Tomorrow's radiologist: what future?

Today's radiology is experiencing two major trends, one negative and one positive. The first is the so-called turf war, in other words, the progressive invasion of the imaging domain by other specialists such as cardiologists, urologists, gastroenterologists, gynaecologists etc. who are taking over various techniques from ultrasonography (US) to computed tomography (CT) to magnetic resonance imaging (MRI). In this process, they are aided by new technologies such as picture archiving and communication systems (PACS) and computed-aided diagnosis CAD and by radiology technologists who collaborate with them, replacing radiologists. The positive aspect is the outstanding technological evolution: the advent of molecular imaging, optical imaging, nanotechnologies, teleradiology and percutaneous gene therapy. While dramatically expanding the diagnostic possibilities down to the subcellular level, these techniques demand new forms of training in radiology and interdisciplinary cooperation. Tomorrow's radiologist will need to acquire appropriate clinical knowledge, restore contact with the patient to take on a prominent role in the diagnostic process, learn the basic sciences, foster a multidisciplinary approach and finally be able to use the Internet for learning and continuing education. Tomorrow's radiologists will survive if they learn to reinvent themselves.

[Ultrasonography plus direct radiography of the abdomen in the diagnosis of renal colic: still a valid approach?]. / Ecografia e radiogramma diretto dell'addome nella diagnostica della colica renale: un approccio ancora valido?

PURPOSE: The authors analyze whether the imaging approach consisting of ultrasonography and plain film in patients with renal colic is still of value when urography is replaced by unenhanced helical CT (UHCT) in unsolved cases. MATERIAL AND METHODS: Eight hundred and three consecutive patients were investigated with US following hydration and KUB, 164 of whom (20.4%) subsequently underwent UHCT (42 with the aim of mapping the excretory pathway and 122 (15.2%) because US and KUB were not considered as fully diagnostic). RESULTS: The 42 patients with detectable ureteral stone (plus possible hydronephrosis) on KUB + US and subsequently examined by UHCT to plan interventional treatment all had a positive UHCT examination. In 62 patients the diagnosis following KUB + US was uncertain (possible stone or possible hydronephrosis) and UHCT depicted the stone and/or the hydronephrosis in 34. In 60 patients the combination of KUB + US was negative but colic recurred and UHCT was positive in 17 patients. DISCUSSION: The comparison of the present results with a previous study in which KUB and US were followed by IVU in unsolved cases underscores the value of the first approach with KUB and US. The need for further diagnostic investigations when KUB + US are either not conclusive or negative and colic recurs is also confirmed. On the basis of our present data and in agreement with the literature IVU can be safely replaced by UHCT. CONCLUSIONS: It is authors' opinion that in settings where KUB, US and UHCT are available throughout the 24 hr the approach consisting of KUB plus US and UHCT in unsolved cases can be preferred in view of its on lower cost and above all lower X-ray dose to patients as compared to UHCT as the sole investigation.

Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols.

The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6 +/- 0.8 mGy; protocol B 14.4 +/- 0.6 mGy; protocol C 12.5 +/- 1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality.

What is left of i.v. urography?

Since its introduction into clinical practice in the early 1930s, intravenous urography (IVU) was the primary imaging technique for the investigation of urinary system disorders for many years, until the advent of digital cross-sectional-imaging techniques gradually started to undermine many of its indications. Intravenous urography has been superseded for some indications such as renovascular arterial hypertension, prostatic dysuria, renal failure, palpable abdominal masses and recurrent urinary tract infection in women. Intravenous urography has been reduced, in the sense that it is no longer a primary examination, for other clinical indications such as renal colic, renal trauma, uroseptic fever, asymptomatic haematuria, medical haematuria, obstructive uropathies and follow-up of various disorders. Intravenous urography is indicated and often mandatory in congenital anomalies of the urinary tract, prior to endourological procedures, possible fistulas, renal transplantation, tuberculosis and ureteral pathology. In conclusion, IVU is still the examination of choice where there is a need to visualize the entire urinary system and to evaluate the state of the papillae and calyces. Computed tomography urography and MR urography are the imaging modalities ready in the near future to replace IVU.

Present-day imaging of patients with renal colic.

