gendered mediated antiviral fight. The aim of this study is to explore and exploit whether a relationship exists between male sex and COVID-19 mortality and the relationship is age dependent. Herein we discuss the possible role of physiological and immunological sex differences into the higher morbidity and mortality of SARS-CoV-2 between females and males. Deciphering gender differences in COVID-19 offers a window into the principles of immunity against SARS-CoV-2 infection and this information on ageing dependent gender disparity might contribute to our current understanding of COVID-19 infection and disease treatment.