In the past decade alternatives to urography have been proposed for the study of patients with renal colic. In 1992 it was suggested to replace urography with KUB and ultrasonography. In 1993 the combination of KUB and ultrasonography followed by urography in unresolved cases was proposed and, in 1995, it was suggested to replace urography with unenhanced helical CT (UHCT). This article illustrates the contribution of UHCT to the study of patients with renal colic and analyses advantages and shortcomings of the technique compared with other diagnostic approaches. Diagnostics of the patient with renal colic is based on the detection of direct and indirect signs which allow identification of not only the calculus, with a sensitivity of 94-100% and accuracy of 93-98% according different authors, but also other signs that can serve to guide patient management and evaluate long-term prognosis. Unenhanced helical CT has the capability to detect extraurinary abnormalities which present with flank pain and mimic renal colic. The examination technique affects the quality of the images and therefore diagnostic accuracy as well as the dose to the patient. With regard to setting parameters, the choice of thickness and table feed should be guided by numerous factors. Multiplanar reconstruction is indicated in the study of the entire ureter course to identify the exact site of the calcification for the urologist to perform an evaluation similar to that obtained by urography. Many authors consider UHCT to be a valuable tool for suggesting the best therapeutic approach. Among these there are also urologists. The evaluation is based on the stone detection, its size and level in the urinary tract. Cost analysis shows that the cost of UHCT is equal to or inferior to the cost of urography. With regard to the dose, different data are reported in the literature. A high pitch (more than 1.5) and a thin collimation (3-mm thickness) are good compromise between quality and dose which can be compared to the dose of normal urography. What is to be done if helical CT is not available? If helical CT is not available, plain film plus ultrasonography should be considered. This approach does not solve all the cases; in unresolved cases urography is indicated. It should also be noted that US has a good sensitivity in detecting other conditions such as biliary lithiasis, acute pancreatitis, acute appendicitis and abdomino-pelvic masses which are responsible for pain that mimics renal colic. In conclusion, IVU should not have any more the priority in investigating the patients with renal colic. Helical CT should be the first choice in imaging a patient with renal colic. If this technique is not available, plain film and ultrasonography should be considered adding urography in unresolved cases.

Cost analysis of different protocols for imaging a patient with acute flank pain.

The aim of this study was to analyse the costs of different diagnostic approaches to patients with acute flank pain. Four different diagnostic approaches were considered: (a) spiral CT without contrast medium (CM); (b) plain film, ultrasonography (US) and intravenous urography (IVU)--the latter procedure is used in our department in cases still unsolved following the former investigations (28% in our experience); (c) plain film, US and spiral CT without CM (as an alternative to IVU in 28% of cases); and (d) IVU. The cost of each procedure in a university hospital was calculated, following analysis of the differential costs of each investigation (equipment, depreciation and maintenance costs, related materials and services, radiologists, radiographers, nurses) and their common costs (auxiliary personnel and indirect internal costs). Finally, we calculated the full cost of each procedure and applied it to the different diagnostic approaches. The full cost of each approach was: (a) spiral CT without CM = 74 Euro; (b) plain film, US and IVU (28%) = 66.89 Euro; (c) plain film, US and spiral CT without CM (28%) = 64.93 Euro; (d) IVU = 80.90 Euro. Intravenous urography alone or in unsolved cases is not to be considered because it provides higher costs and worse diagnostic results, whereas X-ray dose to patient is almost equal between IVU and spiral CT. Spiral CT integrated to plain film and US in unsolved cases could be preferred because of lower cost and dose to patient, though reaching a diagnostic conclusion may take longer than an immediate spiral CT.

Characterization of unifocal liver lesions with pulse inversion harmonic imaging after Levovist injection: preliminary results.

The aim of this study was to evaluate capabilities of pulse inversion harmonic imaging (PIHI) in characterization of unifocal liver lesions. We evaluated with PIHI (HDI5000, ATL, Bothell, Wash.) and spiral CT 46 consecutive patients with a single liver lesion identified by fundamental US [7 hepatocellular carcinomas (HCC), 2 cholangiocarcinomas, 7 focal nodular hyperplasias (FNH), 17 hemangiomas and 13 metastases]. The PIHI was performed before and 30 s, 2 and 4 min after bolus administration of Levovist (2.5 g, 300 mg/ml). Scans were digitally stored and reviewed using a dedicated software. Hepatocellular carcinoma was hyperechoic on 30-s scan, and hypoechoic (n = 5) or isoechoic (n = 2) on 2-min scan. Cholangiocarcinoma had inhomogeneous persistent enhancement. Focal nodular hyperplasia was hyperechoic (n = 5) or isoechoic (n = 2) on 30-s scan, hyperechoic (n = 4), isoechoic (n = 2) or slightly hypoechoic (n = 1) on 2-min scan. Large hemangioma revealed peripheral enhancement on 30-s scan which extended centripetally on 2-min scan. Small hemangioma appeared isoechoic on 2-min scan in all but two cases in which they were hypoechoic on 2-min scans and hyperechoic on 4-min scan. Metastasis was hypoechoic on all scans, 70% with rim enhancement. Similar changes in enhancement pattern have been observed at spiral CT. The 30-s and the 2-min scans revealed a conclusive importance in characterization of HCC, cholangiocarcinoma, and large hemangioma. The 2-min scan often furnished enough information for characterization of small hemangioma and metastasis. The 4-min scan allowed characterization of two hemangiomas which appeared hypoechoic on 2-min scans. In the other cases it did not provide further information. Diagnosis of FNH is usually reached with Colour Doppler US; PIHI should be used when colour Doppler is biased by artefacts or when colour Doppler findings are not characteristic. Our results seem to show that PIHI could be a valuable alternative diagnostic approach to spiral CT for unifocal liver lesion characterization. This hypothesis needs to be confirmed with an increased number of lesions.

[The imaging of chronic renal infections]. / Bildgebung chronischer renaler Infektionen.

From pathological point of view the chronic renal infections include two types, interstitial chronic pyelonephritis and granulomatous pyelonephritis, namely xanthogranulomatous, malacoplakia and renal tuberculosis. Indications for imaging modalities are more common compared to the acute types and allow to depict both factors causing obstruction and infection such as stones ant the renal and extrarenal extension of the disease. In this article the authors review the findings and the role of plain film and urography, computed tomography and ultrasonography.

Short-TE projection reconstruction MR microscopy in the evaluation of articular cartilage thickness.

The aim of this study was to assess the potential of projection-reconstruction (PR) MR microscopy in the accurate measurement of cartilage thickness. Short-TE PR microimages were acquired at 7.05 T on bone-cartilage cylindrical plugs excised from four regions of two disarticulated femoral heads (i. e. superior, inferior, posterior and anterior), using an NMR instrument equipped with a microimaging accessory. The PR microimages were then correlated with conventional spin-echo (SE) microimages and with histology. On PR microimages, acquired with an echo time of 3.2 ms, the cartilage signal was increased, allowing an accurate delineation of the cartilage from the tidemark/cortical bone region. As a consequence, by the PR method a more precise measurement of cartilage thickness compared with that performed by the conventional SE approach was feasible. An excellent correlation between PR microimages and histology was also obtained (r = 0.90). By the proposed method it is possible to accurately determine the cartilage thickness better than with the conventional SE sequences.

Relationships between radiologists and clinicians: results from three surveys.

AIM: To analyse reasons for and the nature of clinico-radiological contacts and their clinical impact. MATERIALS AND METHODS: Three different surveys were performed. (1) Data concerning contacts between staff radiologists (n = 20) and clinicians during 10 consecutive working days were collected; (2) staff clinicians (n = 174) filled in a questionnaire asking for their opinions about relationships with radiologists; (3) staff radiologists collected data about contacts with clinicians related to more urgent/complicated cases. Radiologists assessed the clinical impact of the radiological procedure and of the consultation. RESULTS: (1) During 220 working days 20 radiologists had a mean of 3.95 contacts per day (48.2% personal contacts, 51.8% telephone contacts), amounting to a personal total of 21.65 min per day. These contacts amounted to a total of 7.08 h per day, roughly one whole-time equivalent radiologist. (2) These consultations helped to refine the diagnostic strategy often (12.6%) or sometimes (71.4%) and to alter therapeutic decisions often (10.4%) or sometimes (56.6%). (3) The initial clinical diagnosis was changed in 50% of cases and the therapy was substantially changed on the basis of further radiological investigations and clinical-radiological discussion in 60% of cases. CONCLUSION: Clinical-radiological consultations are time consuming but have a beneficial diagnostic and therapeutic impact.

Dynamic magnetic resonance imaging in the assessment of chronic medical nephropathies with impaired renal function.

We examined the value of dynamic magnetic resonance imaging (MRI) in chronic renal disease with renal insufficiency. In 33 consecutive patients (21 vascular nephropathy, 12 glomerular nephropathy) MRI was performed using a 1.5-T unit and a body coil, with SE T1-weighted (TR/TE = 600/19 ms) and dynamic TFFE T1-weighted sequences (TR/TE = 12/5 ms, flip angle = 25 degrees ) after manual bolus injection (via a cubital vein) of 0.1 mmol/kg Gd-DTPA-BMA. Morphological evaluation was performed in unblinded fashion by three radiologists, evaluating renal size, cortical thickness, and corticomedullary differentiation. Functional analysis was performed by one reviewer. Time-signal intensity curves, peak intensity value (P), time to peak intensity (T), and the P/T ratio were obtained at the cortex, medulla, and pyelocaliceal system of each kidney. The relationship of these parameters to serum creatinine and with creatinine clearance was investigated. A good correlation between morphological features of the kidneys and serum creatinine values was found. Morphological findings could not distinguish between vascular and glomerular nephropathies. A statistically significant correlation (P <0.01) between cortical P, cortical P/T, medullary P, and serum creatinine and creatinine clearance was found. A significant correlation (P <0.01) was also found between cortical T, medullary P/T, T of the excretory system, and creatinine clearance. The cortical T value was significantly higher (P <0.01) in vascular nephropathy than in glomerular nephropathy. Thus in patients with chronic renal failure dynamic MRI shows both morphological and functional changes. Morphological changes are correlated with the degree of renal insufficiency and not with the type of nephropathy; the functional changes seem to differ in vascular from glomerular nephropathies.

Detection of liver metastases with pulse inversion harmonic imaging: preliminary results.

The aim of this study is to evaluate capability of contrast enhanced ultrasonography (US) using pulse inversion harmonic imaging (PIHI) to detect liver metastases in comparison to fundamental B-mode ultrasound and spiral CT. Thirty-six consecutive patients with known malignancies and sonographically proved or suspicious liver metastases have been examined with fundamental B-mode US, with PIHI 2', 4' and 6' after Levovist injection and with four phase spiral-CT. Presence, conspicuity and number of lesions have been evaluated comparing PIHI with fundamental B-mode US and spiral-CT. A strong grey-scale enhancement of the liver parenchyma has been observed 2' and 4' after Levovist injection. The optimum parenchymal enhancement and contrast difference between liver and metastases was observed during the 2' measurements. PIHI revealed more lesions than fundamental B-mode US in 56 % of patients, while in 39 % and in 5 % revealed respectively the same number and fewer lesions. PIHI and spiral-CT were in agreement in 67 % of patients, while in 22 % and 11 % PIHI revealed respectively more and fewer lesions. PIHI accurancy presents restrictions in anterior superficial and in deep liver areas, whereas it may be superior to spiral-CT in studying sub-diaphragmatic liver regions.

Digital vs conventional radiography: cost and revenue analysis.

The objective of this study was to analyse and compare the operating and investment costs of two radiographic systems, a conventional and a digital one, and to evaluate the cost/revenue ratio of the two systems. The radiological activity over 1 year for chest and skeletal exams was evaluated: 13,401 chest and 7,124 skeletal exams were considered. The following parameters of variable costs were evaluated: the difference between variable proportional costs of the two technologies, the effective variable cost of any size film, including the chemicals, and for different sizes of digital film, variable costs of chest plus skeletal exams performed with the two techniques. Afterwards the economical effect was considered taking into account depreciation during a time of utilization ranging between 8 and 4 years. In the second part of the analysis the total cost and the revenues of the two technologies were determined. The comparison between the digital and conventional systems has shown the following aspects: 1. Digital radiography system has a much higher investment cost in comparison with the conventional one. 2. Operating costs of digital equipment are higher or lower depending on the film size used. Evaluating chest X-ray we reach a breakeven point after 1 year and 10,000 exams only if displayed over 8 x 10-in. film and after 30,000 if displayed over a 11 x 14-in. film. 3. The total cost (variable cost, technology cost, labour cost) of digital technology is lower than that of the conventional system by 20 % on average using 8 x 10-in. film size. 4. Digital technology also allows lesser film waste and lesser film per exam

Medical treatment of renal and perirenal abscesses: CT evaluation.

AIM: A retrospective study of our experience of CT evaluation and follow-up of 16 solitary and multiple renal abscesses treated successfully with antibiotics alone and evaluated with CT at the onset of symptoms and after therapy. MATERIALS AND METHODS: Seven patients had a solitary renal abscess, five had multiple renal abscesses and four had renal and perinephric abscess. None of the abscesses were larger than 5 cm. RESULTS: In all 16 patients, the CT examination showed total renal and extrarenal regression of the abscesses. In four patients, scarring of the renal outline was observed on follow-up. CONCLUSIONS: The study demonstrates the opportunity to avoid aggressive interventional or surgical treatment of renal and perirenal abscesses of 5-cm diameter or less which can completely regress after antibiotic therapy of at least 4 weeks. The CT examination results are important both in the diagnostic phase to establish the extent of the lesions and in the follow-up to check the results of medical treatment.

Low-dose phase contrast x-ray medical imaging.

Phase contrast x-ray imaging is a powerful technique for the detection of low-contrast details in weakly absorbing objects. This method is of possible relevance in the field of diagnostic radiology. In fact, imaging low-contrast details within soft tissue does not give satisfactory results in conventional x-ray absorption radiology, mammography being a typical example. Nevertheless, up to now all applications of the phase contrast technique, carried out on thin samples, have required radiation doses substantially higher than those delivered in conventional radiological examinations. To demonstrate the applicability of the method to mammography we produced phase contrast images of objects a few centimetres thick while delivering radiation doses lower than or comparable to doses needed in standard mammographic examinations (typically approximately 1 mGy mean glandular dose (MGD)). We show images of a custom mammographic phantom and of two specimens of human breast tissue obtained at the SYRMEP bending magnet beamline at Elettra, the Trieste synchrotron radiation facility. The introduction of an intensifier screen enabled us to obtain phase contrast images of these thick samples with radiation doses comparable to those used in mammography. Low absorbing details such as 50 microm thick nylon wires or thin calcium deposits (approximately 50 microm) within breast tissue, invisible with conventional techniques, are detected by means of the proposed method. We also find that the use of a bending magnet radiation source relaxes the previously reported requirements on source size for phase contrast imaging. Finally, the consistency of the results has been checked by theoretical simulations carried out for the purposes of this experiment.

Magnetic resonance imaging of articular cartilage: ex vivo study on normal cartilage correlated with magnetic resonance microscopy.

The aims of this study were (a) to compare the MR appearance of normal articular cartilage in ex vivo MR imaging (MRI) and MR microscopy (MRM) images of disarticulated human femoral heads, (b) to evaluate by MRM the topographic variations in articular cartilage of disarticulated human femoral heads, and subsequently, (c) to compare MRM images with histology. Ten disarticulated femoral heads were examined. Magnetic resonance images were obtained using spin-echo (SE) and gradient-echo (GE) sequences. Microimages were acquired on cartilage-bone cylindrical plugs excised from four regions (superior, inferior, anterior, posterior) of one femoral head, using a modified SE sequence. Both MRI and MRM images were obtained before and after a 90 degrees rotation of the specimen, around the axis perpendicular to the examined cartilage surface. Finally, MRM images were correlated with histology. A trilaminar appearance of articular cartilage was observed with MRI and with a greater detail with MRM. A good correlation between MRI and MRM features was demonstrated. Both MRI and MRM showed a loss of the trilaminar cartilage appearance after specimen rotation, with greater evidence on MRM images. Cartilage excised from the four regions of the femoral head showed a different thickness, being thickest in the samples excised from the superior site. The MRM technique confirms the trilaminar MRI appearance of human articular cartilage, showing good correlation with histology. The loss of the trilaminar appearance of articular cartilage induced by specimen rotation suggests that this feature is partially related to the collagen-fiber orientation within the different layers. The MRM technique also shows topographic variations in thickness of human articular cartilage.